Mercury and Bepicolombo

Boy Mercury shooting through every degree

The B52s, ‘Roam’, (c) 1989 CE

Most people, if they wanted to associate music with the planet Mercury, would probably either think of Freddie Mercury or Gustav Holst’s Planet Suite. Not me of course, because I can’t think of the obvious. It seems that this song has erotic innuendo which totally whooshed over my head, but that still doesn’t exempt it from being associated with Beppicolombo today. So far as I can tell, there’s nothing particularly special about today’s encounter compared to the series of other encounters which the probe will undergo over the next few years, but it’s also true that Beppicolombo is only the third spacecraft ever sent to the planet in question. The first, Mariner 10, flew past in 1974 and erroneously reported the presence of a moon, and I think that was also the one which established that Mercury didn’t simply show one face to the Sun all the time. Certainly this is what was reported in the popular science books and articles I read at the time. It also detected a strong magnetic field, which is apart from Earth the only planet in the inner solar system with one.

MESSENGER was the next probe, whose mission took place in the first half of the 2010s. The problem is that Mercury is difficult to reach because spacecraft have to be moving relatively fast and because it’s near the Sun the gravity of the star will overwhelm that of the planet at a low altitude above the surface, since it’s also the smallest and least massive major planet. This would, incidentally, make the presence of any moons hard to maintain. But Mercury is not just a clone of Cynthia even though the two seem quite similar, and even are to some extent.

Mercury and Earth are the densest planets in this Solar System. They also both have strong magnetic fields. The surface gravity is close to that of Mars, but because it’s physically smaller and a lot hotter it has much more difficulty holding onto an atmosphere, which is extremely thin and consists of what to us would seem like a bizarre array of gases such as calcium, sodium, potassium, hydrogen, atomic oxygen, helium and molecular oxygen along with water vapour. The hydrogen and helium are captured from the solar wind by the magnetic field and I presume the water vapour is from ice in polar craters. Because it has hardly any axial tilt, there are craters near the poles, such as Chao Meng-Fu, which are in permanent darkness at their bottoms, where the ice resides. The metals are forced away from the surface by the Sun and form a tail so many millions of kilometres long along the orbit that they are something like an eighth of the way round before they become undetectable. This feature is shared with Jupiter’s moon Io, which also has a sodium tail. However, it seems a bit of an exaggeration to dignify the sparse atoms and molecules of gas hanging around near the surface as an atmosphere, since they never collide with each other like they would in an ordinary gas, but do the same kind of things as they do on Cynthia, ricocheting off the surface, bouncing up and down and so forth.

So far as I know, Beppicolombo has no colour cameras. It was also going to deposit a lander, which it didn’t do in the end because it would’ve been too expensive. Both of these decisions, if the first is true, strike me as bad PR. Colour photos of Mercury and data, and hopefully images, from the surface would surely be really impressive, and it’s worth doing those just to engage the public, but apparently not.

Just a quick infodump to get all this out of the way. Mercury is intermediate between Cynthia and Mars in size, is the densest planet in the Solar System other than Earth and has a lemon-shaped orbit, which is again the most elliptical of any solar planet known. It rotates once every fifty-seven days with a negligible axial tilt and orbits once every eighty-eight. It isn’t as hot as the solid surface of Venus during the day, at around 400°C, but is the coldest planet in the Solar System at night at -200°C. It has a fairly heavily cratered surface and it can be difficult to distinguish whether a small portion of the surface is Cynthia or it. It was instrumental in corroborating the General Theory of Relativity which predicted that its orbit shifted its angle by 1.2 arcseconds each time, but before Einstein it was thought that there was an even closer planet to the Sun, named Vulcan, which explained this orbital perturbation. There are Mercury-crossing asteroids, including the relatively famous Icarus. Astrologically, Mercury often goes retrograde, meaning that it appears to reverse its direction in the sky, because it’s orbiting inside our orbit and will inevitably dip towards or fall away from the Sun from our perspective. There are even some professional astronomers who have never seen it because it stays so close to the Sun and is smaller and further away than Venus along with reflecting less light. It can, however, be observed in broad daylight with the right telescope if you know where you’re looking, though this would be risky to the eyesight. I think that’s it as far as what I assume “everybody” knows about the planet.

The reason it used to be thought that Mercury always faced the Sun was that it rotates three times for each two of its years and its synodic period (the time taken between successive closest approaches to us) is almost exactly two Mercurian days.

The above map was made by the Greek astronomer Antoniadi in the mid-twentieth century. Although like many such maps it’s pretty inaccurate, it does at least record the presence of Caloris Basin in the southeast as Solitudo Hermæ Trismegisti. Some of the features on Mercury have quite odd names. For instance, there’s a series of cliffs called Pourquoi Pas Rupes and the twentieth longitudinal parallel is called Hun Kal after the Mayan for twenty. Caloris Basin is somewhat similar to the Mare Orientale on Cynthia or Asgard and Valhalla on Callisto, being a vast impact crater, but Mercury doesn’t really have maria like Cynthia.

There should as far as possible be a link between people’s everyday experience and scientific phenomena. This is difficult with Mercury because it’s almost invisible to most people. If you believe in Western astrology, you’re probably aware of Mercury retrograde at least, and Mercury does transit the Sun more often than Venus from where we are. This is where Mercury can be seen to cross the Sun’s disc, meaning that it might be projectable using a telescope. They happen in May or November, and occur much more often than Venus at about once every seven years on average. Sometimes Mercury only passes over the edge of the Sun. The planet is both smaller and further away than Venus when it transits. Venus I have observed doing it, and it gave me a major impression of the sheer size of the Solar System that even the nearest planet, practically Earth-sized, looked that tiny when it was closest to us. Mercury is kind of more like Cynthia orbiting alone. One significant issue with Mercury’s transit compared to that of Venus is whether the black drop effect would be visible. When Venus, with her thick atmosphere, crosses the limb of the Sun, there’s a kind of fuzzy line joining the shadow to the rest of the sky, and this is often attributed to that atmosphere, but in fact Mercury, with no significant atmosphere, exhibits the same effect even when observed from space, thereby eliminating the factor of our own air. Hence it doesn’t seem to be due to a planet having an atmosphere. This is also significant for detecting planets orbiting other stars and whether they have atmospheres. Incidentally, it’s also possible to observe changes in light level caused by transits by observing moonlight, although of course it’s very subtle. There will be a simultaneous transit of the two planets in the year 69163, and before that Mercury will transit the Sun during a partial solar eclipse in 6757.

Meteorites very occasionally reach us from Mercury. One was found in the northwestern Sahara containing chromium diopside crystals, which are green, but may not be Mercurian given known facts about the composition of the surface. Although this is not the meteorite, this is what chromium diopside looks like:

By Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10151574

It reminds me of lunar olivine, and like it, is a semi-precious stone. This is an actual chunk of the meteorite itself:

It’s a magnesium calcium silicate, and can become asbestos. There are faults on the surface of the planet, meaning that like Earth and no other planet in the system, it’s tectonically active, which in turn means that if this mineral is indeed from Mercury, it could have been transformed to asbestos on its surface. However, this may not make it intrinsically more hazardous to potential astronauts (and there will be none) than moondust, which is also potentially quite harmful, being jagged and unoxidised until it comes in contact with a terrestrial organism and this rock may not be from Mercury anyway. I would imagine that the extremes of temperature there have considerably weathered the terrain.

The interior is largely taken up by a core rich in iron and the magnetic field may be caused by the same dynamo effect as here, since the Sun’s tidal forces are much stronger there than here, or it may be residual from formation or the result of being directly magnetised by the solar magnetic field. I don’t know if this is true, but I would expect the crust to be higher in heavy elements than here, and for them to be more exposed due to the lack of weather and oxygen, although I would also suppose that their distribution would tend not to be in the form of specific ores due to the lack of liquid water. There are no Van Allen belts because the magnetic field is too weak in comparison with the solar wind. Heat could also be expected to weaken the magnetosphere.

Hun Kal is at 20° because the prime meridian had been decided approximately as the subsolar point at the first perihelion in 1950, and when Mariner 10 got there that location was on the night side. At the time, presumably it had been thought that that point was permanently at noon with the Sun directly overhead.

Caloris Basin is so-called because it’s directly under the Sun at closest approach, and is therefore the hottest area on Mercury. It has about the same area as Mexico, which by scale is similar to the size of Antarctica compared to Earth, and is surrounded by a ring of fairly small mountains. It’s many times the size of Mare Orientale. Around the exact opposite point is an area of so-called “weird terrain”, which is hilly and thought to result from the conduction of seismic vibrations around the planet from the impact into a focal point there. Just as on Earth the type and deflection of quake waves is like an X-ray of the planet, revealing where the solid core is, so does the terrain on the opposite side from Caloris Basin reveal Mercury’s internal structure, since much of it was formed by the shock waves. Superimposed on that are the ejecta splashed up by the impact, which also travelled all round the planet.

Unique to Mercury are the “blue hollows”. Although these are somewhat mysterious they seem to be linked to the evaporation of solid material and resemble craters to a limited extent except for showing none of the usual signs other than being dents in the surface. There’s no rim, central peak or ejecta. They are of course blue, light blue in fact.

The planet seems to have shrunk by seven kilometres since its formation, which has led to ridges appearing on the surface. I wonder if this is to do with substances such as potassium and sodium with low sublimation points being lost to space during the day, which I also think might explain the hollows.

There’s something about craters, though, which I find somehow tedious and deadening. I could go on and on about the craters there at this point but it would probably bore you stiff. And the question there is why? Mountains are not boring after all, are they? This links into my post about whether Cynthia is boring. I suppose the thing about mountains is that you can imagine climbing or exploring them. But a crater such as Arizona Meteor Crater seems very interesting to me, as does the Chicxulub Impact which wiped out the non-avian dinosaurs. Maybe it’s just me. So that concludes this bit of the post.

Only three spacecraft have ever been sent to Mercury. The first of these was in 1974, Mariner 10. For over three decades this was the only source of images of the planet and only just over a third of the surface had been photographed. By a stroke of luck, Caloris Basin was at the terminator at the time, meaning that the weird terrain was also, but this also meant that the full extent of the basin was unknown. It also flew by Venus. Mariner 10 was the first spacecraft to use the gravity of another planet to aid its trajectory and also the first to send back live TV pictures of another planet, although I would expect “live” to be a fairly misleading description of something whose bandwidth was 117.6 kilobaud. This is actually pretty impressive when you consider modems of the turn of the millennium were only half that fast. Because it used the gravity of Venus, it didn’t need to carry much fuel, as that was only needed to make fine course corrections, which it did by attitude adjustment nozzles firing nitrogen along the edges of the two solar panels. It used a sunshade to protect its instruments against the intense radiation at the orbit of Mercury. Like many other space probes it was designed to orient itself using the Sun and the bright star Canopus. It carried a TV camera connected to a Cassegrain telescope, which gave it a long focal length in a short tube, able to image things in ultraviolet as well as visible light. The resolution was a total of 640 000 pixels, which is 800×800 if that’s the aspect ratio decided, each pixel being represented by a byte. There was also a radiometer able to measure temperatures to within 0.5°C, a plasma detector which discovered Mercury’s magnetic field, a magnetometer, a second telescope to detect charged particles which also detected the magnetic field and an airglow spectrometer which was able to detect the glow of sodium in the atmosphere and beyond. This is actually bright enough to be seen by the human eye, so looking into the sky on Mercury an astronaut would perceive a faint orange tinge. Another instrument was able to detect gases by absorption of light.

