Beyond 360

As of this writing, the exploration of the farther reaches of the Solar System, by spacecraft, lander, and telescope, continues apace. Cassini continues its swings around Saturn, with each pass discovering new facts and new questions about the planet and its moons. The MER rovers on Mars roll into new landscapes every day (well, Spirit does; Opportunity’s been stuck in one place for a while, though it should start moving again soon). The New Horizons spacecraft was launched a few days ago and is en route for Pluto; while recent measurements of thermal emissions from the trans-Neptunian object 2003 UB313 show it to be about 30% bigger than Pluto, making it a candidate for a tenth planet.

But there was a time — not so long ago, a little over forty years, well within living memory (and even those of us who are not quite old enough to remember the era directly may have had a little contact with it by being exposed to out-of-date astronomy books) — when we didn’t have to explore the Solar System with satellites — we’d already explored it in our imaginations for sixty-odd years, and we knew what it was like, what we would find when (not if) we ventured off Earth in our rocket ships. And although pretty much everything we knew was wrong — and though the Solar System turns out to be, in some ways, weirder than we ever imagined — nothing quite recaptures the sheer romance of that vision of our planetary neighborhood. Founded, originally, on the science of the day, it ended up taking on a life of its own in pulp magazines, comic books and science fiction novels — only, in the end, to be brutally despatched by the same science that had first breathed life into it.

Let’s take a look at some of the longer-lived fantasies about our solar system, how they were born, and how they died:

Vulcan (1859-1916)
First, one of the shorter-lived fantasies, which was only occasionally echoed in the literature. There was, in 1859, an erroneous report of a telescopic observation of a small planet moving across the Sun, inside the orbit of Mercury. The astronomer Urbain Le Verrier (who contributed to Galle’s discovery of Neptune) called this imaginary planet “Vulcan”. Repeated telescopic searches failed to turn anything up (were the Vulcanians blocking the astronomers using telepathic thought-screens?). But some physicists thought it might account for the precession of Mercury’s highly elliptical orbit. In 1916, however, Einstein’s theory of General Relativity accounted for Mercury’s orbit without reference to Vulcan. Nonetheless, Vulcan occasionally popped up in science fiction stories over the next decades, and perhaps helped inspire the name of the Star Trek planet. The imaginary Vulcan never was very popular, however; being as close to the Sun as it was supposed to be, it would hardly be much more than an orbiting lump of charcoal, and so very uncomfortable.
Mercury (1889-1962)
The planet Mercury has always been rather difficult to observe, because it is so close to the Sun; good observations can only be made when it is at its greatest elongation — the farthest distance from the Sun, as viewed from Earth. For a long time nobody was able to make out anything on its surface. Then, in 1889, the Italian astronomer Giovanni Schiaparelli (who will show up again) claimed to show by observation that Mercury was tidally locked in its orbit — that is, like most of the larger planetary moons, its rotation (day) was the same as its revolution (year) and so it always had one face turned toward the object it revolved around, in this case the Sun. Mercury’s year was well known to be just under 88 days.
Mercury is so close to the Sun that it could be assumed that it would be extremely hot, assuming it exposed all of its sides to the Sun equally. However, if it was tidally locked, then one of its faces would always be turned away from the Sun, and would be not hot but freezing cold, as no sunlight would ever reach it. But if Mercury rocked back and forth in its orbit a little bit, as the Moon does, then there would be a narrow belt of twilight where the Sun would rise and set, just above and below the horizon. Temperatures in that zone might be fairly mild; and if Mercury had an atmosphere, the “twilight belt” could be habitable.

This was actually the scientific consensus for over sixty years, not merely science fiction. It had a grain of truth to it: Mercury’s rotation and revolution are synchronized, only instead of the ratio being 1:1, it is 3:2 (3 rotations for every 2 Mercurian years). As, by chance, the viewing geometry for observing Mercury from Earth is most favorable at just about every 2nd Mercurian year, which meant that the same face of Mercury would be visible in a sequence of such observations. The dream of the “twilight belt” died in 1962, when thermal measurements of Mercury’s “darkside” turned out to be far warmer than would be expected for a surface that never saw the Sun! In 1965, radio astronomy allowed for a precise determination of Mercury’s rotation period — 58.6 days.

