Restoring Pluto And Elevating Cynthia

I was going to blog about the larger asteroids at this point, but in recent days it’s been borne in upon me that there’s a current issue in astronomy, perhaps over-emphasised but definitely there, over whether Pluto was unfairly demoted. The reason I mention this now is Steve’s comment about what the difference between Phobos and Deimos and asteroids might be. It’s a very good question and I’ll address this first.

Phobos and Deimos, the moons of Mars, are a little puzzling. There are two hypotheses about where they come from. One is that they’re main-belt asteroids which were captured by Mars. At first glance this sounds very sensible and logical. After all, Mars is next to the asteroid belt, it could be expected to gather up a few stones from it from time to time and the pair seem to be only the latest representatives of a whole series which have scarred Mars with chains of craters as they broke up and impacted. However, there are problems with it. Firstly, the common type of asteroid found near the edge of the belt closest to Mars is different from the type of asteroid Phobos and Deimos would be if they are asteroids. That type is found near Jupiter. This is due to the inner belt being warmer than the outer belt, so the composition differs because temperature makes a difference to them. Secondly, both moons have almost perfectly circular orbits over the Martian equator, and if they were captured, they would usually have come in at a high angle to the equator and have markèdly elliptical orbits. This can be seen with Nereid, Neptune’s third largest moon, and Saturn’s moon Phoebe orbits backwards compared to most other bodies in the system. Therefore, if Mars’s moons are asteroidal in origin, something needs to be evoked to explain that. A simpler explanation would be that they emerged from the cloud which was forming Mars. This would be spinning in the same plane as any moons which formed from it, and if they were formed in situ they would be more likely to have almost circular orbits. However, as Steve astutely pointed out, the actual nature of the bodies themselves is very close to being asteroidal, and in fact is asteroidal, so maybe it doesn’t matter in most ways. In the sense of the physical nature of the two moons, they basically are asteroids. The way in which they aren’t is to do with their history and orbits, which may not be a sensible thing to focus on. The only thing which goes against this is that both are directly affected by orbiting Mars. Phobos has streaks because of the tidal forces of its planet, and Deimos accumulates fragments and dust from itself as it moves through its rather short orbit. If they were orbiting in the asteroid belt itself, neither of these things would be happening. All that said, I can totally see the argument that they are in fact just asteroids in an unusual place which are also moons rather than minor planets. So I agree with you Steve.

This connects to a wider issue which affects Pluto, and it also affects a number of other worlds in the system which if addressed could solve the problem of knowing what to call the big round things in our Solar System. It could also address the peculiarity of our own “moon”. The 2006 CE definition of a planet by the International Astronomical Union is:

The IAU members gathered at the 2006 General Assembly agreed that a “planet” is defined as a celestial body that

(a) is in orbit around the Sun,

(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and

(c) has cleared the neighbourhood around its orbit.

This definition was motivated by the discovery of a number of relatively large trans-Neptunian objects. Eris, discovered at the start of the previous year, has now been established to have a diameter of 2326 kilometres and a mass of 1.6466 x 10²² kilogrammes. Sedna, discovered in 2003, has a diameter of around a thousand kilometres and an unknown mass because unlike Eris it seems to have no moons. Sedna is less of a threat to the status quo but Eris was initially thought to be larger than it has now turned out to be. For comparison, Pluto is 2376.6 kilometres and it has a mass of 1.303 x 10²² kilogrammes, so it’s actually slightly larger than Eris but also less massive, so the question arose of whether it would be acceptable to admit a potential host of newly discovered planets, thereby reducing the “specialness” of planets, or to invent a new category. This last idea, of “dwarf planets”, seems very odd to me because the category of “minor planet” had existed for a very long time up until that point and instead of inventing an entirely new class of object, it would’ve made more sense, if they were going to do this. Whether or not I agree with the decision, there seems to be no merit in creating a whole new category of “planet” when “minor planet” already existed. I honestly don’t know why they did this.

Many people have disagreed with the decision to demote Pluto. It did elevate Ceres, previously considered a mere asteroid, at the same time. Before that point, for most of its history since discovery Ceres was considered an asteroid, but it’s the only body in the asteroid belt which has managed to make itself round due to its own gravity (there might be other bodies which just happen to be round-ish through chance because asteroids are irregular and could hypothetically be many shapes, including spheroidal), so it probably does deserve special recognition.

