Successfully Predicting The Future

This post is not about Nostradamus, although I have written something about him. It would also be easy to write me off on the strength of what I wrote there, but the approach here is very different and in fact suggested by the opinions of the Zizians and other rationalists. It’s based on probability.

We are first of all aware that the way things were before Trump’s election, the human race was due to die out in the 2060s from respiratory paralysis, along with all reptiles, mammals and fish, the last for other reasons. With the change in policies regarding carbon emissions in the US, that date has now been brought forward, but this is not about that. I now realise that I’ve told you two things this isn’t about.

You might remember my post on the Doomsday Argument (there’s probably more than one) a few years ago. The basic idea behind this is based on an estimate of when the Berlin Wall would come down by someone who visited it in the 1960s. In 1969 CE, when the astrophysicist J Richard Gott III visited the then eight year old Berlin Wall, he posited that the Copernican Principle, that there’s nothing special about a particular observation, individual and so forth, meant that the best assumption about how far through the total number of visitors to the Wall was that he was about halfway through. He gave an estimate of 50/50 that it would be gone by 1993. In fact it came down in 1989, which is quite close. The Doomsday Argument is that from the perspective of an individual human life, one’s birth is best estimated as being about halfway through the total number of human births. With the population growth during the twentieth century of doubling every thirty years and an estimate of the number of human lives being lived so far at seventy five thousand million since 600 000 BP, and taking my own birth in 1967 as an example, it being the only one I can, it appears that the human species will probably be extinct by 2133. There are numerous flaws in this argument, but it’s important to note that it isn’t an argument that overpopulation will cause extinction or that any cause in particular will do so. There will of course be a cause but we don’t seem to be able to tell from this argument what that would be. Nonetheless it is the case that if population growth slows, the prediction extends further into the future and it also depends substantially on assumptions about which entities are likely to have those thoughts, that is, when we became human and started to conceive of the idea of the end of the world, the human race and so forth. In fact, population growth is indeed decelerating and this stretches our probable prospect well into the future. I’ve talked about all of this before, but I think it’s a measure of the occurrence of the thought and not the occurrence of humans. An outbreak of optimism about the future of the human race by the early 22nd century would mean that no more ideas of that kind will occur, or that they’ll be rarer, so maybe what we’re really measuring is the extinction of doomerism, not that of humanity. There are all sorts of reasons why this might happen. It could be that our descendants are all parasitic tumour cells with no brains and therefore no expectations, that we’re all wiped out by AI which doesn’t have that thought or that things are going to get a lot better. Hence this apparently cold mathematical argument has so many hidden variables that it may be worthless.

There is another, similar, argument which I’ve used to predict a future without human space exploration, and it goes like this. Suppose there are a million habitable exoplanets which will one day be within human reach, or alternatively the same area in the form of artificial space habitats of some kind. This is a very conservative estimate as it would mean that only one star system in four hundred thousand would have such a planet or that the technology to produce such habitats is very inefficient. Now suppose that each of these planets (I’ll use the planet settlement scenario for simplicity’s sake) only has an average population of a million, with each such population being considered as a discrete number per century, so for example there are a million people on one such planet and then a century later they’ve died but another million people have replaced them. Suppose this goes on for ten thousand years. That’s 100 x 1 million x 1 million, which is 10¹⁴ people. Going back to the original figure of 7.5 x 10¹⁰ people having lived so far, that makes that a tiny fraction of the number of people who will live in this scenario, namely 0.075%. This means that the probability of living at a time before this has happened, i.e. not being one of these people, is only one in around 1300. These are ridiculous betting odds which nobody rational would risk their money on. Also, the estimate I’ve made is extremely conservative. The Galaxy has been estimated to contain around 300 million habitable planets which will continue to be habitable for on average several hundred million years each and could support a population of ten thousand million people each. If the other scenarios are explored, a much wider variety of stars could support a Dyson swarm, i.e. a roughly spherical shell of space habitats with many times Earth’s land surface area which would dwarf even the second estimate at the order of 10²⁵. If one considers one’s life as a random sample from human history, with these odds it can be guaranteed that if humans settle in space substantially in the future, one would be living during that era and not this one. Our very existence now makes it practically certain it’ll never happen. It doesn’t give the reason for it though.

I actually think this is more productive than the Doomsday Argument, but it’s also flawed. Suppose you consider the much greater probability of being born. The chances of that for each person are lower than one in six hundred thousand million, assuming three hundred ovulations per lifetime and 200 million sperm per ejaculate. This also assumes that our identity depends on genes, which I strongly disagree with, but it’s an interesting thought with substantial basis in reality. It’s still a tiny probability, but even so, every one of us does exist. That probability, incidentally, could perhaps be multiplied by the number of generations since the point at which a single allele could be definitively traced to an individual, which is actually only around sixteen, or by the number of generations since the start of sexual reproduction, although since fish, for example, don’t ovulate single eggs but produce similar numbers of eggs as they do sperm, the numbers get wild before about four hundred million years back. Nevertheless, here we are.

But suppose the argument works. It seems to have predictive power of some kind, although what exactly it predicts is unclear. It might simply mean that we won’t make a Dyson swarm, that distances between stars are too large or even that there isn’t enough phosphorus. It’s also closely coupled to the Fermi Paradox, because whatever stops that from happening may also stop other cultures from doing the same, which is why there are no aliens in contact with us, so maybe we’re about to find out why that is. I personally think it means that something will, or is, happening which will prevent that future from unfolding. It could be something positive. Maybe we will achieve a degree of enlightenment which leads us to stay on our planet and make it an earthly paradise which nobody will want to leave. Or, maybe we’ll just bomb ourselves to bits or die in the ocean acidification scenario, or whatever. Just thinking of this in the wider “where are all the aliens?” setting, it’s also possible that the Great Filter only applies to us because there are no intelligent aliens. Just to spell it out, the Great Filter is the idea that an event takes place everywhere life might be expected to develop and prevents it from getting to the point where intelligent representatives start visiting other star systems. It could be that Earth-like planets are rare, phosphorus is too scarce and vital for life of any kind to develop, there aren’t enough mass extinctions to stimulate evolution, there are usually too many of those for intelligent life to evolve, that intelligent life is just unlikely, that intelligent life is common but tends to develop at the bottom of the ocean, that it’s common but really bad at maths, those all being the past Great Filters, and in the future that AI takes over, we wipe ourselves out through war, pandemics put paid to us, we get too engrossed in online activities to bother and that space exploration is a flash in the pan. There are plenty of others. If there are no spacefarers because there’s no life elsewhere, many of those still apply to us.

Ultimately, we only have the brute fact that we’re intelligent tool using entities which have not colonised the Galaxy. It’s difficult to draw conclusions from that. Lack of information also tend to stimulate speculation too much. Venus is a good example. At some point, astronomers realised that the reason Venus looks so bright is that it’s covered in clouds. They couldn’t see any surface features. Because the only clouds they knew about back then were the ones here on Earth, they drew the erroneous conclusion that Venerean clouds were also made of water vapour, and in fact this is a parsimonious decision because it doesn’t posit that they are made of anything else in the absence of information. From that, they further concluded that Venus must be warm (fair enough, it being near the Sun) and humid, perhaps being covered in swamps, rainforests or just a global water or carbonic acid (fizzy water) ocean. Since at the time it was thought that the planets further from the Sun were older, some scientists also wondered if it was home to dinosaur-like creatures. All this, as Carl Sagan observed by the way, from the fact that you can’t see any surface features through a telescope. Lack of knowledge begets dinosaurs.

We don’t actually know we’re not doing something similar from this lack of knowledge but it’s hard to restrain oneself from trying to fill in the gaps. I want, though, to start from the position that it does seem to be a good argument that this will never happen, for whatever reason. I do think it’d be good if it did, because for example the overview effect influencing a lot of people would make the world a better place. The overview effect is the influence seeing Earth from space has on astronauts, where they begin to see humanity as one and the planet as a precious and delicate place worth preserving. It’s been described as “a state of awe with self-transcendent qualities, precipitated by a particularly striking visual stimulus”. When people have spent some time in space, they come back changed, usually positively so, and actually settling in space, I think, would have a lot of other positive results including those which would promote radical left wing and Green political activism here on Earth, which is why I’m so focussed on it. All that said, it doesn’t follow that it would be a good thing in the end and staying here on Earth and turning our back on all that is seen by many people as a good thing. There’s a pretty good case for this too, as the sums of money and resources spent on space while there are starving people down here. . . well, you know the argument. There’s a famous poster by the artist Kelly Freas from the early 1970s which comes across as being finely balanced in this respect:

Presumed to be copyright NASA and therefore in the public domain but will be removed on request

The motivation behind this picture is to encourage support for the Apollo space program and more widely the space program in general, but I think to a 21st century viewer it comes across as emphasising the problems here and makes the Saturn V seem like a wasteful attempt to escape this and distract the world, along the lines of Gil Scott Heron’s ‘Whitey’s On The Moon’. In other words, the simple possibility that astronauts’ days are numbered can be regarded as a neutral fact rather than utopian or appalling. This still appears to be able to predict the future.

A while ago, I raised questions about the Artemis program. If it’s to be conjectured that a probable result of the return of humans to the lunar surface is a large number of people living in space, which then increases until it outnumbers the population ever having lived on Earth, the probabilistic argument I offered above predicts that that’s unlikely to happen. It could still happen if the number of people in space always stays very small or even if it’s relatively large but short-lived. Something will have to stop this from happening unless it’s along the lines of a pointless publicity stunt. Paradoxically, Elon Musk seems to think that it’s vital for humans to settle on other planets for the sake of the long term survival of the species, and that may well be true but he seems to be very good at preventing that from happening due to incompetence and overreaching himself, plus the mere fact that he’s close to being a (long scale) billionaire (he’s only a billionaire using the American system). To be highly specific, this argument in the current period seems to predict that Artemis will fail. Weirdly, this appears to be a form of retroactive causation — the cause follows the effect. Because one can have a high degree of confidence that there will be no significant human space program in the future, one can conclude that Artemis will fail. It’s as if the failure is caused by the way things are in the future rather than the other way round.

This of course has a Zizian flavour, and more broadly Roko’s Basilisk (don’t look it up – it’s almost certainly wrong but in case it’s right, it’s better not to know what it is). Both of these seem to be examples of the future influencing the past, and that makes it appear to be possible to predict certain aspects of the future. A really obvious one appears to be that time machines which travel back before the first instance of one will never be invented, as if they were we might expect to have witnessed time travellers and we haven’t. There may be some stipulations here, and it’s worthwhile putting in the work to determine exactly what we’re attempting to predict, hence for instance the proviso that they can’t travel back before their first instance. There might be other elements. For instance, it might be that time travel backwards is possible but it kills the time traveller, erases them from ever having come into existence or that it makes them undetectable. We would have to be precise about what we know, but once we’ve reached that precision, we basically have a way of predicting certain facts about the future on our hands and also revealing a weird reverse causality phenomenon. It’s pretty revolutionary in itself that effect can precede cause in some situations.

Something rather similar can be done regarding the present moment and the past. Our existence guarantees that we live in a Universe which is not entirely hostile to intelligent tool using entities, which in our case arose through the appearance and evolution of biochemical life. We also know that Earth formed, is currently habitable, and that there was no time between the appearance of life here and today when it was completely wiped out. However, one thing we don’t know is how improbable it is that we’ve come into existence. Just because we’ve lived on a planet which has been hit by a few comets and asteroids without killing all life on it or been sterilised by a gamma ray burst doesn’t mean that it’s unlikely, because our existence today is a given. That could happen tomorrow for all we know, and there may be nothing keeping the future like the past at all. We just don’t know how precarious our situation is.

I want to talk about something similar now and I don’t quite know how to link it but I’m convinced it’s similar. The past being as it has been in certain ways is assured by “survivorship bias”: we have no option currently but to live in circumstances where we’re still here and where we came into existence. Survivorship bias is a logical error. One example of it is successful guesses made of the psychic test cards with different shapes on them, where a researcher with a large number of subjects might select a subject she thinks is psychic because they’ve guessed correctly each time. Suppose there are 1024 subjects being asked to guess a sequence of cards with one of four symbols on each. Given the null hypothesis, statistically, 256 of them will guess correctly the first time, 64 the second and so on until after five guesses, one person will have done so every time. However, suppose further that there are 1024 of these studies going on in universities all over the world. In this situation, there will be variation in the number of successful guessers and in some of them there will be “super-guessers”, meaning that there can statistically be expected to be one person in the whole group who guesses correctly ten times in a row. Moreover, there’s a twenty-five percent chance that someone will do it eleven times, a chance of one in sixteen that one will do it twelve times and so on, and once it reaches below one in twenty, that reaches the arbitrarily chosen threshold for responsibility and a researcher can publish her result suggesting the statistical significance of guessing in at least one subject thirteen times in a row, and there’s then a danger of that paper receiving all the attention while the papers showing nothing remarkable remain unpublished. This is supposed to be avoided because it distorts the results. Negative findings are as important, if not more so, than positive ones. This is potentially an aspect of academic research which is distorted by a need to be perceived as doing something notable, because it means negative results are buried.

Survivorship bias may influence our perception of how typical our history and planet, and possibly even our universe, are. We’re here, so it follows, for example, that Earth hasn’t recently been hit by a large asteroid and that Covid didn’t wipe us all out – it wasn’t actually that kind of virus anyway, although it could’ve been a lot worse. The fact that the former didn’t happen dictates that the asteroids mainly orbit in a belt far from our orbit rather than us being situated in the middle of an asteroid belt, but it may also be that that kind of solar system is short-lived or rare anyway. We may seem to have lived charmed lives in a sense, and this is where things could be extended into the future.

Quantum immortality is a concept whose scientific respectability has never been clear to me. The idea is that as the timelines branch (I actually don’t think they do branch as such, but that’s not something I want to go into just now), we inevitably end up in the ones where we continue to be conscious. For instance, when I was eight, I rushed out of my primary school and was almost hit by a car, but survived of course. There are, depending on how firm determinism is, other timelines where I was fatally injured, but I’m obviously not in any of those, at least in the current year. In fact I couldn’t be, just given the simple fact that I’m still here typing this. The extension of this thought is that in fact, none of us ever die, and in fact our consciousnesses never end, not just subjectively but in terms of continuing to survive as observed by others. Every time a potentially consciousness-terminating event occurs, we take the road where our consciousness continues. Note that I’m talking about the permanent cessation of consciousness here, since we’re clearly temporarily unconscious on a regular basis during dreamless sleep. Hence the idea is that subjectively each of us will never die. A way of linking it to quantum ideas more clearly is to imagine a machine gun which works like the Schrödingers Cat thought experiment, except that the radioactive particle is replaced by a radioactive sample whose decay gives the firing of each bullet a 50% chance of happening, one bullet per second. The subject sits in front of the gun, aimed at their head. Subjectively, the gun will never fire because there will then be no observer to be aware of the bullets not firing, and of course the death of the observer would mean there is no such observer. This is rather sloppily put together but I hope you get my point. After five minutes the gun has potentially fired up to three hundred times and the probability of it not having fired is equivalent to one against a number more than three hundred thousand times greater than the number of atoms in the observable Universe, so it can be almost guaranteed that no-one else not in the firing line will observe the victim still alive at the end of the five minute period, but for the “victim” the situation is one hundred percent safe. Of course, somewhere out there in the Multiverse there is someone who has the reputation of being fantastically fortunate. Other people exist.

Extending this to every event while keeping the quantum component, it’s easy to imagine that each timeline begins with a quantum event which ends up determining the whole future in that timeline until it’s observed, and since it has to keep being observed, there has to be at least one immortal being in each. This means that in the majority of universes, which appear often to be merely composed of hydrogen rather sparsely distributed throughout space, there are no observers and therefore they actually don’t exist, although this would be countered by either panpsychism or the existence of an omniscient deity. I am of course panpsychist myself. A more conventional way of understanding it is that you are immortal in any timeline you actually experience. The bullet misses you, the car crash isn’t fatal, you recover from the infection and your cancer goes into remission.

However, this is not a recipe for ceasing to worry about the future. If you’ve read ‘Gulliver’s Travels’, you’ll know about the Struldbrugs of Luggnagg, who are born with a red dot above their left eyebrows which changes colour until it’s black. Swift obviously did a better job than I’m about to, so you can read his own words on them here. It’s in Chapter Ten. It won’t surprise you to learn their immortality is not a blessing but a curse. The condition’s not hereditary and a baby of this kind is only born every few years in the whole country. Lemuel imagines Struldbrugs to be mentally liberated from the prospect of death and able to become extremely wise, passing on their wisdom to the younger generations as a positive jewel to the land. However, what they actually do is serve as a dreadful warning to the populace which makes them feel relieved that they’re mortal, as their presence is a constant reminder of old age. They have, as the phrase has it, years in their lives but no life in their years, because they continue to age despite being immortal. Just as the old in our society tend to be world-weary, think they know more than they do and have contempt for the young (don’t shoot the messenger – this is Swift talking here, not me), they have all the more vices owing to their knowledge that they’ll never die. They’re ” not only opinionative, peevish, covetous, morose, vain, talkative, but incapable of friendship, and dead to all natural affection”, and they don’t care about any of their descendants beyond their grandchildren. They’re mainly envious and frustrated, and basically wish they were dead the whole time, lamenting at funerals because they know they’ll never have that release, and past the age of eighty, if they’re married to each other the state mercifully dissolves their union out of compassion, because otherwise their marriage will become a living hell out of being totally sick of each other. They’re also declared dead at eighty in order that their heirs can inherit and although they are either allowed to continue on a pittance from their own estate or receive welfare, they can’t own property or even rent it. Any diseases of old age continue, though they don’t get worse, and due to changes in language, after about two hundred years they cease to be able to hold any conversations with people outside their generation, who in any case are very few, and they also have dementia.

Swift wasn’t the only person to make this observation, although this is of course typical of him. There’s also an ancient Greek myth about Τιθωνός, lover of Eos, who scooped up a handful of sand and was granted to live as many years as there were grains in his hands, but forgot to ask for eternal youth and ended up walled up in a room insane until he was mercifully turned into a cicada. There’s also an Asimov story, ‘The Last Trump’, where the dead and the living are given eternal life and youth and initially suppose they’re in paradise but soon realise that they’re damned and that eternal life will become unbearably boring. They’re then reprieved on a technicality when an angel points out that the date of resurrection is different in different calendars, so it can’t have been a proper doomsday.

For this is what quantum immortality is. You don’t die, and you remain conscious, but you also deteriorate without end so your life becomes unbearable. It’s also entirely compatible with dementia to some extent. You don’t need a good memory, only to be able to sense things in one way or another, perhaps with the last remaining cone cell in one retina. Perhaps you occasionally notice a red dot and then forget about it immediately. It isn’t good, really. In fact it wouldn’t even be good if you retained all your faculties because your life would be poisoned by boredom and over-familiarity.

This raises a few questions. One is that of what ageing actually is. In a sense, not all organisms do actually age or die of old age. There’s a species of petrel, a bird, which is effectively immortal, and a jellyfish who responds to injury by regressing to infancy and beginning to mature again. However, these are not in fact immortal. Both, for example, would die in a fire or if eaten by a predator, and this raises the question of what ageing actually is. Is it the accumulation of internal insults and health problems which eventually proves fatal? If so, it’s effectively the same as accidental death – it’s just that the accidents are things like oxidative stress, cardiovascular deterioration or cancer. Or, do we have an allotted span such that we die after a certain number of years determined by an internal clock? This clearly does affect many species which die immediately after reproducing, which is just as well because otherwise they would use up the resources needed by their children, who would then starve, or end up eating their children shortly after hatching. Some might say that this is what one current generation of humans in positions of wealth and power is actually doing right now. We hang around for our children and grandchildren, but on the whole we need to die to get out of the way for future generations.

Presumably with quantum immortality, the former scenario is assumed to be in play. We don’t have an inherent life expectancy, but simply accumulate injuries until they become fatal, but in each subjective case those injuries never end up killing us. Obviously we’re not surrounded by immortals, so each of us has their own private world in this scenario, dying in an increasing number of timelines but persisting in a dwindling number of them, which, however, never reaches zero. One major problem with this is that it seems to be solipsistic, as all the “people” around you are still mortal and are just shadows with no consciousness. You’re in your own world. This may, however, have a form of retrocausality too. For instance, two ways of living longer are to be lucky with your genes and to inherit or adopt health-promoting attitudes from your family or community, meaning that you are, for example, more likely to have particularly healthy and long-lived relatives in your personal timeline. This doesn’t rule out straightforwardly accidental death, but it does mean you’re likely to have selected long-lived relatives. Therefore, if you believe in quantum immortality it would often be reasonable to conclude that your relatives, while not immortal, might end up living a particularly long time or be especially healthy in old age. It might even go further than that, with the possibility of living a relatively charmed life in a stable political environment, free from local wars and famines for example, or with a particularly low rate of serious crime.

This raises an ethical problem. It could make you complacent. You’d know that everyone else was subjectively immortal and also that you’ll never encounter potentially fatal dangers. Therefore you might well be less motivated to do good to others or even particularly bother to look after yourself. In the initial example, you could just wander in front of the quantum machine gun secure in the knowledge that you’ll be unharmed despite the increasingly vast odds against that being so. But you and others still wouldn’t have life in your years, and that would be worth preserving. It’s a heady prospect, but probably not a good one because you might stop caring about those affected by the troubles and hardships of the world, although suffering would still exist, more in fact than it does if we’re mortal.

Hugh Everett was a prominent proponent of this idea, although I have to say it’s a fairly obvious one so I doubt he was the first. He was the first well-known theorist of the many-worlds interpretation of quantum physics, which is the apparently branching paths (in fact they’d probably always have existed but be indiscernible) idea of innumerable parallel universes forking at each probabilistic event. He believed he would never die because of this. From our perspective, he is in fact dead, although this may not have any bearing on whether he’s immortal as if he was right, he would be “elsewhere”: we just happen to live in one of the majority of universes where he is in fact deceased. He died suddenly of a heart attack on 19th June 1982 at the age of fifty-one, having smoked sixty a day, consumed excessive alcohol and being grossly obese, never exercised and never went to the doctor. His son was very angry with him after his death that he never took care of himself, although he also observed that he just did what he wanted without interference and then just died without withholding any pleasures from himself. He also wanted to be cremated and have his ashes thrown out with the rubbish, something his widow wasn’t keen on for a few years after his death but eventually complied with. Incidentally, if you know the band The Eels, that’s the son who commented thus and there’s an album inspired by his death. Of course, this album doesn’t really exist because Hugh Everett is immortal! It seems to me that this kind of self-neglect may have resulted precisely from his belief in quantum immortality – there’s simply no point in looking after your health in his view.