There remains one smidgen of hope for those who miss the romance of the “twilight belt”; even though all of Mercury is exposed to the Sun, there are two places where the Sun is always on the horizon, and where certain craters might always be in darkness, namely, Mercury’s north and south poles. Astronomers guess that such permanently dark craters might hide caches of frozen water ice.

Venus (1918-1962)
The planet Venus was a complete mystery until comparatively recently. This is because it is shrouded in a layer of opaque haze which prevents visible light from returning from its surface. Even its rotation period could only be guessed at by attempting to observe cloud movements; but since, in visible light, Venus’ clouds barely show any differentiation at all, there was no consensus, with suggestions varying from a 24-hour day (like Earth’s) to a day synchronized with Venus’ 224.7-day year.
Venus was therefore open for all kinds of guesswork, almost all of it wrong. A correct generalization was that, since Venus was closer to the Sun than Earth, it must be warmer. This is true; however, nobody correctly guessed how much warmer it would be. A further line of reasoning came from the supposition that the outer planets had formed earliest, and the inner planets later. Venus therefore must be younger than Earth, and should look like Earth in the past. As for the clouds, the first assumption was that they were clouds of water vapor, like those on Earth. But for Venus to be permanently clouded over, it must have enormous amounts of water and water vapor: it must be a soaked, soggy, swampy planet where it rained all the time.

Add these suppositions together, and you start looking into Earth’s past for a warmer, wetter, more primitive period. The Swedish chemist Svante Arrhenius, a believer in panspermia (the idea that all the planets had been ’seeded’ with life by spores from an outside source), declared in 1918 that “A very great part of the surface of Venus is no doubt covered with swamps, corresponding to those on the Earth in which the coal deposits are formed, except that they are about 30°C warmer”. His evocative description (much longer than the part quoted) of a humid Venus, covered in luxuriant vegetation, more humid than the Congo, and reminiscent of the tropical swamps of the Carboniferous period in Earth’s history (which Arrhenius may not have realized actually formed during a climatological cold snap) was so memorable that it persisted even after spectroscopic studies in the ’20s failed to detect any trace of water in Venus’ atmosphere at all. The concept of a desert Venus never caught on, and as late as the 1950s various proposals were made for a global ocean on Venus — including one made entirely of carbonated water! Fictional portrayals of Venus tended to alternate between a rainforest Venus and an oceanic Venus, and occasionally combined elements of both.
In the late 1950s, microwave studies seemed to show that Venus had a temperature of over 300°C; but nothing was conclusively proven until the Mariner 2 probe flew past Venus in 1962, showing that Venus temperature actually went up to about 500°C (over 900°F) — hot enough to melt lead (admittedly, a metal with a low melting point). It was devoid of water, though there was plenty of carbon dioxide — the high temperatures were driven by a greenhouse effect. The clouds were not water vapor, but droplets of sulfur dioxide and sulfuric acid. Venus’ rotation turned out actually to be slowly retrograde, with a period of 243 days.

Venus was also briefly thought to have a moon, called “Neith”. This spurious moon was observed near Venus at various points from 1672 on; detailed investigation showed that most of the claimed observations were actually stars that happened to be visible near Venus at the time of observation. Other instances may have been optical effects from imperfect telescopes. By the end of the 19th century, Venus was known to be moonless. Nonetheless, Leigh Brackett, in her story “The Moon that Vanished”, described a former Venusian moon which had impacted the planet, thus recapitulating the true story of the vanishing of the imaginary “Neith” as a fiction about the disappearance of a real moon of Venus.

Mars (1877-1895-1965)

The fantastic Mars is probably the best remembered of all the planets; most astronomers, anyway, recall that for a long time Mars was imagined to have impossibly straight lines criss-crossing its surface, called “canals”, and that some people insisted on attributing them to a Martian civilization (never mind that any structure big enough to be visible from another planet is well beyond the capability of any technology we know of).

The Martian canals were born in 1877, when Giovanni Schiaparelli discerned faint lines connecting the dark patches on Mars that had already been observed for centuries. After long periods of observation, he drew up a map — the best that had been made to that date — of Mars, showing it criss-crossed with over sixty such lines, some thicker, some thinner. In all cases they connected the darker areas; in some places, they came together and crossed in darker nodes.

