Artemis And Doomsday

Right now, the chances are that everyone reading this is a basic human like me, living on Earth, or at an outside chance, in low Earth orbit (who am I kidding‽). Consider that condition. What are the chances that that’s what you are if human life goes on and our descendants fan out into the Galaxy? I’ve gone into this many times of course, and the Doomsday Argument, as this is called, is flawed, but it’s worth going into it again for the purposes of applying it to the situation in which the human race finds itself today.

I’ll just recap briefly. There was a guy who visited the Berlin Wall in the 1960s and predicted that it would come down at approximately the time it did through estimating the probability of where he was in the total number of visitors to the Wall, using only probability, statistics and the time since it had been put up. His name was Brandon Carter, and he later applied a similar argument to estimating how long the human race has left based on the assumption that one is about half way through the total number of human births. When I did this calculation based on my own date of birth, the 1977 CE estimate that 75 thousand million people had been born before me, which covered the past six hundred millennia and a doubling period somewhere around three decades, as it was at the time, it gave me the result that the last human birth would take place around 2130. There are various silly aspects to this argument. For instance, if Adam existed and had made this calculation just before Eve appeared, he would conclude that the human race would be most likely to end with Eve’s death. By the way, I am not fundamentalist and therefore do not believe Eve and Adam ever existed. I just want to make that clear.

Although this is not a particularly marvellous argument, I do think a similar one works fairly well in one particular area, as I’ve mentioned before. It does in fact seem fair to assume the principle of mediocrity about one’s own existence. In that respect, it’s fair to assume I’m a typical example of a human and have been born at a time when prevailing conditions are “normal”, i.e. that the fact that I find myself living at a time when we have only ever lived on one planet and are not cyborgs to a greater extent than Donna Haraway claims. Transhumanism is not the usual human condition and there are neither orbiting space colonies nor settlements on other worlds. If we even settled ten other worlds they would only need a population over the whole period humans dwelt on them about equivalent to the current population of this planet for us to be outnumbered, and that’s a very modest estimate of how human history would unfold if we began to live elsewhere than on this planet. It would be more likely for there to be numerous settlements, either in the form of space stations or people living on other habitable planets. Say there were a million planets settled, which is still a conservative estimate for the number of suitable planets in the Milky Way, and they were settled for only a thousand years each. That’s an æon of human life on other planets. For it to be more probable for us to be here now than there then, it would need the population on each of those planets to average out at less than seven dozen. That is clearly absurd, so we have to conclude that as a species we will never settle on any other planets or build any permanent space habitats, or that our existence here and now just happens to be fantastically impossible.

For this to be the case, we have to conclude that our efforts to go into space are also only ever going to be very minor to non-existent, something which is confirmed right now by the fact that only twelve people have ever visited another celestial body. Even that was difficult because one crew didn’t make it. Now we’re supposed to try again with the Artemis Project, the current plan to go back to where Apollo went. Incidentally, I’ve long thought that one of the issues with the conspiracy theory is that getting there is only equivalent to going round the world ten times. Patrick Moore had a car which had gone further than twice that distance, and the average flight crew probably notch that up in a couple of weeks. Not that it wasn’t an amazing achievement. But humanity didn’t go on to do anything else afterwards, is the issue.

We’re confronted with a problem in the current moment then. It’s looking like there will be more people walking about up there in a couple of years, but if that happens it looks suspiciously like this version of the Doomsday Argument will have been refuted. But before I go there, I want to talk about Brooke Bond.