I’m not sure this follows, to be honest. I think that apart from anything else you probably would want to be healthy for as long as possible in order to enjoy life, and also to spare the feelings of people close to you. Also, what if you’re wrong? I don’t think many people who have recently touched grass, as the phrase has it, would willingly step in front of that machine gun. Certain persons, of course, haven’t done that recently.

The Doomsday Argument and Quantum Immortality feel like they’re from the same stable, so it’s worthwhile working out what they have in common. They both start from a kind of Descartes-like position of noting that one is currently conscious and attempting to draw conclusions from that bare fact, though unlike Descartes they neither raise the possibility that the physical world doesn’t exist nor that God does, which gives them greater traction on the consensus view of reality and the Universe. Both constrain the Universe through the fact that we’re observing it, like the anthropic principle that the Universe must have certain physical constants and laws to produce conscious beings. Both involve vast numbers of items. In the Doomsday Argument, this is everyone who has or will ever live, and in Quantum Immortality it’s the number of possible worlds in which one has existed or currently exists. In fact I don’t believe the many worlds are strictly separate but that’s an argument for another time. Oddly though, they draw opposite conclusions from their reasoning. The Doomsday Argument concludes we’re all going to die but Quantum Immortality decides each of us is individually, though perhaps unhealthily, immortal, and that our consciousness will never permanently end. Neither of them are amenable to observational testing. The former can’t be observed by human scientists because it says there won’t be any, and the latter can only be observed by all the lonely people, but individually.

Another significant concept linked to both of these is Roko’s Basilisk, which we cannot talk about. A fourth one is the Simulation Argument. This is an argument which has been popular with Elon Musk but doesn’t seem to work. This is that we are much more likely to be living in a simulation than the real world because any civilisation which existed for long enough and became advanced in computing will eventually decide to simulate the world. Those simulated worlds will then simulate other worlds when their own simulations are sophisticated enough to do so, and so forth. This would mean that of all instances of apparently real worlds, almost all are simulated. This argument compared to the others seems almost trivially easy to refute. Firstly, taking it at face value this means a cascading tree of simulations, each generation more numerous than the last and also more simplistic and therefore less realistic due to lack of computing power, so the fact that the universe is more complex than it might be means we aren’t in the most numerous types of simulation, so why would we be in a simulation at all? Secondly, again taking it at face value, the three-body problem and beyond can in most cases eat up all available computing resources. I actually don’t think this argument works because in the non-special cases a pseudorandom number generator could just be used to prevent this from happening and the chances are nobody would be any the wiser, since the movements of the large number of bodies is in fact unpredictable. I suppose this could be tested by looking at one’s own simulations of three-body problems using various pseudorandom generator algorithms or for that matter true randomness. But beyond all this, the really big assumption seems to be that any civilisation would inevitably end up bothering to simulate the world in the first place. As I’ve said before, apart from anything else they might just be really bad at maths, and with anything else maybe they’ve got more important things to do.

All of these seem to have a self-centred element to them. There’s also an arrogance to them, in that they boldly assert that the person proposing or learning of them has taken everything into consideration and nothing can assail the argument. The Simulation Argument is obviously full of holes, but the holes are the blind spots of a probably autistic sociopath in that the assumption is that just because one person or a group of people working in a particular field would try to do this, thereby incidentally becoming a God to the sims, everyone else would, regardless of their personality or neurodiversity. Quantum Immortality and the Simulation Argument both seem to leave us with “non-player characters”, i.e. zombie shells of people who aren’t really conscious and don’t really matter, so that’s sociopathy and lack of empathy again. They seem to provide an excuse to ignore people’s needs. The Doomsday Argument assumes that humans all contemplate the end of the world or the human race and are all that matters, rather than it being the thought of the end of the world which is significant. There needs to be a cut-off point or certainty that we are the only conscious beings in the Universe for it to work.

In the end, although these arguments are interesting I think they really say more about the people who think of them than the actual world they’re supposed to be applied to. I do think that something will prevent the Artemis Project from succeeding, and that is because of the future galactic civilisation thing, but there could be really positive reasons why it won’t. As for the others, well, they all have a kind of solipsistic and self-centred air to them which it doesn’t seem healthy to entertain. But who knows? Maybe there are other kinds of argument of this nature which do have real predictive power, and if there are that would be fascinating and also useful.

Diagonal And Vertical Time Travel

This is a bit of a thought dump where I try to work out the details of something I’m planning to use in a story, along with other bits I’ve adapted from elsewhere. It’s about time (travel).

I want to talk first of all about metaphors for the passage of time in language and, well, gestures I suppose, and it’s possible that this also comes into sign language. We tend to talk about going forwards and backwards in time, about “past” events and events “to come” and so forth. We also have links between the direction of writing, and what follows from that, and that of time. Our clocks move clockwise and progress bars on audio and video place the “early” direction on the left and “late” on the right. This has been going on for longer than the existence of easy video and audio playback on digital devices, because on tapes, for example, we have fast forward and play, with arrows pointing to the right, and rewind, with arrows pointing to the left. One thing I don’t know is whether Arabic and Hebrew use the same convention, even though their writing proceeds from right to left, but I would expect the dominance of Western culture to have dictated this. A less well-known aspect of this is somewhat more jarring for us as humans, as opposed to us as humans literate in Latin script. Languages are often described as having features to the right or the left, for example as having prefixes to the left and suffixes to the right, focussing on spoken language, but written language doesn’t always go that way, so it means that Hebrew, for example, might be described as having the definite article to the “left” of a noun even though as written that would be on the right. Incidentally, when people pause to think during a conversation, they will look to their right and up in cultures where writing is left-to-right and to their left and up where it’s right-to-left, and since this is learnt from other literate individuals and diffuses through culture that way, it’s even true of illiterate individuals such as small children. This illustrates how pervasive our time flow metaphors and conventions are. It should also be mentioned, for the sake of completeness as this probably won’t come up again here, that time can be thought of as linear or cyclical, and in theory cyclical time could be moving in any direction, although again this would depend on clockwise or anti-clockwise convention.

I could be wrong about this but I seem to remember that Chinese culture, inasmuch as it’s a single culture, agrees with my own view that the passage of time is vertical, falling from top to bottom. I presume the reason for this is the vertical direction of Chinese and related scripts, which brings me to wonder how it worked in Mongolia when it too had a vertical script. Another set of options for script direction exists in boustrophedon, where direction alternates and characters can be either inverted or mirrored, and I have no idea if that has any bearing on temporal metaphors. However, I want to put a case for a vertical time flow metaphor besides script direction, which seems fairly arbitrary, and then I can get on with this.

X, Y and Z axes are usually organised in order of left-to-right, front-to-back and low-to-high. On a graph, the Z axis usually points into the paper or screen and away from the viewer. The time axis is often referred to as W, because they ran out of letters and had to go backwards. As H.G. Wells pointed out in ‘The Time Machine’, gravity conventionally restricts our movement in the third dimension, i.e. height, in that if we consider the centre of, in our case, Earth as below us, we are liable to fall in that direction without support and have difficulty increasing our height above a reference level because it pulls us down. This difficulty is paralleled by our perception of the passage of time, because we are relentlessly propelled into later time from earlier, a process which is usually described as “forward” in time. Because of this similarity, it makes more sense to me to think of the passage of time like a waterfall, falling from top to bottom, and also as facing upwards since we have greater difficulty with accurately perceiving the future than the immediate past. This also has the advantage of working better in gestures and diagrams, because a vertical picture of the passage of time is the same for all observers, unlike time itself, whereas a time flow metaphor of forwards and backwards, or left and right, is reversed for someone opposite. That said, I’m pretty sure I don’t consistently gesture in this way. This vertical metaphor also works for the likes of family trees, and may also be used for timelines although this contradicts the order in which, for example, strata are laid down. A chronicle written in Latin script would, however, proceed vertically down the page, in a scroll, and in a codex (spined book) this would also be true when it was closed – the Book of Genesis is at the “top” of the Bible and Exodus is underneath it, in an English Bible, though in the Tanakh it’s the other way round. Family trees, incidentally, are actually the other way up compared to real trees.

Thinking of spacetime as a block, and simplifying space to two dimensions to make it possible to visualise it, it can be thought of as a kind of transparent cube with events embedded in it like flies in amber. The longer something goes on for, the longer its world-line is, from top to bottom, and at ordinary speeds, something moves around horizontally but is always earlier at the top than at the bottom. Then there’s the light-cone, which I regard as a crucial concept for time travel. The Sun is eight light minutes, Alpha Centauri four light years and Betelgeuse six hundred light years away. The upside-down, but still vertical, version of the light cone can be illustrated thus:

Flipping this over, events occurring above, such as the emission of light from a star, have only impinged upon an observer at the peaks of the cones if it happens within the top cone, and events occurring below, i.e. in the future, will only influence other things if they are within the light cone below the point where the peaks meet. The surface of the cone is defined by the speed of light because nothing can exceed it, and therefore there can be no causal connection between anything outside the light cone. Every location at a particular moment has these light cones.

This is where time travel comes in. The classical objection to travelling backwards in time is that it can create two types of paradoxes, or rather involves two types: the grandmother paradox and the ontological paradox. The grandmother paradox is illustrated most starkly by the possibility of becoming one’s own grandparent, leading to a loop in time with no cause and also a contradiction with recorded or otherwise “known” events. I know I’m not my own grandparent, or have a high degree of confidence that I’m not, because their identity and history aren’t mine. A slightly different paradox is the ontological one, exemplified by such events in fiction as the apparent eighteenth century CE glasses given to Captain Kirk by Bones in ‘Star Trek’ which were later pawned in 1986 in San Francisco, later possibly being acquired by McCoy and regifted. This means that certain complex objects have no origin at all, and raises questions such as what happens if someone sends a 21st century signed copy of the sheet music for Beethoven’s Fifth Symphony to Beethoven which he then copies instead of composing it for himself. It might be less disturbing if all that happens is a single electron or photon is transported in time.

My long-standing answer to this is to evoke what is called either the Novikov Self-Consistency Principle or the Blinovitch Limitation Effect, depending on whether you go with the real world or science fiction version of the effect. The Novikov Self-Consistency Principle holds that if an object travelling in time would cause a paradox of this nature, the probability of that occurring is zero. The Blinovitch Limitation Effect is similar and originated in ‘Doctor Who’, and means that either timelines cannot cross themselves or that if they do, some kind of catastrophe occurs. This happens for example in ‘Father’s Day’, where Rose encounters herself as a baby and it leads to damage to the time stream which can only be resolved by her father meeting his fate, that is, death under the wheels of a car.

My own solution to this has been to suppose that time travel “upwards” is only possible outside the light cone. That is, for example, you can move upwards in time but if you did so you would find yourself displaced at least the same distance in space from your point of origin as it would take light to travel to it by the moment of your departure. Hence if you travel three years upwards in time, say from 2023 to 2020 you might find yourself near Alpha Centauri because it then means that you can’t have any influence on where you came from. You might send a radio message warning people about Covid-19 but it wouldn’t get there until after the outbreak, for instance.

For this reason, I have tended to portray time travel as a “diagonal” process. You can’t stay in the same place and travel into the past, but will be displaced by the same distance in time and space: four light years for four years and so on. I also applied this to the idea of parallel universes, which I see as separated from us by extra dimensions, so your creation of a different history would simply mean that you had been transported to a parallel universe where that would always have been the case. The problem with this is that it kind of makes it look like any significant historical event was caused by time travel, or that there would be duplicate universes different only because in one a time traveller had turned up and made the same change as had happened without such intervention in another parallel universe. Thus in one universe, JFK isn’t shot because the guns jammed but in another someone came along and secretly did something to the guns in advance which caused them to jam. This seems suspicious.

There is a further problem with intersecting light cones, because events which can’t impinge on one light cone can do so on another, but I have to admit to being rather hazy about that, so I won’t go further. That, then, is diagonal time travel. There’s also vertical time travel.

Vertical time travel is what any object or person does when they’re sitting still, although of course real sitting still (or standing still) is not a trivial, or maybe not even a possible, thing because of things like orbits, rotation of planets and so forth, and the probable complete absence of an absolute frame of reference. Hence a vertical path through time is not a straight line, although it might look straight to observers who are stationary with respect to the object or event in question. Simplifying this, as in fact we always have to deal with this in other ways but generally think of ourselves as moving or stationary with respect to the scenery or neighbourhood as opposed to the reality that we are on a rotating, orbiting planet and in a solar system orbiting through the Galaxy, and so forth, time travel from the past to the future for most of us is almost perfectly vertical in nature. We are moving straight “down” in time, not diagonally. Sunlight is diagonal. In fact, all light in vacuo is diagonal because its velocity is the same for all observers.

Back to vertical time travel. Ignoring the complications mentioned just now, vertical time travel into the past should be impossible. Into the future it’s the norm. However, the conventional depiction of time travel in most popular culture is that of the protagonist moving through time, either into the future or the past. The latter clearly brings up the question of paradoxes, and conjures up the idea of a wise and intervening Universe for which there is no evidence stopping such things from happening. This is not, though, the only conceivable way an object or entity might move through time, and this is where my new ideas come in, and where this becomes a kind of world-building thought dump.

There is a second, less often used, version of time travel in fiction which is not used to explore paradoxes so far as I know, and it’s this which I’m going to call “vertical time travel”. This is illustrated only occasionally, as far as I know. The first example which comes to mind is found in Isaac Asimov’s ‘The Ugly Little Boy’. In this story (SPOILERS!) a Neanderthal child is brought into the twentieth century, although he eventually returns to his time with his H. sap. nurse. In this story, energy is required to hold objects in the modern world and budgetary constraints lead to them being returned to the past, including ultimately the Neanderthal boy, so this is not a one-way street and paradoxes are still possible. The TV series ‘Primeval’, which I haven’t seen, seems to have the premise of a similar effect where animals arrive in the present through temporal anomalies, but again this seems bidirectional. You also see the same kind of thing in «Les Visiteurs» and ‘Catweazle’, where a similar process brings characters from the Middle Ages into the twentieth century. Most of the time, perhaps to provide resolution in plot terms, the protagonists or objects are returned to the past and I can’t offhand think of any unidirectional time travel stories. They probably do exist as they allow for “fish out of water” stories. In fact most of the time this is satisfied by the idea of someone going into a state of suspended animation and being revived, as with ‘Rip van Winkel’, ‘Idiocracy’, the story that was based on, and Woody Allen’s ‘Sleeper’. This is a device allowing for time travel in a much more realistic manner than something like ‘Doctor Who’. However, actual vertical time travel allows for other possibilities which are quite intriguing and not available to such tales.

Time travel into the past can never be invented, only discovered. Look at it this way: the first time in history someone devises a time machine that goes upward in time, it will already have gone into the past. Hence it will have come into existence before it was invented. It might not be discovered in the sense that someone comes across it on its trip furthest back into the past, but the “inventor” has come across the machine at a later time than when it first sprang into existence. Alternatively, time travel might exist due to a peculiar combination of events and circumstances arising without the intentional use of technology, perhaps, for example, where a wormhole has orbited another at relativistic speeds due to one side being close to the event horizon of a black hole, resulting in an object able to capture masses and transport them to an earlier time in its history because time has passed more slowly at one end than the other. Incidentally, I’m not saying this is feasible, but such a situation could be discovered and wouldn’t’ve been invented. Hence there is a sense in which it’s impossible to invent a time machine completely aside from any technical reason why they would be impossible in themselves. Even possible time machines cannot be invented.

Given that, there is also a sense in which instances of time travel from the past might be discovered rather than deliberately or accidentally perpetrated, but I’ll come back to this. For now, imagine the following scenario. Objects move from the past to the present without ageing. By “ageing”, I mean any change due to the passage of time, so for example if a watch reading 4:45 pm moves an hour down the line, it still reads 4:45 pm on arrival, at 5:45 pm, and it still works. This amounts, I suppose, to the suspension of entropy, although it would seem inevitable that the object in question would not have a location, and in a sense would not exist, between the two occasions. It isn’t frozen in time: it has discontinuous existence. Otherwise any object on the surface of this planet, assuming it follows Earth, would remain in the location it succumbed to time travel and would seem to be a frozen item whose location could be discovered, and it would be observed. But maybe it wouldn’t, because this would involve interaction with the rest of the universe, and this would seem to imply change. Being subjected to millions of years of ionising radiation in an instant, and millions of years of thermal energy in the same time, would be likely to destroy such an object. Therefore suspension of entropy would mean the apparent absence of the object, perhaps existing in a merely latent state for geological epochs. After all, if time isn’t passing for an object, its electrical charges cannot attract or repel, its particles can’t change energy state, preventing their ability to emit or absorb photons, it has no weak interaction in its nuclei and so forth. It literally does nothing and does not interact with the Universe, although it has to be assumed that it retains momentum or it would end up buried inside the planet or in deep space.

This, then, is the fictional scenario I wish to present. There are objects which enter a kind of dormant state of existence for various intervals, or perhaps they simply enter a dormant state of existence until disturbed in some way. Then, after a period of time, a device comes along which can revive them back into existence. This does not occur causally, i.e. this is not a device which can actively retrieve objects from the past, although that is what it appears to do, because sub specie aeternitatis this is what would always have happened to such objects. Because of this, there can have been no interaction between such objects and the operator of the “discoverer” machine, or a paradox could be created. Even so, the operator of the discoverer subjectively experiences the decision to focus the machine on a selected target in the past which they would then bring into the present. That decision, though, was always casually determined, perhaps like all apparent instances of free will. Therefore, as far as the operator is concerned, they are making a decision to retrieve an object from the past, operating the machine and being presented with the intended object. So far, so good.

From this description, there seems to be no possibility of paradox, which makes it rather boring. Consider this though. If you have already interacted with an object in some way, you cannot bring it into the present. You can’t target last night’s dinner just after you’ve cooked it and eat it tonight, because if you did that you wouldn’t have had last night’s dinner. That said, what if you targeted someone else’s dinner from last night? You’ve had no causal interaction with that dinner. It could be in a kitchen you’ve never visited and be eaten by a complete stranger. What if that led to them developing a false memory that they had eaten the meal, because in one timeline they had but in yours they hadn’t?

To be highly specific, just suppose you went back to the set of ‘Moonraker’ and removed Branche Ravalec’s braces. You would then know what had happened, but everyone else would have the false memory of her having braces when they watched the film. In other words, and I would stress that this is fictional, this is an explanation for the Mandela Effect.

And it has legs! Now imagine a sealed box containing a cat. You have no knowledge whether this cat is dead or alive owing to a poison gas canister broken or remaining intact according to radioactive decay values. Also, you save the cat by removing her from her predicament before the canister is at all likely to be broken. A familiar example, but with a twist involving time travel. If you’d opened the box, you would never have succeeded in bringing the cat through time. Schroedingers Cat of course, but with a twist.

Now imagine a young woman shopping for groceries – yes, this is a heteronormative example. Her bag falls apart and her orange rolls along the pavement, to be picked up by a handsome young man. Their eyes meet and the rest is history. There are wedding bells and children. Then, one day a third party focusses their discoverer on the aforesaid orange and removes it to their present day. For that individual, this was always going to happen because they don’t know these people and it has no consequences for them. Meanwhile, spouses wake up in their own beds, perhaps at opposite ends of the country married to different people, with different children, with no memory of how this happened or anything, but with distinct memories of meeting each other, getting married, settling down and having children, who will now never exist. On the other hand, assuming they can do anything about this, and I suspect they can’t unless they can trace who did it and stop them without causally interacting with them, and how could that happen, they would end up back together but again, their own children conceived with their other partners would, again, never have existed.

I would maintain that all these possibilities are highly fruitful, and intend to write a story based on them. In the meantime, this post has served as a means of working out this detail of such a story for me. Thanks for your patience.

Sodding Phosphorus!

Here is a sample of the aforesaid element:

Phosphorus has two main forms, or allotropes. When first extracted, it’s white and extremely toxic. The form illustrated above is red phosphorus of course. Left to itself, white phosphorus gradually turns into its red form, which is why the so-called “white” allotrope usually looks yellow:

By BXXXD, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1096986

This is not, however, supposed to be “all about phosphorus”. Rather, it’s about two issues which affect the element, both to do with life, one on this planet and one in the Universe generally.

I’ll start by explaining the importance of phosphorus to life as we know it. There are six elements making up most of the body of a living organism on Earth. These are carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. Carbon is important because it can form chains and rings from which complex molecules can be built. It’s notable that even though silicon is far more abundant on this planet than carbon, life is nonetheless carbon-based. This is to do with things like carbon’s ability to link itself into chains, form double and triple bonds with other atoms, the fact that its atoms are small compared to silicon and the difficulty of getting silicon out of molecules such as silica which may be formed as a result of any putative biochemical processes. Carbon dioxide, the analogue of silicon, is a gas at fairly low temperatures and can be incorporated into other structures. It so happens that I do think silicon-based life is possible, but it would have to be created artificially and exist in some kind of closed environment whose contents were carefully selected. The chances of silicon-based life arising without intelligent intervention are very low. The greater terrestrial abundance of another element should be considered again here, but not right now. Hydrogen and oxygen are of course the constituents of water, a compound which is really unusual in many ways, such as its unusually high melting and boiling points on the surface of this planet, its ability to dissolve other compounds and the fact that it gets less dense as it cools below 4°C. These properties mean respectively that the chemical reactions needed for life as we know it can occur at a temperature where there’s enough energy for them to take place but not so much that they’d be unstable, that the compounds are in a liquid medium conducive to reactions in the first place and that the oceans, lakes and rivers don’t freeze solid from the bottom up. The two constituents are useful in their own right. Oxygen and hydrogen are components of countless compounds, including carbohydrates, amino acids, proteins and fats. Oxygen, unlike chlorine which has been considered as a possible alternate breathing gas for alien life, can form two bonds, meaning that it isn’t the dead end single-bonding atom which the halogens are. Nitrogen is a essential component of protein via its presence in amino acids. Amino acids have a carbon connected to a carboxyl group and an amino group, which can bond together to form chains, and a functional group such as a benzene ring or a sulphur atom which can have other biological functions. Proteins, in other words. There are also chemicals called alkaloids which occur mainly in plants and vary a lot, which have striking pharmacological effects, and the nucleotides are also rings containing nitrogen, encoding genes in DNA and RNA. Nitrogen is actually so reactive that it bonds strongly to other atoms, including other nitrogen atoms, and consequently it’s vital that various organisms can uncouple it and combine it for the benefit of the rest of the biosphere. This is known as nitrogen fixation and is performed mainly by bacteria and certain plants, and also by lightning, but if life had to rely on lightning to do this, it would not be widespread and nitrogen fixed by lightning would be the limiting factor in global biomasse. Sulphur is significantly found in a couple of amino acids and allows proteins to form more complex shapes as are needed, for example, by enzymes and hormone receptors, because they form bridges with other amino acids making the molecule tangle usefully together. It’s also found in hair, nails and various other substances such as the substances responsible for the smell of garlic and onions. Sulphur is actually a bit of an exception in the chief elements required for life because sometimes it can be substituted by either selenium or tellurium, and there are amino acids which have these elements in sulphur’s place, but both of them are much scarcer than sulphur.