In Schiaparelli’s scheme, these lines, which he called canali — Italian for grooves, channels, or canals (the term canale had already been used for a Martian feature by Father Secchi, though in a different sense) — spanned the Martian continents and drained into vast seas, which was how the dark patches on Mars appeared to him. The whole thing looked like some kind of planet-wide drainage system — could these canals have been deliberately built in order to dispose of excess water on a soggy Mars?

Schiaparelli’s discovery excited an amateur astronomer with a great deal of excess cash, one Percival Lowell, of a rich Massachusetts family. Retreating to Flagstaff, Arizona, he began observations of Mars from what was then a place with excellent viewing conditions — and he confirmed the existence of Schiaparelli’s canals (in his book Mars, published 1895). Not only that, but he saw more of them — in fact, he was seeing lines all over the place. (He also saw canals on Venus, but this was never made much of.) Of course he believed that they had to be made by intelligent Martians; no lines that straight, no system that vast, could be produced by nature. More importantly for the image people would have of Mars, Lowell saw lines running through what Schiaparelli had assumed were oceans; that meant that they could not be oceans at all, but had to be dry land. In fact, given that there were lines everywhere on Mars, all of Mars had to be dry as a bone, except for the polar caps (which Lowell assumed were made of water ice - which they in fact are, though overlaid with layers of frozen carbon dioxide). The dark patches — some observers perceived them as green — might be some sort of surface vegetation, seeing that they changed with the seasons.
Lowell’s conclusions on the dryness of Mars were correct, though for the wrong reasons. For of course, the lines did not exist. They were, at worst, entirely imaginary, and at best an attempt by the eye to connect minute features too small to be resolved individually. The dark patches (only green when perceived against the reddish background of the rest of Mars) were neither oceans nor vegetation, but simply a darker soil, whose borders shifted with each sandstorm - which on Mars can sometimes be planetwide in scale.

Many astronomers could not see the canals and disputed their existence. Cartographers of Mars sometimes drew canals, sometimes not, more often sketchily hinted at them. Lowell however believed firmly in their existence to his dying day; in his mind, they were the vast architectural project of a dying race on a waterless planet, doomed to maintain their existence by pumping water from the polar caps.

This is the vision of Mars that was taken up by science fiction writers, first of all by Edgar Rice Burroughs in his A Princess of Mars (first serialized in 1912). Burroughs was not, then or later, a good writer, but his choice of topic was new to most, and his picture of a decadent civilization on a dying planet overrun by savage, inhuman hordes left a deep impression. Burroughs introduced many details incompatible with Lowell’s vision — for instance, Lowell had to believe that, in order for his canal system to function, the surface of Mars had to be flat as a marble, something decidedly uninteresting for a fiction writer. Burroughs’ Mars had once had seas, but they had vanished; thus, once again, the history of beliefs about a planet was recapitulated in the fictitious history of the planet.

Later writers composed much better stories of Mars than Burroughs ever wrote, and many details of the fantasy Mars changed; but the general concepts of an arid Mars dotted with ancient decaying civilizations remained in stories of Mars written as late as the 1960s. The canals were usually marginal to the stories, but they were usually there. Then, in 1965, the Mariner 4 probe flew past Mars and took pictures which revealed a cratered, moonlike terrain — but no canals. Later probes showed more interesting features, including real “channels” — but these were natural features, carved during gigantic floods at a very ancient epoch in Mars’ past. The fantasy Mars of seventy years had ceased to exist.

Beyond Mars

Beyond Mars there were no such fixed conventions as dominated the mental images of Mercury, Venus, and Mars. The asteroid belt was viewed then as now, as collection of small, airless, mostly uninteresting rocks. There was however a theory that it had once been a single planet, which had then violently disintegrated — recapitulating, perhaps, the brief period in the early 19th century when the asteroid Ceres had indeed been accepted as a “fifth planet”. It is now generally thought that the asteroids never formed a single cohesive mass, though doubtless there has been a good deal of mutual impact and shattering of the original bodies of the belt. Some asteroids are little more than piles of rubble, only loosely held together by a very weak gravity. However, the “fifth planet” concept, suggesting some occult power that could have destroyed an entire world, figures in a number of science fiction stories, and may have suggested the idea of the exploding world of Krypton in the Superman mythos.