In 1971, Brooke Bond brought out a series of collector’s cards on the Space Race which started with Sputnik 1 (let’s Russ that up a little: Спутник-1) and proceeded through the various early satellites, planetary missions and the like up to Apollo and then past into the future. I collected the cards and got the book to stick them in. It must’ve been 1971 because it had the pound marked in both shillings and “p”, and they only did that in that year if I recall correctly. Anyway, it was from this publication that I learnt of the plan to send a human mission to Mars via Venus launching in the late ’70s. I remember looking at the years and thinking “1979” and “1980” looked really strange and futuristic, like the numbers on the public library date stamp which had yet to be used. But yes, there was a tentative plan at that point to send astronauts to Venus and Mars which everyone seems to have forgotten. There have in fact been a very large number of such proposals, but I didn’t know that at the time:

Actually, looking at this I realise I got it the wrong way round. They were going to visit Mars first and then do a Venus flyby. My confusion arises from the fact that there were so many different plans to do this. The Russians even considered a Venus mission to be launched in the early 1960s. I remember eagerly awaiting this, in full expectation that it would happen, and the dates passing with nothing to show for them, and how disillusioning it all was. This was a feature of my life at the time. When they found CFCs were destroying the ozone layer and that carbon dioxide emissions were causing climate change, I was convinced that they’d just go, “right, lets take the fluorocarbons out of aerosols and stop using fossil fuels”, and it’s the same kind of disappointment, from which you can see that I wasn’t your typical space nerd or environmental activist, because I suspect rather few people were equally enthusiastic about Green politics and astronautics, but that’s who I am. There is a seamless disappointment there. It’s all part of my same imaginary world, and it was very hard to cope with at the time. I can’t believe how slowly everything except IT progresses, and it’s also weird that IT did advance that quickly compared to everything else. I have certain theories about that, not conspiracy theories but something else, which I’ll leave for another time.

The space-based Doomsday Argument, which I’m going to call “Space Doomsday”, can easily explain why this didn’t happen, although maybe “why” is the wrong word here. The immediate reason the Mars mission didn’t happen was budgetary cuts to NASA in 1970. However, considering our lives as a relatively random sample of human history, we are aware that it’s improbable that human space exploration will ever make much progress, or we probably wouldn’t be here sitting on this single planet where we originated. It’s possible but improbable. The idea that we will in fact end up doing this isn’t ruled out by the fact. It’s similar to the idea that if you have lung cancer, you have probably been a long-term tobacco smoker. That’s something you can reasonably conclude about someone’s previous life given their current condition, although it may also be that they got it from passive smoking or asbestos exposure, for example. It isn’t a dead cert, but it’s probable. Hence it’s probable that something would happen to prevent people from landing on Mars, assuming of course that the expansion into space follows such activities, and in that sense Space Doomsday has predictive power, or perhaps forecasting power. We know we’re here on Earth, so we can reasonably believe the human race does not have a spacefaring future. A slightly less reasonable conclusion is that there will be no human missions to other celestial bodies in our future.

This could potentially lead to a weird version of “Moonlanding” denial conspiracy theory. Obviously I accept humans landed on Cynthia six times owing to not being delusional in that respect, but suppose Artemis happens. I am wedded to the idea that humans will never go there again because of Space Doomsday, so if they do go there I’m tempted to deny that due to it not fitting in with my world view, and the same applies to any planned Mars mission. Am I perhaps a tinfoil hat conspiracy theorist in the making? If someone believed in Space Doomsday in the 1960s, would they have ended up denying the Apollo missions were real? If the news that Artemis does succeed appears in the media and we see pictures from the lunar surface and the rest, it’s fair to conclude that we probably have gone there in a second batch of missions, but one’s belief in Space Doomsday could be so strong that it would lead to K-skepticism. For me, that would be motivated by depressive thinking, but others might have more positive reasons for doubt, such as the idea that it isn’t appropriate for so much money and resources to be spent on space missions when there are enough problems on this planet to be addressed.

Speaking of this planet, there could be a link between these two major sources of disappointment emanating from my childhood. Alternative futures are possible from these. In one, we simply don’t go into space much. Perhaps robotic probes become ever more sophisticated, take over from us, and colonise the Galaxy themselves, or maybe there’s just no impetus to do so and we all become more focussed on whatever’s going on down here. This is a relatively positive future compared to the other one, which is that this apparent lack of concern for environmental disaster simply wipes out the human race in a few years, before anyone gets the chance to go to Mars. This chimes with the apparent, though egocentric, forecast that the last human birth will occur around 2130.