Then there’s phosphorus. Phosphorus has more limited functions than the others but these are incredibly vital. It forms part of adenosine triphosphate, which organisms use to transfer energy from respiration to the other functions of the body. It also forms part of the double layers of molecules which form membranes and allow controlled and specialised environments to exist in which the chemical reactions essential to life take place, and also enables substances to be packaged, as with neurotransmitters. Thirdly, it forms the strands of sugar phosphate which hold DNA and RNA together, so even if it didn’t do anything else, some kind of method would have to exist to store genetic information. This is perhaps the least vital role though. A more restricted role is found in most vertebrates, in that it forms part of the mineral matrix of bones and teeth, but there’s plenty of life that doesn’t do this and the usual substances used to make hard parts of animals are silicates and calcium carbonate, among other rarer examples such as iron pyrite. Nonetheless, humans need phosphorus for that reason too, as do our close relatives. However, even the closely related sea urchins use calcium carbonate instead.

Hence several facts emerge from all this. One is that an apparently similar and more abundant element can’t necessarily be used for a similar function, assuming here that life can start from scratch. Another is that elements can get themselves into such a strongly bound state that it would take too much energy to use them for it to be worth it for life. A third is that life will sometimes substitute another element for the one it usually employs if it can. If a rare element is used, there’s usually a good reason for it.

Now the first problem with phosphorus is that it’s much more abundant inside a living thing than in its non-living environment, and the cycle that replenishes it is very slow. Phosphorus usually becomes available to the biosphere on land as a result of continental drift, the formation of mountains and erosion and weathering, and it’s lost to the land when it’s washed into rivers and the sea, where it disappears into sediment before becoming available again millions of years later. In the sea, it’s less of a problem but still a significant one because it’s only available to life as phosphates and it’s often found as phosphides instead. Ironically, there’s also an overabundance problem with phosphates in fertilisers being washed into bodies of water and leading to algal blooms, which can in fact be of cyanobacteria rather than algæ as such. Since some microörganisms can produce extremely powerful toxins, this can lead to massive marine die-offs and contaminated sea food. Where I live, a nearby reservoir was afflicted by an algal bloom and had to be closed off for quite some time, and this can also poison wildlife on land. These can also lead to high biochemical oxygen demand, which is where all the oxygen gets used up and the water becomes anoxic, which is incidentally a cause of mass extinctions, though on a much larger scale, in the oceans. This happens because phosphorus is relatively scarce and a significant limiting factor in how much life is possible in a given area, so a sudden influx of usable phosphate is likely to cause a chemical imbalance.

The Alchemist Discovering Phosphorus, Joseph Wright, 1771 and 1795.

This painting is thought to refer to the discovery of the element by Hennig Brand in 1669. Brand discovered it when searching for the Philosopher’s Stone, by heating boiled down urine and collecting the liquid which dripped off it. It turns out that this is actually quite an inefficient process and it’s possible to extract a lot more of the phosphorus by other means. The allotrope illustrated in the painting is unfortunately the highly toxic and dangerous white variety, so the alchemist is putting himself in peril by kneeling so close to the retort. The point to remember in all this is that phosphorus is found in urine, not in huge amounts but enough. This points towards a particular problem, highlighted by Isaac Asimov in his 1971 essay ‘Life’s Bottleneck’, which points out that humans “may be able to substitute nuclear power for coal, and plastics for wood, and yeast for meat, and friendliness for isolation—but for phosphorus there is neither substitute nor replacement”. Urine goes down the toilet and is flushed into the sewers, processed in sewage farms and the phosphorus from it ends up in the sea. It does gradually return to the land in biological ways. For instance, a seagull may die on land and her bones may become part of the terrestrial ecosystem, or she might just poo everywhere and return it that way, but the occasional gull or tern conking out in Bridlington is no compensation for millions of people flushing the loo several times a day. By doing this, we are gradually removing phosphorus from the land and returning it to the sea, whence it won’t return on the whole for millions of years.

Two ways round this suggest themselves. One is to eat more sea food. For a vegan, this is unfeasible and in any case fishing causes a lot of plastic pollution and is unsustainable, but of course it is possible to eat seaweed, and I do this. The other is not to allow urine into sewage in the first place or to process sewage differently. I have been in the habit of dumping urine in the garden, although I haven’t done this as much recently. It also contains potassium, and in particular fixed nitrogen, so in diluted form it is indeed useful for raising crops. However, this is on a small scale and a better system might be to process the sewage differently and put it on the land, being careful to ensure that harmful microbes and medication have been neutralised before doing so. Regarding seaweed, dulse, for example, is 3% of the RDI of phosphorus by dried weight, compared to the much lower amounts in most fish. Cuttlefish is the highest marine animal source. Human urine averages 0.035%, so you’d have to eat a lot of seaweed. However, in isolation, if you don’t, there will be a constant loss of phosphorus to the land. Guano is one solution, but not ideal and only slowly renewable.

The other problem with phosphorus follows from the same scarcity and the same use in living systems, but is more cosmic in scale, and I personally find it more worrying: phosphorus is rare on a cosmic level. In a way, all atomic matter is rare in this sense because the Universe is, as the otherwise really annoying Nick Land once said, “a good try at nothing” (apparently nobody has ever quoted that before, so that’s a first!). The cosmic abundance of the different elements looks like this:

The Y axis is a logarithmic scale, so for instance hydrogen is about ten times as abundant as helium and even in terms of mass is more common than any other element except helium. One notable thing about this graph other than the clear rapid decline in abundance with atomic number (the X axis) is that it zig-zags because even-numbered elements are more frequently found than their odd-numbered neighbours. This is because many elements are formed by the collision of α particles, which consist of two protons and two neutrons. Phosphorus is flanked by Silicon and Sulphur on here, though it isn’t specifically marked, and its atomic number is fifteen, i.e. an odd number. Chlorine, which is quite common in living things because it’s part of salt, is less common still.

Elements are formed in various ways, and this relates to how common they are. The Big Bang led to the formation of mainly hydrogen and helium a few minutes later, as soon as the Universe was cool enough to allow their nuclei to hold together and their nucleons to form, although they would’ve been ionised for quite some time rather than being actual atoms. Small amounts of lithium and beryllium formed in the same way, and if the graph is anything to go by this looks like it might’ve been the main way beryllium in particular formed. Then the stars formed and the pressure inside them led to helium nuclei in particular being pushed together to form heavier elements. The crucial step in this phase is the formation of calcium when three helium nuclei collide. Then, a number of other things happen. The star may end up going supernova and scattering its heavier elements through the local galactic neighbourhood. It may also form new elements in the process of exploding through radiation. This was until fairly recently thought to be the main means heavier elements were formed, but another way has recently been discovered. When a star not quite massive enough to become a black hole collapses, it forms into what is effectively a giant atomic nucleus the size of a city known as a neutron star. When these collide, they kind of “splat” into lots of droplets. Neutrons are only stable within atomic nuclei. Outside them they last about a quarter of an hour before breaking down, and they often become protons in doing so. This means that many of the neutronium droplets form into heavier elements, which are then pushed away by an unimaginably powerful neutrino burst from the neutron stars and again scattered into the galactic neighbourhood. Two elements, beryllium and boron, are mainly formed by cosmic rays splitting heavier atoms. Some, particularly transition metals such as chromium and manganese, formed in white dwarf stars which then exploded, and technetium along with all the heaviest elements, have been generated by human activity.

At first, the abundance of phosphorus didn’t seem to be a big problem. However, after studying supernova remnants, scientists at Cardiff University seem to have found that there is a lot less produced in supernova than had been previously thought. This means that phosphorus is likely only to be as common as it is here in this solar system in star systems which formed near the right kind of supernova to generate it in relatively large amounts. Couple this with the essential function of phosphorus in DNA, RNA, membranes and ATP, particularly the last, and it seems to mean that at this point in the history of the Universe, life as is well-known on Earth is likely only to be found in initially localised areas, surrounded by vast tracts of lifeless space. The systems containing life would gradually separate and spread out through the Galaxy due to the migration of the stars as they orbit the centre of the Milky Way, but they would remain fairly sparse. However, as time goes by and the Universe ages, there will be more such supernovæ and phosphorus will slowly become more common, making our kind of life increasingly likely. If life always does depend on phosphorus, we may simply be unusually early in the history of the Universe, and in many æons time there will be much more life. This possible limitation may have another consequence. We may be living in a star system isolated from others which are higher than average in phosphorus, meaning that to exist as biological beings with a viable ecosystem around us elsewhere, we would either have to take enough phosphorus with us or make our own, and even the several light years between stars which we already find intimidating is dwarfed by the distances between phosphorus-rich systems in the Galaxy, which may once have been near us but no longer are, and not only do we have to schlep ourselves across the void, but also we have to take a massive load of phosphorus with us wherever we go.

But that is biological life as we know it. A couple of other thoughts occur. One is that there could conceivably be life as we don’t know it. This doesn’t work as well if the substitution of phosphorus is the main difference, because if that could happen, it presumably would’ve happened with us, and it didn’t, because other elements with similar functions would’ve worked better if they were more abundant and out-competed with the life which actually did arise unless there’s something about this planet which does something else like lock the possible other options away chemically or something. However, there could just be drastically different life, based perhaps on plasma instead of solid and liquid matter on planets and moons, which has no need for phosphorus or even chemistry, on nuclear reactions taking place between nucleons on the surface of a neutron star as suggested by Robert L Forward’s SF book ‘Dragon’s Egg’, or even nuclear pasta inside neutron stars. Maybe it isn’t that life is rare in the Universe, but that life as we know it is, partly because it needs to use phosphorus.

There is another possibility. We are these flimsy wet things crawling about a planet somewhere in the Galaxy, but we’ve also made machines. In our own history, we are the results of genes, and perhaps also mitochondria and flagella, concealing themselves inside cells and proceeding to build, through evolution, relatively vast multicellular machines to protect themselves. Maybe history is about to repeat itself and we are going to build our own successors, or perhaps symbionts, in the form of AI spacecraft which go out into the Universe and reproduce. Perhaps machine life is common in the Galaxy and we’re just the precursors. There is an obvious problem with this though, mentioned a long time ago: what’s to stop swarms of self-replicating interstellar probes from dismantling planets and moons and making trillions of copies of themselves? If this arises through a mutated bug in their software, it would be to their advantage, and they could be expected to be by far the most widespread “life” in the Universe. Yet this doesn’t seem to have happened. If it hasn’t, maybe the beings which built these machines never existed either. Or maybe they’re just more responsible than we are.

Mega-Moon

No, King John did not sign the Magna Carta here. Buddy Holly is not alive and well here. Christmas has never been celebrated here. Nor is this in Surrey. That’s Runnymede. Incidentally, Buddy Holly doesn’t live there either, although Christmas has definitely been celebrated in it. However, this is Ganymede, the largest moon in the Solar System and therefore the largest Galilean. It’s larger than Mercury and Pluto, but smaller than Mars. That said, it’s only 45% of Mercury’s mass.

To explain the rest, ‘1066 And All That’ claims that King John signed the Magna Carta on Ganymede. This opens up the possibility of a weirdly transposed version of English or British history where all the stuff that went on in our Middle Ages could be copied and used to tell the tale of a British version of the entire Solar System, perhaps with Jupiter as its capital. That makes me wonder where Scotland is. Ganymede also turns up in the rather startlingly entitled ‘Buddy Holly Is Alive And Well On Ganymede’, a novel which recounts the tale of one Oliver Vale, conceived at the moment of Buddy Holly’s death, who thirty years later finds that all the TV stations in the world have their signal hijacked by a broadcast of a rather bemused Buddy Holly on Ganymede who knows nothing of his situation except that there’s a TV camera pointing at him and a sign next to it reading

For assistance, contact
Oliver Vale, 10146 Southwest 163rd Street, Topeka, Kansas, U.S.A.

It’s actually quite a good book.

As for Xmas, Isaac Asimov wrote a 1940 CE story called ‘Christmas On Ganymede’ about a mining company on said moon whose employees hear about Christmas and proceed to go on strike until visited by Santa in his flying sleigh pulled by reindeer. This version of Ganymede is much denser than the real one and has an almost-breathable atmosphere containing oxygen. I suspect Asimov already knew Ganymede wasn’t like that.

I’ve always called it “Ganymeed”, but it’s supposed to be pronounced “Ganymeedee”, which is how Buddy Holly says it in the book so it must be true, but I think both are acceptable pronunciations. Ganymede, or Ganymedes, himself, was a Trojan prince abducted by Zeus to serve as a cup-bearer to the Olympians. This means Ganymede was Zeus’s sexual partner in a pederastic setting, so the situation is mixed. On the one hand, we have a moon acknowledging homosexuality, but on the other current values place him as a victim in the same way as Io and Europa are of Zeus’s insatiable lust. He’s the basis of Aquarius, but the constellation Crater has nothing to do with either. I don’t know why Ganymede was the name given to the largest moon and I’m now wondering if Kepler or Marius, who named them in 1614, was secretly gay.

The next largest moon is Saturn’s Titan, which is also larger than Mercury. This makes it the ninth largest known object in the system. It’s the tenth largest by mass, again just ahead of Titan and giving it a larger surface area than Eurasia by quite a margin, and slightly larger than the Atlantic. It also contains an internal ocean with more water than exists on Earth. It takes four times as long to orbit Jupiter as Io does, and twice as long as Europa, so once again it’s in orbital harmony with other Galileans. It’s also the most massive moon, which puts it in a slightly odd position as its surface gravity is lower than Io’s or Europa’s, because it continues the trend of decreasing density with distance from Jupiter. It gets closest to Europa, at 400 000 kilometres, just over the distance between Earth and Cynthia. Callisto is somewhat apart from the others. Io and Europa taken together are less massive, but the imbalance between a single large moon and several or many smaller ones whose combined mass is less doesn’t apply in the Jovian system. In a way, Ganymede is the Jupiter of Jovian moons. It also, perhaps surprisingly, has the lowest escape velocity of all the Galileans, meaning that it won’t be able to hold onto anything like a proper atmosphere, or even the kind of atmosphere the inner two have. Like those though, it orbits within the radiation belts. Until the outer planets and moons were more thoroughly explored in the 1980s and more recently, it wasn’t clear out of the three moons of Ganymede, Titan and Triton which one was the biggest.

The moon was big enough for large Earth-bound telescopes to make out at least one of its surface features, Galileo Regio. The rather vaguely named regiones are Galileo, Marius, Perrine, Barnard and Nicholson, and are the dark patches. They also have sulci across them, of which there are over a dozen. Unlike the two inner Galileans, Ganymede’s surface has not been extensively reworked due to tidal forces and it therefore has a fair number of craters, though not as many as somewhere like Mercury. It’s the brightest of all the moons in our sky other than Cynthia, although it’s dimmer per unit area than Europa, because it’s also the largest. To some extent it resembles Cynthia, as the darker regiones are like the maria (seas) and there are also craters, but the broad sulci are not found on the lunar surface. Due to the surface being largely ice and at this temperature being softer than rock as we know it, it isn’t as craggy either, although it’s not as smooth as Europa. The gravity being lower might contribute to this. The maximum elevation is found among the sulci, which reach about seven hundred metres above the surface.

Galileo Regio is the size of Antarctica. It covers a third of the hemisphere facing away from Jupiter. Putting this into perspective, this means that as far as Earth is concerned, our continents and oceans would mainly be visible from Jupiter with a good telescope, although Australia might not be, and Jupiter is almost our neighbour in cosmic terms. All we’d be able to do from that distance is discern that the continents and oceans existed and were differently-coloured from each other. The most distinctive feature of the moon, and let’s once again affirm that by a more recent view than the 2006 IAU definition Ganymede is also a planet as much as Pluto is, is its grooved surface and the stripe-like features where they’re bundled together. These lighter sulci are newer than the dark regiones. It and Earth are the only known bodies which have lateral faulting, that is, where a fracture in the ground leads to the surfaces sliding along the fault rather than subsiding or rising. These sulci divide the terrain into polygonal blocks, the regiones, up to a thousand kilometres across. Although the moon is not currently active and drifting doesn’t occur, it has done in the past and this arrangement of plates separated by lateral fault zones is similar to Earth’s continental plates, making Ganymede the only other world in the system which has this kind of arrangement. Not even Venus, which is geologically quite like Earth in many ways, has this feature.

The crust is somewhat weak and can’t stand heavy weights upon it, and is underlaid by a much deeper layer of water. This leads to “drowned” looking craters which look quite similar to the ones on the lunar surface which became flooded with lava in æons past, but unlike them their origins are not associated with flows of liquid but mere collapse into the surface due to the weakness of the material. Most craters are on the regiones because they’re older. About half of the bulk of the planet (let’s call a spade a spade now we’re allowed to again) is ice and half is rock, although it isn’t clear how this is distributed. It does have a very large rocky core under the deep oceans, and also its own magnetic field, practically guaranteeing an iron-rich centre like Earth’s. Although one way of looking at the interior is as a frozen-over deep ocean of salt water over an ocean bed, it could equally well be described as a planet where ice and water replace our rocks and magma, with a mantle of water rather than molten rock. However, because the gravity is so low there, the pressure at the bottom of the ocean/mantle wouldn’t be excessive. As well as ice, there is clay mixed in with the crust, and there may also be ammonia ice. There’s also more dry ice at the poles, and as with several of the other moons the leading and trailing hemispheres of the planet have different surface compositions, probably because of Io again as the trailing side has more frozen sulphur dioxide. I have to admit that I don’t understand why these moons have deposits from Io on the trailing hemisphere rather than the leading one because it seems to me that they’d be entering a cloud of the stuff, which would then land on the “front” of the moon.

The crust is eight hundred kilometres deep and contains the kind of ice we’re familiar with here along with, as I’ve said, clay, but may also contain bubbles of the same kind of oxygen as we have in our atmosphere. Above it is, for the same reasons as on Europa, an extremely thin atmosphere of oxygen and ozone, and I’m guessing the ozone is formed by Jovian radiation in the same way as an electrical spark forms ozone here. This is a small fraction of a nanobar in pressure. Deep in the crust are large clusters of rock, which might either be piles at the bottom due to its inability to support their weight or embedded in the crust due to its ability to support it! There is then what may be a further hundred kilometres of water, ten times deeper than our Marianas Trench. This is salty, as can be seen by the way aurora behaves on the planet, influenced by the magnetic behaviour of the brine. The fact that there is so much water seems appropriate for a planet named after Zeus’s water-carrier. Ganymede is the only moon in the system with a magnetic field.

Beneath the ocean lies a layer which makes the existence of life as we know it unlikely. Although the lower gravity reduces the pressure, the ocean is so deep that it manages to compress the water back into ice, but of a different kind than we would come across here: tetragonal ice. There is more than one kind of tetragonal ice, and this one is referred to as “ice VI”. The ice we encounter close at hand on Earth’s surface is hexagonal, as can be seen for example in hexagonally-symmetrical snowflakes and the hexagonal columns which form in frost and elsewhere. Ganymede’s lower layer of ice is heavier than water and more akin to the normal behaviour of freezing materials than our ice, because it contracts on freezing. Its crystals consist of elongated cuboids composed each of ten water molecules. Depending on the pressure, its melting point can be as high as 82°C or as low as 0.16°C and it’s 31% denser than water. This kind of ice turns up in the interior of some icy moons. In Ganymede’s case it seems to rule out the existence of thermal vents which could provide energy for life, as it probably does elsewhere in the Universe in many ocean planets, because it forms a thick layer on top of the rocky surface below it which volcanism wouldn’t be able to penetrate.

The structure of the ocean may not be that simple though. The ocean may in fact be arranged in four layers separated by shells of ice of different kinds. Beneath the “ordinary” ice crust on the outside, there may be a relatively shallow ocean on top of a layer of ice III snow. Ice III has a similar crystal structure to ice IV, but because this is snow it would consist of non-hexagonal flakes, perhaps more like needles than hexagons or six-pointed stars. This could be floating on top of a second, deeper ocean, below which is a layer of ice V. This is tens to hundreds of kilometres deep and is monoclinic in structure – that is, two of its axes of symmetry are at 90° but the third is slanted. Examples of monoclinic minerals include gypsum (blackboard chalk), jade and some feldspars (which can be enormous crystals the size of buses found in caves). Then there’s a final layer of water followed by the aforementioned ice VI base.

Below the rocks is a liquid outer core consisting of a mixture of iron pyrites (fools’ gold – this is a sulphide of iron) and iron, and the final solid inner core is made of iron.

A few other bits and pieces. The radiation on the surface is sufficiently weak to be fatal to unprotected humans after a few weeks, but it still wouldn’t be a good idea to go there. There are ray craters like those we see on Cynthia, such as Tycho, which may have light or dark rays depending on where the impact occurred. The “drowned” craters are described as “palimpsests”, after the faint remnants of writing seen in old documents which have been over-written later. Nobody understands why there is a strong magnetic field.

For such a large moon I find it a little disappointing that Ganymede isn’t better known. It feels like there’s either a lack of information on the place or that it’s overshadowed by its more exciting neighbours. Io has the hyperactive volcanism, Europa the possibility of life. Ganymede has if anything a greater right to be thought of as a planet than any other moon in this solar system, being larger than Mercury, and might be expected to be either more interesting or a better-studied place but it definitely comes across as more placid. Also, for its size it’s surprisingly light. This lack of knowledge is likely to change in the next few years when the European Jupiter Icy Moons Explorer (JUICE) is launched to investigate Europa, Ganymede and Callisto, excluding the non-icy Io. This will ultimately orbit Ganymede for around two years before being crashed into its surface. There’s a lot of that, isn’t there?

Next stop Callisto.

Vesta – Curry World?

Not to be confused with PC World, Vesta is saddled with a problem a number of other celestial bodies also experience of having weird pop culture associations. There’s Pluto, after which the Disney dog was apparently named, and while I’m at it, as observed in ‘Dazed And Confused’, why does a cartoon dog have another cartoon dog as a pet? There’s also Uranus, whose name can be pronounced as either “your anus” or “urine-us”. And getting back to the original subject, there is Vesta.

I don’t know how widely the fame of Vesta curries extends, but certainly in England the name has been substantially associated with the things White people used to get in boxes from the supermarket in the 1970s CE, and one of my friends reckoned that the TV series ‘Adrian Mole’ succeeded in nailing the working class Leicester experience perfectly when they ate a Vesta. Goodness knows what South Asians would’ve thought of them. Having said that, I’ve never tried them and that’s even though I’ve been reduced to buying samosas from Sainsbury’s because of the cultural desert I seem to live in nowadays. A quick Google confirms that they do still exist. I mean, I liked Marvel dried milk and Smash instant mash back in the day, so maybe I’d’ve liked them, I dunno.