Jupiter and Saturn were sometimes regarded as habitable worlds; it was understood that their cloud layers obscured whatever surface lay beneath, but it was not until the late ’30s or ’40s that it entered the fictional consciousness that there was nothing underneath except more clouds. That left the moons of Jupiter and Saturn; consideration of their distance from the Sun might prompt the reflection that they were too cold for life; however, many writers simply ignored this (even putting jungles on the moons of Jupiter), or gave some excuse for warmer temperatures like the moons’ internal heat.

As a matter of fact, Jupiter’s innermost large moon, Io, is volcanic, and in spots can be remarkably hot; but the overall temperature is still bitterly cold. Jupiter’s other moons are no better, though there is believable speculation that the icy outer shell of Europa hides a sub-surface ocean of water. Saturn’s moons are even colder; on Titan, ice is as hard as rock and methane flows like water.

Uranus, Neptune, and Pluto had even fewer fans than Jupiter and Saturn, being generally correctly judged to be too cold and dim to support life, and too far away to be terribly interesting even as colonies.

The consensus view of the solar system, accepted as science in the early 1920s and propagated, even after it had become doubtful, by science fiction writers long after, lasted in its entirety less than 50 years — though some of its elements were far older. Nonetheless it was curiously powerful and produced a vast literature, which though of very variable quality, is at its best both inspiring and thought-provoking. As the memory of that period fades, it is worth preserving a record of what was believed to be true, or at least possible, about our neighboring worlds at that time.

When I first read Edgar Rice Burroughs’ Martian novels as a child, I was somewhat perplexed by his references to Martian “fliers”. These flying boats and ships appear from the first novel, “A Princess of Mars” (1912), but are nothing like the airplanes which were still in their infancy at the time of their writing, nor even like the somewhat more advanced dirigible airships. But Burroughs refers to his “fliers” rather casually, without much description or explanation, as if he expects his readers to know exactly what sort of thing they are.

I didn’t learn until much later that Burroughs was drawing upon an already well-established vein of fiction that preceded him, and which was filled with fantastic aircraft of all sorts. I’ve now begun reading some of this old science fiction (arguably, the earliest science fiction), written in a time when the air was mankind’s next frontier, and was invested with some of the romance, danger, and speculations on technology that a later generation would associate with spaceflight. The period of this type of fiction goes from the 1880s (and quite possibly earlier) to soon after 1910, at which time aeroplanes had become common enough that it was no longer possible to write purely speculative stories that did not take into account the existing technology.

Human flight had been possible since 1783, when de Rozier and d’Arlandes flew over Paris in a Montgolfier balloon; but most fictional balloon-related literature related to the exploits (or mishaps) of individuals and did not envisage cultural or social changes as a result of flight. Probably this was because the early balloons were uncontrollable.

Perhaps the earliest reference to a world socially changed by flight appears in Alfred Tennyson’s poem “Locksley Hall” (1842 - but begun in 1830), lines 119-126:

For I dipt into the future, far as human eye could see,
Saw the Vision of the world, and all the wonder that would be;
Saw the heavens fill with commerce, argosies of magic sails,
Pilots of the purple twilight dropping down with costly bales;
Heard the heavens fill with shouting, and there rain’d a ghastly dew
From the nations’ airy navies grappling in the central blue;
Far along the world-wide whisper of the south-wind rushing warm,
With the standards of the peoples plunging thro’ the thunder-storm…

Here the “argosies of magic sails” are probably envisioned as balloons, but the imagination here encompasses both aircraft of commerce and aircraft of war — both prophecies which would be adequately fulfilled within a hundred years of Tennyson’s writing.

It would not be for some decades, however, before book-length stories would begin to chronicle the imaginary future of air flight — a future that would be recounted time and time again, until the present caught up with the future, and imagination, hindered by reality, went on to wider pastures.