The interesting thing about Space Doomsday is that it seems to have predictive power. For instance, it predicts that there will be a reason why nobody will go to Mars or the Artemis project won’t come to fruition. In fact, Artemis has indeed met with problems. The plan is for at least eight missions, the first two of which won’t involve a lunar landing. Artemis I is an unoccupied test of the spacecraft which will orbit Cynthia and return, splashing down on Earth, next year (2022). Artemis II happens the year after and involves a crew orbiting Cynthia, which would be the first time anyone has left cis lunar space since 1972. 2024 is expected to see humans back on the surface for the first time since Apollo, and a series of missions after that will involve building a lunar base for permanent habitation. This looks like the point of no return for human settlement in space, although it might just not happen or not go any further. But in order to be “scientific” about this, I need to define exactly what I mean by the statement that humans will never settle on other worlds or establish a permanent presence in space. That initial statement looks wrong for a start because of the International Space Station, which is a permanent presence. Otherwise, I’m moving the goalposts, and I might say after Artemis I, “well I never said the hardware wouldn’t work” or after Artemis II, “well I never said nobody would ever leave cis lunar space again” and so on. I need to be more precise, and base it on evidence.

My claim is based on the idea that the total number of human births is likely to be at most 150 thousand million. More than this and the chances of living now rather than later in history fall below fifty percent. In fact, therefore, it’s possible to forecast from this position that the total population of space will always be less than seventy five thousand million minus the population still on this planet. In fact if it were ever close to being that high, that would seem to herald the extinction of the human species for probability-related reasons, which suggests further that there will never be self-sufficient space colonies or that some perhaps solar-related disaster will befall life in this Solar System.

Artemis is supposed to lay the foundations for the eventual exploration of Mars. This in itself means it’s unlikely to succeed, not because that’s over-ambitious but because it means it does in fact appear to be a stepping stone to people living permanently off Earth, which either can’t happen or is likely to end in disaster, or at best peter out. Hence it can be expected that there will be major snags in the program. Now it’s difficult to tell whether I’m seeing patterns where there are none, as any major long-term complicated undertaking is likely to meet with the occasional problem. Thinking again of our hypothetical Space Doomsday person living in the ’60s, they might focus on the Apollo I fire and the Apollo XIII disaster as signs that it wasn’t going to work, that there would turn out, for example, to be insurmountable safety obstacles to strapping three guys into a seat on top of a hundred metre column of high explosive. I mean, who’d’ve thought it? But there were six successful missions as well as more successful translunar incursions (excursions?). It is probably true, speaking from my deeply uninformed position, that the risks taken on those missions were much higher than they would be today, and presumably are on the Artemis program, but maybe not. I confess to not paying much attention to Artemis because I don’t want to be disappointed again, so I don’t know much about it.

There are sound economic reasons for returning, including the presence of metals such as titanium more easily accessible than here and, if fusion ever happens, and that’s another thing which seems infinitely deferred, helium-3 in the soil, and water is now known to be available, in the form of ice in the parts of polar craters in permanent shadow, freeing a base from the necessity of a water supply from Earth. It was detected by the Clementine mission in March 1996, in Shackleton Crater.

The spacesuits for Artemis have been delayed, it was announced this August. This will prevent a 2024 landing, since they won’t be ready until April 2025 at the earliest. That puts it later than the next presidential election, and if for example Trump is re-elected, which unfortunately is still possible it seems, he could cancel the program before then. The current space suits are not intended to be used for extensive periods on the lunar surface, hence the need for new ones. One reason for the delay is budget cuts and another is the pandemic. But you could look at it, rather unscientifically, as a curse or fate. There is reason to deduce that something will always stop it happening because it’s possible that we can be confident nobody will ever go there again or to Mars at all. The details of the cause are apparently not available, but right now they seem to include Trump, the pandemic and budget cuts.