Why, though, has Vesta got the same name as Vesta, or for that matter Vesta or Vesta? There’s a car, a box of matches and a world in the asteroid belt, and that last one I will get round to in a minute, but for now it’s in order to mention the original Vesta. Vesta was the Roman goddess of hearth and home, which of course immediately makes me think of Dexy’s Midnight Runners because my brain doesn’t work properly:

This is the surrealist painter Max Ernst’s 1937 painting ‘The Angel Of Hearth And Home’, which will be removed on request. It’s one of his few overtly political paintings and represents the spirit of chaos spreading across Europe in the wake of the Spanish Civil War. The title is meant to increase the sense of unease and disorientation one feels on looking at it. It is a vaguely humanoid figure with a fierce-looking fanged mouth and a seven-fingered hand sprouting from its knee. It’s actually the opposite of what one might expect from an angel of hearth and home, and more like death. Well, this opposite figure is the Anti-Vesta. The main association people make nowadays is of course with Vestal Virgins, who undertook not to have sex for thirty years while tending the sacred fire in Rome, considered to be vital to the city’s security. Hence they were tending the hearth of the whole Empire. This is part of a theme in asteroid naming in the early nineteenth century, where the names of female figures were chosen who were also somewhat domestic in nature. I’ve already mentioned Ceres, there’s Vesta, and also her Greek counterpart Hygeia, Juno goddess of marriage and childbirth as well as rather more outward-going things like the state, Flora, Hecuba (Priam’s wife), Victoria and so on. They also often have their own sigils at this early stage, but the point appears to have come when there were so many of them that they gave up.

⚶

This is Vesta’s sigil, clearly representing the eternal flame. Maybe one day it’ll grace a flag. This is Vesta itself:

I’ve selected this rather dingy picture because it shows two features of the body (I’ll talk about its exact nature in a bit) which are particularly distinctive, namely the streaks and the “Snowman””, which is the cluster of craters on the right hand side of the picture. Once again, then, there’s a body with a number of distinctive streaks, like Phobos.

What, though, is Vesta? Is it an asteroid? Ceres kind of turned out not to be, and Vesta may be the second largest. Whereas Ceres is large enough to eclipse the whole of Great Britain and Ireland, Vesta is only big enough to cover Ireland. It’s also the brightest member of the asteroid belt, bright enough in fact to be visible to the naked eye on occasion, although it wasn’t actually discovered until 1807, which happens on occasion. Uranus is also sometimes visible but wasn’t discovered until the eighteenth century. Then again, for many millions of years there must have been animals on whose retinæ images of Vesta, Uranus and even fainter worlds must’ve registered and influenced their visual cortices, but actually recognising it as something orbiting the Sun is another matter. But in any case, Vesta is the brightest asteroid, if asteroid it be. It’s probably also the second largest body orbiting twixt Mars and Jupiter except that Pallas is very close to it in size and it may therefore not be. It has a diameter of 525 kilometres on average, but is considerably less round than Ceres. This makes it definitely larger than Ireland, and in terms of area it gets harder to work it out, but assuming it to be a sphere, which is definitely not true, it’s slightly smaller than Pakistan. Perhaps surprisingly there is no straightforward formula for working out the perimeter or an ellipse, and therefore I’m assuming that no such formula exists for working out the surface area of an ellipsoid either. It’s larger than Mimas, which I always think of as the smallest round body in the system and as a kind of limit below which I kind of have less respect for objects, which may be unfair. Hence there must be something about Vesta’s substance which enables it to retain non-sphericality at a fairly large size, and I imagine this is linked to its rockiness as Mimas is probably much icier.

Although Ceres is the largest object in the asteroid belt, Vesta is the largest one native to it. The large amount of ammonia on and in Ceres suggests that it was originally in the outer system and only arrived in the belt later. Vesta is not like that and has probably always been there. It takes up nine percent of the mass of the asteroid belt and is quite close to being spherical, but just misses out on being a dwarf planet, although it may be the largest object in the system which is decidedly non-spherical. Unlike Ceres, it actually was discovered by the celestial police force set up to find bodies between Mars and Jupiter, and was the fourth discovered by Heinrich Olbers of Olbers’ Paradox fame (why is the night sky dark rather than bright? This is actually a very important question with massive consequences for the nature of the Universe but I don’t want to talk about it here. It’s basically because space must be expanding). It was in fact the last asteroid to be discovered for a long time, and it’s a little surprising that it was only the fourth to be found because it’s so bright and large. The next one, Astræa, wouldn’t be found until 1845, after all the original discoverers had died, then there was a spate of further revelations after that. Vesta therefore probably counts best as the largest asteroid, unless Pallas is, and traditionally people would’ve said Ceres.

Vesta isn’t like Ceres at all, but it is very much like a number of other asteroids in the belt. Some of these are former bits of Vesta which have chipped off due to impacts, but some have orbits which indicate they could never have been anywhere near it and must therefore have formed separately. It’s also responsible for quite a large number of meteorites which reach Earth, and therefore we actually have samples of it. Some of them are even from quite deep inside the asteroid, so its composition can be ascertained fairly well, and it can be seen from these that the asteroid is layered rather than mixed, as a smaller one would be, meaning that it’s heated and melted internally at some point. Its surface has for some time been known to be basalt, which on Earth comprises ninety percent of igneous rocks. On most rocky worlds in the system, igneous and metamorphic rocks are almost all there is. There are some exceptions, such as the strata on Mars, but on the whole there are no sedimentary rocks and the idea of sedimentary as a category is fairly specific to Earth, although there is, for example, clay and the layers of substance on Io, which aren’t sedimentary but are stratified. However, tuff, which is layered volcanic ash, is sedimentary, so water or any other fluid medium isn’t required.

Vesta and Ceres are kind of in each others’ vicinity. The average distance is 2.36 AU from the Sun compared to Ceres’s 2.77, which is around 61 million kilometres apart, about the same as Earth and Mars. This isn’t particularly close of course and reflects the fact that the asteroid belt is actually pretty sparse, but it is roughly as close as the orbits of Earth and Mars. However, the minimum distance is only five million kilometres, although this can only occur when the orbits are precisely aligned. It wouldn’t happen every orbit or even every thousand orbits, because it would depend on the ellipses shuffling round. Vesta’s orbit is also less tilted than Ceres’s at 7°, so they may not pass as closely to each other as might initially seem. The year is three and two-thirds longer than Earth’s. Vesta actually approached the Sun most closely only a month ago, on 26th December 2021.

Earth is slightly flattened at the poles and bulges at the Equator because of its rotation pulling the substance of the planet outwards during formation, when it rotated much faster and was softer. I’m not sure how much contribution the current centrifugal effect has on it. Nonetheless the deviation from sphericality in our case is only 0.3%. In Vesta’s case, the asteroid is kind of tangerine-shaped and its oblateness is around 22%. Also, its equator is elliptical too. An object whose gravity is so low (2.5% Earth’s, which is somewhat lower than that of Ceres) is able to have higher irregularities on its surface, and therefore Vesta also has a mountain which is almost the highest in the system – Rheasilivia is the biggest crater and unlike those on Ceres has a central peak, in this case two hundred kilometres across and is twenty to twenty-five kilometres high, comparable to the Martian Olympus Mons. The crater surrounding it is relatively enormous too, at five hundred and five kilometres diameter or roughly a “πth” of the circumference. In other words, the crater is actually wider than the asteroid in one of its dimensions, and in a way the asteroid could be looked at as simply the site of the crater. As such the rings of streaks may make a lot of sense as ejecta, although I don’t know for sure that’s what they are.

The streaks, known as fossæ, are troughs in the surface encircling the asteroid at the equator. They include Divalia and Saturnalia, the former being larger than the Grand Canyon and twenty kilometres deep. This scale reflects Vestan low gravity, which allows absolutely larger features which give worlds of this size an almost cartoonish or “cute” appearance, with exaggerated features which look out of scale to humans like the big eyes or other features of an animated or cartoon character. The fossæ are grabens, that is, valleys caused by faulting between which the surface has dropped, caused by the impact of the object which formed Rheasilvia. The central belt of Scotland is an example on Earth. Divalia is around ten kilometres wide and 465 kilometres long, making it four times as long but only a quarter as wide as the Lowlands. The fossæ collectively are in the top twenty largest rift valleys in the system. Earth is actually the world with the most large rift valleys, although the very largest is on Venus. Earth’s largest is the Atlantic. Saturnalia Fossa is associated with Veneneia, a crater overlapping with Rheasilvia and only slightly smaller than it at 400 kilometres diameter. Saturnalia is thirty-nine kilometres wide and 365 kilometres long, possibly longer because its end was lost in shadow when Dawn surveyed the asteroid.

Although Vesta is near Ceres and other asteroids relative to the scale of the system, it’s still pretty remote considering its size. If you were living on Vesta, it would take a lot of resources to bring anything you didn’t already have to you. It’s like a desert island in a way, and has resources of its own. Geologically, it’s stony, unlike Ceres which has a lot of clay stuff going on, and is more like an inner system planet in its composition than Ceres is. It’s like a mini-rocky planet, although it isn’t large enough to be a dwarf planet.

About six percent of meteorites falling here on Earth are from Vesta. This can be determined because they are exactly the same colour, that is, their spectra are identical. This is more common than any other body, even though Cynthia is so close and there are also meteorites from Mars and Mercury, both of which are closer most of the time. The light grey colour of the asteroid can be seen in the meteorites too. Vesta’s brightness is partly due to it being large and close, but it reflects more than 42% of the sunlight falling on it, which is more than any of the large planets except Venus. This is because it hasn’t been subject to “space weathering”, which occurs on bodies with only weak magnetic fields and is caused by the attraction of solar wind particles to the surfaces, where they vaporise iron on the surface, turning it into a dark coating. This means that Vesta is either low in iron or has an appreciable magnetic field. Since samples of the asteroid are readily available, it’s possible to test this by seeing if magnetic specks within the meteorites are lined up, and they do seem to be, meaning that the asteroid must be generating the same kind of dynamo-style magnetic field as we have on our home planet.

This brings up the issue of the innards of the place. NASA’s Dawn mission was able to collect data implying that unlike Ceres, Vesta does indeed have an iron core, which is about 110 kilometres in diameter, which means it must have melted early in its history. There are so many meteorites from the asteroid that it’s possible to mount a similar kind of museum exhibition about its mineralogy as it is of Earth’s, actually better in some ways because its smaller size means relatively deeper samples are available than from Earth. As mentioned previously, the most common such asteroid is known as HED – Howardite-Eucrite-Diogenite. I’ve covered these on the linked post. Incidentally, I love the fact that some are called “diogenites”, which suggests they’re either very messy inside or don’t require much in home comforts. It’s just a shame they aren’t called damoclites, like they’re hanging over us waiting to wreak havoc, although that would be rather geocentric.

I ought to mention the Snowman. This is a short chain of relatively large craters, named from bottom to top of this image, Marcia, Calpurnia and Minucia. Together they form a shape reminiscent of a snowman. The method of relative dating of craters works well here as impacts will cause newer crater borders to impinge on older ones rather than the other way round, making it possible to reconstruct what happened, though without much of a timescale.

Like Ceres, Vesta is a protoplanet, though one not given much chance due to being close to Jupiter. Had it been able to form into a proper planet, what can be seen today would’ve been buried deep within its core, or rather, its substance would’ve been distributed throughout the planet’s interior. It has a relatively short day for an asteroid of five and a third hours and a tilt of around 29°, meaning that again unlike Ceres it has seasons.

One of Asimov’s earliest short stories was called ‘Marooned Off Vesta’. It’s actually his first published story, from March 1939, where a spaceship is hit by a meteoroid, leaving three survivors in a fragment with only enough air for three days but the entire water supply for the spaceliner. They’re near Vesta, where a few people have settled. It was followed up by a later ‘Anniversary’ story twenty years later where the survivors have a reunion and discover something surprising about what they salvaged. It dates from the time when the asteroid belt was thought to be strewn with hazardous débris, which is now known not to be so.

That’s it really. Vesta is the largest proper asteroid, the brightest asteroid and, most remarkably, the source of more meteorites which reach Earth than any other body in the Solar System. That’s it really.

The World Ceres

Title nicked from Asimov.

On the first day of the nineteenth century CE, the astronomer Giuseppe Piazzi pointed his telescope at an area of sky in the hope that Bode’s Law wouldn’t fail him, and indeed found the first independently-orbiting body within the orbit of Saturn since ancient times. This was in spite of an organised posse of astronomers, the “Celestial Police”, searching the heavens for such a planet. They were later to find more, but Piazzi, who had actually been considered for membership of this group, beat them to it. This was the world later to become known as Ceres.

Bode’s Law is the rather unfairly titled principle which appears to determine the distances of the planets from the Sun. It was actually first arrived at by Johann Titius some time before. It uses the sequence 0, 3, 6, 12, 24, . . . , to each of which four is added, giving 4, 7, 10, 16, 28, and has been fairly successful in predicting the positions of various planets. It was popularised by Johann Bode, hence the name. The units amount in this case to tenths of an AU, which is the distance between Earth and the Sun, as is seen in Earth’s position in this series at 10. The series isn’t perfect. For instance, it’s anomalous that it starts at zero and Uranus doesn’t fit, although Neptune does. Nonetheless, astronomers noticed there seemed to be a gap at 28. Mars is 1.524 AU from the Sun on average, with an aphelion of 1.666, whereas Jupiter averages out at 5.204. Astronomers used the sequence as evidence for another planet, and they found it.

However, the planet they found was rather odd compared to the others known at the time. The smallest known planet in the eighteenth century was Mercury, now known to have a diameter of 4 879 kilometres. Ceres is much smaller than this at 946 kilometres. During my lifetime this figure has been revised several times, so I imagine it was different in the early nineteenth century too, but in astronomy books at the time, Ceres is clearly shown as much smaller than the other known planets, yet still acknowledged as one, before the asteroids were discovered.

Over the next few years, a number of other bodies were found between Mars and Jupiter, and the planets were split into the categories of major and minor planets to account for them. Ceres was relegated to the status of a minor planet or asteroid for a long time, up until the decision to redefine planets in 2006 as mentioned here, at which point it was put in the same category as Pluto, a “dwarf planet”. As I’ve said before, I’ve never really understood why there needed to be such a category when that of “minor planet” already existed, but it did at least put Ceres in the same pigeonhole as Pluto, which was some kind of progress. It’s an interesting history though, because it means its tale with us began as a planet, stopped being one and then became one again. Also, in the light of what I’ve said previously, nowadays it could even simply be seen as a planet.

Ceres is not like the asteroids, even though it orbits among them. It conforms to the second 2006 criterion of planethood in being round due to its gravity. No other asteroid is so close to being spherical and the margin is actually quite sharp. The next closest seems to be Hygeia. Taking all known bodies in the system into consideration, the smallest round one is Mimas, which orbits Saturn and has a diameter of 396 kilometres, although it has an enormous crater which prevents it from being perfectly round. It isn’t “lumpy” though. Hygeia is actually larger than Mimas with a diameter of 444 kilometres, and is in fact a candidate dwarf planet in itself. There could be much smaller asteroids which are round, but if so this wouldn’t be due to their gravity.

The planet, for that’s what it is really, is the smallest in the system which orbits the Sun independently, but it also contains the bulk of the mass of all bodies between Mars and Jupiter, at about 30%. This means that even if the hypothesis about a lost, shattered planet there had been correct, or if Jupiter was in a different place and the mass of the asteroid belt had been able to assemble itself into one, it would still be smaller than Mercury or even Cynthia. Because it’s long been dismissed as an asteroid, Ceres has occupied a kind of second-class place in the system for a long time and consequently I for one, and presumably most other people who have learned abut these things, can’t easily reel off a list of statistics and facts about the planet as I would with, say, Uranus or even Pluto. I know its day lasts nine and a bit hours, that it has a very thin atmosphere indeed, not really even worth mentioning, but I don’t know its largest craters, axial tilt, how long it takes to orbit the Sun, highest peaks, climate or any unusual features. I do know that it has more water ice as part of its actual internal structure near one of the poles and that it has some water ice on its surface.

The distance from the Sun is kind of “unusual”. In fact it isn’t unusual at all as the zone Ceres occupies in its orbit is the most crowded of any in the system. However, because we haven’t tended to think of Ceres as a planet, and to be fair it is still something of an outlier as far as planets directly orbiting the Sun are concerned, we haven’t considered what happens at this distance. The main consequence is that it has an unusual range of surface temperature, between -163 and -38°C, which means that at its warmest its temperature overlaps with Earth’s. In other star systems there are probably larger planets in this kind of orbit because of other characteristics being different, such as no giant planets or giant planets in different positions, but for our system this is notable for being intermediate between the coldest (on average) terrestrial planet and the warmest gas giant. If it had the same atmospheric pressure as Earth, Ceres would be able to have liquid ammonia on its surface which could both freeze and evaporate, and the chances are there’d be an ammonia cycle like our own water cycle, along with rivers, lakes, rain and even snow and glaciers. However, in reality there’s practically no atmosphere. Even so, ammonia is rich on the surface and participates in the planet’s geochemistry, which suggests that it originated far out in the outer system where the compound is more abundant. There are clays rich in ammonia and ammonia salts in some of the craters. There is also the intriguing ammonium ion, NH₄⁺. This is distinctive in both bearing a single positive charge and being about the same size as some alkali metal ions, meaning that it behaves as if it’s a metal ion like sodium in sodium chloride, and can even form amalgam with mercury and sodium like solid metallic elements. In other words, it can form into metallic alloys even though it isn’t itself a metal. Due to all this, the geology of even the surface of Ceres is unique, at least for the more reachable part of the system. I may be wrong about this but I think of it as a clay-covered place, except that instead of water making it moist, ammonia does that job instead, and also unlike water (although the hydronium ion is common in the Universe, which is to water as ammonium is to water) in that it behaves a little like an alkali metal.

The asteroid belt divides the five inner terrestrial from the five traditional outer planets (gas giants plus Pluto) of the outer. Hence Ceres can be thought of as the middle planet of the Solar System, or to put it another way, central to it. This is not literally true because as the Titius-Bode Series shows, the planets are each almost double the distance of their predecessors from the Sun counting outward. This means that its composition and temperature are intermediate. It may or may not have a global ocean under its crust. This may have existed but will now have frozen. It would be possible to detect because it would be salty and this would make it detectably magnetically.

There is a single remaining extinct cryovolcano on the surface called Ahuna Mons, which is five kilometres high. At some point I will need to address what counts as height on planets without bodies of liquid on their surfaces. In this case there’s a clearly visible crater next to the mountain, Occator Crater, and it wouldn’t be sensible to assess its height from the bottom of that crater although it might influence its structural integrity. There are white streaks on the slopes like lava flows, and also like the white patches elsewhere on Ceres, all of which are probably salt. Incidentally, although “salt” brings sodium chloride to mind, I can’t find out whether this is the salt in question or whether it’s ammonium chloride, which is also white, or something else. It could be a mixture, but that’s my speculation. There are also possible traces of smaller volcanoes. There’s a concentration of mass about thirty kilometres below it, which suggests it was formed from a plume of mud rising from the mantle (which was probably watery). There’s also sodium carbonate (washing soda) on the slopes, which is found on Earth in desert regions as the mineral natron, used in the Egyptian mummifying process and to make glass. Ahuna is almost exactly opposite to the largest impact crater, Kerwan, suggesting that it may have resulted from shock waves moving around the planet and concentrating on the other side, where they fractured the crust. This happens a lot with large impacts. For instance, Caloris Planitia on Mercury is opposite so-called “chaotic terrain” on the other side, and in fact this is making me wonder right now what was opposite Chicxulub when the impactor hit, killing the larger dinosaurs.

Occator, next to Ahuna, has the largest concentration of bright spots. I have to say, looking at images of all the large bodies in the Solar System, Ceres is distinctive in having small white areas fairly sparsely distributed across its surface. These have been named faculæ, meaning “little torches” in Latin, a name first used to refer to bright spots on the Sun’s photosphere. They’re near ammonia-rich clays and are rich in magnesium sulphate, which is Epsom salt, so the whole planet has a kind of domestic chemical theme going on. These are on a hill in the centre of the crater called Cerealia Tholus, and at this point it’s worthwhile mentioning the name. Ceres is named after the Roman goddess of arable farming, after whom cereals are named. Ceres is known substantially for her daughter Proserpina, more often known by her Greek name Persephone, who was forced into marrying Pluto and living in the underworld, but finding that she could return provided she didn’t eat any food there. However, she ate three pomegranate pips and is therefore condemned to spending a third of the year there. Ceres mourns this by causing winter, and celebrates her return to the upper world with spring. The Greek equivalent of Ceres is Demeter, after whom a moon of Jupiter is called although this was renamed in 1975. Thereby hangs a tale, incidentally: Jupiter’s smaller moons all got renamed in the mid-’70s. The whole domestic flavour of the place is once again confirmed by the mention of cereal. This is a planet made of washing soda, ceramic (kind of) and Epsom salts named after the goddess of cereal! The rare earth metal cerium, discovered two years later and now used in lighter flints and the subject of an essay by Primo Levi, is named after the planet, rather like uranium, neptunium and plutonium.

Occator is unusual in having a central hill. This is normal on many craters on other bodies, but Cerean craters tend just to have dents in the middle. The largest crater is the previously mentioned Kerwan, one hundred and eighty kilometres in diameter. It isn’t clear if it had a central peak because a smaller impact has created a crater where that would be. It’s named after the Hopi cereal nymph, this time for sweetcorn.

Zooming out a bit and treating it as a planet like any other, as opposed to the asteroid it was formerly presumed to be, Ceres averages 2.77 AU from the Sun, approaches it most closely at 2.55 and has an aphelion of 2.98, which makes its orbit slightly less elliptical than Mars’s at 0.0785. It takes somewhat over four and a half years to orbit the Sun and is inclined 10.6° to the ecliptic, which is greater than any other planet out to Neptune unless you count the moons of Uranus (see the post on planet definitions if you don’t get why I’m calling them planets rather than just moons), though less than twice that of Mercury. Looking at the three planets Earth, Mars and Ceres as a, well, series, there is a trend of reducing size. Mars bucks the apparent trend of increase in size up to Jupiter followed by a decrease in size out to Pluto, but if Ceres is included a new possible tendency is revealed, also reflected in reducing density as Earth is over five times as dense as water, Mars and Cynthia around three times as dense and Ceres a little over twice as dense. This may just be playing with numbers, but it’s also possible that Earth hogged all the material, only leaving a few leftovers for the planets closer to Jupiter’s orbit. As for density, the closer planets to the Sun would have been warmer when they formed and this seems to have caused the icier components, or simply those with higher melting and boiling points, to evaporate off. However, Ceres seems to have formed in the outer system. It has an axial tilt of only 4°, so ironically the planet named after a goddess closely associated with the seasons has no seasons of its own. Surface gravity is less that three percent of ours, so if I went there I’d somewhat exceed my birthweight but only because I was small for dates.