Better examples of this type of story include:
Robur the Conqueror (1886) by Jules Verne
The Angel of the Revolution (1893) by George Griffith
Olga Romanoff (1894) by George Griffith
The Outlaws of the Air (1898) by George Griffith
Master of the World (1904) by Jules Verne
With the Night Mail (1905) by Rudyard Kipling
The War in the Air (1908) by H.G. Wells
As Easy as A.B.C. (1912) by Rudyard Kipling

One of the first conclusions one can draw from these works is that, although these writers shared the faith that the coming decades would see humans take to the skies, for good or ill, there was no clear understanding of the form air travel would take: it might be predominantly by some form of dirigible balloon, or else lift might be achieved by a series of propellor-bearing masts (experiments with multiple helicopter rotors suggest that this is not really a great idea). For a form of science fiction, the science is skipped over with a good deal of handwaving, and not surprisingly so — the science of aëronautics was so much in its infancy that its basic principles were not well understood until decades after the Wright Brothers and Alberto Santos-Dumont had succeeded in getting what were essentially human-bearing kites into the air — for the most part on the strength of new gasoline engines and sheer willpower. Some of the more charming visions of what air travel might look in the pre-Wright æra can be seen on this page celebrating the artist Harry Grant Dart: great battleships of the skies, borne up by dangerously flimsy-looking “planes” of canvas stretched over wood.

The general tendency of the authors is to view air travel as an inevitable but probably world-changing (sometimes devastatingly so) event. The horrors of aërial bombardment were envisioned, but the capacity of air power for changing the course of a war was overrated — it was not the destructive power of aircraft that was underestimated, but the resilience of human psychology. It was assumed that the ability to launch death from the air would result in blind panic and surrender to whatever authority controlled the aircraft; leading, in The War in the Air to world devastation and civilizational collapse, and in With the Night Mail to dictatorial control of the world by a board of air traffic controllers.

This short-lived genre of literature has many of the characteristics of later brands of science fiction — the assumption of easy technological progress, the skipping over technical hurdles to concentrate on the gross social and historical effects of the (assumed) technology, as well as a nearly morbid fascination with imaginary machinery, and its destructive effects, that places most of these works in the same mold as contemporary so-called “hard sf”.

Where it differs, of course, is in seeing its predictions fulfilled — if one can say that of an actual present in which almost every detail of engineering and social history has been given the lie — within a very short time, and in the case of Wells and Kipling, with the lifetime of the the writers. The entire genre lasted less than thirty years. Nobody writes about air travel now, as such; it has merely become a prosaic and irritating exercise that can, at best, form the background to some other kind of travel (as in Ursula Le Guin’s Changing Planes).

One can sense the earlier science fiction writers — in this case, underestimating the technological difficulties — rushing to avoid a similar fate overtaking them. Assuming that their lesser predictions would come true in a matter of decades, they quickly bypassed first voyages to the Moon and Mars (in contraptions that, it was assumed, two or three good scientists could build in their backyards), rushed through the Solar System, and headed out to the stars — hoping to get a good enough head start that it would take the scientists some little time to catch up with them.

The results are paradoxical. Much that is science-fictional is simply not written about, in the assumption that it has been or will soon be done, even if there is little truth to the assumption. Nobody writes now about voyages to the Moon, because Apollo 11 “did that” — though, in truth, the Moon is almost as much a stranger to us now as it has been since the 17th century. The rest of the Solar System is deemed too boring to write fresh stories in, as if we had already fully explored and colonized it — though it contains millions of square kilometers of completely uncharted territory. Imagination has leapt beyond to imaginary star federations and space empires, but science and history have not yet taken hold of the territory thus abandoned. Nobody is really doing much thinking about just what a network of space colonies within the bounds of the real solar system would look like, for instance.

It wasn’t always thus. There was a time when the Solar System teemed with life and opportunities, and brave pioneers sought out danger and adventure in the sands of Mars, on the moons of Jupiter, and among the rings of Saturn. But of that more anon.

The newly released cinematic adaption of The Lion, the Witch, and the Wardrobe is a good movie. If you enjoyed any of C.S. Lewis’ The Chronicles of Narnia, you will probably like it. It is, however an uneven movie. There are parts that are so good they can make you cry; there are other parts that are, not awful, but simply do not measure up to the good parts.

Part of this is due to the source material. When the movie is spot on, it is, I may say, better than the book; not that it falsifies the book (it is in fact extraordinarily faithful) but it manages to convey in pictures what Lewis was only able to hint at in words. When the movie falls short, it is sometimes because of defects in Lewis’ story.