When I look at something like that, it always makes me think that technology even that long ago was a lot more advanced than we give it credit for. Although it obviously wasn’t using internet protocols, this probe was able to transmit wireless data over millions of kilometres at twice the rate of a dial-up modem two dozen years later, and 800×800 resolution in eight-bit colour, which is what this and many other spacecraft had in conjunction with Mission Control, wasn’t achieved in affordable PCs until the late 1990s either. On the other hand, the processing power of these machines was very limited. Although I can’t track down the details, Mariner 10 cannot possibly have been using a microprocessor to do its stuff and even the Mars rovers only used CPUs which went out of date in about 1980. This isn’t so much a criticism of them as the hardware which exists now. If you can build a spacecraft which goes to Mercury and does all that stuff without even using a microchip, and if later on very modest processors indeed can be used to achieve even more, why are we now using so much more advanced computers to do much less impressive stuff?

We had to wait until the next century for the next probe, MESSENGER. This is named after the messenger of the gods, Mercury, but it actually purports to stand for “MErcury Surface, Space ENvironment, GEochemistry, and Ranging”, clearly a backronym. MESSENGER managed to image the entire globe, as it was designed to go into orbit around it. It detected the first clear images of the blue hollows, which Mariner 10 had only managed to get rather blurry pics of. It imaged the whole of Caloris Basin, measured the concentration of calcium over the planet anddiscovered that the magnetosphere was at twenty degrees to the axis of rotation. It also imaged a “family portrait” of the whole Solar System and was eventually crashed into the planet. It described one of the more recent and to me baffling trajectories which seem to involve a large number of orbits around the Sun while the spacecraft gradually approaches its destination, therefore taking several years to reach it. If you think about it, no destination within our orbit ought to take more than half a year. I’m sure there’s an answer.

Bepicolombo is of course the current mission. It’s joint European-Japanese and I’d expect it to be a lot more sophisticated again, although I’m not sure what that would mean. Like MESSENGER, and presumably all contemporary probes, it’s doing the same kind of weird orbit which takes a very long time to get anywhere. I really want to know what that’s about. It comprises a photographic orbiter and a magnetosphere investigating satellite – two different satellites and is named after the scientist who came up with the slingshot idea for Mariner 10. Since its name is in the title, I’d better go on about it.

It’s flown by Venus twice, the second time on 10th August this year (2021) and has just flown past Mercury for the first time, only seven and a half weeks after Venus. I think this may be the fastest journey between planets ever. It will fly by the planet a further five times, then go into orbit round it on 5th December 2025. It has an ion drive, using xenon. It’s about time really – the concept behind these, which is to ionise atoms and accelerate them out of the engine using linear induction and can theoretically accelerate up to over 160 000 kph, is decades old and even though it has one I have my doubts about whether it’s really using it in earnest or it’s just there to be fancy. It isn’t being used as the main propulsion system and will only be used with a very low thrust, and there are also chemical rockets. One of the instruments was built in Leicester, which makes me happy. It isn’t the first time either.

Mercury is seen as breaking a pattern because for the other terrestrial planets there is a relationship between their density and their size, such that the smaller a planet is, the lighter the materials it’s made from are. This applies to Cynthia as well. However, Mercury is an exception. It’s also particularly close to its (and our) sun and this is a possible clue as to what happened in other solar systems, which also have very close planets. There’s a hypothesis that Mercury was previously a gas giant but has lost all its atmosphere because it fell so close to the Sun, but I think this idea is deprecated now. It also has an unusual orbit, which is also strongly influenced by the other planets in the Solar System. For all these reasons, the European Space Agency and the Japan Aerospace Exploration Agency are quite interested in it. It’s also searching for asteroids inside Earth’s orbit. The bandwidth is slower than Mariner 10’s was, I presume because data compression is better nowadays.

The Mercury Surface Element, which was cancelled, would’ve been a 44 kg disc ninety centimetres across to land 85° from the equator near the terminator, battery-powered due to 40% of the landscape there being likely to be in shadow and it would’ve had a camera. I just think it’s really sad they didn’t do this.

Right: that’s it. This is unfortunately later than I’d hoped as I missed the actual first rendezvous, but it is what it is.

Green Lights

Photo by Pixabay on Pexels.com

Zubanelchemale, as I call it, may be a quite remarkable star. Incidentally, the name, which is Arabic, can be spelt in various ways and the way I spell it might be quite old-fashioned. Zubeneschamali is another spelling. It means “the northern claw”, from الزُّبَانَى الشَمَالِي , and an accompanying star from our perspective is Zubenelgenubi, “the southern claw”. It might be thought from the name that these stars are in Scorpio or Cancer, and they are in fact next to Scorpio, but it appears that over the centuries what used to be thought of as the scorpion’s claws are now considered a pair of scales, since they are now considered part of Libra. Zubenelgenubi is actually a double star, designated α₁ and α₂, and this is significant because of the remarkable thing about β Libræ, Zubanelchemale, which is that some observers say it’s green. To my naked eye plus glasses, it does actually look slightly green.

Although other stars are reported as being green, they’re usually binary or multiple systems, such as Rasalgethi and ζ Piscium, both of which are multiple. The latter is in fact quintuple. The reason for their apparent colours is probably the contrast with the colour of their companions. The peculiar thing about Zubanelchemale is that it is an unaccompanied star with which there is no contrasting companion to make it look green. In fact it may have a companion but it can’t be seen from here if it has. It isn’t always seen as that colour and there seems to be no explanation for it. It’s a B-type star, making it hotter than the white A-types, but this should make it blue-white if anything rather than green. Because there are no green stars, so it’s said.

This sounds like a really sweeping statement. However, without immediately going into the astrophysics of the situation, it’s relatively easy for astronomers to observe millions of stars in this galaxy and many in other galaxies, and whereas we are somewhat stuck to stars in our own galactic neighbourhood for here, the same doesn’t apply to other galaxies, which can often be seen more or less in their entirety. It isn’t like looking for planets or megastructures. Every star has a window onto the Universe through which it can be seen unless there’s something obscuring the view. Clearly distance leads to stars being too faint to see, but it seems a fair assumption that the stars we can see in our own galaxy along with the ones visible in those nearby are a representative sample of the stars in the Universe, and with the possible, but likely illusory, exception of Zubanelchemale, none of them are green.

I would, though, add one caveat to this which applies to extremely distant stars. Space is expanding, and more distant objects are receding from each other faster than relatively nearby ones. This causes the Doppler Effect to influence the colour of the light such objects emit, meaning that presumably a very distant blue supergiant might look green. However, it would also be too far away to see as an individual star, and from a low velocity relative to it, it wouldn’t look green.

As well as observation, basic astrophysics can be used to demonstrate why there are no green stars. As an object heats up, it emits infrared radiation at shorter and shorter frequencies, until eventually it’s hot enough to glow visibly red. It then becomes orange, yellow, white and blue-white with increasing temperature, as the wavelengths at which it radiates enter the visible spectrum. But these are along a band. The red glow is not isolated but accompanied by infrared light which we can’t see, and the colours of stars, and most hot objects in fact, radiate across a range of frequencies rather than pure colours like a laser or an LED would, and consequently they are never green. There is a point at which the brightest colour is green, but it’s swamped by the other colours being radiated. There are therefore no green stars.

That’s the standard explanation, and it makes a lot of sense, but there’s something it seems to have failed to take into consideration: there are in fact luminous green objects in space, along with purple ones, which would also be impossible for an object glowing simply beause of heat to do. A fairly well-known example is Hannys Voorwerp:

“Voorwerp” is just the Dutch for “object”. This was found as part of the Galaxy Zoo project, which presents images of galaxies to the general public for them to identify and classify. Hanny is Hanny van Arkel, a schoolteacher. The galaxy at the top of the picture is referred to as IC 2497, and is 650 million light years away in the constellation Leo Minor. The Voorwerp is a burnt out quasar which would have been visible from here early in the last Ice Age, and is around sixty thousand light years from the galaxy in question. A quasar is a relatively small object which gives out as much radiation as a thousand galaxies. They used to be thought to be inside our own galaxy because they’re so unfeasibly bright that they surely couldn’t be gigaparsecs away, which many of them are, but they nonetheless are. This confusion turns up in the Star Trek TOS episode ‘The Galileo Seven’, where a quasar is depicted in the Alpha Quadrant. They consist of supermassive black holes surrounded by gaseous discs constantly falling into them and generating light through friction and extreme gravitational pull just outside the event horizon. This object is a trail of gas pulled out from a galaxy IC 2497 was passing and then ionised by a quasar at the centre of the galaxy through the radiation it was emitting. Although it’s gone out, the electromagnetic radiation is still in transit to the object, causing it to glow green. This is known as a quasar ionisation echo. Normally this would be hidden by the glare of the quasar. Around one and a half dozen such objects have since been found in the Galaxy Zoo data. There’s a new class of galaxies based on them called “pea galaxies” because of their colour, and the reason they’re green is that they contain doubly ionised oxygen, which emits primarily cyan light.

This emission of green light is, though, known as a “forbidden mechanism”, because in normal circumstances it can’t happen. It can, however, happen in places such as Hannys Voorwerp because the individual atoms and molecules of the gases are far apart enough that they never collide, as they are in the upper atmosphere of Earth and the lunar atmosphere. This means that when atoms are energised, they will release that energy in unusual ways, such as the greenish light emitted by doubly ionised oxygen. Similar or the same phenomena can be observed in nebulæ and aurora polaris. Oxygen is the third most common element in the Universe taken as a whole. It used to be thought that the light emitted by these mechanisms was an element referred to as “nebulium”, rather similar to the discovery of helium on the Sun before it was discovered here, but it turned out to be oxygen in an unfamiliar state.

Hence, although there are no green stars, there are plenty of luminous green objects in space. There are also green planets, or at least greenish ones, such as Uranus:

Although Uranus is hardly viridian, this comparison to Neptune to his right clearly shows the green tinge. Uranus is that colour due to methane in the atmosphere, and clearly isn’t very green.

However, I do suspect there would be a fairly straightforward way for a star to become green. There doesn’t seem to be any reason why a star wouldn’t be surrounded by a sparse cloud of gas relatively high in oxygen which it could then excite with its radiation, causing it to glow green, although the problem there may be that a star bright enough to do that would drown out the green tinge. Alternatively, maybe a so-called “brown dwarf” could be green due to having an atmosphere of this nature filtering out the red and blue light. It really does not seem to be such an unlikely set of circumstances that not one single star humans can observe in the entire Universe looks green.

Although for some reason no process superimposed on the unimpeded light from any star seems to have turned it green, it would be relatively simple for an advanced civilisation to erect some kind of filter or create some kind of process which would do so. This hasn’t happened either, and these two facts taken together may have some significance. Firstly, the absence of an apparently fairly straightforward process which would make a star green indicates that even in such a large Universe, not all things which are possible actually happen. That could apply to life, complex life or the appearance of intelligence as well. Maybe that’s only happened once, and this too is suggested by the absence of green stars. If intelligent entities wanted to advertise their presence in the Universe, they could do so by making a star green. The absence of such stars might mean there is no other intelligent life in the Cosmos. Or, it could mean that it’s dangerous, or perceived as dangerous, to give potentially hostile aliens a “go” signal, as it were, or that all successful spacefaring civilisations have a sense of environmental responsibility to leave stars as they found them, or that they wish to hide their presence from more primitive civilisations due to something like the Prime Directive.

The other notable non-occurrence of green is among mammals, but that’s another story.

Every Side Up

A couple of posts ago I mentioned what I understand to be the anomalous nature of not having a widely-accepted proper name for that thing in the sky which lights up the night, looks about the same size as the Sun and is often shown as a crescent in children’s books: the so-called “Moon”. Well, it turns out this is just the start, and relates to a number of other ruminations I’ve had over the years. Although we intellectually accept that we are on a tiny blue speck orbiting the proverbially unregarded yellow star in the Perseus-Carina-Cygnus Arm of the Milky Way, which is in turn just one of countless other galaxies like grains of sand, as Brian Aldiss once put it, emotionally we tend still to operate day to day by the “sandwich” model of the Universe, where we live on a flat surface with the ground underneath us, the sea off somewhere across the way and the sky above us, with the Sun and Cynthia rising and setting above us. But is it psychologically healthy to do this? Is it a sign of having well-adjusted brains? Or, should I say, being well-adjusted brains, if we are indeed our brains.