Looking at the planet and knowing that most of what I’m seeing is clay puts me in mind of the idea that Ceres has an affinity with the various planets which show up in claymation shows. I can imagine its appearance turning up on someting by Aardman Animation, and it makes me wonder what the Clangers planet was originally made of. However, this is largely in my mind. It’s all very well looking at an image of Ahuna Mons or the planet as a whole in full knowledge that it’s mostly salty clay and seeing it like that, but on the other hand many of the craters are æons old and don’t seem to have sagged in all that time, although they do lack the central mounts found elsewhere. It may be more accurate to think of the planet’s surface as being made of frozen clay rich in ammonia, and it also isn’t clear what clay’s like if it’s mixed with liquid ammonia and well below freezing point as opposed to the stuff we make pots out of. I think Ceres may be the kind of place where our intuitions based on how things are here, or even in the outer system, may mislead us. That said, the edges of the craters are less well-defined and the floors are smoother, and when it was actually being hit by something it would presumably have melted or boiled the material, so at that point maybe it does behave like clay or go through a phase of clay as we know it as it cools down.

Although it doesn’t have an iron core, the planet is likely to have a core high in metals, but also in silicate rocks. The pressure on it will be far lower than on Earth’s core. Our planet is close to 6 371 kilometres in radius, more than twice as dense as Ceres and has thirty times the gravity. Put all of those together and it makes the pressure at the core something like (and these are back of the envelope calculations) what it would be only ten kilometres down in our own crust, or even less. This is only the level of an ocean trench and only a few times deeper than the deepest mines. Consequently the settling out effect of the originally molten planet is milder and not so influenced by pressures beyond easy imaginings. Outside that core is a mantle of silicate rock which may have squeezed out the water and ammonia, or they could have separated out due to being lighter. Above that is a probably frozen solid ocean, and finally on the surface lies the clay-rich crust with salty deposits. All this notwithstanding, it’s also been accurately described as “icy, wet and dark”, i.e. it has a dark surface. It isn’t particularly dark as far as sunlight is concerned.

There are several more ways in which Ceres is special. It’s a survivor from the early Solar System, in that it’s a protoplanet. Near the beginning, there would’ve been hundreds of small planets like this, large enough to undergo interior melting, which mainly happens due to radioactivity, and therefore stratification like Ceres has, but many of them would have collided with each other and stuck together, possibly been thrown out of the system entirely by close encounters with others accelerating their movement. Along with Vesta, which is more battered and smaller, Ceres is a surviving relic from shortly after the Sun formed. It’s also the closest dwarf planet to Earth, the first dwarf planet to be visited by a space probe, the first time a space probe had orbited two bodies on its mission and the largest body except Pluto-Charon not to have been visited up until 2015.

The spacecraft which visited it is also quite interesting. It’s called Dawn, and was actually launched at dawn one day in 2007. It used Mars to accelerate its path and visited and orbited Vesta, also a first, in May 2011. Vesta is interesting in itself, and I’ll be covering that soon as well. It then left Vesta and made its way to Ceres, becoming the first spacecraft to actually orbit two bodies in the Solar System unless you count the orbits made of Earth before some spaceships have headed off into the void. It’s still orbiting Ceres but its mission is now over. Dawn was also the first craft to use ion drive, an idea for a very efficient but slowly accelerating engine which can accelerate vehicles so fast they could cover the distance between us and Cynthia in less than two hours, without using gravitational assist, which is the usual reason space probes are accelerated to this velocity and beyond.

There is plenty more to say about Ceres, but I want to finish as I started: with the pun. Isaac Asimov used to be very fixated on puns, and several of his short stories were only written to make puns. In the case of his article ‘The World Ceres’, published in 1972, he may have been primarily motivated to write it just because he could use a good pun in the title. I have read it but I don’t remember how much detail he went into. It doesn’t seem likely that much was known about it at the time, but I may be wrong. It might be interesting to compare factual articles on astronomy before and after they were visited by probes. For Ceres, this period was a lot longer than usual, but also occurred only 206 years after it was discovered, which is pretty good going.

The Solar Mass Transit System

Space is in a sense mostly empty. In another sense it really isn’t because there are virtual particles everywhere, the quantum vacuum may not be at its lowest energy state and there are at least a couple of atoms per litre of space. Also, everywhere feels the pull of gravity. There is nowhere in the Universe you can go to escape any object’s gravitational pull. Actually, I question that, for this reason. Suppose you are orbiting a lorry floating in space in an otherwise entirely empty Universe a billion light years away. Someone sitting in the lorry reaches out, breaks off its driver’s side wing mirror and flings it into space. This will alter the number of objects in the Universe and the wing mirror will change the gravity acting upon you. How much difference would that make to your path? I suspect it will make so little that your accomplice may as well not have bothered, to the extent that it may actually be smaller than the grain of the Universe as expressed by Planck units, although I haven’t done the maths. If the Universe is big enough, there will definitely come a point where the influence a particular mass has on another will never add up to more than the Planck length, and this, to me, seems to mean zero influence. Then again, maybe this is the kind of quantum gravity thing which physicists have been slaving away for decades to solve and it’s more complicated than I think.

All of this notwithstanding, the Solar System is practically a point compared to the Universe, so the gravitational forces acting within it are considerable. There are of course nine major bodies the mass of Mercury or higher plus a further seven moons of planetary size, and various other smaller but still quite massive worlds such as Ceres and Vesta.

By Lagrange_points.jpg: created by NASAderivative work: Xander89 (talk) – Lagrange_points.jpg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=7547312

Each pair of these bodies has five points in space around it which, assuming they’re the only two bodies in the Universe, have balanced gravity. Objects placed at these points are stable. Either side, they will tend to fall towards these points. Something similar was mentioned by Jules Verne in his ‘Round The Moon’ («Autour de la Lune») whose astronauts’ weights drop to zero five-sixths of the way to their destination. Perhaps surprisingly, I haven’t read «De la Terre à la Lune», so for all I know it’s mentioned in there as well.

Given the eight planets and the Sun, there are of course five Lagrange points associated with each at any one time. This gives a total of forty. There are also five for every planet-moon pair, although not all are significant, so for example Jupiter and the Galileans have twenty as well as the five associated with Jupiter and the Sun. Some of these points are very close to each other and all are in constant motion relative to other frames of reference. There should also be similar balanced points between any two objects, such as, to be silly, Chiron and Hidalgo, or Ariel and Phobos.

All this means that in order to reach another world in the system, you don’t actually need to expend the energy necessary to get all the way from, for example, Earth to Mars because you’ll get help on the way. There will be a point following Earth in its orbit but further whither spacecraft might be aimed rather than Mars itself, and since there’s an increasing tendency for objects to fall towards these points, even the energy required to get there is less than it might be. Once in that location, it would be necessary to thrust a little further in order to approach the destination. The locations of the Lagrange points are along a line passing through the centre of gravity of the system and also forming the third point of an equilateral triangle with the two masses. Hence for the Sun and Earth, there’s a point between Earth and Venus, another between Earth and Mars, another where Antichthon would be, and one each 60° ahead and behind on our orbit. They would presumably also shift their positions slightly as Earth moves around its elliptical orbit. For immediate transport, the most useful locations for the Earth-Sun system are L1 and L2, which are both 1.5 million kilometres from Earth. Venus approaches Earth to about forty million kilometres, and of course it will have its own L2 point with the Sun at around a million kilometres closer. There will also be an equilibrium point about halfway between the two planets due to their masses being roughly equal, at twenty million kilometres, and the cis and trans lunar L1 and L2, 61 350 kilometres either side of Cynthia. Hence there’s a kind of “ladder” between Earth and Venus, with the lunar L1 and L2, the Earth-Sun L1, the midpoint between Earth and Venus and Venus’s L2. The respective distances are:

• Earth to L1: 323 050 km.
• L1 to Cynthia: 61 350 km.
• Cynthia to L2: 61 350 km.
• Translunar L2 to Earth-Sun L1: 1 054 250 km.
• Earth-Sun L1 to Earth Venus equilibrium: approximately nineteen million km. This one will be slightly closer to Venus than Earth.
• Venus equilibrium to Venus-Sun L2: approximately nineteen million km.
• Venus-Sun L2 to Venus: approximately a million kilometres.

Hence there are seven rungs to this ladder, and yes there are issues with what happens when you get to Venus but I’ll go into those when this blog gets there! Each of these stages can be aimed at without using anywhere near as much fuel as would be required otherwise, partly because the spacecraft would be drawn towards them in any case. The difficult one is the equilibrium point, which is constantly circling the Sun and is influenced by its gravity too. A slingshot manoeuvre around Cynthia would accelerate the craft to some extent, but it’s hardly worth it as the escape velocity is lower than Earth’s so the speed would already have been moving that fast.

Mars is a more popular imaginary destination than Venus of course, and it too has a ladder of this kind. In its case, the Martian L1 is much closer to Mars but there are also the translunar and Earth-Sun L2s. The equilibrium point is also closer to Mars and since the gap between the orbits is larger, considerably further away. There would also be Lagrange points associated with the Martian moons but they wouldn’t be very useful as they’d be very close to the moons, but with the two moons rather than one, we start to get a hint of the complicated situation seen further out in the system. Venus has an almost perfectly circular orbit and Mars quite an elliptical one, to the extent that the seasons in the northern and southern hemispheres are very different and of different lengths, hence the larger southern ice cap. For the Lagrange points, this means they would move around quite a lot, and in doing so would move objects within them around too. All of these points would move by as much as 42 million kilometres over the 687-day Martian year, and that amounts to free travel, though only at 2600 kph, which isn’t significant over solar system scale distances although it is more than twice the speed of sound at sea level, and if you just care about getting there eventually rather than how long it takes you, it can help. This kind of “shuttle service” exists in equilibrium points between planets all over the Solar System, and technically there are eighty-seven of them overall, although not all are useful. They’re most concentrated in the inner system, where there are two dozen between the local planets and several more between them and the outer ones.

As well as all this, there are four planetary examples of L3 in the inner system, three of which move past Earth regularly and once again this is free travel, sometimes very fast. In Mercury’s case it can be almost 60 kps, and it would be possible to hop between them as well, carrying you closer to your destination with very little expenditure of energy. The question might arise in your mind of how this doesn’t violate the laws of thermodynamics, because it looks like a free lunch. The answer is that it isn’t because although there is a huge difference between the mass of a spacecraft and a planet, these activities do in fact ultimately add up to making minuscule differences to the planets’ orbits, but not significantly.

The equilateral points are often considered because they have features not often found elsewhere. There is a series of short stories called ‘Venus Equilateral’ written in the ’40s CE by George O. Smith about a radio relay station at the L4 point of the Venus-Sun system. Another well-known set of stories in this vein includes one by Asimov, all based on the same setting, where there are two stars of different spectral types (colours) occupying two points of the triangle and an Earth-like planet occupying the third. This gives it a day lasting two-thirds of its rotation period because it’s illuminated by both suns at a 60° angle to each other. In the real world, the most striking example of L4 and L5 are found in Jupiter’s orbit, where the Trojan asteroids are situated 60° ahead and behind Jupiter itself. This has led to the points themselves being referred to as “trojan”. For Jupiter there’s a “Greek” and a “Trojan” camp, although the actual names are mixed up between the two so that Greek characters from the Illiad are found in the Trojan camp and vice versa. The first of these to be discovered was Achilles, which is a dark red D-type asteroid, roughly spherical and around 133 kilometres in diameter. L4 is the leading point, and is referred to as the Greek camp because Achilles is there. There are more than six thousand asteroids here, the largest of which in either camp is Hektor, averaging at 225 kilometres across, which even has its own twelve kilometre wide moon called Skamandrios. Hektor is cylindrical and a lot longer than it is broad. The Trojan camp follows Jupiter at L5 and includes just over four thousand asteroids. Neptune also has Trojans, two of which are called Otrera and Clete. Twenty-two are known but of these only three are at the L5 location. They’re centaurs rather than asteroids, a category of object intermediate between asteroid and comet.

L5 was first introduced to me in 1976 when I heard about the Stanford Summer Torus Project (I may have got that name wrong). In the ’70s, a plan was devised to build a mile-wide wheel in space at the terrestrial-lunar L5 point which constituted a permanent space habitat. The July 1976 National Geographic includes a popularised version of the plan written by Asimov but the documents themselves made interesting reading. The general idea was to construct a six-spoked spinning wheel around 1 800 metres in diameter protected from radiation with a two metre layer of lunar regolith and have alternating agricultural and residential sectors with industrial processes and research carried out in the spokes, which constitute something like skyscrapers with lift shafts running along to the hub, which is a docking station and a low gravity environment. In the article this was envisaged as happening by 2026. Clearly it won’t be. Yet another space-related disappointment.

Another more serious omission is the possibility of building a solar power station at L5, which would solve all out energy and most of our climate problems at a stroke. I’ve mentioned orbital solar power elsewhere though, so I won’t be going into detail here. As it stands, these L4 and L5 locations are occupied by the Kordylewski Clouds, which are collections of dust. Their existence has been confirmed but there’s some confusion because when the Japanese lunar spacecraft Hiten flew through both as a form of gravitational assist, basically the same manoeuvre as I described for Venus, it didn’t detect an increase in dust concentration. However, it’s claimed that they can be visible to the naked eye, as they’re a dozen times the width of the Sun and slightly reddish compared to most other visible dust. There are a number of spacecraft situated at various Lagrange points.

The moons of Saturn, apparently unlike those of Jupiter, are sometimes in trojan relationships with each other. Tethys and Dione have a pair of them each: Telesto, Calypso, Helene and Polydeuces. However, Saturn is for another time on here, so for now I’ll leave it at that. However, the same kind of “rapid transit system” that I outlined in the inner Solar system would operate for the four complex satellite systems of the gas giants. Technically they would have a very large number of Lagrange points, but for most of the moons these would be unimportant because they are so small compared to their planets. For Jupiter’s four Galilean satellites, though, there are two dozen equilibrium points and twenty Lagrange points, and for Saturn’s seven roughly spherical moons, which excludes the rather large Hyperion, there would be over five thousand equilibrium points and thirty-five Lagrange points. This is more significant than it might appear, as by making the two regions around the planets more navigable, not only does it ease travel within those systems, but it also aids travel across them, particularly when one bears in mind that there will also be equilibrium points between the systems.

To conclude then, the Solar System is riven with locations which ease space travel, although sometimes they would mean that spacecraft traversing it would have to do so rather slowly. Another option is to hop onto an Earth grazer asteroid and hitch a lift to another part of the system, although again this could be rather slow. Some spacecraft have already taken advantage of the former approach, though not the latter, and it’s worth bearing in mind that when you look out into the system, there are many invisible but rather special points orbiting along with the visible planets and moons.

The Opposite Of Astronomy

I have committed myself to alternating posts on the Solar System with posts on anything but that. Today, I am strongly tempted to write something about recent discoveries in the neighbourhood of Tabby’s Star, but that would be somewhat similar to writing about the other topic, so I won’t be doing that today except to say, really, look it up because it’s absolutely amazing. You may have come across it already. Then there’s the millipede in Northumberland the size of a car. Also very interesting but quite sciency. I tell you, maybe I should’ve chosen that. But I didn’t, so instead I’m going to write about what the opposite to astronomy is, or rather I will after I’ve got something else out of my system: the idea of opposites.

When I was at primary school, we were doing opposites. We were asked what the opposite of black or white was, and unsurprisingly answered accordingly with whatever the other one was. This so far was controversial. We were then asked about the opposite to red, to which I replied that it was violet because it was at the other end of the visual spectrum. We were told that colours don’t have opposites. I disagreed with that then although nowadays my answer would probably be different. I would probably say that the opposite to red was aqua, because there are three additive primary colours, red, green and blue, and if red is 100, then aqua is 011. But this doesn’t always work because there are also subtractive primary colours, often described as red, yellow and blue, but possibly more like magenta, yellow and cyan (AKA “aqua”). If you go with the first, the answer will be green, and that also makes sense in terms of traffic lights, since red means “stop” and green means “go”. I think the opposite on a colour wheel would be the same but I’ll have to investigate. Hang on. Yes, it’s green apparently, although I will bow to the better judgement of whomso might be reading this, hint-hint.

I’ve been here before with my attempt to determine the essence of anti-custard. Here the issue is more complicated because custard has multitudinous qualities, but I provisionally decided that anti-custard was probably a blue breeze block. Bear with me on this one. Custard is of course a non-Newtonian fluid extremely suitable for speed bumps in many people’s opinions, but this kind of custard is rather far from being considered vanilla flavoured, yellow or edible. I happen to hate custard as a food item, so thinking of it as something to put in your mouth seems strange. Custard flows freely when treated gently but thickens up when hit hard, meaning that if you fill a swimming pool with it you ought to be able to walk on it. Hence the opposite of custard, in this sense, is a substance which flows freely when hit hard but resists gentle treatment, which is similar to most Newtonian fluids. However, very few real fluids as encountered in everyday life happen to be Newtonian. For instance, water resists the very gentlest treatment due to surface tension, which is stronger for it than most other liquids, then becomes more yielding as it’s treated more forcefully, so to some extent even water is non-Newtonian, and since most liquids we come across as humans on Earth are based on water, they’re likely to behave like that even if that’s unusual. Hence there are a number of axes along which custard can be placed, and it isn’t clear how to reverse them. There could be a reflection about the origin, the X axis, the Y axis, both X and Y axes and so forth. This discussion on the Halfbakery led to the invention of the delightful term “eigencustard”. The German word “eigen” is often translated as the adjective “own” but can also be translated as “proper” and this is probably more informative in this context. In maths, there are things called eigenvalues and eigenvectors, and here the word probably works best if understood as meaning “characteristic”. It’s probably most helpful to use diagrams to address what these are rather than formulæ, but I may have some difficulty doing this, so instead, consider this. Suppose you have a square made of latex (or lycra if you prefer – actually that might be more useful). If you then stretch that square vertically, the poisson ratio being positive (when it gets longer in one direction it gets shorter at right angles), the height will increase and the width decrease. This means that somewhere between the horizontal and the vertical is a direction in which the square does not stretch at all. This is an eigenvector of that square under that transformation. Similarly, in a fairground mirror one’s reflection may appear to be distorted but there may be some lines along which one looks exactly the same (this works better with two mirrors). These lines are eigenvectors. Now back to custard. If you imagine some kind of multidimensional space containing the essence of custard, doing something like flipping the custard through different angles and axes will result in substances with different eigenvalues and eigenvectors. Decide which are the most significant and you get anti-custard: the opposite of custard. However, there are a variety of eigencustards, which will not vary under these transformations.

This could be treated very seriously. The resistance of a fluid to flow under increasing force could be plotted on a line graph and turned upside down to produce whatever the opposite of that was. There are quite a number of markèdly non-Newtonian fluids around, such as tomato ketchup, quicksand, wet cement, silly putty, mayonnaise, the fluid inside automatic vehicle transmission, synovial fluid (in joints between bones) and non-drip gloss paint. It would be fairly straightforward to assert that in physical terms, tomato ketchup comes close to being the opposite of custard, but it’s also red. For it to be proper anti-custard, tomato ketchup must be blue, because blue is the opposite colour to yellow. However, it does seem to taste very different to custard, so it makes sense to consider the opposite to custard to be blue tomato ketchup. This is feasible.

What, then, of astronomy? One suggestion is that the opposite of astronomy is geology, and in a way this makes sense. If one considers the proper study of astronomy to be everything which is “up there”, geology can then be considered to be concerned with everything which is “down here”, or perhaps “down there”. The trouble is, this doesn’t really work. For an alien on another planet, astronomy would include geology in the sense that it’s the study of the physical material and processes affecting Earth. In another sense, geology is a speciality of planetology, and most people would say that planetology is a generalisation of geology as well as a speciality of astronomy. So it doesn’t work. In fact I find the idea that geology is in any way special quite distasteful as it seems narrow-minded, although of course Earth is very special because it’s kind of our mother – Tellus Mater. In that case it gets quite difficult to imagine what astronomy would exclude.

But then I think of the 1960s CE, and the idea of inner space in three different ways. If astronomy is the discovery of outer space, then the opposite of astronomy is the study of inner space. Inner space could be the interior of the atom, the interior of the body or the interior of the mind. All these have their merits. Atoms are very small as opposed to star systems and galaxies, which are very large. There are stories such as ‘The Girl In The Golden Atom’ which imagine that atoms are solar systems in their own right, and on a much larger scale it’s common to imagine that our own solar system is a mere atom in a macro-world around us. This doesn’t really work though, because of what really goes on inside atoms. If a solar system was like an atom, the Sun would consist of a ball of smaller stars, planets would move in strange orbits shaped like clover leaves in three dimensions and would not be located in definite places, and would emit other planets or have other planets crash into them as they teleported instantaneously across the system, and they would also tend to be bunched together. If, on the other hand, atoms were like solar systems the situation might be a bit more like matter as we know it, but solid matter would tend to break down and probably always be metallic, and there would be no such thing as valency and perhaps no such thing as chemistry. Nonetheless, as Demokritos once said,

νόμωι (γάρ φησι) γλυκὺ καὶ νόμωι πικρόν, νόμωι θερμόν, νόμωι ψυχρόν, νόμωι χροιή, ἐτεῆι δὲ ἄτομα καὶ κενόν – “By convention sweet is sweet, bitter is bitter, hot is hot, cold is cold, color is color; but in truth there are only atoms and the void”.

This doesn’t apply to atoms themselves nowadays but it does to a particular not very quantum view of the Universe: it’s mostly empty space with widely separated lumps in it. So is the opposite of astronomy nuclear physics then? I would say not for a major reason. Nuclear physics is a vitally important part of astrophysics in that it explains what stars and some other objects are and how they work, so once again there’s an issue with excluding a fairly central part of astronomy – from astronomy!

The makers of ‘Fantastic Voyage’ seem to have thought along the lines that the interior of the human body is like an alien planet or space, and to us it is our own inner space, so perhaps anatomy and physiology are the opposite of astronomy. I’m going to permit myself a diversion here into that work and its surroundings, as it used to be my favourite film when I was about nine.