The scriptwriting is quite good, and conveys the essence of Lewis’ story without being verbose or banal. The pacing is excellent; I was never once bored, though I knew the whole story beforehand, minus a few minor alterations made in the script beforehand. I cannot praise enough the two actors and two actresses who played the Pevensie children. They were the outstanding highlight of the movie — which is good, because they have to carry it pretty much by themselves. This is especially remarkable because not only it is hard not only to find good child actors, it is especially hard to find good child actors who can play well in ensemble. The casters, the directors, and the children themselves are highly to be commended.

Edmund (Skandar Keynes) is the first character to develop a clear personality — as a thoroughly tiresome lout, frightened to death of spending the rest of his life in the shadow of his older brother. His reformation of character is thoroughly believable, driven as it is by circumstances rather than by some miraculous revelation.

Peter (William Moseley) is almost as irritating as Edmund, and appropriately so — a child trying to shoulder the burden of taking care of his three siblings, and doing so by putting on a rather pathetic fatherly impersonation. He comes in time to develop some real, as opposed to mock maturity.

Lucy (Georgie Henley) is ten years old (nine at the time of shooting) and doesn’t even look her age (the costuming helps here) but is astoundingly mature and poised as an actress; yet she is thoroughly believable as a playful, imaginative girl who bounces around on the tip of a range of emotions, from delight to tears.

Susan (Anna Popplewell) is the most mature of the four siblings, trying to project a rational, intelligent demeanor (as well as playing mother to Peter’s father), but eventually shows some vulnerability. She is by far the most likeable and charismatic character in the movie.

The playwrights have improved on the book by setting the action clearly in the context of World War II and the bombing raids on London. We see a German bombing raid taking place, so we know what the Pevensies are trying to get away from (younger viewers are not likely to be familiar with this history). The heartache of the parting of the children from their mother at the railway station is extraordinarily well-presented and emotionally wrenching. The Wardrobe itself is an extraordinarily beautifully decorated piece of furniture (with dimly-viewed carvings alluding to its history — a small nod to those fans who know more of the Chronicles than just ‘Lion’).

The magic of the movie begins to falter, surprisingly enough, when we enter Narnia. The main problem, as you might expect, is the special effects. These would be more than adequate for 1995, but one has come to expect a little more. There are certain problems, for one thing, with shooting a large part of the story in a snowy landscape — the fake snow currently in use in the movies is good enough for brief shots, but in closeup it simply doesn’t look, or behave, like real snow. And there is a great deal of it in the movie.

James McAvoy does a good job as a somewhat timid Mr. Tumnus, and looks appropriately faunesque, although (not surprisingly) he’s much tamer than the fauns of Roman mythology. There is something jarring in this day and age in seeing a little girl accept a strange faun’s offer to go up to his cave for tea. You want to shout “No! Never go home with a strange faun!” But this part of the plot could hardly be altered.

Tilda Swinton does her best as the White Witch. There are, however, flaws in the presentation of this character which have nothing to do with Swinton herself. She attempts, particularly in the early scenes, to project something of the charisma and serpentine sexuality of the Witch; her embrace-like
wrapping of Edmund in her furs (straight out of the book) has chillingly sensual overtones, which combined with her subtly mocking flattery of Edmund strikes just the right note. Unfortunately, as the story proceeds, this part of the Witch’s character fades; made up to look waxy and dressed in amazingly ugly rigid dresses — perhaps so as not to contrast too much with the animated graphic characters who form the Witch’s retinue — the Witch’s charisma disappears behind a translucent mask, rarely to reappear. Otherwise, she serves adequately as a powerful and frightening villain — though her trademark transformation of creatures into stone only occurs rarely. Viewers should note the peculiar neck- and head-dress that she wears into the last battle, a very subtle touch that almost escaped me (it is not from the book) and yet believably barbaric.