I’ll start with Cynthia. As I mentioned the other day, I chose to call her Cynthia because that is in fact the name of one of the Greek goddesses associated with the big round hunk of rock some astronauts went to to prove a point about capitalism in a rather heavily government-assisted program half a century ago. Other Western options include Diana, Artemis and Selene, and there are wider possibilities which it might be only fair to include considering the heavy Greco-Roman bias for the names of the larger planets, moons and asteroids. Other sky lores are available. Such deities include Ge, Coyolxauhqui, Meztli, Tecciztecatl, Aucimalgen, Mama Killa, Qango, Tsuki Yomi, I mean I could go on, there are lots of course. The Latin word “luna” and its descendants, found in Romance languages and for some reason apparently Russian as well, is itself a euphemism for the earlier “mensis”, which became too strongly associated with menstruation and presumably made it sound to them that there was a “period” in the sky, which considering the taboos many cultures have around it led them just to call it “the light”, “lumina”, which then became “luna”. The Etruscan goddess is Tiur, with other names, and it seems to me that they could just have called Cynthia after that, but they didn’t. There are also kennings, which I’ve considered using directly or as an inspiration, but old Germanic literature doesn’t seem to have much occasion for mentioning the big light in the night sky for some reason. The options there seem to be “moon-wheel”, which is obviously a bit unsuitable but is a nice idea, conjuring up a rotating half-light, half-dark sphere viewed from its equator, “year-counter”, “waxer” and “waner”. I suppose I could’ve called it “sky-rabbit”, but the word “sky” is problematic too. In order to avoid the rather jarring and eccentric “Cynthia”, I do try to circumlocute references to her.

A couple of you have said it all seems a bit unnecessary, and I have sympathy with that idea. That said, calling our moon something other than “Moon” asserts her individuality. Just on the question of gender, although moon goddesses are more common than moon gods, the Old English word “mona” is actually masculine and “sunne” feminine. Once again, sun gods are more common than sun goddesses, such as Apollo, Helios, Ra and Sol Invictus. It’s not unusual for Germanic folk to get things the “wrong” way round, such as using nights instead of days to count time (“fortnight”), winters instead of summers on a longer timescale and considering the tail rather than the head as the “start” of an animal (“redstart”).

There is a secondary point regarding Cynthia: she may not count as a real moon, in spite of the fact that the word “moon” is now out there being used for ones which are. Isaac Asimov came up with the concept of the gravitational “tug of war”: the ratio of gravitational pull on a satellite between its planet and the Sun. He looked at the thirty-two known satellites in the Solar System at the time and found that of all of them, only Cynthia was pulled more by the Sun than Earth. He also found that the most distant moon of Jupiter know at the time, Sinope, was only slightly more attracted by Jupiter than the Sun. The Sun attracts Cynthia, however, more than twice as strongly as Earth does. Looking at the orbits of the planetary moons as they move around with their planets, you get a kind of “spirograph” pattern with them looping the loop. Cynthia alone doesn’t do this but is always concave to the Sun. It’s more like she’s just drifting along as our companion. Among the official planets, but not Pluto, Cynthia is also much larger relative to the size of her primary than any other body considered to be a moon. Hence the “Moon” is arguably not a moon at all but a companion planet. This, I admit, is a little like the botanical “nut” and “berry” situation, where bananas are officially berries but blackberries aren’t, and peanuts aren’t nuts but nutmegs are, but consider these sentences and which one sounds less peculiar: “The Moon is not a moon”, or “Cynthia is not a moon”. I would say the first sounds much sillier than the second. In fact I think we’d all agree that Cynthia is no moon, but we’d probably be thinking about someone we know called Cynthia who is not a ginormous ball of rock in space, which would be entirely sensible of us. For me, then, the word “moon” has a murky history where it was used to refer to said massive craggy sphere but that’s all in the past now apart from the few hundred million speakers of English who haven’t gotten with the program yet.

Then there’s the question of the definite article. We say “THE Earth”, “THE Sun” and “THE Moon” (well I don’t, but most people do), as if to pick them out and make them special. Now I do say “the Sun”. “The” is used a bit oddly in English compared to the use of definiteness in other languages which have that distinction. There are, for example, languages where omitting a definite article makes a noun indefinite, which doesn’t happen with us, and it often has other rôles common to many other languages which are absent in English where it tends to be more widely used, with proper nouns for example. “Earth” and “Sun” in these usages are indeed proper nouns, which don’t take the definite article in English. However, both words have other meanings: “earth” means “soil” for example, and “sun” refers to any star with planets. It’s fairly common for “Sol”, the Latin for “Sun”, to be used as a name for the Sun in the same way as Sirius A or Betelgeuse might be used as names for those stars, and again this has a Western bias which in fact is unusual for a star name, many of which are Arabic. The Arabic word for “The Sun” is “Al-Shams”, ignoring certain grammatical considerations. There are also Bayer designations to be taken into consideration, which are Greek letters followed by the genitive of the constellation the star is seen in from Earth. Clearly this can’t apply to the Sun here because it (“he”?) moves through the Zodiac once a year, but from α Centauri for example, the Sun is a bright star in the constellation of Cassiopeia and from τ Ceti, twelve light years away, it’s a rather fainter star in a constellation made up by Carl Sagan called the Six-Leggèd Unicorn (Monoceros Sextupedalis), at the base of whose tail we are situated. The constellation is unusually large compared to the ones in our sky.

Speaking of sky, this is also a bit of a planet-bound concept. It’s the view we have of the atmosphere and the rest of the Universe from our vantage point which is not blocked by the body we’re situated on. Space is not “up there” but all around us, and we are also in space. This is news to nobody of course, but it isn’t how we think of things in general. Wherever one happens to be within the atmosphere, the sky is above and Earth below. In order to be “in space” conceptually, we probably need Earth to occupy less than an eighth of our field of vision. The actual situation is complicated mathematically because it’s technically impossible to see an entire hemisphere regardless of one’s distance from a sphere, although one gets so close to being able to do so that this is rather fussy. The sky often refers to something which is almost an optical illusion where the rest of the Universe is obscured by the gas and clouds in the atmosphere, so it does exist during the day, but a clear sky at night is just a good view of part of our environment, to the naked eye up to about two million light years away but which we perceive as a black dome with pinpricks of light in it, plus Cynthia. Once again, we all know this. I’m aware I’m not saying anything new here, but although I reject the Saphir-Whorf hypothesis that our language completely determines our world, I do think it’s significant.

An illustration of how new this isn’t can be found in the work of the mid-twentieth century architect Buckminster Fuller. It was he who popularised the idea of “Spaceship Earth”, emphasising our interdependence on each other in a hostile void and the need to ensure that the systems which keep us safe here are maintained. Ironically, he was also a frequent flier. He used to speak of “Universe” as a proper noun without articles, which is of course similar to how I suggested dropping them for “The Earth”. The rationale behind this was “the aggregate of all humanity’s consciously apprehended and communicated (to self or others) Experiences”, a definition I feel is rather anthropocentric but which also acknowledges the fact that what we perceive just is the world to us. This brings to mind the error apparent in John Norman’s thought of confusing his own preferences with the wider idea of essential human nature, and as Norman has inadvertantly illustrated, the folly present in that confusion, which is something whereof we should all be aware. Buckminster Fuller’s frequent flying, environmentally unsound though it may have been, did also give him the insight of authentically experiencing Earth as a globe, and this influenced his use of the English language. For instance, he would talk of “world-around” rather than “worldwide”, in a move practically the opposite of the flat earthers in the recent satirical novel ‘The End Of The World Is Flat’, and it’s notable that this links to what might be seen as a more rational and just approach to humanity than “worldwide”, which suggests we’re not living on a globe. I personally find the specific phrase clumsy and would prefer to substitute “global” as more succinct and less intrusive, which makes it more likely to be accepted. He also substituted “in” and “out” for “down” and “up” respectively and used to talk about “going outstairs” instead of “upstairs”, emphasising the fact that we’re all clinging to the surface of a ball in space. That sounds precarious, but it’s worth considering our situation as precarious in a different way and therefore serves us as a reminder of that.

He also replaced “sunrise” and “sunset” with “sunsight” and “sunclipse”. The second sounds a bit artificial to me but the first is fairly okay, although still quite attention-grabbing in a way which doesn’t help unobstrusive adoption. Then again, calling Cynthia that doesn’t exactly seem unobtrusive either, so maybe I’m being hypocritical. In my unfinished novel ‘Unspeakable’, I refer to the limb of this planet concealing and revealing the Sun rather than sunset and sunrise, or something like that (I can’t remember the exact wording). Another approach is to refer to the terminator, which in astronomical terms is the locus of points on a body tangent to the Sun, enabling the synonymity of “my location crossed the terminator”, which can refer to either sunrise or sunset and emphasises movement and rotation rather than the illusory stasis we imagine we’re in.

Then there’s this:

The Australasian branch of the Society For Putting Things On Top Of Other Things is in a sense actually doing the opposite to what the Staffordshire branch didn’t do. Do they really deserve the praise of the chair? Although the angle isn’t perfect, what the Australasian branch have in fact done is put twenty-two things underneath other things. Alternatively, a less Eurocentric view would allow for the Staffordshire branch not to have done anything wrong and to have at least not undone the work of the Society. Then again, it appears that the Society as a whole does in fact grasp that Earth is round and gravity pulls towards the centre, and as a side issue the Society For Putting Things On Top Of Other Things does succeed in doing something very similar by putting things underneath other things, because the end result is that something is still on top of something else. What it’s actually doing, from a non-gravity dominated perspective, is putting things next to other things. If there is also a Society For Putting Things Underneath Other Things, they are not their enemies and in fact there could be a federation of societies for putting things next to each other to which they would both be entitled to belong. Their real enemies are such groups as the Society For Taking Things Off Other Things. Incidentally, a less well-known society is the Society For Putting The Letters “SPR” At The Spreginnings Of Sprertain Words, but their rôle is rather different, though also interestingly similar.

However, it is in fact important to know what’s on top of things on this planet, dominated as we are by gravity, and it would be dangerous to remove this distinction from language. It’s scant comfort to a crew trapped in a sub at the bottom of the ocean that they’re in another sense at the top of the ocean with a force pulling the water towards them, and their rescuers would be confused if they were to have the situation described to them as “the intermarine is situated next to a major phase change in matter” without specifying that that phase change was liquid to solid and therefore more likely to be at the bottom of the ocean than the surface. There’s a time and a place for these things and they aren’t always appropriate. Nonetheless, our intuitions can be misled by using language based on outmoded concepts such as these, which are particularly outdated for two reasons: they are based on a flat Earth, which was superceded in Ancient Greek times, and also a geocentric view, which began to be replaced five centuries ago.

Another aspect of this is the realisation that spacetime is a single set of relationships rather than two separate things, meaning that, for example, a unit such as a light year is a measure of spacetime and not just distance as we’d usually understand it. Relative to us, light travels in a diagonal line, and its spacetime coördinates are four-dimensional, as is everything else. Hence when we consider Earth’s rotation and her orbit about the Sun, among other forms of motion, we are in a sense referring to angular motion when we use ideas about the passage of time to some extent. At midday any location on the Equator is 90°from the terminator in all directions across the surface of the globe. Although the situation is harder to describe in different places on Earth, the fact is that time of day can still be considered to be an angular measurement in our planet’s rotation. Likewise with the year, which is close to amounting to a degree’s movement per day although it’s slightly under on average and Earth also accelerates and decelerates somewhat according to time of year, being fastest near the northern summer solstice and slowest half a year later. Of course, the whole Solar System is orbiting the black hole at the centre of the Milky Way once every 225 million Earth years or so, meaning that Earth is describing a shape locally similar to a helix but in fact part of a larger approximate helix. Moreover, the Great Attractor in the direction of Virgo is pulling the Local Group of galaxies, including our own, towards it, and space itself is expanding, although that has little bearing on most of the rest. It might mean that whatever is pulling us all towards Virgo will be more distant in the sense that it will take longer than might be expected at a constant velocity because it will in a sense be in a different place.