First of all, ‘Fantastic Voyage’ is part of a whole complex of works. It has a little in common with ‘The Incredible Shrinking Man’ and ‘The Girl In The Golden Atom’ and a lot more in common with the later ‘The Men Inside’ and ‘Innerspace’, Doctor Who’s ‘The Invisible Enemy’ plus a whole load of parodies from such animations as ‘Rex The Runt’, ‘Family Guy’ and Radio 4’s ‘Old Harry’s Game’. Like Willy Wonka, it’s one of those films which has so captured the public imagination that sometimes it seems like every TV series out there has to pay homage to it. It also spawned an entire animated series of its own, rather like ‘Star Trek’ did. Isaac Asimov wrote the novelisation but didn’t associate himself closely with it. He agreed to write it because there were so many plot holes in the film that he considered it a challenge to address them. He also tried again with his own version of the story in the late 1980s, ‘Fantastic Voyage II: Destination Brain’. I gave this a go but got very bored with it as like many of Asimov’s stories it was all talk and little action. In the sequel, miniaturisation is achieved by reducing Planck’s Constant. The first novel, so far as I can remember, has a discussion of miniaturisation parallel to that made by Arthur C Clarke in his ‘Profiles Of The Future’, where the options are reducing the size of the orbitals in the atoms, removing some of the atoms or shrinking the size of all the particles involved. The problems are, respectively, that reducing the size of the orbitals leaves the object with the same mass, making it like a neutron star or black hole and causing it to fall to Earth’s core, which in a way would be a fantastic voyage but more Verne than Asimov, reducing the number of atoms simplifies the object, and if that object is human, its brain, resulting in a not very intelligent organism instead, and the third one is the Goldilocks solution – “just right”. Unfortunately the last answer is also the least plausible. A rewrite of this story today might have the people interact with nanobots from the safety of a VR facility, but that would take away all the peril. Maybe there would still be a way of manufacturing it, such as a harmful immune reaction triggered by the presence of the nanotech, which is quite similar to what happens in the film.

For a time, it’s said that the film was used in medical classes to teach certain aspects of medicine. I’m not sure this can be true, because it gets a number of things wrong. The blood corpuscles, for example, don’t look like real ones but seem to have been done with oil droplets in water, giving the impression of a lava lamp. It also suffers from higher definition versions, which for instance make the capillary epithelium look like printed curtains, which is presumably what they are. The phagocytes end up looking like white balloons, rather similar to the Rovers in ‘Prisoner’. This wasn’t so much a problem back in the day not only because of the lower quality of the prints (I’d only seen it on PAL TV, so I can’t vouch for the cinematic experience) but also because suspension of disbelief used to get more exercise back then. One of the notable things about the film is the fact that it was produced while New Wave SF was in its heyday, with its emphasis on mental rather than physical interior life. ‘Fantastic Voyage’ sends the crew into the brain where they’re able to view nerve impulses moving between brain cells and this provokes them to wonder about the soul. Hence they are actually inside a living human brain, but in a physical sense, while much of popular culture was exploring consciousness and therefore inner space through drugs and meditation, inter alia.

And then of course there’s New Wave SF and the exploration of consciousness, and therefore inner space in that sense, as seen in ‘The Ultimate Trip’ segment of ‘2001’ but also many other films of that era such as ‘Charly’ and remarkably ‘Willy Wonka’ with its tunnel scene. It seemed to be de rigeur to do that at the time, possibly to appeal to people on psychedelics. This is a different kind of inner space again, and seems to correspond to something like qualitative psychology, or maybe depth psychology. This is psychology, but not in the mainstream academic sense. It may seem arrogant to posit that the human mind is on an equal footing with the physical Universe, but the fact is that we cannot step out of our subjectivity.

To summarise then, these are the possible anti-astronomies: depth psychology, human biology, nuclear physics and geology. Alternatively, maybe it’s astrology.

Where Are All The Aliens (Part I)?

Alchemist Hennig Brand looks focused, if maybe a bit drained, in this 1795 painting by Joseph Wright. The painting depicts Brand’s discovery of the chemical element phosphorus.

I have repeatedly, perhaps incessantly, referred to the Fermi Paradox on here, but one thing I have never done is to do a survey of the most often given explanations, plus a few less common ones, so I’m going to do that here.

Before I start, it’s probably worth stating clearly what the paradox is. It goes like this. There are thousands of millions of stars in this galaxy, and innumerable galaxies in the Universe, and many of those stars are suitable for life-bearing planets, yet we never seem to detect or encounter any intelligent aliens. Why is this?

Before I get going, I want to mention the Drake Equation. This is a surprisingly simple equation thought up by the space scientist Frank Drake in 1961 CE. It’s simply a series of factors, all unknown at the time, multiplied together. It looks like this:

To explain the variables and the unknown constant N then, N is the number of civilisations with which communication might be possible in this galaxy. This figure is arrived at by multiplying the following factors:

R_* is the rate of star formation in this galaxy.

f_p is the fraction of those stars with planets.

n_e is the average number of planets which can support life per planetary system.

f_l is the fraction of planets on which life appears at some point.

f_i is the fraction on which intelligent life develops.

f_c is the fraction of intelligent life which develops technology making it detectable from elsewhere in the galaxy.

L is the length of time detectable signs are there.

There is said to be a problem with this equation first of all, which is that it’s susceptible to chaotic influence. The Club Of Rome released a report called ‘Limits To Growth’ in 1972 which predicted that various mineral resources would run out very quickly, but this didn’t come about because at the time it wasn’t appreciated that the results of a mathematical model often depend very sensitively on the exact values of the variables involved, now known as the Butterfly Effect. It’s been suggested that the same issue appies to the Drake Equation, in that most of the variables are not even approximately known, let alone exactly. And there’s another problem, which I’m going to illustrate with something personal. I used to have a list in my head of the ideal partner, and there weren’t many criteria on it. It amounted to similar values, personality traits of particular kinds and common interests. A short list. I stopped taking this approach eventually because I decided it wasn’t ideal for a number of reasons, but I also noticed something quite odd. There was one person who was absolutely ideal in these respects, and was also unavailable, so I began to look elsewhere, and was surprised to find that after many more years there wasn’t even one other person who satisfied those criteria even remotely. Don’t worry about me, by the way – I took a different approach and it worked out fine. The same phenomenon afflicted the a particular army when it attempted to produce a small range of uniforms somewhat suitable for everyone. Given criteria such as arm and leg length, chest and hip circumference and the like, all quite important for the clothes to fit, they found that nobody at all had the same such dimensions, and it was impossible. I’ve mentioned this before of course. Applied to this equation, it’s easily conceivable that working through all the variables, if they were known, could result in N equalling one, namely us humans here on Earth, and that’s it. Some of them are much better known now, or at least f_p is: there are a very large number of stars with planets, probably most of them in fact, and the ones which don’t have them would be unsuitable for life anyway because they’re short-lived and life doesn’t have long to develop on them anyway. There also seem to be examples of planetary systems in which multiple worlds are suitable for life, such as TRAPPIST-1, with at least three planets orbiting within the habitable zone. The wording of the Drake Equation is also somewhat inappropriate, as it fails to take into account that moons might also be suitable for life. These increase the value of n_e considerably. f_p is effectively close to one, and n_e is quite possibly quite high. For instance, in this solar system it could be as high as 8 if moons are included. The presence of life on, or rather in, moons is, incidentally, one possible answer to the Fermi Paradox.

Using the information available at the time, Isaac Asimov worked his way through the equation in his 1979 book ‘Extraterrestrial Civilizations’ and concluded that there were 530 000 such civilisations in the Milky Way. His approach was quite exacting. For instance, he excluded the nine-tenths of stars which are in the galactic core and assumed that the total length of civilisations per planet averaged at ten million years, but was shared between different intelligent species evolving on the same planet. On the other hand, the book was written before it was realised that the Sun would make this planet uninhabitable æons before it would start to become a red giant. I think Asimov’s approach was a little tongue-in-cheek, but there is an issue about whether once intelligence evolves, it will ever disappear again on a planet until it becomes uninhabitable. We may also be in a position where once evolution enters a certain state, the appearance of the kind of intelligence which leads to technology may occur repeatedly. It’s been noted that there are a number of other primate species which now use stone tools, for example, and the nature of intelligence among crows, parrots, elephants and dolphins as well as primates is quite like ours. Given that Asimov’s estimate is exactly correct, which is unlikely, this makes it possible to estimate the average distance between such civilisations. The volume of the Milky Way Galaxy has been estimated at eight billion (long scale) cubic light years. The central nucleus, according to Asimov and others, is unsuitable for life, so assuming that to be spherical, which it isn’t of course, that gives the rest of the Galaxy a volume of around six billion long scale cubic light years. If there are 530 000 civilizations in that volume, that makes one per eleven million cubic light years, so that would make the average distance between them roughly 224 light years with spurious accuracy.

I’m actually going to do headings this time!

Absent Aliens

The most straightforward, and in a way even the most scientific and sceptical explanation, is that Earth is the only place in the Universe with life on it. There are various versions of this, but the simplest is just that life arose on this planet by sheer luck, and is practically impossible. Nowhere else in the Universe is there so much as a bacterium. Since we only seem to have one example of life known to human science, this is the only explanation which doesn’t rely on conjecture. At first sight, it might seem unlikely that there’s no life anywhere else although strictly speaking life would only need to be rare for this to be the explanation. There is in fact a peculiar issue with the origin of life on this planet. Although taking a few simple compounds as would’ve been found in the primitive atmosphere and oceans and exposing them to ultraviolet light and electricity does produce many of the more complex chemicals found in living things, there is an important set of compounds which are completely absent. DNA and RNA are very complex of course, but are made up of fairly simple building blocks of ringed nitrogen-containing compounds called purines and pyrimidines which comprise the rungs of the ladder and encode the genetic information. As far as I know, such compounds have never arisen in laboratory conditions. Clearly living systems can all synthesise them or they wouldn’t exist, but this happens through complex enzymes and already-organised biochemical pathways which rely on genes, made of those very same compounds. It’s a chicken and egg situation, and perhaps this means that the appearance of purines and pyrimidines is the single unlikely missing link on the way to life which has arisen just once in the entire history of the Universe, and therefore that the only place in the Universe where there is life is this planet. However, even if this is a one-off event, it doesn’t necessarily entail that life is found only here because it may still be that it arose somewhere in the Universe and spread widely. A few million years after the Big Bang, the whole Universe was much smaller, denser and warmer, to the extent that all of it was between the freezing and and boiling points of water and matter was dense enough to support life as we know it in space, and the elements from which it’s made were already available. Hence it’s possible that life has been around for almost as long as the Universe, and that it has a common origin, being able to spread as the Universe expanded.

There are even hints that life is present elsewhere in this Solar System. Some people, myself included, interpret the 1976 Viking missions’ ‘Labeled Release Experiment’ as positive in detecting life. This involved taking a sample of Martian soil (I always find it strange when extraterrestrial materials are described as soil. Martian soil is more like a mixture of rusty talcum powder and bleach), exposing it to a radioactively labelled soup of nutrients in water and measuring any carbon dioxide given off for radioactivity. It assumed that water would not be harmful to any organisms living in the soil. Anyway, the experiment was positive, but cast in doubt in view of the fact that the other two were negative. On Venus there have been three separate pieces of evidence for life in the upper atmosphere, not just the claim of phosphine. There is also something in some clouds which absorbs ultraviolet light and a compound called carbonyl sulphide is produced which is difficult to account for in the absence of life. On one of the several moons in the outer Solar System with subterranean water oceans, Saturn’s Enceladus also has geysers in which biochemical compounds have been detected. Other candidates include Titan, Europa, Ganymede and Callisto, and perhaps Jupiter. However, I don’t think this is good evidence for life elsewhere in the Universe. I think it could easily turn out that if there is life in these places, it has spread out from a common origin somewhere in this Solar System and without good data from elsewhere in the Galaxy we might still be alone apart from that.

One argument for life being common is that it began so very early on this planet, very soon after it first formed in fact, which makes it seem almost inevitable given the right conditions. Alternatively, it may have infected this planet from elsewhere, possibly Mars. However, this doesn’t follow because we only have one example of life known to us. There is also a very specific reason why life might be rare or non-existent elsewhere: phosphorus.

Back in the day, Isaac Asimov (yes, him again!) scared the living bejesus out of me in his article ‘Life’s Bottleneck’, highlighting a peculiar and largely ignored major environmental problem. There are all sorts of chemical elements needed for human life of course, but the major ones for all life make a short list: carbon, oxygen, hydrogen, nitrogen, sulphur and phosphorus. Phosphorus is far less abundant than the others and living things are distinctive in that they concentrate phosphorus way more strongly than the other elements compared to their surroundings, on the whole. The way industrial societies tend to deal with human excretion is often through sewers which expel the treated waste into the water and ultimately the sea. This waste is of course quite high in all sorts of elements, but is also sufficiently high in phosphorus that the alchemist Henning Brandt was able to discover it in the seventeenth century from performing transformations on human urine, as in the picture opening this post. The phosphorus which enters the sea only returns to the land very slowly because it’s mainly recycled by continental drift and gets washed off the land by rain anyway. Humankind began to notice in the early nineteenth century that the limiting factor in food production was phosphorus, and proceeded to mine phosphate rock for fertiliser, which has liberated a lot of phosphorus into the environment and leads to algal blooms and the like, which tends to poison the oceans and deprive aquatic environments of oxygen due to increased biochemical oxygen demand. It’s hard to know exactly what anyone can do about this which would make much difference, but a few steps which could be taken are to increase the amount of food from marine sources in one’s diet, which doesn’t mean fish, crustacea and the like because of their unsustainable “mining” but seaweed, and change the way one gets rid of urine, fæces being more a public health hazard which would probably be best dealt with by sanitation services, which does however need to happen, so that is a lobbying and pressure group-type issue. Anthropogenic climate change is of course vastly important, but it’s only one of various vastly important environmental issues, and the phosphorus one in particular is disturbingly ignored. Things are far from fine in that area.

Phosphorus limits biomasse. It’s the limiting factor in it to a greater extent than other elements because they are far more abundant. It might not be going too far to call the kind of life we are “carbon-phosphorus-based” rather than “carbon-based”, because the element has two completely separate but vital rôles in all life as we know it. One of these is that it stores energy and provides a chain for its release from glucose, even in anærobic respiration, in the form of adenosine triphosphate (ATP). This is how the Krebs cycle links with the rest of metabolism. Without ATP, there is simply no life. The other is that it forms the sides of the DNA and RNA molecules along with a sugar, in the form of phosphate. Again, without nucleic acids, there is no life, which harks back to the difficulty in finding a feasible process for purine and pyrimidine synthesis. The discovery that phosphorus was a major limiting factor in biomasse may not simply apply to life on this planet, but throughout the Universe.

Why is this an issue? Wouldn’t we find that other planets in the Universe have about the same amount of phosphorus as there is on Earth or in this Solar System? Well, no, or rather, quite possibly not. Odd-numbered elements are usually rarer than their even numbered neighbours in the periodic table, and phosphorus is element number fifteen. Of the other elements playing a major rôle in life here on Earth, only nitrogen and hydrogen have odd numbers. Hydrogen is a special case because it’s the “default” element. In parallel universes whose strong force is slightly weaker, the only element is hydrogen. Its abundance there is one hundred percent, and most atomic matter in the Universe is in fact hydrogen, because the rule doesn’t apply to it. It’s a given. Nitrogen is still the seventh most abundant element because it’s fairly light and therefore likely to form. Phosphorus is the seventeenth most common everywhere on average, and is only formed when silicon atoms capture neutrons and decay. Only 1‰ of Earth’s crust is phosphorus and 0.007‰ of the matter in this Solar System. Its main mode of formation is in Type II supernovæ.

Supernova 1987A, a Type II supernova in the Large Magellanic Cloud

Type II supernovæ result from the collapse of stars whose mass is between eight and four dozen times the Sun’s. They only “burn” silicon for a very short period of time, during which a few silicon atoms will become phosphorus. Then they explode, scattering their elements across their region of the Galaxy in a shockwave. As time goes by, these supernovæ slowly increase the abundance of various elements, including phosphorus, but the regions of the Galaxy where the element is relatively abundant may be quite small and scattered, at least for now. This means that effectively the Universe, and on a smaller scale our galaxy, may be a phosphorus desert with a few small oases where it is even remotely “abundant”. Asimov said of phosphorus that we can get along without wood by using plastic, without fossil fuels by using nuclear power and without meat by substituting yeast, but because phosphorus is such a fundamental part of our metabolism there is no such substitute.

Now the question might arise of why so much importance is placed on phosphorus here when life seems to be so very adaptable and able to find ways round problems, and this is indeed so, but there are reasons for believing that this cannot happen with this element. It’s locally more abundant in geothermal vents and carbonate-rich lakes, which have fifty thousand times as much oxygen as seawater has, and it can also become concentrated in rockpools due to capturing the runoff from water and concentrating it when it evaporates at low tide, so there are various high-phosphorus places on this planet where life could have begun, which may well not be elsewhere in the Galaxy. Now suppose there are various different processes which could lead to life beginning here which do not involve phosphorus, which seems feasible and in fact it’s considered slightly odd that all life known here seems to have a common origin. The one which needs phosphorus is at a disadvantage compared to the ones which don’t, because it relies on a scarce element and wouldn’t be able to spread so easily to environments where other life for which it was not a limiting factor would be able to thrive. Therefore it very much looks that the kind of life which exists on this planet has the only kind of biochemistry possible here.

This could have major consequences for our own space travel. It might mean, for example, that we can’t settle on planets in distant star systems and thrive without bringing our own massive supply of phosphorus, and this also makes it more difficult for other intelligent carbon-based life forms to colonise the Galaxy, because not only are there vast distances between the stars, as we already know all too well, but even those distances are small compared to the small spheres of phosphorus-rich systems scattered sparsely through the Milky Way. They could be thousands of light years apart. Moreover, although the Universe is very old, it may have taken this long to accumulate enough of the stuff for life to be possible at all, meaning that the idea of elder civilisations out there which appeared æons ago may be completely wrong. This leads to a second variant on the idea that life is rare.

We’re The First

It may be that we don’t know of any aliens because there aren’t any, but there will be one day, either because of us or because they will evolve later. The phosphorus bottleneck is one explanation for this, but it could also be that we got very lucky with evolution. Over most of the time this planet has existed, it’s had life all right, but it was single-celled and those cells weren’t even the more complex ones like amœbæ, and life chugged along just fine, though it didnæ end up producing anything very impressive-looking or even visible to the naked eye. It could very well, for all we know, have continued in that vein until the Sun roasted it out of existence, but it didn’t. In fact this is another explanation entirely which is worth exploring as such: simple life is common, complex life rare.

One way to look at evolution as it’s happened here is as a series of improbable events. Some even say that the advent of oxidative phosphorylation is improbable, and that even anærobic respiration was an improbable step, which would limit life so severely as to effectively rule it out in any meaningful sense. Beyond this, the evolution of cells with separate nuclei containing DNA surrounded by an envelope of cytoplasm with symbiotic bacteria living within it also seems quite unlikely, and we haven’t even got to the simplest animals and plants yet. Maybe on other planets these improbable events have taken longer than they have here, or don’t happen at all, and although there will be intelligent life there one day, that point is hundreds of æons in the future. There are a couple of unexpected things about the Sun. One is that it’s a yellow dwarf rather than a red dwarf, and since those are both apparently suitable for life-bearing planets and liable to last many times longer than the Sun, a random selection of intelligent life in the Universe might be expected to result in finding an organism living on a planet circling a red dwarf 200 000 000 000 years in the future. The other weird thing about the Sun is related to this. If there is something ruling out life on red dwarf planets, such as frequent flares, it’s still more likely that intelligent life would evolve on a planet slightly cooler than the Sun, that is an orange dwarf such as α Centauri B or either of the 61 Cygni binary system, because the star would both last longer as such and have a habitable zone which lasted longer in the same place. Perhaps the reason the Sun is a yellow dwarf is that we are ourselves unusual and have evolved unusually early, so the absence of aliens is in a way connected to the unusualness and apparent unsuitability of this star.

The ‘Red Dwarf’ universe has the second version of absent aliens which in fact amounts to “we’re the first”. There are other intelligences in ‘Red Dwarf’ but they’re all derived from Earth in one way or another, and this is “word of God” because Rob Grant and Doug Naylor have said so themselves. In this version of us being first, we are indeed the first but will go on to seed the Universe with our machines and organisms until it teems with intelligent life. We just happen to be living before that’s happened. I would argue against this for the same reasons as I did here: if that’s the case, aren’t we just incredibly unlucky to have been born before it happened? My answer to this is that it will never happen, but there’s a further probabilistic difficulty in the fact of our existence here and now on this planet 13.8 æons after the Big Bang: the scepticism about our future is about time, but could equally well be applied to space. If I am a random intelligent entity in the Universe and it’s normal for intelligent life forms to expand out and settle the Universe in untold high population numbers, why am I not one of their much greater number? Here’s a possible answer:

Intelligent Life Destroys Itself

This was a popular idea from 2016, when Donald Trump got elected, but has been stated many times, in connection with climate change, the Cold War and hostile nanotech. Maybe there’s something about monkeying around with the world which ends up killing species off. This could be quite low-key. For instance, it’s possible that if we had continued with a mediæval level of technology and population and it had spread around the world, although climate change might not be as severe as a result of our own activities, we might still reduce the fertility of the soil and have plagues and famines wipe us all out in the long run. However, once an industrial revolution has occurred, bigger problems start to emerge, the most prominent and obvious being anthropogenic climate change in our case, but another issue is the use of weapons of mass destruction, or AI, complexity or nanotechnology causing our extinction. The Carrington Event is a famous solar flare in the mid-nineteenth century which led to electrocutions from the only electrical telecoms which existed at the time, telegraphy. If this happened now, and it is likely to recur quite soon statistically, the internet and devices connected to it could be physically destroyed, and we are now very dependent on it. Nanotechnology is another potential threat, with the “grey goo scenario”, where tiny machines reproduce themselves and end up eating up the entire planet. This has been explored and seems to be impossible, because limiting factors like phosphorus for life also exist for such machines in the form of other elements, but one thing which could happen with nanotech which is much cruder is that it simply becomes a ubiquitous particulate hazard for everyone. Complexity probably amounts to unforeseeable apocalyptic scenarios. For instance, climate change could lead to wars over water which would restrict access to metals needed to maintain a physical infrastructure we need to provide food. In a way, as an explanation of the Fermi Paradox the absence of aliens might constitute an important lesson for us, but the details are less important than the consequences, which are that there are no spacefaring or communicating aliens because they always die out soon after becoming capable to doing anything like that.