The talking animals — of whom the beavers, a fox, and some wolves have the chief parts — have obviously been laboriously worked on by the graphics studios. Unfortunately, they are not quite good enough. Save for a few moments where they are seen from a distance, moving as animals in fact do, they are not very believable. Mr. Beaver on all fours, or in the water, is convincing; Mr. Beaver plodding along on his hind legs is absurd. The wolves running as a pack through the snowy forest could be mistaken for footage from a nature documentary; the chief wolf, Maugrim, talking is a self-evident fake. Part of the problem there — besides the impossible lip movements on a wolf’s muzzle — is that the voice of Maugrim (Michael Madsen) seems to me thoroughly wrong either for a wolf, or for a secret police chief. The eyes of the creatures are also strangely dull and glassy. The same problems occur with the lion Aslan (about which more below).

One should therefore not go to this film for the effects. You should go to enjoy the stellar presentation of strikingly touching moments, moments that J.R.R. Tolkien would call “eucatastrophic”. These gem-like set pieces where things fall just right are beautiful enough to call tears to the eyes. When the snow begins to melt and the flowers come out; when the sleigh pursuing the children turns out not to be the Witch, but Father Christmas; when a tree-spirit materializes out of blown blossoms into a transient human form; when the mice nibble on the cords binding Aslan, and other such — these are the moments that really make the movie.

Oddly, the moment of the Resurrection of Aslan — according to Tolkien’s dicta, the supreme eucatastrophic moment of the movie — falls somewhat flat. The parallels to icons of Christ rising triumphant from the tomb are there, all right, but even that exploitation of associations fails to ring quite true. One is left thinking “well, he was a lion-god anyway, so here’s just another case of him using his powers”.

And this gets to the heart of a problem, not so much with the movie as with Lewis’ story, which the movie simply drives home. If “Lion” were meant to be an allegory of Christ, it would be poor and inexact one — though it might be all the better for a closer similarity. Aslan, King of the Beasts and of Narnia, is intended to be God in the form of a lion; but the combination of the two makes him less than both. Too godly to be fully leonine, at the same time he comes across, not so much as the Son of God or even as a saint, but as a slightly irritable and insular clergyman or professor. If Liam Neeson, who provided Aslan’s voice, was aiming for majestic paternality, he actually hits donnish avuncularity. The scene where, after Peter has just killed Maugrim, Aslan admonishes him to “wipe his sword” strikes a discordant and bathetic note — as much in the book as in the movie.

Aslan is no Prince of Peace; he spends much of the beginning of the movie making sure that things will come to a sanguine clash of arms at the end, and although we do not see it graphically, it is strongly suggested that he bites the Witch’s head off at the end. This event is slightly more obscure in the book, but a careful reading makes it clear that Aslan either bites or mauls the Witch to death.

I imagine this can be defended as a portrayal of the victorious, royal Christ Pantocrator of the Middle Ages, rather than of Jesus the teacher. Aslan does not teach about anything but the most mundane and practical matters; he is not worshipped because of what he says or does, but because of who he is. He is not even, except in the briefest and most perfunctory way, Jesus the “suffering servant”.

Any attempt to read the story of Christ against the story of Aslan will make the differences painfully clear; for instance, Aslan returns in order to replace the Witch’s rule with the rule of the four children (”Sons of Adam and Daughters of Eve’). But the purpose of Christ’s advent is not to invest a particular group of people with his delegated power — even if you try to read the Pevensies as saints. [The way Susan and Lucy stand in for the Marys at the sacrifice of Aslan, and, in the movie, the graphic depiction of haloes on the throne-backs at Cair Paravel, certainly implies this.]

In Narnia, the conflict between good and evil is more violent, and the resolution less ambiguous, than in Christian gospel and legend; though Lewis does allow his Judas-character (Edmund) a return to “sainthood” which Christianity denies. Lewis is simply not telling the same story, and it falsifies both Lewis’ story and the Christian story to equate them, though the many influences are undeniable.

If Lewis’ brand of Christianity doesn’t bother you (or if you can watch the story on its own terms, without worrying about Christian allusions); if you aren’t concerned about slightly subpar computer graphics and an occasional slip in characterization, but would like to see some truly fine acting by wonderful child actors and enjoy any number of emotionally resonant “eucatastrophic” moments, I strongly recommend that you see “The Lion, the Witch, and the Wardrobe.”

The grid that Claudius Ptolemy used to map the earth is a superb instrument. The exact position of any point on the surface can be defined by just two numbers. It has only one arbitrary element: the position of the Prime Meridian. It has only one big drawback: it only works on spheres.