There’s also the question of the light cone. This is in fact a sphere of influence rather than a cone, concerning the distance between points which can influence each other in a given time. Say a star explodes. After ten years, the explosion will be visible ten light years away, after a hundred, it will be visible a hundred light years away and so on. Its sphere of influence spreads out at a maximum speed equivalent to light’s. Therefore it may not make much sense to consider that anything really occurs simultaneously. If something is happening now ten light years away, it’s impossible for it to make any difference here for at least a decade. For this reason, again in ‘Unspeakable’, I used a calendar system based on the Crab Nebula pulsar about five thousand light years away, with the date beginning at the instant light reached the location in question, and with units of time based on the period of the pulsar, which is very gradually slowing. Hence because the Crab Nebula was first observed on Earth in the year 1054 CE, I chose that as the year zero for us, but for Antares that calendar would begin in about 1600 CE because it’s more than five hundred light years further away from that supernova. I was trying to illustrate the ties between time, space and causality by doing this, and in fact I’m quite keen on the idea that such a calendar would work for real. In practical terms it would make very little difference on this planet because it only takes light forty-two milliseconds to cross Earth’s equatorial diameter, but using the period of the pulsar as a unit of time takes it away from Earth- or solar-based units. The current period of the Crab Nebula pulsar is approximately 33.1 milliseconds, a figure insufficiently accurate to base a calendar or clock system on. SN1054 took place on 4th July 1054, which was Julian Date 2106209. Today’s date as I write this is 18th September 2021, or Julian Date 2459476.08125 (it’s 1:57 pm). The tropical year 2000 was 365.24219 days long, which is 31 556 925.22 seconds. However, it makes more sense to treat this in terms of days rather than years, which makes it 353 267 days since we saw SN1054, or 30 523 046 400 seconds, bearing in mind that the exact time of night was not known. In terms of current pulsations, which will have slowed a bit by now, that makes 922 146 416 918.429 with spurious accuracy. I have to say that using base ten to express this is not ideal, and in the case of timekeeping, we are in fact used to not using that radix anyway, as is the case with angles.

A little while ago, I wrote a post considering what Latin would be like today if Rome hadn’t fallen, bearing in mind that Latin does survive as an everyday widely-spoken language in the form of languages such as French, Romanian and Catalan. In particular, something to consider here is that scientific nomenclature would probably have arisen directly from spoken language rather than having been mainly based on Latin and Greek but without native sensibilities or a firm grasp of the language itself. Hence elements could be referred to by their atomic numbers directly, which does happen today for placeholder names to some extent, as in “ununpentium”, now known as moscovium but clearly dependent on Western Arabic numerals used in decimal and employing place value. Similarly, when Uranus, Neptune and Pluto were discovered, they were given classical names in accordance with the spirit of the names of the other planets but perhaps not in direct accordance with how “modern” Romans would have named them. Hence it’s easy to imagine a language which is somewhat like Italian and Romanian but uses different, though still classically-based, technical terms. It’s also possible to decouple these terms from the vagaries of history and the techology available when they were first discovered, leaving us with a more logical scientific vocabulary. There are in reality tendencies to address this in human anatomy, where we no longer speak of Fallopian tubes and the Achilles tendon but uterine tubes and the calcaneal ligament. It would be interesting to address this across the board and see how it changed our way of thinking, but it’s also difficult to anchor it accurately because new discoveries are being made all the time which could turn this upside down. Whatever we came up with would become a kludge in the long term and need a rethink.

To conclude, we are imprisoned on this planet and in our present state by the way we use language. It’s very uncomfortable and interferes with communication and clarity to mess about with it too much, but it’s also profitable at changing how we perceive the world, and might enable us to come up with new outlooks and solutions in the long run. Hence although all this is a game, it’s quite a serious game and it’s worth playing if we achieve some kind of conceptual breakthrough as a result.

Super-Habitability

Photo by Pixabay on Pexels.com

Yesterday I mentioned in passing the concept of super-habitability. I’m happy to say that ‘Handbook For Space Pioneers‘ introduced this concept, although it may have passed unnoticed. In this book, which describes the eight habitable planets available for human settlement in 2376 CETC (Common Era Terrestrial Calendar), the final planet, Athena, 77.6 light years from Earth in the HR 7345 system, is actually more habitable than Earth. The book rates the different planets according to their habitability using the ‘Von Roenstadt Habitability Factor’, with the least habitable, Mammon, having one of 0.79. This is a largely desert planet with a thin atmosphere which was largely settled due to its rare earth metals, which are useful in matter-antimatter reactors. Earth has a factor of 1.0, and Athena one of 1.09. This is because Athena is not only similar to Earth but lacks a polar continent, meaning that more of its land is hospitable to human settlement. Therefore it was this book that came up with the idea. Ahead of its time.

The search for exoplanets tends to be biassed in various ways as I’ve previously mentioned. One of these is that the ideal planet to be detected would be a super-Jupiter orbiting very close to its rather dim star, orbiting parallel to the line of sight. This is indeed a very common type of planet to be found but not at all Earth-like. It also gets a bit depressing after a while because the planets concerned may make their systems unsuitable for more hospitable planets further out. This situation has been somewhat remedied more recently and many somewhat Earth-like planets have now been found.

However, it’s been suggested that we may be setting the bar too low here. I mentioned the Copernican principle yesterday, also known as the principle of mediocrity, that it’s often informative to look at the world with the assumption that there’s nothing special about us as a species, and perhaps more closely, apply the same principle to ourselves as individuals (e.g. “accidents always happen to someone else until they happen to you” – this is not some kind of exaggerated humility and self-effacement). When we look for Earth-like planets, we are in a sense only looking for worlds which are good enough, and also good enough for humans, as opposed to worlds which are fantastic. That is, Earth is all very well, and yes it is precious and rare and all the other stuff, but there could in principle be worlds which are even more hospitable to life than this one. Super-habitable planets, in other words.

I feel a sense of hesitancy here because it’s like insulting my own mother, but the fact is that this planet may be particularly suitable for humans, but it could have, and has been in the past, more comfortable for life than it was when we first evolved as anatomically modern humans. At that point, it was plagued by regular ice ages, had larger deserts and had little in the way of continental shelves, meaning that fishing, for example, would’ve been very difficult without boats in most places. Not that I care, as a vegan, but there is a theory that I accept that we went through an amphibious phase when we depended on sea food, which could be relevant to the development of the our brains and ability to speak. Even now there are issues with this planet regardless of the influence of humans on it. Looking beyond humanity confronts us with the fact that although this planet is really quite a nice place to live, it may not be ideal for other life. There are two aspects to this as well. One is “life as we know it”. That is, life which breathes oxygen, drinks water, uses sunlight to synthesise food, is carbon-based and depends on biochemistry, which may not be the only kind of life. We don’t know that there cannot be other forms of life which are very different, to which Earth would seem a very hostile place. For instance, it’s easy to imagine aliens detecting the high level of corrosive and hyper-reactive free oxygen in our atmosphere and concluding that this is not the best abode for life because they have simply never encountered body chemistry which actually requires that. They might feel the same way about this place as we would about a planet whose atmosphere was high in elemental fluorine or chlorine and had seas of aquæous hydrofluoric or hydrochloric acid. Or, if there were life forms based on plasma, and I strongly suspect this can happen, they might wish to avoid anywhere with even a trace of liquid water in its atmosphere or on its surface and only survive in the very driest deserts here. But the current popular conception of superhabitability is to be biocentric in the sense of looking for the ideal conditions for life to begin, develop and thrive on it. Perhaps surprisingly, Earth is not currently ideal for this, and it isn’t even entirely due to human technological development. Moreover, Earth has been more habitable in the past that it currently is.

Seventy-one percent of Earth’s surface is underwater, and of that most of it is so deeply so that no daylight ever reaches the ocean bed. This doesn’t rule life out at all of course – there is life in the deepest part of the ocean – but it does reduce the energy available and there is less diversity down there than elsewhere. It relies on food raining down from further up, sometimes including dead whales, which provide a huge amount of nutrition for quite some time. The water column above the beds is also rich in life, getting richer the closer to the surface it gets, and there are of course ecosystems around hot water vents at the bottom of the ocean. However, the euphotic zone, where there’s enough light for photosynthesis to take place, is only two hundred metres deep, and that’s where the ocean teems with life. Shallow seas are much richer in life and more diverse for that reason. Hence, withough being disrespectful of the ecosystems of the trenches, abysses and abyssal plains, more than half of the surface of this planet could be said to be “wasted”. Two ways in which things could be different here are for the seas to be shallower. The shallow sea biome is quite rare nowadays on Earth, but in the past has been much more extensive, and would mean that plants could grow on the bottom of the sea and support many other organisms. The same could apply to another possible situation, where the Sun was either brighter or we were closer to it, meaning that although there might still be extensive abyssal plains, the light would penetrate further down. Alternatively, photosynthesis, which currently operates using red light, could possibly be based on shorter wavelengths which penetrate further. A planet with a red photosynthetic pigment, for example, might have seaweed growing deeper. It’s possible that chlorophyll only appeared on this planet because a preceding purple pigment used by another taxon of organisms meant that only red light was available to plants, and if that second stage hadn’t happened, “plants” would now mainly be purple.

Stars are also different colours. From the viewpoint of photosynthesis, this could also have implications for the colour of the pigments. Habitable planets were long thought only to be possible for worlds associated with F-, G- or K-type stars but it’s now thought that red dwarfs may be more suitable (for a summary of spectral types, look here). K-type stars last longer on the Main Sequence and are orange, so I presume a planet orbiting one would be in a constant “rosy-fingered dawn” situation, though much brighter, but this gives life longer to evolve than it does here. Our own planet will be able to support microörganisms for up to 2 800 million years in the future, but these will to some extent resemble the æons when only microbes existed here. Large multicellular life is likely to become extinct only about 800 million years hence when there won’t be enough carbon dioxide in the atmosphere to support photosynthesis, which will happen due to the increasing brightness of the Sun. This is also driven by plate tectonics, as carbonate rocks are forced from the sea bed into the mantle where they react and release carbon dioxide while forming silicates. This means that a fainter, more long-lived star or more active continental drift would make this planet more hospitable to life for longer.

A larger planet would often have a number of advantages for life. Here I’m talking about rocky planets rather than gas giants. This is where the biocentric approach becomes more evident. The definition of a “superhabitable” planet here is to do with how suitable it would be for life of the kind we’re currently familiar with rather than humans, because large, dense planets would have higher gravity than Earth. LHS 1140b, for example, may be superhabitable, but not for us. It’s seven times the mass of Earth and 40% larger in diameter, giving it a surface gravity more than three times ours. This is beyond the capacity of human beings to survive unaided without some form of modification, but its dense atmosphere may provide it with a greenhouse effect which heats it to a temperature compatible with life as found here. Larger rocky planets will take longer to cool, meaning that there will be more active plate tectonics and more carbon dioxide recycling, although there may be a limit here because higher gravity would slow it beyond a certain point due to the weight of the continental plates. Larger planets, particularly fast-rotating ones, would have stronger magnetic fields and therefore be more easily able to hang on to their atmospheres and protect the surface from ionising radiation.