I actually do think this explanation has some factual basis, although it isn’t quite as drastic as it seems. I think there is a brutal pruning process in technological and social progress which prevents harmful aliens from leaving their star systems, and unfortunately in that process there are myriads of innocent deaths and enormous sufferings, holocausts and the like. The way I think it works is that tool-using species may either smoothly develop in a consistently altruistic way or in a more internally aggressive manner which may or may not be resolved by the time they attain the ability to travel through space. We are now at such a crucial stage, and we may destroy ourselves, solve our social problems and opt not to go into space or solve our social problems and expand into space. There may be a law of nature which means an overtly belligerent attitude is self-defeating and such species, although they may not be essentially aggressive, always destroy themselves rather than travel to other star systems. In other words, I believe in this explanation, but it may not be an explanation of the Fermi Paradox. I think it means that any aliens we encounter who have left their own star systems will automatically be peaceful and coöperative. If this is too tall an order then nope, there are no interstellar civilisations, although there may be aliens who haven’t wiped themselves out yet, and even aliens who occupy an entire star system. This is the opposite answer to the Fermi Paradox to the next, fairly recently devised, one:

The Dark Forest

This is named after the work in which it was apparently first suggested,  黑暗森林, by the Chinese SF writer 刘慈欣, Liu Cixin, in the ‘noughties, although it’s hinted at in the preceding novel, 三体, whose English title is ‘The Three-Body Problem’. Avoiding spoilers, the basic idea is that we never hear from aliens not because there are none, but because they’re hiding from each other. I’ve mentioned this before but it bears repeating here. Aliens are assumed to see each other universally as potential threats and will therefore act to destroy each other whenever they become aware of their existence. In response to this, they all hide themselves and the reason we detect no signals from them is that they assiduously avoid making themselves detectable. Against this dark background, humans are recklessly advertising our presence to all and sundry, positively inviting ETs to come along and destroy us, even if only to avoid attention being unwantedly attracted to themselves by even more powerful minds which would swat them like flies.

It can be argued that this situation reflects the real situation we observe in ecology, where camouflage and mimicry protect organisms from each other and disguises of various kinds are adopted to prevent themselves from being sensed, killed and eaten. I think 刘慈欣 has a rational approach to the issue, and in fact quite a positive message as he believes that we’ve got the idea of humans and aliens the wrong way round. He believes that there is a prevailing view that aliens will be friendly while we are aware of the hostility prevailing between powers in the human world, but that the real situation is that human beings are potentially much more altruistic than we give ourselves credit for, and it’s likely to be the aliens who behave in a vicious manner towards us. Other believers in the Dark Forest answer say that non-believers in it are being anthropomorphic by imagining that aliens would not be hostile, because the biosphere we know of is quite savage. I’d say that this is a projection, and also that to extend the comparison, there are circumstances where organisms positively advertise their presence, for example to seek a mate or as warning colouration. The former is a little hard to fit into this scenario, but the closest analogy would probably be something like exchange of information for the benefit of both cultures, a relationship described ecologically as symbiosis. For instance, assuming the presence of multiple hostile civilisations in the Galaxy, it would seem to make sense for two less powerful cultures to tell each other about the threats. Something like warning colouration is another possibility. A species of aliens might wish to broadcast its potential hazardousness to others in order that it not be bothered, rather like the Mutually Assured Destruction (MAD) scenario, and in fact the Dark Forest is based on game theory, which is influenced by MAD.

The idea of more powerful civilisations disrupting and destroying less powerful ones has a persuasive-seeming precedent in human history, because in general European and European-derived cultures have tended to do that to a horrifying degree on our own planet to other human cultures. This,though, is based on what happens within our own species in highly specific circumstances which rely substantially on the idea of territory and land use, along with a religious and political outlook used to justify those atrocities. It’s this which seems anthropomorphic to me. The Dark Forest seems to be the same situation translated into interstellar space and assumes that the species or entities involved are similar to us in the mode we have employed during history, which is likely to be highly atypical even for us, and we may also be projecting our own assumptions onto ecology when we assert these things. There are plenty of examples of peaceful coöperation between species, such as symbiosis and the very fact that multicellular organisms are themselves alliances of unicellular ones for mutual benefit in the same way as an ant colony is. There’s also the consideration that life on this planet has been around for a very long time now and it would seem to make more sense to nip things in the bud before intelligence of our kind has even evolved, but this hasn’t happened. However, I do maintain a modicum of sympathy and interest in 刘慈欣的 argument because I suspect it’s linked to dialectical materialism, and in order to assess it properly I would have to know more about Maoism, the current status of the Chinese 共产主义, his status with respect to the Chinese government and so forth. I would maintain that China, because it has a stock market, is capitlist, but that doesn’t mean it doesn’t have valid philosophical views built upon its ideology. It’s all a bit complicated, and interestingly something he goes into himself in his novels. Although I don’t agree with the Dark Forest at all, laying it out as a Marxist-influenced argument is interesting and may suggest other solutions to the Fermi Paradox which are freer from the taint of capitalism.

Spending Too Much Time On The Internet

I have felt since the early 1980s that there may be a trade-off between Information Technology and human space exploration. I don’t want to go into too much depth here but I suspect there is an inverse relationship between the two, such that the more IT advances, the less effort is expended on sending people into space and the more human beings explore the Universe, the less happens in the sphere of computing and the like. This is a subject for at least an entire post, and I won’t do more than mention it in passing here. Suffice it to say that when the Drake Equation and Fermi Paradox were first thought of, IT was very primitive compared to how it is now, although the internet itself is quite possibly the most predictable thing which has ever happened (see for example Asimov’s ‘Anniversary’ published in 1959 or Old Burkster’s Almanac in the 1970 ‘Tomorrow’s World’ book, which actually predicted the exact year it would take off (1996), so the link could’ve been made then. In fact, Olaf Stapledon predicted something similar in ‘Star Maker’ in 1937, where he imagined a species of aliens which ended up never leaving their home planet, which is doomed due to losing its atmosphere, because they end up lying in bed all day hooked up to a global information communications system, which also tellingly begins by encouraging cosmopolitanism but soon degenerates into echo chambers.

The “spending too much time on the internet” solution to the Fermi Paradox goes like this. We went through the Space Age and appear to have come out the other side. On this other side, we have an almost universally accessible network of devices for information and communication. If we are able to develop sufficiently convincing virtual worlds, we might all end up in the Matrix and not bother going into space at all. Perhaps this is what always happens to sufficiently advanced technological civilisations. The author of the Dilbert cartoons, Scott Adams, once stated that if anyone ever managed to invent the Holodeck, it would end up being the last thing ever invented because everyone would just end up living in that virtual world and not bothering with anything else. This is different to the idea of the Universe being a simulation because in this situation everyone knows where they are is not “real”, although Gen-Z-ers might argue with a definition of reality which divides meatspace from cyberspace with considerable justification, and willingly participates anyway. If you’re doing that, why bother to explore strange new worlds or seek out new life and civilizations. In fact you could do that anyway because I’m sure a virtual Enterprise would be one of the first things to be created in this virtual world, if it hasn’t been already. It wouldn’t be “real” in the way we understand it, but who are we to say? It would, however, mean we aren’t going to meet any aliens because they’re all on Facebook or something, which we may already have noticed is so.

One problem with this answer is that it assumes aliens are all similar enough that they get to a stage when they not only start to create communal online environments but also then get addicted to them and abandon space exploration. It isn’t clear that they’re similar enough even to have the same mathematics as we have, so why assume this is what happens? It may well happen to humans, but that could have little bearing on what happens anywhere else.

This can be turned round:

The Planetarium Hypothesis

There are several different versions of this and it blends into another version. The most extreme and probably easiest to state version is that we are living in a simulation, which Elon Musk claims playfully and perhaps not very seriously to believe. The argument that this is so in his case is based on the expectation that technological intelligences would very commonly get to the point where they could simulate the Universe, and within those simulations, more technological intelligences would do the same and so on, meaning that the number of virtual worlds compared to the real one is very large and therefore that we are much more likely to be living in one of those than the unadulterated physical Universe. Hence this is not the real world, and for simplicity’s sake, or perhaps as an experiment, we’re sitting in a simulation which, unlike base reality, is devoid of aliens. The alternative, according to Musk, is that in the near future we’re likely to become extinct, because there would then be no intelligent civilisations capable of simulating the Universe and therefore that we are living in base reality, but not for very long because there is about to be a massive calamity which will wipe us all out. I don’t find this argument to be at all satisfactory. Like the previous argument, it assumes that history will proceed in the same manner for everyone and that we all end up producing simulations. It also assumes simulations are possible when there are at least two good reasons for supposing they aren’t. One of these is the three-body problem. Three bodies whose attraction to each other is significant will behave chaotically in almost all cases and there are no ways of predicting their movement with a finite number of mathematical operations. There are exceptions to this. A few entirely predictable stable situations exist, most of which are too rare to occur in the observable Universe although there is one which may well exist somewhere in a star system in a galaxy far away. However, that’s the three-body problem. The Universe we experience has many more bodies than that in it. The number octillion has been mentioned in connection with this. For the Universe as we know it to be simulated, even the bits we’ve visited with space probes, an infinitely complex computer would be needed. Another problem is that of consciousness. Simulating consciousness doesn’t seem to be the same thing as actually being conscious, yet we know ourselves to be conscious. We could be mistaken about our substrate – maybe it’s transistors or qubits rather than brain cells – but for that to be so, panpsychism also has to be true, which as far as I’m concerned is fine but most people don’t accept that view of the nature of consciousness. There may be a functionalist solution though. A further objection is based on Musk’s own thought about the multiplicity of simulations. If a powerful computer can run a simulation of the Universe in which other computers can also run simulations of the Universe and so on, the largest number of simulations running would also be the most rubbish ones, at the bottom of the pile, because that’s the point at which the “tree” has its final twigs, and that means we’re more likely to be in a rubbish simulation, but we aren’t, and that simulation would also be too simple to allow any further simulations to be run. Minecraft exists, therefore we are not living in a simulation!

One point in favour of the Planetarium Hypothesis is that it’s highly sceptical and makes very few assumptions compared to some other solutions, and in that respect it’s similar to Absent Aliens. There are also less extreme versions of this which take the word “planetarium” almost literally. We have never bodily travelled more than 234 kilometres into trans lunar space, which happened with the ill-fated command module of the Apollo XIII mission in 1970. Therefore, for all we know the rest of the Universe could be faked for our benefit, although this assumes that the likes of the Pioneer and Voyager probes are just sitting somewhere being fed loads of false data or something. There’s a decision to be made in this explanation as to where one cuts things off and decides everything else is fabricated, and it begins inside one’s own head. This thought has been used at least twice by major SF writers. In the 1950s, Asimov (again!) wrote a story where the first astronauts to go behind Cynthia (“the Moon”) found it was painted on a board and propped up by wooden struts. Later on, Larry Niven, who had written himself into a bit of a corner with his Known Space series because he had to try to maintain continuity, playfully came up with the idea that none of it had happened and it was just being simulated in VR on Cynthia.

It’s been suggested that the almost perfect match between the apparent size of Cynthia and that of the Sun is a kind of Easter Egg, that is, a clue that we’re living in a simulation. It doesn’t seem necessary for the existence of intelligent life here that that match should be so perfect, and there seems to be no explanation for it other than chance. And it is peculiar. It will only hold true for the approximate period during which oxygen-breathing terrestrial animals can thrive here because the distance between Cynthia and Earth is increasing by a few centimetres every year. It would be interesting to run the figures about this, to see for example how big and/or distant a moon would have to be if we were orbiting within the habitable zone of 61 Cygni B or something, because there might be a clue there.

I have to admit it’s tempting to believe that the empyrean, as it were, is hidden from us by some kind of holographic Dyson sphere, i.e. that the planetary Solar System and Kuiper Belt are surrounded by a fake display of the rest of the Universe, just because it’s an appealing idea, and there are even reasons for supposing this to be the case. However, that would mean that Pioneers 10 and 11 along with Voyagers 1 and 2 either hadn’t hit the solid sphere of the sky, as it were, yet, or that they had but are themselves in a simulation of interstellar space. It was recently suggested that the Solar System may be enclosed in a vast magnetic tunnel as it moves around the Galaxy, but it seems to be several hundred light years wide and a thousand light years long, so if that’s the edge of the simulation it seems a bit pointless. Another appealing idea associated with this is that all that stuff about Venus being a hot, steamy jungle planet and Mars having canals and Martians living on it could be entirely true and we’re just having all that concealed from us and, again, fake data being fed to space probes. Of course, if human astronauts actually did go out there this would be harder to maintain, unless one begins to suppose that they’re all abducted and brainwashed or something.

The answer this kind of blends into is the

Zoo Hypothesis

This used to be my favourite answer when I was younger, and I just basically assumed it was true, but it lacks the parsimony of absent aliens or the Planetarium Hypothesis. If you’re familiar with ‘Star Trek’, you’re probably aware of the Prime Directive, also known as Starfleet General Order 1:

“No starship may interfere with the normal development of any alien life or society.“

We don’t know how extensive or organised any technologically advanced species or other intelligence which might exist outside our Solar System is, or anything about their ethics or politics. However, the admittedly anthropomorphic analogy with how things are here with uncontacted people on our planet, we do have at least a rudimentary ethic to protect them. We note that they are self-sufficient, unfamiliar with how things work in global society, highly vulnerable and at risk of extinction. Often the reason their lives do end up disrupted is due to governments or multinationals wanting to get hold of resources which happen to be located where they are. This is never going to be the case for Earth in terms of mineral resources, as even phosphorus is found elsewhere in sufficient quantities, if that turns out to be important, and there isn’t going to be any kind of invasion to get hold of metals or whatever from here. What we may have is culture and biodiversity. Speaking of biodiversity, there are reserves and national parks in many countries on this planet, so maybe we’re in one of those. It isn’t clear whether to an alien we would be more like an uncontacted indigenous culture or endangered wildlife, depending on how different our intelligence and minds are, but there are measures in place here for the protection of both. Moreover, when the difference is large enough, it’s possible for human technology to maintain an environment in captivity which may create a persistent illusion of the habitat an animal is found in before human interference, and we could be in such an environment.

I’m going to present my train of thought, as was, on this issue, starting with the premises of the Fermi Paradox. The Galaxy is more than twice as old as this Solar System, so it’s fair to assume that intelligent life evolved many æons ago, even before the Sun formed. This is also more than ample time for the Milky Way to become thoroughly known to the technological cultures that exist within it, and it can also be assumed that any species able to leave its star system must have achieved some kind of utopia in order to be able to use the energy and resources efficiently enough to do so. Therefore the probable situation across the Galaxy is that a peaceful and benign community exists which will protect the less advanced civilisations found within it. This applies to Earth. We are observed by aliens and there is a non-interference ethic which prevents us from being contacted because of the disruption that has been seen or modelled to occur in the past if it happens too early in the history of a species. This policy has been in place for thousands of millions of years. When we reach a certain stage in technological and perhaps social development (I actually think these always occur hand in hand), we will be contacted and, perhaps after a probationary period, invited to join the “Galactic Club”. There is well-worn standard procedure for doing this. It can also be supposed that because this society is so ancient and long-established that it works as perfectly as any society could, so the procedures can no longer be improved upon. I should probably also mention that back then, as now, I thought in terms of technological cultures rather than species. Individual races come and go in this scenario just like individual humans in society, but the culture is permanent, or at least very durable. This is the condition of the Galaxy.

Although my use of the word “culture” calls Iain M Banks’s fiction to mind, I began to use it before they were first published. The word is just very apt to describe this kind of situation. I used to be very confident that this was how things were, and it is more or less the Zoo Hypothesis. Where it falls down, I think, is in having a quasi-religious tone to it. It could be argued that this is akin to our own ancient tendency to project our wishes and stories onto the sky, and I do think this is significant. However, there are different ways to respond to that thought. One is that we unconsciously know how things are and therefore made various attempts to express that fact given the current state of knowledge throughout our history. Alternatively, the reverse could be true: we have a tendency towards magical thinking which results in religion, and this leads us towards imagining how to have things this way in the face of what we perceive to be powerful evidence against the supernatural. Some fundamentalist Christians accept the existence of aliens but see them as demonic. It’s very difficult to examine oneself closely and neutrally enough to come to a firm conclusion as to what belief in the Zoo Hypothesis is motivated by, and therefore to assess it scientifically or rationally. There are certainly inductive inferences operating within the argument, but perhaps not deductive ones. “Accusing” it of having a religion-like flavour is not the same as refuting it, and part of the decision as to whether to accept or reject it relates to how one feels generally about religion.

That said, there are some ways of arguing rationally against it. It only takes one small group within the Galaxy, perhaps the closer star systems in this case, to behave differently for First Contact to occur. Since I’ve concluded also that mature interstellar cultures must be anarchist, there would be no law enforcers to prevent this from happening. However, anarchist societies are not necessarily chaotic and may have customs which prevent such things from happening. For instance, queues are not generally legally enforceable but people rarely jump them due to social disapproval or the simple act of people providing the service one is queueing for ignoring violators, and there are apparently places where there are no laws regarding traffic priority at junctions, but people behave harmoniously according to custom. It hasn’t escaped my attention that I’m talking about Douglas Adams’s “teasers” here. As far as we can tell, though, this hasn’t happened. Or has it?

UFOs Are Alien Spacecraft

Like most people, I reject this out of hand but there’s a point to stating in detail examples of what people who believe this generally think. There is some variation in the details, but I think it works roughly as follows.

For quite some time now, perhaps since prehistory, this planet has been regularly visited by spacecraft ultimately originating outside this Solar System, containing intelligent aliens. These aliens sometimes abduct humans and other animals to do experiments on them. The governments of the world are aware of the situation but keep it secret from the public to avoid panic or because they’ve made some kind of deal with the aliens.

This view has a number of variants and is the basis of several religions. One such view is that ancient astronauts are responsible for world religions and have interfered in our history, perhaps even interbreeding with our ancestors or genetically engineering them for the appropriate kind of intelligence. Incidentally, this is known as “uplift”. Another view, of course, is that the human world is run by alien reptilian humanoids or shapeshifters for their own nefarious purposes and not for human benefit. There are also notions such as aliens wanting to get elements or substances from this planet which are rare elsewhere in the Universe, such as human enzymes or for some reason gold.

I stopped believing that UFOs were alien spacecraft when I was about ten, I think. There are a number of very good reasons to suppose this is not the case. The initial trigger that ended my belief was that the occupants of the craft were said to be humanoid in possibly all cases, which I saw as completely incompatible with them being aliens. For a while, I believed they were time machines and the beings on board were highly evolved humans from the future. Although I no longer believe this either, I still think it’s more plausible than the alien idea. I had a bit of a blip in my disbelief when I heard about the star chart aboard the spacecraft in the Hills’ abduction, which closely maps nearby star systems from a certain angle, but now think that this could be made to conform to the pattern drawn by projecting the stars in various different ways until a rough fit was achieved, which is in fact what happened with this.

There are various problems with the flying saucer hypothesis. One is the fact that people report humanoid occupants, although there are possible explanations for this. The entities could be manufactured or genetically engineered to look like us or convergent evolution might ensure that tool-using species are humanoid. Another is more serious: UFOs are visible. People report detecting them in various ways, such as on RADAR screens or more often visually. Even with our own relatively limited technology, we are able to make things almost invisible and undetectable on RADAR, but we are expected to believe that aliens can’t do this even though they can cross interstellar distances with ease. The alternative is that they want to be seen, but this is an unsustainable intermediate position because it doesn’t make sense for just a few craft to be seen occasionally. It can be confidently asserted that if they wanted to be invisible, they would be, so it then becomes necessary to explain why they don’t want to be. It’s fine as such if they don’t, but it would also mean the idea that they only associate with the “leaders” of the human race goes by the by. Also, the very idea that they would respect governmental power structures makes no sense. There’s no reason to suppose aliens would have government or that they would pay more attention to the people who happen to think they’re at the top of the pyramid. Of course, I’m personally convinced that they’re all anarchist, but there are other circumstances in which aliens might wish to subvert the hierarchy or just end up doing it anyway. Apart from anything else, they are after all aliens. They may not have the capacity to understand the nuances of human governmental systems, or they may arrive here not having learnt how it works. Or, they may wish to disrupt human society for nefarious purposes by inducing the panic world governments are supposèdly trying to avoid by keeping them secret. The nub is that if aliens were visiting us, they’d be able to hide from everyone, and if they didn’t hide from everyone they’d hide from no-one.

I do believe in UFOs of course. There very clearly are aerial objects which remain unidentified by any human observer. These are often things like Venus, birds, drones, weather balloons and so on, but I do also think there is another, very small set of other objects. These are secret military aircraft which happen to get spotted by people from time to time but whose existence isn’t openly admitted by the authorities. The one time I saw a UFO I couldn’t explain, that’s what it turned out to be, so maybe I’m biassed because of that.

I also believe that aliens would be benevolent for the reasons I set out under the Zoo Hypothesis.

Simply not believing that UFOs are alien spacecraft is not the same as believing we aren’t being visited or observed though. Maybe they are here. Maybe we are the aliens without knowing. I’m getting ahead of myself though. Here’s another similar idea to UFOs being alien spacecraft:

They’re Here But We Haven’t Noticed

This one is something of a mental health hazard because it very much stimulates paranoia, and again there are several versions of this. The closest one to the previous explanation is that there are indeed alien spacecraft, or perhaps nanoprobes, visiting or monitoring this planet but we can’t detect them, or haven’t done so. It does make sense that if they wanted to remain hidden, they would succeed in doing so, given their level of technology. One suggested means of eploring the Galaxy is to launch swarms of minute spacecraft in order to save energy and avoid collision with dust and other bodies between the stars simply by being smaller. It would also be relatively easy to secrete a reasonably large completely visible probe somewhere in the Solar System or in orbit around Earth without attracting much attention. Another somewhat disturbing further option exists. Right now, we can do 3-D printing and have some ability at genetic engineering. We aren’t that far off inventing a replicator, should that prove possible at all, bearing in mind that things often seem easier before they’ve been done. But for a technology far in advance of our own, it should be possible not only to produce a completely convincing living human, but even one whose memories are false and doesn’t even realise they’re the product of an alien machine. In other words, we could ourselves be aliens without even knowing. This kind of prospect is very similar to the kind of beliefs many children have and also has some resemblance to Capgras Syndrome. Whereas all of these things are possible, they are almost by definition non-scientific as they have no way of being falsified. Perfect camouflage is just that. No test can be performed to verify or refute that it happens. Therefore, whereas all of these things seem entirely feasible, they aren’t actually particularly meaningful as a simpler explanation for what we observe is that there are no alien spacecraft or “pod people”.