In spite of this definition, which is quite unpopular, a paper has recently been published on the subject arguing that Pluto, among other worlds, does in fact merit planethood. The paper can be found here. It’s sixty-eight pages long and I haven’t read the whole thing but the general gist of it seems to be that there used to be a scientifically arrived-at understanding of what a planet was, but over a period in the early twentieth century when astronomers focussed more on what was happening outside the Solar System, the popular uneducated public understanding of what a planet was took over. I have to say this doesn’t reflect my perception of what happened based on my knowledge of astronomy. I’m aware of the controversy about the canals, the discovery of Pluto, the idea that Mercury always faced the Sun and so on, all ideas which resulted from astronomical research at around that time. I’m aware of the research that was being done at the time about stellar evolution and the realisation that there were other galaxies, but it really doesn’t seem like they were concentrating that much on that more than this Solar System, but anyway, that’s what this paper claims.

Further, it claims that because they adopted a kind of folk understanding of what a planet was, it had led to them adopting earlier, non-scientific ideas about it. So for example, the public was really into astrology and had only recently got used to the idea that the Sun was at the centre of the Solar System rather than Earth. The authors of the paper give examples of how scientific classifications differ from public ones. For instance, most people think of fruit and vegetables as two different things but when it comes to botany, vegetables include fruits, which are the reproductive organs of plants, so from a culinary viewpoint fruit and veg are separate but scientifically they aren’t. To this I would add a couple of things which are I hope relevant to astronomy. One is that I think of a lot of things as fruit, such as tomatoes, aubergines, courgettes, peppers and tomatoes, which other people seem to think of as vegetables because it makes sense to me to think of them nutritionally and in terms of flavour in that way. The other is that the culinary arts are also sciences, and it seems a bit hierarchical to see them as inferior to botany for some reason. After all, we all need to eat. Applying that to astronomy and planets, that would mean that although some things are planets and some things aren’t according to astronomers of a particular vintage, that doesn’t mean there isn’t another branch of science which would view them differently. For instance, everything is subject to the laws of physics, and geology would seem to apply pretty much equally to planets, moons and asteroids in their own way. They’re just bodies in space like everything else. Therefore, I’m not convinced about this. Also, the general public were specifically irritated at the idea of Pluto not being a planet any more, so I don’t see how exactly they were using the public view of what planets were if they managed to annoy so many non-astronomers with their assertion that Pluto wasn’t one.

What seems to have happened is that the problem crept up on astronomers and they kind of panicked and made a fairly slapdash and hasty decision. As various large bodies were discovered on the edge of the Solar System, they became uncomfortable with the idea that they were probably going to end up with a very long list of planets, which seemed unwieldy and not very “neat”, and they also perceived it as an imposition on education that people were going to have to learn about so many worlds. They seemed to feel like this would be regarded as off-putting. The paper compares the situation with how mammals are defined. The official definition of a mammal is now rather abstruse, because it actually hinges on how many bones are in the jaws and the ears, but this is partly because of the need to identify fossil mammals. The widely-used definition is “animals who suckle from their mothers as infants, maintain a different body temperature from their environment, are often covered in fur or hair and mostly give birth to live young”, and the first criterion is the most important. There are exceptions to most of these. For instance, some hibernating mammals don’t keep their body temperatures above their surroundings and humans, whales and elephants are largely hairless, but this is a fairly good definition. However, claim the authors, astronomers have taken a weird approach to planets, having concentrated on whether they dominate their local region, which is in any case vague because what’s local? They’ve also looked at how they move. If mammals had been defined in this way, as warm-blooded vertebrates who walk in herds on land for example, a lot of mammals would’ve been excluded. Bats and whales would then not be mammals and any mammal who has a largely solitary life, such as leopards or sloths, would not then count as mammals either.

Looking at the history of the idea of planets, for a long time any round object in the sky which didn’t appear to stay in the same place was a planet. This used to include Cynthia and the Sun, when people thought Earth was at the centre of the Universe, and it didn’t include Earth. Later on, the four largest moons of Jupiter were discovered and also referred to as planets, and even the thick parts of the rings on either side of Saturn due to the poor quality of telescopes at the time. Later still, Ceres was called a planet because it seemed to fit into Bode’s Law, and turned up where it was expected. By that time, however, the known satellites had been relegated to moons, and soon after Ceres was also demoted because it was realised that there were thousands of other bodies between Mars and Jupiter, some even quite large.