When Earth has been warmer, there has been more biodiversity, although just to comment on anthropogenic climate change that doesn’t work out now because it’s a rapid change and also unstable. Evolution might eventually fill in the gaps of course. This planet has a tendency to edge into colder conditions rather than hotter ones, for instance the current spate of ice ages and the Snowball Earth scenario in the late Cryptozoic Eon, but most of the time it’s been hotter on average than it is today. Consequently we’d’ve done better if we were somewhat closer to the Sun, although it’s not clear how much, at least to me. Another circumstance where there’s been more diodiversity and larger animals has been when oxygen was higher in the atmosphere, although this has a limit above which there would be devastating fires and other oxidative damage. The highest partial pressure of oxygen ever on this planet has been 350 millibars, amounting to 35% of the atmosphere, but in a denser atmosphere this proportion would be smaller because the absolute quantity of oxygen is what matters, not the proportion.

The final helpful criterion is a combination of about the same water cover combined with a larger number of landmasses. Earth currently has six continents, one of which is circumpolar. At other times it’s had as few as one. I’m not sure why this is considered advantageous but I can make a few guesses. It would mean that evolution would take place in isolation on each of the continents, as it has here with Australia, South America and the rest of the non-polar continents taken together, and that arid areas would tend to be smaller, although rain shadow deserts would still exist. Those, however, would be less common as well because there would be fewer mountain ranges due to fewer continents crashing together. There would also be more land near the coast than there currently is here, and more shallow sea areas on continental shelves. I’m reminded of Douglas Adams and his description of Ursa Minor Beta as consisting largely of beaches.

Some of these characteristics are impossible to detect with existing technology. For instance, although I think there is a way of finding continents and mapping them crudely by measuring fluctuations in brightness and colour, only a very few planets have even been imaged as points of light so far and they’re much larger than Earth. There’s probably a way of coördinating and processing telescope images taken in different parts of the Solar System to simulate the effect of an enormously magnifying lens, but I’m just guessing there. Nonetheless, there are certain known planets which do appear to satisfy some of these conditions. One is Kepler-442b. Incidentally, many of these planets have rather boring, monotonous names at present because they were all found by the same project. This planet, also known as KOI-4742.01 orbits its K-type sun at a distance of 61 200 000 kilometres once every 112.3 days, has a mass 2.3 times Earth’s and a diameter of around 17 100 kilometres. This gives it a surface gravity twenty-eight percent higher than ours, which is just about bearable. Without other factors being involved, its surface temperature would be about -40, but it could easily be warmer due to the Greenhouse Effect, low albedo and so forth. This last factor is of course the way in which it isn’t super-habitable, if it’s so.

It’s possible that there are more super-habitable planets than strictly Earth-like ones because there are more orange dwarfs than yellow dwarfs. Nine percent of stars in the Galaxy are of this kind as opposed to seven percent of the Sun’s spectral type, and several of the criteria simply follow from a planet being more massive than Earth. For instance, higher gravity could make the oceans shallower and give the planets more tectonic activity, and as a personal interjection continents on larger planets have more chance of being widely separated and having different evolutionary histories. A planet 1.4 times the diameter of the Earth whose surface is 29% covered in land, i.e. proportionately the same as Earth’s at the moment, has almost twice as much land, which if the average continent size were the same would be represented by a dozen continents. Likewise, we currently have five oceans here but there could be more there, although oceans are not well-defined and in a sense there is only one ocean. Planets with more than fifty percent land coverage could have landlocked oceans, and even worlds with less land due to quirks of geography, but this won’t apply to planets of this kind.

What might such a planet be like? Here I’m going to choose an example which satisfies all the criteria. There will be many others, if they exist at all that is. The average temperature would be somewhat higher than Earth’s and there would be no permanent ice caps at the poles, although snow-covered mountains and glaciers could easily exist. The climate would be warm and humid, with more cloud cover than Earth. Tropical rain forest vegetation would cover much of the land and there would be smaller desert areas. The oceans would be shallower and there would be copious vegetation on the sea beds. Atmospheric oxygen content would be higher in absolute terms but lower in terms of percentage than Earth’s. The denser atmosphere would mean stronger winds and more devastating rotary storms such as tornados and hurricanes. Also, these planets are likely to be more similar to each other than strictly Earth-like planets would be. The general picture is a little similar to the way Earth was at the climax of the age of dinosaurs or during the Carboniferous, although the higher gravity would limit the size of terrestrial megafauna.

These larger planets have a kind of momentum to them, which allows them to continue with fairly stable climatic conditions for many æons. By contrast, Earth-like planets run the risk of becoming permanently ice-covered, tipping into runaway Greenhouse effects and ending up like Venus, losing much of their atmospheres or relying more on large moons to maintain their magnetic fields, and therefore perhaps the ones that don’t have them or something else to raise internal tides only have thin atmospheres and no land life.

However, this does raise another question in my mind. As far as we know, we are the first technological civilisation to arise on this planet, although there’s tantalising evidence that there may have been advanced industrial processes here during the Eocene, maybe not from terrestrial species. If that’s so, it means that the periods of time during which Earth was more hospitable to life than it is today didn’t give rise to tool-using species. Therefore, is it possible that a more hospitable habitat is like the Swiss with their cuckoo clocks? Would stability end up providing little challenge to species and prevent it from evolving humanoid intelligence? Are these planets too comfortable? And there’s another question. Although these planets seem stable, they would be nearer a set of limits for biological habitability. Our planet has issues, but maybe that’s a sign of it being able to endure change. If something happened to one of these planets, like a large asteroid impact or a change in the luminosity of the sun, would this proce too much for life to handle? For instance, on this planet the life could be replenished by that surrounding undersea vents even if it died elsewhere, but I’m not sure whether there’d be many extremophiles – organisms who prefer hostile conditions – on such a world. Also, these planets are superhabitable by the needs of life as we know it in general, but not by human standards. We’d do okay, probably, on a planet which was somewhat larger and warmer than Earth although we’d have to be wary of the storms, but these super-habitable worlds wouldn’t be pleasant places to live for us. There’s a potential second set of hypothetical planets which are super-habitable for us, for instance with the Galactic Association example of Athena, a planet with no polar continent. Some of the characteristics would be similar, such as smaller but more numerous continents, but the set of criteria is not the same.

Taking this the other way is even more speculative because we’re only aware of one example of how life can arise and evolve, which is based on chemistry, organic matter, water and to a lesser extent oxygen for respiration. If there are other ways for life to exist, there could be whole other sets of “habitable” environments – I hesitate to say “planets” here because for all I know this would be happening on the surfaces of neutron stars, in nebulæ or the photospheres of “ordinary” stars. This is rather more difficult to discuss, but if life can exist in different ways it would seem to multiply the probability of life in the Universe, and also of the types of world which could support it. But I can only really leave this as a possibility thus far, or at least without making this post really long.

To conclude then, all this looks rather cheerful as regards the possibility of life as we know it in the Universe, but it also kind of pushes us Earthlings into a corner, as if all of this is true, we’re quite atypical of life in the Universe and our planet’s a bit weird. So who knows?

The Ringed Earth

View of Earth’s rings from California. Image created by Kevin Gill

Unlike the Planet Zanussi, we have no rings circling our home planet. Glancing at the rest of our Solar System, we appear to be able to discern a pattern. The inner planets Mercury, Venus, Earth and Mars have no rings. The outer gas and ice giants Jupiter, Saturn, Uranus and Neptune do have rings. From this it would be easy to conclude that rings are the exclusive preserve of either the outer Solar System or large planets. This is, however, probably not so, and will certainly not be so a few million years from now.

Until the late 1970s the only known ringed planet was Saturn, whose rings are particularly bold and striking. In 1977, a star was observed to blink on and off a number of times before Uranus passed in front of it, and again the same number of times on the other side at the same intervals. Later, one of the Voyager probes managed to get a good photo around the time it was leaving the orbit of Saturn, of the whole ring system. By that point, the same spacecraft had discovered that Jupiter too had rings, although much less substantial ones than Saturn. Then there seemed to be a long period, relative to my life anyway, when it was just those three, and it seemed odd that Neptune wouldn’t have them but there was not yet any evidence. After the detection of rings around Uranus, astronomers started to look for Neptunian ones but were unlucky with the placement of the planet during the 1980s because it was in a particularly blank part of the sky, and since it takes around a hundred and sixty-five of our years for it to get round the Sun the opportunities to observe occultations of stars are rare compared to Uranus, which moves against the dark background more than twice as fast. That said, there was an occultation, but it was a freak event caused by a tiny moon called Larissa which wasn’t discovered until Voyager got there. It’s under a hundred kilometres across, so the chances were minute.

It has also emerged in the meantime that some asteroids have rings. This seems to be because they tend to be “rubble piles” – bodies consisting of lumps of solid matter held together by a weak gravitational field but not compacted into a single solid body. Amalthea is probably like this too. Consequently, particles can get kicked up from their surfaces by various gravitational events or collisions which then orbit and end up forming rings due to collisions among themselves or momentum from the spin of the asteroid. That’s my guess incidentally. I have no idea if it’s actually true. For the same reason, the anomaly of Earth having an unusually large moon for its size may remain anomalous, because although there are many smaller bodies with relatively large satellites, notably Pluto, this may reflect the fact that their gravity is lower. Again, that’s me guessing. Pluto’s moon Charon is, though, 12% of Pluto’s mass, which means that if the situation were replicated here our moon would be larger than Mars.

I mentioned previously that there will one day be a ringed planet in the inner Solar System. That planet is Mars. Mars is the only planet other than Earth inside the asteroid belt with its own satellites, in the form of Phobos and Deimos. I’ve long thought of them as captured asteroids, and I’m sure they are, but the reality seems a bit more complicated. Mars may have had rings in the past and may have them again in the future. I need to explain the Roche Limit.

We’re accustomed to thinking of objects orbiting, say, Earth as having no gravity. We think of them as being in free fall. On the scale of something like the ISS, this is so close to being true it’s probably not worth considering that it isn’t. In fact, if a rigid body is orbiting a planet, only its centre of gravity is likely to be at zero G because the rest of it isn’t following the exact orbit. The further from the centre of gravity you get, the stronger the gravity becomes. This would be noticeable on a human scale if an astronaut was orbiting a neutron star, for example, because in that case the effect is so extreme that the gradient of increasing gravity is too, and a person in that situation would be quickly torn to pieces. This effect is also true of Earth in both the lunar and solar gravity fields. The core of the planet, more or less, is orbiting the Sun, but the surface is always slightly deviant. This puts minor strains on the crustal rocks, which move up and down by a few metres twice a day, but since they’re solid the effect is quite small. The same does not apply to liquids, notably the ocean, and consequently the level of the sea goes up and down twice a day, somewhat influenced by the Sun’s gravity but much more by lunar gravity. These are of course tides, and this kind of gravitational influence is called “tidal”.

If a body, such as a moon, has a sufficiently large orbit it can be large and hold together under the tidal forces applied to it by the planet, but if it’s within about 2.44 times the planet’s radius, known as the Roche Limit, it will be pulled apart by the tides. Amalthea is somewhat affected by this. The ends of the moon in the orbit have such a low gravity that rubble and dust from the surface is constantly leaving and entering into orbit around Jupiter, forming a ring. Clearly if Cynthia (“the Moon”) were sitting on the surface of this planet, assuming it wouldn’t crash through the crust, which is what would actually happen, it’s easy to see that it would break up and turn into a pile of rocks, which would still be too high and therefore collapse under its own weight until it covered Earth’s surface in tiny moon fragments.

Something similar to this seems to have happened on one moon in our Solar System. Iapetus, also distinctive in being almost black on one side and abruptly changing to almost white on the other, has a huge ridge running round its equator which is thought to be a collapsed ring.

The Martian moons are in highly unstable orbits. Over a period of many millions of years, the orbits of all planets, dwarf planets, asteroids and moons in the Solar System are unstable, but this is particularly true of Phobos and Deimos. Phobos is covered in streaks where Martian gravity tears at it. It will be torn apart and form a ring in something like fifty million years. This is actually something like the sixth or seventh time this has happened, because it appears that this is a regular process, and each time Phobos moves outwards, having lost most of its mass to form an increasingly tenuous ring.