The Artemis program involves the building and transport of infrastructure and equipment separately from the crewed missions. This is a factor in its demise. If it was just about astronauts visiting without setting up a permanent base, it could well go ahead as that’s a less significant step in establishing a foothold elsewhere in the Solar System. Hence the crewed lunar orbital mission is more likely to happen, although this is also a step on the way. It would also be more likely to happen if it wasn’t supposed to be a preliminary to going to Mars. There was a plan, decades ago, for the first astronaut to arrive to start putting together a permanent lunar base, which it’s possible to predict wouldn’t happen for the same reason.

I’m not going to deny that a lot of this post is motivated by depressive thinking, although I’m not actually depressed just now. To counter that, I want to point out that depressive realism helps one perceive unpleasant truths, one of which appears to be that our descendants are trapped on this planet forever. And I’m not even saying that Earth is not a wonderful and beautiful place. It’s for this exact reason that humans should move many of their activities, and for that matter bodies, into space, off this planet, to preserve it and allow it to recover. Moreover, there was always going to be positive fallout from space travel, such as the Overview Effect, the Spaceship Earth concept, the discovery of the possibility of nuclear winter, the reminder Venus gives us of how easily climate change can get out of hand, not to mention the various technological benefits. Nonetheless, some people would see being stuck here as a positive thing, and it has positie aspects. It means, for example, that there is no escape from the effects of pollution, reduced biodiversity and anthropogenic climate change, except that maybe there is for the rich and powerful but not the poor and oppressed.

So wouldn’t it be nice if we had a lunar base, went to Mars and built space colonies for the people left here on Earth?

Why The End Might Not Be Nigh

Yesterday’s post, as well as being mistitled, was probably quite depressing, although that depends on your view of human extinction since many people don’t consider that to be a bad thing. As a kind of antidote, I’ve decided today to offer a more encouraging view of our future, assuming that you consider the continued existence of the human race as positive. I’ve covered the Doomsday Argument before, but did it in quite an idiosyncratic manner, concentrating on my own thoughts about its possible flaws. This post is more an outline and survey of the Doomsday Argument and its rebuttals.

The Doomsday Argument has its origins in the astrophysicist Richard Gott’s visit to the Berlin Wall in 1969. The Wall began to be built in 1961 and Gott visited it eight years later. After speculating about how long it would be there, he did a quick calculation, and I get the impression this was mental arithmetic, and reached the conclusion that it would be demolished some time between 2⅔ and two dozen years after that date in 1969. In fact it came down in 1991, twenty-one years later. This provoked him to publish his calculation in a scientific paper in 1993 where he applied the same calculation to the history of the human race, concluding with 95% confidence that we would cease to exist between twelve and eighteen millennia from 1993. This is of course quite a big range, but it’s notable to me that the Berlin Wall came down towards the end of that period.

The Berlin Wall version of the argument is the original and has also succeeded in predicting its demise, and is therefore worth looking at closely. A random visitor to the Berlin wall will be there at some point in its history. It’s likely that Gott visited the Wall some time between 25% and 75% of the way through its duration, because that’s half of its history, so a steady stream of visitors would put them somewhere in that interval half of the time. If they then make a prediction about when it will come down, the most confident period would be that it would last between a third and three times as long as it had been in existence, because they can believe fairly confidently that they’re between a quarter and three-quarters of the visitors in chronological order (more than 50% probability) and therefore it will last somewhere between a third as long again (if they’re at 75%) and three times as long again (if they’re at 25%).