They’re Too Alien

Many answers to the Fermi Paradox seem quite anthropomorphic in one way or another. For instance, both the Zoo Hypothesis and the Dark Forest attribute perceived human-like behaviour, in opposite directions, to these unknown and possibly non-existent beings. But what if the reality is that aliens are in some way intelligent but also truly alien? What if they’re just fields of singing potatoes? They’re very intelligent, to be sure, but all of that cleverness is channelled into art so sophisticated and arcane that it can’t be grasped by humans, and also they sit there and do nothing else. They might send up a shoot or two with eyes on the end every now and again and look at the stars and planets in their night skies, but it doesn’t grab their interest. Of course, the singing spud scenario is borrowed from Grant and Naylor, but it’s one of many possibilities, some unimaginable and all unanticipated. We are one example of a tool-using species. Another one may be dolphins, and it doesn’t look like they’re going to develop our kind of technology at any point, not only because they live in the sea and don’t have anything like hands, but also because they’re just not interested, and that’s just on this planet and quite closely related to us. Or they could be a spacefaring species like some humans aspire to be but just have no concern about meeting any aliens or getting in touch with them. We might not even recognise each other as alive. For instance, what if they were a rarefied plasma drifting between the stars?

Different Or No Maths

I went into this one the other day here. Most of us humans don’t distinguish between subitising, which is the ability to judge how many items there are at a glance and which we are usually able to do about five, and the kind of activity which counts as arithmetic and mathematics. I won’t wade in here but there doesn’t seem to be any good reason why we would have evolved an aptitude to do mathematics given our lifestyle, or for that matter for any other species to do so given its niche, but we’ve done so anyway and this has somehow proven to be useful in rocket science and the like. Maybe it’s this which is missing from other intelligent life forms’ faculties, so they do fine building some kind of civilisation where everyone isn’t just a number, but they never leave their home world because they never develop anything able to do that.

Right, so this has turned out really long, so at this point I’m going to stop and publish. Part II in a bit, possibly tomorrow.

Mind Over Antimatter

Illustrative purposes only – will be removed on request

Spoilers for Doctor Who’s ‘Planet Of Evil’, Buffy The Vampire Slayer’s ‘Normal Again’ and Space 1999’s ‘Matter Of Life And Death’ follow.

I’ve been watching a lot of old SF TV and films recently, and have now reached the mid-’70s. Well, I say that. What I’m actually doing is following Anderson productions through from ‘The Dark Side Of The Sun’ down towards the present, but that isn’t exactly my focus today because I’ve noticed two interestingly similar uses of a science fiction motif which don’t seem to make a lot of sense, one in ‘Space: 1999’ and one in ‘Doctor Who’: antimatter.

Antimatter is definitely not what it’s shown to be in either of these. Starting with ‘Doctor Who’, there’s the serial ‘Planet Of Evil’, whose air dates are 27th September to the 18th October 1975, and with ‘Space 1999’ (is there a colon there?), the episode ‘A Matter Of Life And Death’, broadcast on 27th November 1975. Hence these two are very close together. This could almost be titled ‘The Depiction Of Antimatter In British SF Shows of autumn 1975’. The weird thing about the two of these is that both of them make antimatter into something it absolutely is not.

I’m going to start with describing what antimatter really is, how it was discovered and so forth. The first hint that antimatter was possible was Paul Dirac’s 1928 CE paper ‘The Quantum Theory Of The Electron’ which pointed out that there didn’t seem to be any reason why electrons should have negative charge. They just did. Now there’s a device called a cloud chamber, which contains humid air almost at the point where it starts to form droplets of water in a fog, and this is used to detect subatomic particles, which leave vapour trails behind them due to upsetting the delicate balance of the conditions. Other, similar devices are bubble and spark chambers. If a magnetic field is applied through a cloud chamber, it unsurprisingly causes charged particles to curve in a direction corresponding to their charge, so for example α particles, which are doubly positively charged helium nuclei, will go one way and electrons, which are negatively charged, will go the other. At any time, cosmic rays are passing through the atmosphere, objects on Earth and Earth itself in the case of neutrinos, so any cloud chamber will detect various particles from those, although most are filtered out by Earth’s own magnetic field. Thus you get a wide “zoo” of different kinds of particles constantly raining down from space, including β particles, which are just fast electrons and can be bent by a magnetic field. At some vague and disputed time in the late 1920s CE, scientists began to notice that not only were there electrons, but there were also other particles which seemed to be exactly the same as electrons except for one thing: they bent the other way in a magnetic field. In other words, they were positively rather than negatively charged. These particles were dubbed “positrons”.

Since I’m primarily talking about fiction here, I’m going to talk about Isaac Asimov’s use of these in his “positronic robots”. Asimov’s robot stories are primarily about the ethics practiced by said robots, but there’s a blurry technical background to them in that they all have positronic brains. This is essentially technobabble, but the idea is that robots’ heads contain something rather like a computer (and Asimov’s first stories in this vein more or less predate the invention of the digital computer) made of platinum-iridium alloy which operates by the creation and destruction of positrons. On one occasion, Asimov comments “no, I don’t know how this is done”. Since his focus is on the Three Laws, this is just off happening to one side and is rarely the focus of his fiction, but one thing he does say is that a positronic brain cannot be made without conforming to those laws. However, the reason for this seems to be that they have been such a central part of the ethics of US Robots that in order to do so, one would have to reinvent the wheel, so it isn’t that there’s a fundamental physical principle that makes this impossible. That said, in one of his stories a human character is captured by an alien robot which also obeys the Three Laws to the extent that it, too, “cannot harm a human being or through inaction allow a human being to come to harm”, so it seems that whereas there is no physical reason why using positrons prevents a robot from acting unethically, it’s more like the utility and function of such a machine is fundamentally ethical, in the same way as, for instance, any light source is going to have to emit visible light to be worthy of the name, so there is a reason why they’re like that which is as immutable as the principle of using positrons, but it works on a different basis which is more social, perhaps related to Asimov’s other big concept, psychohistory.

Although all of this is very vague, it’s still possible to discern a limited amount of nebulous creativity around the concept, if it’s worthy of that name. Platiniridium, as the alloy is in reality known, has some real world features which communicate something about the situation. Their use signals that the positronic brain is of extremely high value, since platinum is dearer than gold. The two metals are among the heaviest, that is the densest, of the chemical elements, communicating that positronic brains are very weighty, i.e. important. Platinum also has the reputation of being shiny, so it’s bright, an attribute which can be used metaphorically for intelligence, and also a sense of high technology – a gleaming bright ultra-scientific future. I can’t say that all of these things were operating in Asimov’s mind when he thought of it, but they are all in there for a reader. Another less obvious aspect, bearing in mind that he was originally a chemist, is that the alloy is particularly unreactive and has a very high melting point, so it’s resistant to physical assaults, which is what constant bombardment with positrons would be. However, this can’t be taken far beyond the figurative realm because in fact there’s no reason to suppose, and nor was there in the 1930s, that platiniridium would be any more resistant to damage from positrons than any other kind of atomic matter. If significant amounts of positrons were moving through platiniridium alloy, they would increasingly ionise both elements, they would become oxidised and probably melt from the extreme heat generated.

There does in fact seem to be a way of building a valve-based positronic computer, and it would have certain advantages, one of which is that it wouldn’t need an external power source, but any such device would also be extremely radioactive and dangerous, so it could only really safely operate in deep space, and there’s no particular reason for doing so. Another area in which positrons could be said to have sort of come up is in the electron holes which allow transistors, and therefore microchips, to operate. These are the absence of particles behaving as if they’re real, but oppositely charged, so if there could be a form of matter allowing electrons and positrons to co-exist, this would be a genuine aspect of computing where they would have a rôle. However, Asimov was writing at a time before electronic digital computers existed as such. Colossus, the first stored-program digital computer, was built in 1943, three years after ‘Robbie’ was written. Also, although the possibility of antimatter had first been thought of in 1898, at the time he was writing, positrons were en vogue but other antiparticles had yet to be detected and were probably absent from even the scientifically-educated public consciousness, though of course not to actual physicists.

The key feature of positrons in this usage was probably their ephemeral nature, like that of thoughts in the conscious mind, and in general there is no complex set of ideas in his fiction to back this particular one up. In fact it’s rather unusual in that respect, as he was a professional scientist and often provided a lot of technical detail regarding such things. For instance, at around the same time he wrote a story about a spoon made of ammonium ions which looked exactly like it was made of metal but turned out to stink horribly and was therefore unusable, and this is based on the common observation that the ammonium ion, NH₄⁺, behaves rather similarly to an alkali metal such as sodium or potassium and could perhaps be made to form into a bulk metal in some way. This is speculative, to be sure, and doubtless impractical, but the scientific detail involved is considerable and important. Compared to that, his positronic brain is very vague. In fact, whereas Asimov is generally a hard science fiction writer, the only major exception being the usual one of allowing faster-than-light travel when he’s actually writing SF as opposed to fantasy, the positronic brain is more a soft sci-fi idea, more like a light sabre or a food pill than a robot (ironically) or an alien.

The concept was borrowed from his work into a number of others, including ‘Doctor Who’ and ‘Star Trek’. The earliest mention in the former seems to be in 1966, in the Second Doctor story ‘The Power Of The Daleks’, where a character erroneously speculates that the Daleks might be controlled by one. In ‘The Evil Of The Daleks’, broadcast the same year, the same regeneration attempts to implant the “human factor” into such a device, to be placed in a Dalek. Later, in the Fourth Doctor serial ‘The Horns Of Nimon’, a robot is understood to be controlled by a “positronic circuit”. In ‘Star Trek’, the android known as Data has a positronic brain, and the phrase “Asimov’s dream of a positronic brain” is used at one point as if it was a well thought-out concept with firm theoretical underpinnings, and also some sort of technological Holy Grail. In the ‘Star Trek’ universe, they’re supposed to have the ability to configure and program themselves in a way which would be impossible with electronic circuitry. What the concept does, insofar as it is one rather than just a vague idea, is create a non-existent type of technology which can have all sorts of things projected onto it without annoying plausible scientific facts getting in the way. I’d go so far as to say ‘Doctor Who’ does the same thing, particularly where the human factor is being induced into the Daleks using them. When asked about whether his robots were conscious, Asimov replied that they were, and ‘Reason’ certainly suggests that they are through the deployment of the Cartesian method of doubt by QT-1. If you believe that some objects are conscious and others not, as most adults in the West probably do right now, you are stuck with the problem of what could make something like a computer conscious, and his solution to that, and even more so that of ‘Star Trek’ and ‘Doctor Who’, is to posit the positron as a potentially perceiving particle. This is possible because it’s outside everyday experience.

Positrons are simply one example of antimatter, and moreover, one which managed to escape from the general science-fictional concept, possibly because although they are anti-electrons they’re only rarely called that. The wider concept of antimatter turns up particularly in the matter-antimatter generators which release energy to power star drives in all sorts of stories, and this, assuming antimatter can be manufactured in bulk, is an entirely feasible use, because the total energy locked up in matter and antimatter would be released if they came into contact with each other, usually creating an almighty explosion. This is what the equation E=mc² expresses, or rather, it expresses the quantity of energy present in matter. There’s enough energy in a single grain of sugar to keep the population of Melton Mowbray alive for life, and from this it can be seen that chemical energy is ridiculously inefficient. However, such a prodigious release of energy is potentially very dangerous, and this has been used in science fiction as well, in the form of the Total Conversion Bomb.

These are both relatively scientifically plausible ideas, and given that enough antimatter could be found or produced, both would be entirely feasible. They blow fusion power and bombs out of the water of course, and given that existing weapons of mass destruction are worrying enough, they may not be desirable but the fact remains that they probably could exist quite easily. But for some reason, in autumn 1975 two science fiction TV series ended up using the concept of antimatter in a really weird way which is completely alien to scientific theory and shows no signs of ever being realistic.

The first of these is ‘Planet Of Evil’, a Doctor Who adventure, with the classic Fourth Doctor and Sarah-Jane Smith lineup at the start of the Hinchcliffe era. I read the Terrance Dicks novelisation rather than the TV version, probably because I was watching ‘Space 1999’ on the Other Side! The Tardis picks up a distress signal from Zeta Minor, a planet on the edge of the Universe, over thirty thousand years in the future from whenever Sarah Jane comes from (see Unit Dating Controversy) in the year 37 166 CE. It turns out there’s an antimatter monster on the planet who is killing everyone, and is able to pass between this Universe and the antimatter Universe via a pool of antimatter, which is black and has no reflections. The Morestrans are a species or race whose sun is going out and they’ve arrived on the planet to mine antimatter ore, which will provide energy for their planet for generations to come. However, the antimatter is prevented from leaving the planet by the planet itself, and it also acts like the potion in ‘Strange Case Of Doctor Jekyll And Mister Hyde’ by gradually bringing out a primal, evil side in people.

To analyse this, antimatter in this does seem to share some properties with real antimatter in one way, sort of, in that it provides a prodigious source of energy. However, it isn’t clear that this is only because it interacts with matter, which is potentially just as good a source. It isn’t a property of antimatter specifically. Antimatter also seems to be “evil”. It opposes matter in the sense that it’s its enemy. In a sense this is also true, because matter and antimatter are each others’ enemies in that they annihilate each other, but here it’s more like matter is good and antimatter evil. I haven’t read Robert Louis Stevenson’s novella so I don’t know if he goes into what’s in the potion or whatever, but I suspect that antimatter here is largely a plot device to represent that potion in an updated way. The idea of antimatter being present in an ore of ordinary matter probably doesn’t make much sense, because if there were actual atoms of antimatter, there’d also have to be a way to prevent them from coming into contact with matter or they would immediately mutually wipe each other out. The idea that such a thing could exist somewhere “out there” depends on Einstein’s famous dictum that “the Universe is not only stranger than we imagine, but stranger than we can imagine”. This is clearly true, but there’s no reason to suppose that antimatter ore made largely of matter is possible at all. To me, it suggests some kind of electromagnetic suspension of particles in a cage-like crystal structure, and it might happen that positrons could be captured by positively charged ions in a rock. This raises the question of how close bits of matter and antimatter could get before they interact destructively, and this is an important issue because of the quantum mechanical implications of the probability of a particular particle being in a specific location. Given that, it seems that two pieces of matter and antimatter approaching each other would increase their probability of annihilation as they got closer, which also means there’s an issue regarding the speed of light. But all of this is beside the point because it isn’t about the properties of real matter and antimatter but what it means in this ‘Doctor Who’ story, which being based on the novella will presumably be to do with the potential for good and evil coexisting in all of us and in Victorian terms the hypocrisy of private actions and public appearances, which is likely still to have been valid in 1974, when I presume it was written, and of course today. Given our current hindsight and the likes of Savile at the BBC doing what he did, and this being kept quiet or just rationalised away, ‘Face Of Evil’ comes across in a more sinister way as almost a commentary on child abuse happening at the time. In this context, antimatter becomes the inner evil, secret, hidden side, and there’s also a sense of greed in wanting the power from antimatter ore and that power corrupting.

The location of the planet, at the edge of the Universe, is probably also relevant and in fact this is what I mainly got from reading it. The pool, mysterious and bottomless, is like a portal into a neighbouring universe where antimatter dominates. I get the impression that there’s a kind of “Duoverse” with a plane down the middle, with matter on one side and antimatter on the other, and that the two sides are in an uneasy truce. Zeta Minor is like a border checkpoint between two mutually hostile territories. There’s also the influence of ‘Forbidden Planet’ and therefore also ‘The Tempest’, and the Doctor does in fact quote Shakespeare in the story. The famous jungle set is clearly linked to the isle which is “full of noises”. The monster is thus very obviously Caliban, although the story is directly based on the film rather than the play and there are differences. The semi-visible monster closely resembles that in the film, and in the case of the Doctor Who story the semi-visibility is to do with it only being partly in our Universe, i.e. world, and incapable of reaching all the way into it, and therefore being essentially other-wordly. But the trouble is that I can’t go into much depth about ‘Planet Of Evil’ because of my unfamiliarity with it, and also with Shakespeare and Robert Louis Stevenson.

The other example is much fresher in my mind, as I only watched it yesterday. ‘Space 1999: Matter Of Life And Death’, and I think there’s no article in this title either, so it refers directly to antimatter having those fundamental qualities, or perhaps matter being life and antimatter being death. So far, the entire series of ‘Space 1999’ has seemed quite odd to me, being closer to space horror like ‘Alien’ and ‘Event Horizon’, and of course the children’s book ‘Galactic Aliens’, than science fiction or space opera. Then again, ‘Doctor Who’, particularly of the Hinchcliffe Era, has strong elements of that genre too, but because it wasn’t on the Other Side, I might judge it less harshly. Even so, ‘Matter Of Life And Death’ is a problematic episode among many of the same in the series, which however I’ll leave largely aside for a future date. If the viewer takes the idea that Helen Russell is simply being allowed to see things less apocalyptically after the calamity at the climax of the episode, it makes the whole of the rest of the series take place in her imagination. It’s very like the Buffy episode ‘Normal Again’, but if a series of such high quality is allowed to do that, so should ‘Space 1999’ be judged fairly. In any event, I’m not here to discuss the whole of that series in depth although it is worth remembering that this is very far indeed from hard SF at this point.

Here’s the plot: An Eagle reconnaissance mission has discovered an apparently perfect planet for human life, which is named Terra Nova. During their visit, their craft is struck by lightning, knocking both crew members senseless, and returns automatically to Moonbase Alpha. When it lands, Dr Helen Russell goes aboard to find a third person present: her missing presumed dead husband, mysteriously revived and present on a distant planet he never went anywhere near, as far as she knows. When taken to Alpha’s medical bay, their equipment is unable to detect heartbeat or any other vital signs and it also turns out that he only has a normal pattern of body heat when he’s in her presence. There is pressure to discover more about the planet and considerable enthusiasm to settle on it, so he’s injected with a dangerous stimulant drug. He’s monosyllabic and largely unresponsive to everyone after this except his wife, with whom he has a more involved conversation and others conclude that he is using her life force to sustain his own life. He’s taken to be questioned and says he can’t tell where he came from but can tell them the planet is dangerous to them. He also says that Terra Nova is inhabited, “but not in the way you think”, then dies when he hears they will go there anyway. After his death, his body begins to “reverse polarity” (it actually says that!), which is a sign that it’s going to become antimatter, and this is dangerous because of the release of energy which will probably destroy Moonbase Alpha when it’s complete. The corpse then vanishes, after shocking someone with a burst of energy. They land on the planet. All seems well at first, and in fact this scene of their arrival is one of the few in the series I clearly remember. Everything seems fine, with parrots, edible fruit, breathable air and potable water. Then the Moonbase fails and the entire satellite explodes, a landslide kills Koenig and Sandra goes blind. After all that, Helen’s husband appears again and tells her it’s all about perception and she can choose to see things the way they were.

This is a largely unsatisfactory story of course, partly because it’s in the “it was all a dream” category, which at least one other ‘Space 1999’ episode, and also an episode of ‘UFO’ also do, and this is really scraping the bottom of the barrel. It’s been seriously suggested that the writers were on acid when they came up with the idea, but leaving all that aside it’s still interesting to consider how it portrays antimatter. First of all, apparently a gradual transition from matter to antimatter is possible. Professor Bergman refers to “reversed polarity”, which I think is probably also a reference to ‘Doctor Who’, but also presumably means there’s an intermediate stage during which the subatomic particles making up the corpse only have some of their properties reversed, such as spin or charge, without being fully-fledged antiparticles. To be honest I do have some sympathy with the idea of there being particles preserving symmetry in other ways, but I get the feeling this is a very naïve view of physics, so I’m going to stick with the idea that it’s all or nothing: something is either a specific particle or its antiparticle with nothing in between. Otherwise it would be like saying something is slightly reflected. Alternatively, maybe it means that some of the particles have converted but others haven’t, which is again unfeasible as this would cause a huge surge of energy fuelled by mutual annihilation.

This episode is clearly inspired by ‘Solaris’, originally a story by Stanisław Lem and later made into two films (and an operating system). However, for some reason both films and the novel are so much better than this. ‘Solaris’ is extremely thought-provoking and lends itself to many interpretations. Its sentient ocean is replaced here by antimatter, which has a protean nature and is utterly alien. The idea seems to be that antimatter does not belong in this Universe but is able to mix with it to a limited extent, and is essentially mysterious and incomprehensible to us. The statement that the planet both is and is not inhabited is part of this. It corresponds to a wider sense of mystery and alienness found throughout the series. And of course, antimatter is once again metaphorical.

I can only presume that the concept of antimatter was topical at the time due to some kind of scientific breakthrough, which led to it being included in these scripts. Having said that, I do think the perception of antimatter is significant for both. The particle I think of as “gypsy”, also known as a psion or psi meson, was detected first in 1974, and whether it was valid or not there was also the idea that atomic matter included a small admixture of charmed matter where one of the quarks of a nucleon was replaced by a charm quark. This is not the same as antimatter, because there’s no fundamental incompatibility involved, but I don’t know if it’s actually the case or possible. My own impression of charm at the time was that it made some nucleons slightly more massive, causing matter to clump together in the form of galaxies rather than be spread smoothly throughout the Universe, but please remember I was only seven at the time and didn’t know much about nuclear physics. In any event, if this kind of mixture was a current idea in science at the time, the popular understanding of it might allow for the notion that there could be a metastable mixture of matter and antimatter which lasted more than a tiny fraction of a nanosecond but was still unstable over a short term compared to a human lifespan, and this mixture idea occurs in both works – the corpse in ‘Space 1999’ and the ore in ‘Doctor Who’. Both of them include a strong component of otherness in their idea of antimatter. In ‘Planet Of Evil’ it seems to be linked to ideas of horror and another universe at war with this one, which is kind of metaphorically true of matter and antimatter. In ‘Matter Of Life And Death’, antimatter is dangerous but also just utterly alien and beyond our understanding, and may also be linked to the idea of the Other Side in the sense of a spirit world beyond death. There’s an occult flavour to both of these.

On one level I find it quite annoying when scientific concepts are used like this. There doesn’t seem to be a good reason for using those specific ideas rather than something more fantastic and obviously made up which has no pretensions to a scientific basis. On another, I do have sympathy with it, because it attempts to express the essential mystery of what I might call “The Beyond”. There’s a very human projection here of fear of the unknown, but also sense of wonder, which is essential to science fiction. I’m not sure whether I’d describe either of these series as science fiction though.

One of the factors in play here is having to put series on screen for popular consumption. ‘Star Trek’ has this issue too, as do probably all TV series aiming for more than a niche audience. It’s like the limeflower tea sold in supermarkets which also has lime peel in it because that’s what some consumers expect. On the other hand, a character in ‘Space 1999’ itself makes an interesting point in another episode, that as time goes by a mythology for the modern age will be created, and it’s possible that this is what’s happening here. But we also have to live in a scientifically literate civilisation.

I’ve also noticed that I’m a lot more forgiving of technobabble and its consequences on ‘Doctor Who’ than I am on ‘Space 1999’, and I can’t help thinking that this is simply because the latter is on the Other Side. Maybe to me, BBC TV matters, and ITV antimatters.