This is crucial because it shows that small planets in the inner Solar System could in fact have rings like their big sisters. Mars is in a sense a special case because it’s next to the asteroid belt and can more easily capture asteroids which then get smashed up by tidal forces, but it’s also the second smallest planet and this is significant. It’s also significant that ring systems are generally temporary. We happen to be living at a time when Mars lacks rings and Saturn has particularly visible ones. The lower reaches of the rings are braked by the planet’s upper atmosphere and constantly rain down onto the clouds at a rate of about 2 500 tonnes a minute. This could explain the Crêpe Ring, which is a fainter inner ring closest to the atmosphere, clearly losing particles. They’re due to be gone completely by 300 million years from now, which is around seven percent of the age of the Solar System, suggesting that they haven’t always been there. On the other hand, Mars does intermittently have rings but they regularly appear and disappear. It’s more or less mere chance that we happen to be around at a time when Saturn has prominent rings and Mars has none. That said, Saturn does have unusually bright and extensive rings, which is because they’re made of ice and reflect sunlight well. Incidentally, I’m going to mention this here although it really belongs on homeedandherbs, my home education and herbalism blog: herbs are traditionally categorised into different planetary governances and zodiacal signs according to their features, so for example plants who vigorously defend themselves with spines or stings are governed by Mars. Plants with prominent rings are governed by Saturn, which seems to make sense until you realise that they were in fact already considered Saturn’s before Galileo discovered them in 1610.

Two rival theories about ring formation have been offered in the past. On the one hand, they could result from bodies which are torn apart because they entered the Roche Limit of the planet concerned, which at the time was Saturn because no other planetary rings were known to exist at the time. On the other, it could simply be that planets gather planetesimals (small chunks of potential future planets and moons) around themselves early in the history of star systems which fail to coalesce because of these tidal forces. This second theory probably isn’t correct as an explanation of the rings which currently exist, but it may nonetheless have been true in the early Solar System. Perhaps all the planets originally had rings, including Earth.

The transient nature of ring systems has another consequence: Jupiter may have had more obvious rings in the past or acquire them in the future. Moreover, these rings could be made of ice and brighter than Saturn’s because they would both be closer and reflect more powerful sunlight. A substantial Jovian ring system would have a diameter of 341 160 kilometres, considerably larger than Saturn’s 270 000 kilometre system, and at closest approach would be about half the distance to Saturn, making them reflect 60% more sunlight, be twice as large and therefore four times as bright anyway, which is over six times brighter. However, unlike Saturn, Jupiter’s axis is almost perpendicular to its orbit and we would only see them side-on. They would be detectable but not spectacular from Earth, although they would be large enough to be visible to the naked eye as a separate structure from the disc of the planet. Moreover, this may well have been the case in the past because Jupiter is close to the asteroid belt and many of its moons do in fact appear to be captured asteroids, and since it’s the largest known solar planet it stands the best chance of developing a substantial ring system, and in fact has done so. In a way, we are living at a slightly anomalous time in Solar System history because only the second largest planet has the most vivid rings.

The development of rings at this stage in the history of the system is most likely to be caused by planets capturing substantial bodies within their Roche Limits which do not immediately impact on their surfaces. The probability of this happening, assuming an even distribution of asteroids and the like, which is of course not so, increases with the size of the planet. Saturn has relatively weak gravity due to its low density, which is less than that of water, but the radius of its Roche Limit is large, so it’s relatively likely to acquire rings even though it doesn’t have much oompf. The Roche Limit is also a volume – effectively a hollow sphere with a planet at the centre – so the relative probability of rings can be calculated as the cube of the radius of the Roche Limit relative to another planet. This means that Saturn is about 760 times more likely to get rings over the same period of time than Earth, but also that Jupiter is 73% more likely to get them even if it occupied Saturn’s orbit rather than sitting next to the asteroids. It’s actually a bit of a freak occurrence that Jupiter’s rings are so much fainter than Saturn’s.

Our home world is the largest planet in the inner Solar System and all other things being equal is therefore the most likely planet of the four to develop rings. Venus is also quite likely, which would lead to a fairly spectacular view even from here, mainly in the form of a brighter Venus. All ring systems are likely to be similar in several ways. They will be the same relative width compared to the disc of the body at their centre, they will have gaps in them corresponding to the distances of large satellites, they will be circular and they will encircle the equator. They would, however, differ in other ways. The four gas giants are cold and therefore likely to have icy rings. Inner planets could also have this for a short period of time if they capture an icy body descending from the outer system, but this will be very temporary, only lasting a few decades at most in Earth’s case. They are more likely to have fairly dark rings made primarily of rock, carbon or iron, or a mixture. However, this doesn’t mean that the picture at the top of this post is unrealistic because although Cynthia is fairly dark, the surface still reflects enough sunlight to be clearly visible during the day and very bright at night. The rings would also be much closer and larger than our satellite, and therefore much brighter.

Earth’s rings could be seen as a kind of compensation for not having auroræ. The view near the Equator would be magnificent, and they would continue to be visible as one moved towards the poles, then as they disappear below the horizon, the auroræ hove into view. A ringed Earth would have a beautiful sky from everywhere.

Before considering the possibilities of how it might happen, it’s worth taking a break to smell the flowers at this point and have a go at imagining the situation of our own planet having rings in detail. From the equator, the rings would be invisible. Planetary rings are extremely thin. For example, Saturn’s are only ten metres thick. In order to get a good view, we would have to be away from the Equator, and with increased latitude two things would happen. The full width of the rings would become more evident and the rings would approach the horizon. The best view would be in places like Aotearoa/New Zealand, Argentina, Chile, the Mediterranean and the northern states of the US and southern Canada, which are all around halfway between the Equator and the poles. It would be a bit like having a permanent rainbow in the sky, although a less colourful one oriented east-west rather than somewhere near north-south, and quite a bit larger. Near the poles they would be very close to or below the horizon. There might also be a division in them, like the Encke and Cassini Divisions of Saturn’s. These are caused when particles orbit in resonance with a large moon. There would be a radius within the rings which would orbit ten times a month, and it’s possible that this would at least be sparser than the rest, but the resonance is quite far from the simpler, larger fractions involved which lead to Jupiter causing the Kirkwood Gaps in the asteroid belt or Mimas, the Death Star moon, causing the Cassini Division. Even these are less visible close up, so we would probably end up with a single solid-looking ring in our sky, although since it was so close we’d probably see something like the “record grooves” appearance Saturn’s have when seen from nearby, and there might also be “spokes” moving through them as they do with those. These spokes might be caused by lightning storms in Saturn’s atmosphere or meteorite impacts on the rings, causing static charge to repel some of the particles and make them slightly wider at those locations.

It would have various consequences. They would cast very large shadows corresponding to the seasons. There would be none at the equinoctes and they would be biggest near the winter solstice in the appropriate hemisphere. These would also be colder than the surroundings and there would therefore be winds blowing into them, and in certain places the shadows would be present intermittently for months at a time, notably in the mid-latitudes where the climate would usually be warmer. This would reduce photosynthesis, although since they would also be very bright there would be some compensation and this could also ameliorate the cooling effect. They would also occupy the position used on the equator by communications satellites. However, they wouldn’t impede space travel since this can occur away from the Equator.

That, then, is Earth with rings. It seems to be compatible with life but it would have significant effects on our climate, and there could also be a steady rain of meteors into the atmosphere at the equator, though these would mainly vaporise. This in itself might lead to more metal ions in the upper atmosphere, and I’m wondering if this would influence the auroræ and attract them towards the poles, making them brighter and more colourful.

Now the question is, has this or will this ever happen without human intervention?

When Earth first formed, it very probably did have rings like all the other planets, as the planetesimals orbited prior to colliding with the gradually accreting protoplanet. Slightly later on, the Mars-sized planet Theia collided with us, breaking off the outer layers of the planet and forming Cynthia. This too would have shown up as a ring, a very substantial one in fact. Saturn’s rings has a mass of less than half that of Mimas. Earth’s at this point would have had more than one percent of our own mass, which is many thousands of times greater on a planet whose mass is only one percent of Saturn’s. This is another illustration of how out of proportion our satellite is.

There is no evidence in favour of this next bit, but also nothing to rule it out and it’s entirely compatible with established facts about the history of this planet and the Solar System.

A large asteroid collides with this planet every few million years, including, of course, the Chicxulub Impactor which wiped out the non-avian dinosaurs. The Śiva Hypothesis holds that this planet moves through a galactic arm every 27 million years, causing an increase in impact events, although there isn’t a huge amount of supporting evidence for this. There was a period during which the Chicxulub Impact worked so well as an explanation for the extinction of the dinosaurs that cosmic impacts were evoked to explain all six prehistoric mass extinctions, the current one being excluded for obvious reasons, but there are various other events which could also explain them quite well. There are therefore sometimes direct hits by large bodies on this planet. How often does this planet encounter another body without an immediate collision? How often does it get within the Roche Limit, almost striking a glancing blow, and instead of hitting us is ripped apart by tidal forces and forms a ring? I don’t think anything at all rules this out, and in fact I think it must have happened a number of times in our history.

Looking specifically at the Chicxulub Impact, a ten kilometre wide object clearly did hit the future Gulf of Mexico 66 million years ago. However, how do we know that wasn’t simply the biggest or most unfortunate remnant of a larger body which had been orbiting the planet for some time previously? It may have broken up within the Roche Limit and given the planet rings, and also, less controversially, some of the rocks smashed up into space by the impact would have created rings. Maybe Palæocene Earth did have rings after all, and maybe they took millions of years to break up.

I can’t prove any of this of course, and in fact I can’t even think of how someone would go about testing this hypothesis. Even so, I would say that the balance of probabilities strongly supports the idea that this planet does sometimes acquire rings. It’s the largest inner planet, it has associated asteroids and for every impact there are countless near-misses. I think we used to have rings, have probably had them several times, and will one day acquire them again. As to when, who knows?

Middle-Sized?

I don’t know if you’ve ever seen the short film “Powers Of Ten”. It starts with a photo of a picnic and zooms out to one hundred million light years, then zooms in to a hundred attometres. It can be seen here:

I have a distinct memory of a different film and wonder if it’s been remade. Despite the date on this I think this is the 1968 version. ‘The Voices Of Time’ was published in 1966. The maximum zoom out is to 10²⁴ and the maximum zoom in is to 10^-16 metres, neither of which are absolute limits. Nor does the upper bound correspond to the limits of knowledge at the time so far as I can tell, and a metre is not in the middle of that range. The middle would be somewhere like ten kilometres, which is of the order of the width of Chicago, probably somewhat smaller. The idea of it being in the middle is a bit nebulous-sounding. What I mean to ask is, how big are we in terms of powers of ten, or for that matter any other number, in the scheme of things? Are we as much bigger than the smallest possible length as we are smaller than the largest length, or are we off to one side, and if so, which?

The smallest possible length is the Planck Length. This is 1.616255(18)×10⁻³⁵ metres. Strictly speaking there is no upper limit because it appears that space will continue to expand for ever, and even if it doesn’t it isn’t because there’s a geometrically ordained maximum size, but the diameter of the Universe is said to be 28 gigaparsecs, which is 8.635317 x 10²⁶ metres. Incidentally, the upper figure has spurious accuracy. While we’re “out here”, I may as well work out the volume of the Universe, and I may have this wrong. The Universe is not spherical but hyperspherical, and its volume corresponds to the surface area of a sphere in the same was as that corresponds to the circumference of a circle. The formula for the circumference of a circle is of course 2πr and the surface area of a sphere is 4πr², so I, perhaps naïvely, would deduce that the formula for the volume of a hypersphere is 16πr³. It’s a bit difficult to work out what the “diameter” of the Universe means because it isn’t spherical, but assuming it means the diameter of the hypersphere which in practical terms constitutes space, this gives it a volume of 4 x 10⁸¹ metres. It’s also worth using these figures to calculate the difference between this and the volume of a sphere of the same size, that formula being (4/3)πr³, which would give the Universe a volume of “only” 3.37158 x 10⁸⁰ metres, which is only a dozenth of the size. This illustrates the significance of the fact that Euclidean geometry doesn’t apply at this scale, and it also means that a sphere exactly half the size of the Universe is twelve times bigger on the inside than it is on the outside. In Whovian terms, it’s dimensionally transcendental. It’s also possible to stick these two big figures together and work out one in terms of the other: how many Planck volumes are there right now? The answer is a figure with a hundred and eighty-seven digits, which permits an upper limit to the useful value of π, although as time goes by it would drift out of kilter so many more places may in fact be necessary. In the unlikely event that you need this figure, go here, which gives it to a million decimal places. I find this quite reassuring because it suggests that memorising the number in question isn’t entirely pointless, or maybe that’s disappointing.