Now apply that to human history. It might at first seem that it predicts that if anatomically modern humans came into existence around 300 000 years ago, we would continue to exist for between a hundred millennia and getting on for a million years, again with 95% confidence, which should be taken as read from now on. This doesn’t work quite the same way though. Visitors to the Berlin Wall were assumed, fairly reasonably, to have occurred at a roughly constantly frequency according to Gott’s argument, but the same doesn’t apply to the whole human population, which increases exponentially. Therefore it isn’t about where in history you are chronologically so much as the order of your birth among all the human births that will ever be. The figures I use for my version of the argument are the population of the planet in about 1970, my own birth in 1967, the figure of all human lives up until 1970 quoted at the time and a thirty-year doubling time. The population at that time was around 3000 million and the estimate at that time was 75 000 million. Given that figure of 3 000 million, 6 000 million would be the population by 2000, 12 000 million by 2030, 24 000 million by 2060 and 48 000 million by 2090. It reaches 96 000 million by 2120 at this rate of doubling, meaning that the last birth could be said to occur by that time at 50% probability assuming that everyone born in 1970 was still alive, but earlier than that otherwise because there would’ve been more human lives. We can assume, for example, that almost everyone born in 2000 would be dead by 2120, the figure only needs to go as high as 150 000 million in toto anyway, and so on. But the figures work out as between 25 000 million and 225 000 million further births after 1967 given these rather inaccurate figures, which place the earliest time before 2060 and the latest before the end of next century. You will gather from my vagueness that I can’t do calculus. Or look at it this way: if everyone who ever lived considered the question of whether they were in the first or second half of the number of human births which will ever be, almost half will be correct. (It’s possible that there is an exact “middle” birth if the total number of people who will ever live is odd rather than even.)

Most people agree that this argument is flawed, and I’ve previously mentioned my own objections to it, but there are superficial and deeper causes of the flaws. The superficial reasons for the above figures are that they’re sloppy and inaccurate. Population doubling time has been quoted at between twenty-eight and thirty-five years during the period it was widely considered a major concern, and adjusting for those moves the dates to between 2054 and 2225. It also turned out that the doubling rate fell recently and that economic development reduces the size of families, so it’s been estimated, and again this is an old figure, that the world population will stabilise at eighteen millard (thousand million) in the mid-twenty-second century, which gives us centuries to go. A rather less superficial argument is based on selecting my own birthdate, because the argument can be made for anyone who has ever had this thought, and therefore there could easily be a prediction thousands of years ago that puts us way beyond the latest 95% confidence limit today. The argument is equally valid no matter whose life you use as an example. The date changes as time passes. If someone had made the prediction about the Berlin Wall in 1990, the lower bound of their confidence interval would’ve been in 2000.

But there are other problems with the argument which are not to do with these details or even applying it to human extinction. Before I go into them, I want to make two observations. Firstly, there’s a tendency for people who do believe in its validity to dismiss other’s (go on, ask me about that apostrophe, I dare you!) arguments as indicating that they haven’t understood it properly. Secondly, although it’s widely agreed that it’s invalid, the reasons are multiple, and people who believe it’s invalid for one reason often don’t agree with the other reasons given. This complicates things.

One objection to the argument is that it assumes nothing is known about where one is in human history. It seems to make sense to flip a coin if one is asked the question “was your birth in the first or second half of the total number of human lives?” and go with that answer only if one believes the coin to be fair. If one knows it isn’t fair and will always come up heads, it’s no longer rational to choose tails. If anything relevant can be known about our place in history, it changes the odds. For instance, it could be discovered that there was a correlation between the prevalence, lethality and spread of pandemics on the one hand and the level of population on the other which would make it very likely that a population above ten billion would lead to human extinction within an average human lifespan, in which case as soon as it hit that number and stayed there for seventy years or so, our demise was guaranteed. I don’t personally like this argument because I can’t think of anything which is that reliable which is relevant to human survival. I believe that we are in fact in ignorance, partly because measures might be taken to prevent the apocalypse once its likelihood had been calculated. On the other hand, that might be optimistic given how keen everyone seemed to be, for example, on ignoring the finding that pandemics were in fact much more likely to happen in current circumstances.