The 2006 definition also has a rather silly consequence which a few people have noticed: it means Earth isn’t a planet! As I’ve mentioned before, from the Sun’s perspective Cynthia doesn’t orbit Earth, but the two weave in and out of each other’s orbits. I’m not completely clear what the astrological influence is supposed to be, but I think it’s the emphasis on orbits, i.e. the kind of definition which would’ve excluded bats, whales and leopards from being mammals. Whatever the definition of a mammal is, it seems to make more sense to use their anatomy and physiology than other more dubious criteria. Both of the definitions I mentioned above do this. The first is rather abstract and strange to most people, although there are good reasons for it – mammal jaws and teeth survive better than the rest of their bodies so it’s like identifying a body by dental records – but both of them focus on what their bodies are like, which seems entirely sensible compared to that fictional other definition.

What, then, is proposed as a more sensible definition of a planet? Well, it’s closer in spirit to that way of defining a mammal. A planet is a geologically active body. I have to admit I’m not sure about this because of various things, such as “eggshell planets”, and I’d also want planets to be round and I can’t tell if they also stipulated that. What it means (I’ll get back to eggshell planets in a moment) is that Pluto’s Sputnik Planitia which is created by frozen nitrogen and is active even though the Sun isn’t strong enough at that distance to have that effect. In talking about asteroids, I’ve mentioned the fact that the larger ones tend to be layered like Earth is, but the smaller ones are either rubble piles or mixtures of different minerals and other substances which aren’t separated out in the same way. A geological process has done this sorting in the larger ones, and consequently Ceres, for example, could count as a planet: it has been geologically active.

This applies also to some moons. Io, the innermost large moon of Jupiter, is intensely active with continual volcanic eruptions, to the extent that it’s thought to “turn itself inside out” every few years – some much of its interior is spewed onto the surface that the former surface becomes the interior and proceeds to get thrown out itself a few years later. This is because of the tidal forces effectively “wringing” the moon all the time, with the other large moons in the Jovian system along with Jupiter itself wreaking havoc on the place. By this standard, Io is definitely a planet, albeit a planet which is also a moon.

I’ll now permit myself a digression into eggshell planets. An eggshell planet is a surprising kind of “planet” which kind of “does nothing”. It isn’t necessarily possible to tell from a distance which planets are like this. Earth’s crust is divided into plates, and other planets have a thick, solid layer all the way round, but there is another possibility or which at least three examples may have been found already. This is where the crust is thin and fragile, and so cannot have plates or thick layers, and also can’t even support mountains or hills, so the surface is solid and also smooth, and nothing happens there – no volcanic eruptions, continental drift or erosion, because there’s nothing to erode. The question arises of whether this even counts as a planet under this new definition, since it isn’t geologically active. However, there are no such planets in our Solar System as far as anyone knows, and they’re probably quite rare.

There are three categories of planets suggested in this new definition: terrestrial planets; giant planets; satellite and dwarf planets. The last category is the largest. It includes the large moons of Jupiter, Ceres, Titan, Pluto, Charon, Eris and Sedna, and in fact there are more than a gross of these. Far from the expected response, apparently people tend to be quite excited at the idea that there are so many planets around the Sun. The giant planets include Jupiter, Saturn, Uranus and Neptune, so no surprises there, although this clear-cut division may be an artifact of how our own Solar System is, with its complete absence of the very commonest type of planet, the mini-Neptune, intermediate between Earth and Neptune in size.

There are five planets in the terrestrial category rather than four, because once the criterion for dominating its orbit has been removed, Cynthia becomes eligible, which makes me very happy! Cynthia is not even in the same group as the satellite and dwarf planets, but a planet just like Mars and Mercury. This also means that the Apollo astronauts landed on another planet, not just our moon. As well as that, Earth now has no moon!

It seems that the process leading to the decision to redefine planets was not very scientifically grounded and was in fact rather acrimonious. The orbital dynamics people took umbrage at the geophysical definition and there were only a few days available for debate, forcing people to take sides quickly without due consideration. Planetary scientists were underrepresented because they’re apparently not officially astronomers, which is a bit astonishing. Another motivation was to keep the number of official planets low because the IAU didn’t expect the alternative to go down well with the public because previously, i.e. in Victorian times, they’d felt more comfortable with a small number of planets. They were used to seven at that point, including the Sun and Cynthia. This is probably no longer the case, so in 2006 they made a decision based on misjudging the mood of the general public.

To finish, I’m going to make a commitment. Henceforth I will be referring to every spheroidal body in the Solar System as a planet, although I will also acknowledge what kind of planet it is, such as a moon or dwarf planet. And Pluto is a planet!

I’d be delighted to hear your views on this.

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.