Why is a Planck Length the shortest possible length? The reason for this originates in the “ultraviolet catastrophe”. It’s been known for thousands of years that when an object gets hot, it glows red, then orange, then yellow, then white. However, nobody knew why for most of our history. Given classical physics, why is it that hot objects don’t simply glow white and get brighter as they get hotter? There would, however, be a problem with them doing this. If they just glowed at the entire range of frequencies of light, this would include all frequencies shorter than visible light and this would be infinite if the variation of frequencies could be any figure at all between any two other figures. Obviously a hot object is not infinitely bright, but why?

The answer is that there is a minimum difference between frequencies of the light emitted by a hot object. This means that physical reality has a granularity to it. It has, in terms of computer graphics and video, a frame rate and a resolution, all determined by Planck’s constant, h, and the speed of light, c. Light can only be omitted in discrete quantities. There is not an intermediate energy level below a certain fineness and instead energy leaps between these levels without having any values in between. The minimum quantity is known as a quantum, and the energy of a photon is equivalent to its frequency multiplied by h. It solves a lot of problems. For instance, if electrons in orbitals constantly radiated energy over a continuous range, they would spiral into the nucleus and the atom would collapse. Instead, an electron can only have certain clearly defined energy levels. The Planck Length is given by the formula:

. . . where G is the gravitational constant and ℏ is h divided by 2π. The Planck Time is then the time taken for light to travel this distance.

The thing about the Planck Length in terms of scale is that it’s so much smaller than anything significant which seems to be happening, such as the size of the “smallest” subatomic particles. A zoom into the Planck Length would mainly be very boring because it’s nineteen orders of magnitude smaller than the limit in ‘Powers Of Ten’, which is equivalent to a speck of dust compared to something like ten dozen times the diameter of the orbit of Neptune. However, assuming that the film was made in 1968, certain fundamental particles such as quarks had not been established to exist yet, so nowadays it would be possible to go further. At this scale, it’s conceivable that “quantum foam” exists. Spacetime may be fluctuating in nature at these dimensions like a stormy sea, which also suggests that there is energy present in a pure vacuum. How this might be extracted, and whether it would be desirable to do so, is another question. It’s sometimes thought that the Universe is not at its lowest energy level and if that level were to be reduced to zero, for instance by “mining” the energy of quantum foam, that true vacuum would spread out at the speed of light from where it was formed and destroy everything.

Getting back to the question in hand, the smallest possible scale is the Planck Length of the order of 10^-35 metres, and the largest possible scale is the Universe itself, whose current diameter is of the order of 10²⁶ metres. This means we are on the large size. Of the sixty-one orders of magnitude possible at the moment, we’re the thirty-fifth smallest and the twenty-sixth largest. Middle-sized is around the thirtieth from either end, which is around ten microns or somewhere between the size of a white blood cell and a red blood corpuscles. Organisms of this size include protists and single-celled algæ. They are to the Universe as the Planck length is to them. Even so, we are close to being middle-sized in the grand order of things in that a factor of a million is not hugely significant when the number considered is around ten decillion. A hundred thousand times bigger than we is the size of a region of England such as the Midlands, and that’s not terrifyingly and incomprehensibly enormous. Therefore we are, very roughly, in the middle.

A More Literary Bit

I don’t know what pretensions I have to dare describe anything I write as appropriate for the above heading, but there it is. Yesterday I made this YouTube video:

Incidentally, I’m thinking of going back to making YouTube videos, but in future they’re likely to include no speaking and I won’t be showing my face on them, if I bother at all.

I found this rather unsatisfactory. I was going for the impression that the rather overgrown back garden was like a jungle at a smaller scale, but there were a couple of issues. One was that most of this wasn’t truly at ground level, and the other was that there seemed to be precious few animals in that video. I may give it another go at a later date. What I wanted was a lush forest-like appearance teeming with animal life, such as spiders, ants, beetles and flies. Something like this but with animals:

We do, to Sarada’s chagrin, have plenty of horsetails in our garden but they’re not forty metres tall. It’s really a testament to them that they’re still around after 300 million years, and to me it raises the question: when you get smaller, is it like going back in time? After all, on a sufficiently tiny level there are no vertebrates, or rather the vertebrates who do exist are great hulking monsters. There’s a frog who is less than eight millimetres long, and in Britain the minimum size seems to be a few centimetres. Mammals and birds as they’re now constituted can’t be smaller than a certain size because they would be physically incapable of eating enough food to keep their body temperatures at the right level to survive, so getting smaller is a journey into the past in terms of the animals all being “cold-blooded”, except of course that as discussed previously a flying insect isn’t really cold-blooded at all if it has to put much effort into flying. However, also at this scale animals don’t so much need to put effort into flying as into not flying, because for them the air is a fairly thick, buoyant fluid which they don’t so much fly through as swim in.

J G Ballard’s novel ‘The Enormous Space’ tells the story of a man who resolves never to leave his house again. As the days go by, his house expands until even the room he’s in is too vast to traverse. It’s been adapted into a TV play by the BBC:

Because of lockdown (I almost gave that a capital letter), some of us have found our homes becoming our worlds like the character in this piece, but to the various denizens of our dwellings they already are. The longest line section (actually geodesic) which can be drawn in the area I have lived my entire life within is about two thousand kilometres long, from Inverness to Rome, so that’s my world, in a way. Reducing this by a thousand gives an area the size of a small town, so for an ant, say, this is their world. The vegetated area of the garden is about twelve metres long, so magnifying that by a thousand makes it twelve kilometres, like a large forest in terms of England today. But this is mainly a bamboo forest with prodigiously high “trees”, since it’s largely grass. The tallest bamboo species is Dendrocalamus giganteus, which is up to thirty-five metres high, and at a scale of one to a thousand this is equivalent to a fairly well-manicured lawn, which we don’t currently have. To an ant, the moderately tall grass in the back garden is something like ten times the height of the tallest bamboo, making it more like a redwood forest, though of course not woody because of the relatively lower gravity.

This is truly a different world. The gravitational acceleration is less important there because the relative masses are a thousand million times lower. An insect could easily fall out of a skyscraper without being harmed, even though the gravity operating on a two millimetre long organism is in a sense a thousand times as strong. The atmosphere becomes a much more important factor, even the dominant one. Water becomes if anything more dangerous because its surface tension not only allows it to be walked on but also to capture an insect permanently even though they wouldn’t sink, and this opens up a whole ecological niche of predators who can prey on the victims of surface tension such as raft spiders and pond skaters. At the same time there are still the more familiar predators and prey in the form of ladybirds, wolf spiders and aphids.

It’s easy to think of oneself as trapped in one’s home, and since I’m a carer that is particularly a hazard for me. However, not only do I continue to have communication with the outside world, but also I have access to the microcosm. Even without a microscope I can observe the relatively large animals living in the house and garden, and when I get down to the middle-sized animals such as the hundred micron Colpoda, which will be present in the soil here like it is all over the place, and the crinoid-like Vorticella likely to be present in the guttering whose stalks are around the same length, the garden is relatively the size of that good old colloquial unit Wales. How could I want for any more? I can also go the other way, though since I live in England with its grey skies, not quite so far. But on a clear night, like anyone else I can realistically see individual stars thousands of light years away. The whole observable Universe is around me and half of it is accessible, though this presumes I have my own observatory and in practical terms is far less so because I’ve only got a pair of binoculars. But even so, I can see the Orion Nebula, 1 300 light years away, and the Pleiades open star cluster, 440 light years from here, and so on.

In the end, then, although it’s important to get out of the house, to some extent it’s what one makes of it, and the scope for what I might call adventure but is probably better called observation, even just from this one small house and garden in an English Midlands town, is vast. Just because the slightly larger than medium scale at which we happen to live lacks, in the East Midlands anyway, rainforests, elephants, lions and whales, doesn’t mean it doesn’t contain an equally fascinating array of wildlife on another level, and just because we’re confined to Earth doesn’t mean we can’t observe a fascinating wider Galaxy. What more could anyone want? Isn’t it great to be middle-sized?

The Stage For ‘Rage’

The stage for ‘Rage’

Obvious spoilers for my forthcoming story ‘Rage’.

A while ago, I became aware of a project called the ‘Blake’s 7 Annual 1982’ and committed myself to working on two things to contribute to it. I’ve mentioned them already on this blog. Clearly the death of Yahoo! Answers has removed one source of procrastination from my life. Nonetheless I want to stick to the commitment of blogging daily for as long as possible, but today I’ve decided to do it in a way which will aid my writing process rather than hindering it. Here, then, is an outline of various issues relating to the story and some cogitations on the way I write. I’m also hoping this tangential essay will constitute a catalyst for the actual story-writing.

The story is mainly set in Series D of ‘Blake’s 7’, although it begins in the 22nd century, long before the events of the show itself. In it, the People’s Republic of China masterminds the manufacture of a space ark to colonise a planet circling 82 Eridani, which is in reality a Sun-like star about twenty light years away. It’s made from a largely iron-nickel asteroid in a similar manner to how Larry Niven, and probably others, proposed it would be manufactured: take an iron-nickel asteroid, put tanks of water inside it and superheat the water either with lasers or focussing sunlight so that it becomes steam and eventually gets hot enough to melt the metal of which the asteroid is made, expands and pushes out the surface, so that rather than having to hammer something together in space, a hollow structure is essentially created from readily available resources. The steam can then be allowed to condense, although in order to do this an atmosphere needs to be provided. Some moulding is also necessary in order to form a cylindrical surface, which is needed because the illusion of gravity needs to be created by rotating the structure and for that to be equal, it needs to be on a surface parallel to the axis of rotation. Shielding from ionising radiation can then be provided by crushed stony asteroid, which could also form soil. Slight irregularities in the surface lead to land and water topography, with streams and other bodies of water such as lakes. The interior then needs to be lit. Near a star, that’s feasible simply by providing windows, but this is a vehicle, not a space station, and has to travel between the stars. Nicking an idea from Arthur C Clarke’s ‘Rendezvous With Rama’, a strip light can be placed along the axis of the cylinder. It needs to have enough red light to support photosynthesis and really needs to have the same spectrum and brightness overall of the Sun, although the fact that it’s a strip rather than a disc reduces this somewhat. It also needs to turn on and off in a twenty-four hour cycle which includes reddening at dawn and dusk. All of this also needs a prodigious energy source and energy storage, and it shouldn’t be presumed that technobabble handwaving will provide this, so I’m going to say there’s a fusion power source backed up by solar. The entire outer surface of the ark is plated with solar cells.