There’s also a converse argument which goes like this. The more intelligent life forms which will ever exist, the more likely it is that I exist. There are various ways in which my existence, like everyone else’s, is improbable, and the combination of traits which lead to someone like me existing becomes increasingly probable the more people there will ever be. If there are going to be 200 thousand million people, the chances of someone like me existing might be ten percent – nine out of ten possible worlds with 200 thousand million people in their history don’t have me in them. But if there are going to be 200 billion in that scenario, a thousandfold greater, each world would end up having around a hundred examples of someone like me in its history somewhere.

Here’s another argument, and I may have got this wrong. The Doomsday Argument is an early example of other similar arguments. One of these is the argument that the human species will never substantially settle anywhere off Earth because if there were, for instance, fifty million habitable worlds in the Galaxy and each had a population of a million with a life expectancy of a century for a millennium, all of which are very conservative assumptions, the probability of living before that era is only 0.015%. There are other similar arguments. Therefore there is a sense in which those who are aware of this argument are early adopters. They’re like the people who bought the bug-prone version of a new gadget who were used as guinea pigs by the manufacturer, and therefore the argument they accept is likely to be less sophisticated and more flawed than its successors. We could be working towards a more successful predictor of the future than this argument, and since we’re aware that it only has a short history, we probably have the wrong one. This sounds peculiar to me, which is why I think I might have got it wrong.

We could also be early humans. It might be that the fact that we’re human-basic rather than transhuman is an argument for us not being very advanced in history. We don’t currently augment our bodies much internally, but the technology to make that possible is already in its infancy and will become more advanced. The fact that we don’t download music directly to our brains yet, unlike practically everyone who will be born more than two centuries from now, is evidence that we are unusual.

The fact that mass extinctions only seldom happen has also been used. This is again a probabilistic argument, and can be modified to refer to individual dominant biological taxa. But there seem to have been six mass extinction events in the past 540 million years, so the chances of us being in one are small. Whereas I think that’s valid, it clearly isn’t true because we are in fact in the middle of one right now, probably related to our activity. But dominant species are said only to go extinct about once in a million years, so that’s another odds-based argument for this not being a threat.

Another objection is based on the St Petersburg Paradox. Suppose you bet on a coin coming up heads, and every time the coin is flipped and doesn’t, your winnings double. The expected winning is infinite even though intuition suggests that it will in fact be small compared to how much you put in, because the probability of losing halves with every flip. The rational choice would therefore appear to be to place all your money on the game. I may not be following this argument correctly, but it seems to relate to each generation of human existence being a toss-up between being the last and not being the last, and in the same way, the expected number of human beings is infinite. To be honest this makes no sense to me and I’m not sure I’ve expressed it correctly.

Carlton Caves has offered this example as a rebuttal. Imagine you encounter someone whose fiftieth birthday is today. By the logic of the Doomsday Argument, they have a one in three chance of living to one hundred and fifty. I see this as referring to the idea of having special knowledge, because we know that nobody seems to have lived more than about ten dozen years.

A little like the early adopter argument, there is a self-referential counter-argument. The Doomsday Argument was thought of fairly recently. Including the Berlin Wall calculation, it’s currently four dozen and two years old. Therefore, it is likely to be refuted some time between sixteen and one gross and a half dozen years from now, in other words 2037 and 2171. However, if this argument for its refutation works, it means the Doomsday Argument is valid, which is a paradox. This, though, is problematic because it assumes that the argument can be disproven, which may not be so.

I haven’t found this to be a particularly satisfactory post because I’m not feeling on top of the arguments. Attempts to disprove the Doomsday Argument are very popular and the whole field is rather confusing to a non-mathematician such as myself. That said, if you look at my other post on this topic, you’ll see my own reasons for doubting it. Unfortunately though, or perhaps unfortunately, merely disproving the argument itself doesn’t prevent the possibility that we will soon be extinct. Tomorrow I plan to talk about that.