The interior then needs to be terraformed. This is done by providing the right organisms. The Biosphere II project turned out not to be sustainable even in the short term. This was a closed dome-like environment in Arizona intended to test whether a viable self-sustaining environment was possible, or rather to learn from the mistakes made in these circumstances. It lasted two years and the ultimate problem was that respiration outstripped photosynthesis, leading to a rise in carbon dioxide and a drop in oxygen. Some of the biomes encountered problems. For instance, the desert ecology ceased to be so because of condensation from the windows providing precipitation and there were problems in the rainforest zone because of the lack of wind preventing proper wood from forming. Coral throve though, which is surprising considering the presumed acidification of the water from the carbon dioxide, which could’ve been expected to dissolve the mineral matrix it relies upon. One issue with Biosphere II was the small size at 1.27 hectares. The larger such a system is, the longer it takes for entropy to take over. This can be seen, for example, in small and large aquaria and ponds. The larger your fish tank, the easier it is to maintain.

A somewhat separate and predicted problem with Biosphere II resulted from the psychological interaction between the human inhabitants. This is particularly important to ‘Rage’ because in the end it’s a story and the drama in many such pieces arises from these interactions. Antarctic bases can also be studied in this way, and since this is a twenty-second century scenario, it can be presumed that interpersonal psychology has advanced as well as technology and natural science. Anyone who’s lived in a shared house will be familiar with some of this. The group, which comprised eight people (there were actually two sessions), split into two inimical factions after about a year, even though they’d been close friends at first. However, they all felt very proprietorial about their habitat and a sense of bonding with the project. It was special to them. Nobody was ‘phoning it in. It wasn’t helped that in the early part of the project, everyone was constantly hungry. Eventually, someone decided they would start eating seeds which had been provided from outside rather than relying on crops grown inside the project, and this person was sacked, but stayed inside the dome because she realised it was unenforceable – if she’d been forcibly removed it would’ve ended the project as it would’ve exposed the environment to the outside world.

Some of this is kind of petty, and I don’t mean this as a criticism. There’s a radio sitcom called ‘Bird Island’ which is about three people on an Antarctic island, because this “trapped” situation works really well for those purposes (and is also low-budget). This kind of pettiness is part of human nature, and since the group was very small it can be expected to happen. The ark, which I’m going to call  天園, Tian Yuan, for reasons I’ll go into in a bit, will have a population of about fifty thousand, so the entropy which applies to smaller social groups will be more limited. This population is of the order of many small island nations such as Gibraltar, and the land surface area is about the same as that of the Isle of Wight at 380 km². However, there’s also extensive water, perhaps about the same as Earth’s surface at 71%, making the total internal surface area 1310 km². Given a twelve kilometre diameter, this makes the ark around thirty-two kilometres long, so it’s not particularly densely populated at 131 people per square kilometre, about the same as Thailand and a quarter that of the UK. Hence people wouldn’t get under each other’s feet that much and it’s more like a micronation than an outpost. Perhaps a medium-sized town.

One issue which is frequently ignored or waved away in science fiction is the language barrier. H2G2 has the Babel Fish and Star Trek the Universal Translator, both of which are said to work in the same way. But these are plot devices intended to remove that specific barrier and allow other stories to be told. I have no intention of doing this here. Iceland is a small nation of around three hundred thousand people, and consequently its language is very conservative and hasn’t changed much since the Dark Ages. I envisage seven centuries passing between the settlement of the Tian Yuan and the arrival of our heroes, but in that time the Mandarin Chinese spoken initially on board is unlikely to have changed much, although it might have had time to become a dialect. By contrast, the Terran Federation probably does not speak English. This is ignored in ‘Blake’s 7’ where almost everyone, even the aliens, speak southern English English, but in fact they can be surmised to be speaking a language which could be called something like Terran or Standard Galactic, as close to a language spoken in the twenty-first century as that would be to one spoken at the time of the European Middle Ages. We also don’t know the roots of that language, as it could be a mixture of the dominant languages spoken on Earth now, a development of a specific language spoken by the conquerors or even an artificial language that aids mind control. We do appear to know that certain idioms and puns are the same as in English, for example Vila’s jokes in ‘Ultraworld’, and there’s some mileage in the possibility that the existence of audio recordings since the twentieth centur has slowed the change in the English language, but it seems unlikely that no linguistic change has happened at all. Therefore I choose to posit that it has, and that the encounter between the Scorpio crew and the people on board the Tian Yuan will involve some kind of linguistic obstacle along with a way round it which doesn’t involve an easy technical fix. Arguably, ‘Blake’s 7’ is in the Whoniverse and the usual explanation there is that there are nanotech motes which rewrite the brains of people communicating in order that they understand each other, but that technology is Gallifreyan and very vague-sounding, so it isn’t available to the Federation

Then there’s the question of genetics, the founder effect and the number of generations involved. The ark launched seven hundred years before and has a steady population of roughly fifty thousand. This can’t be allowed to fluctuate because of resources. Assuming a generous average age of thirty, there are twenty-three generations (and a bit) in seven hundred years. This means that someone living on the ark will have had over eight million instances of an ancestor in the first generation, meaning that people will have overlapped over a hundred and fifty times, so any genes available will be thoroughly mixed by now and will have been for seven generations, unless something happened like factions developing which don’t interbreed. This means there will be a founder effect: loss of genetic variation compared to the wider human population. In many ways this is an island ecosystem, and there will also be founder effects among the crops and any non-human animals who may be along for the ride for whatever reason.

I’ve decided that one individual, Dr Hu Wei, has a monogenic trait which gives him intermittent explosive disorder. This is a condition giving the individual sudden violent anger. Before he boarded the ark, like everyone else Dr Hu underwent extensive testing and it was decided that he needed anger management without it being realised that his issue is genetic. Hence he is able to manage his anger but he passes the trait onto his children, and it’s triggered by the red light emitted by the central illumination column in the evenings, causing everyone afflicted to have an outburst of destructive rage for about an hour every evening. This is more poetic than realistic of course. This means that the structures of the habitat are in ruins, since they’ve been smashed up by the people involved, and of course many of the people themselves are injured through fighting. Hence the title of the story, ‘Rage’.

The initial plan was to send the ark to settle the 82 Eridani system. In the real world, 82 Eridani has three “super earths”. These are rocky planets considerably more massive than Earth. Even the third planet is likely to have a mean surface temperature of about 115°C, probably higher, although extrapolating the situation here to there, that could mean the poles are at a hot but just about bearable temperature. However, I choose to imagine there is also a habitable body in that system, since the gravitational pull of these planets would be too high for human survival long term. Since it’s a space ark, the Tian Yuan can take centuries to reach its destination, two hundred years in fact, but that’s still one heck of a clip at 10% of the speed of light, bearing in mind also that the craft could comfortably cover the Isle of Wight, so that’s a very large mass to accelerate to that velocity. It also has to accelerate and decelerate gently enough that it doesn’t interfere with the artificial gravity.

While the ark is underway, technology marches on. Faster than light travel is achieved and people from Earth overtake the Tian Yuan and settle 82 Eridani anyway. Meanwhile on board, the population becomes attached to its home and develops its own culture, and by the time they reach the nearby star, they don’t want to disembark and the people in the system don’t want them to settle, so instead they upgrade the engines and they decide to continue near a line of sight to a star system with more powerful radiation, namely the triple star system of Acamar, because what they really need is starlight. They recharge their batteries and set off for a five century journey to Acamar, a further hundred light years away. As they continue on their way, the genetic issue of the daily rage comes to affect the entire population and they forget that it isn’t usual because to them the ark is the world, although they’re aware of the Galaxy gradually being settled around them. In the outside Galaxy, technology continues to advance but about three centuries into this second journey, the Terran Federation takes over, having become a totalitarian régime. Tian Yuan has been forgotten by the wider Galaxy at this point and they eventually reach Acamar, by which point the Federation has undergone the Intergalactic War with the Andromeda Galaxy, ending in stalemate, and has begun to claim back the Galaxy with its soporific gaseous mind-control drug Pylene-50. They stumble across the ark and attempt to subdue it by injecting the gas into their atmosphere, assuming it will work. Because of the genetic variation leading to the daily rage, it doesn’t and all the troops end up getting killed.

And this is where our heroes come in. Xenon Base intercepts a distress signal from Acamar to Earth and Vila and Soolin are sent to investigate. On reaching the ark, they are greeted warmly by the inhabitants but notice that the whole place is a bit smashed up. They realise that the atmosphere has been filled with Pylene-50 but notice that they too are immune. Tarrant comes over to repair their guidance system and they work to extract the gene and splice it into a virus they can use as a vaccine against the effects of the drug. They go back to the Scorpio and try out Pylene-50 followed by the drug on Avon. His sociopathic character is altered by the drug. Meanwhile, back on the ark, the daily rage starts and the natives start attacking Tarrant. In a break with his usual character, Avon decides to rescue Tarrant and teleports him back on board the Scorpio. The Federation then turns up and, realising the Tian Yuan is a threat, blows it up and kills everyone. On the Scorpio, Vila gets the drug and the vaccine mixed up and accidentally throws away all the vaccine, so hopelessness is satisfyingly restored.

That last paragraph is the actual story, which is currently about a quarter written. I still need to fill in a couple of details here.

Tian Yuan, or rather 天園, is the Chinese astronomical name for the part of the constellation of Eridani the ark is headed for. It means “Celestial Orchard”, and therefore works quite well as a name for the ark. Acamar itself is either a binary or a triple star system consisting of two or three type A (white) stars. I’ve seen two estimates for its distance from here: 120 and 160 light years. It’s also known as θ¹ & θ² Eridani, because the components are far enough apart that they can be seen separately from Earth through a fairly small telescope. It’s also suspected that the first may be a double itself. For some reason I don’t know, triple star systems are always organised such that two companions are much closer together than the third, and this is the case here if the system does turn out to be triple. Θ² is around 300 times the distance of Earth from the Sun, and is slightly less massive than θ¹, and as is usual with binary systems the two stars both orbit their centre of gravity around half the distance between them. The possibly double one has a mass of 2.6 times that of the Sun and is due to become a red giant quite soon as it’s used up all its helium, and the other one is slightly less advanced. Like any star of that kind of mass, for instance Sirius A, their lifetime up until becoming red giants is only a few hundred million years, so if they have any planets which support life that won’t be more than simple microbes unless they’ve been settled from somewhere else. Tian Yuan can nevertheless use them as a power source.

Grafting all this onto a ‘Blake’s 7′ story makes it rather hard SF compared to the series itself, which usually lacks the scientific rigour required. Real stars and planets are not often mentioned in the series and there are huge issues with the often frankly confusing science. However, in order to do any kind of job at all here, I have to be able to believe in what I’m doing rather than letting myself go along with mushy science. However, the series really scores with the characters, and this is what I find most difficult. This is partly because I’m not good at characterisation, but the way the series is written doesn’t help, particularly with female characters. Not all of this is even the writers’ fault because of the pressure of time. Terry Nation said there was a tendency for first drafts to become the actual script for broadcasting due to pressure of time. However, particularly with female characters there’s a tendency for them to start strong and well-drawn and for them to end up “making the tea”, and for this reason actresses tended to leave. I currently have this problem with Soolin. She was in it for most of Series D but at the start she was given Cally’s lines to some extent because of Cally being written out and leaving rather suddenly and firmly, so the characterisation is difficult. She’s said to be a “female Avon” and her back story is good. She is supposed to have had a mining operation taken over her planet and kill her family, then be raised by one of her family’s killers, have been trained in use of weapons by this man, then gone on to murder him and everyone involved, even off-world, in the mining. This is somewhat clichéed by today’s standards and reminds me somewhat of ‘Leon’, but at the time may have been quite original. I don’t know. Vila is the easiest character to write, at least for me, but it’s important to remember that by Series D he had substance abuse issues and was unable to get over Cally’s death. Avon is the sociopathic cynic. Tarrant I’m not sure about except that he’s supposed to be a good pilot and is quite arrogant and self-centred.

Finally, every episode of Series D has a one-word title, hence the title ‘Rage’.

This has been an exercise in putting compost on my story in the hope that it doesn’t turn out to be compost itself. I hope it has served to amuse to some extent. It’ll end up having about 3400 words, which is almost as long as the story.