The earth, as most people know, is not quite spherical. A circle drawn around the equator is just about 68 kilometers, or 42 miles, longer than a circle drawn through the poles. Now, the earth is quite a bit larger than that figure, so from a distance it doesn’t seem to matter. Close up, when measuring actual points on the globe, it becomes a bit of a pain.

From a strictly mathematical point of view, it shouldn’t matter; the grid can be applied anyway. The fact that the Earth rotates creates two non-arbitrary points from which your grid can start. Simply draw a line through the earth from its north pole of rotation to its south pole. Find the halfway point between these two poles — the “center of the earth”. Then find the halfway points on all the circles joining the north and south poles on the surface of the planet: this is the Equator. Now, divide each quarter-circle from pole to Equator into ninety degrees and draw a line from the center out to infinity through each degree mark. Where the lines intersect the surface, there are your parallels.

Only if your planet is a little bit out of true, the distances between those parallels are not going to be equal; if the planet is a flattened spheroid, each degree is going to be just a bit larger toward the equator than it is toward the poles. And if you try to make each parallel exactly the same distances apart, they won’t be at the same angles. This is true of the Earth; the length of a degree of latitude varies between 68.7 miles at the equator and 69.4 miles at the poles.

Of course, it’s not just the Earth that’s a spheroid. All of the other planets and a fair number of moons are spheres and spheroids as well. Why are they spherical? The basic answer is gravity. Given enough mass, and sufficient proximity in space, two masses will be attracted to each other. When one object is as big as a planet or moon, the attraction is pretty much one-sided; everything is dominated by the planet or moon’s center of mass. Anything that gets lifted up away from the center — waves, volcanoes, mountains — feels the pull of gravity to go back toward the center again. As gravity pulls equally in all directions from the center, when every atom has fallen as far as it can fall, you get a sphere, all the fallen objects being piled up at an equal distance from the center. Probably most of the spherical shapes were formed early in the history of the Solar System, when the planets were molten; their liquid shapes would naturally form spheres, distorted only by the centrifugal force of their spinning, which would flatten them a bit.

But rigid, non-molten objects may not collapse into spheres. When they are quite small, the pull of gravity can be too weak to counteract their structural integrity. How small?

Of the various natural objects currently circling the Sun, about thirty are known to be spheres or spheroids. The largest tend to be very even and smooth in shape — they do not really have surfaces, only outer gaseous layers whose cloud-tops form their visible outer boundaries. Since they are non-rigid, very massive, and rotating rapidly, these “gas giants” are also quite flattened.

The “oblateness” of a spheroid is measured by dividing the difference between the equatorial radius and the polar radius by the equatorial radius. If there is no difference, then the form is a perfect sphere; if it a positive number, then it is an oblate spheroid, and the larger the number, the flatter it is. Earth’s oblateness is about .0034. Jupiter’s is much greater: .0637. But Saturn, not Jupiter, is the king of oblateness, with a number of .102. If you look at an image of Saturn, you will see that it presents an oval face when viewed from the side; looking down from the poles, however, it is quite round. Uranus and Neptune, being smaller and more dense, are rather less oblate.

Earth is the largest of the rocky planets with a solid exterior. Venus, the next largest, is nearly a perfect sphere. Mars is slightly more oblate than Earth, but not much. Mercury, the next largest planet, is also an almost perfect sphere. Pluto, the smallest planet, has not yet been imaged adequately to make an estimate of its oblateness.

In addition to the planets, there are several planetary moons and at least a handful of asteroids that are large enough to be approximately round. I don’t have oblateness figures for them, but the largest of them are very nearly spherical. These include two that are even slightly larger than Mercury Ganymede, the largest moon of Jupiter, and Titan, Saturn’s biggest moon — though measurements of the latter have to take its very thick atmosphere into account; recent observations by the Cassini spacecraft have shown that the atmosphere actually differs in thickness by latitude. The next largest moons are Callisto, Io, our Moon, Europa, and Triton (the largest moon of Neptune), all of which present a nearly spherical profile, being too small for their rotation to redistribute their mass much.

As we descend in size and mass, however, the chances of a satellite being irregular become larger again; the smallest satellites are just irregular chunks of rock, chipped away by frequent meteor impacts; their mass is not great enough to form them into spheres. Between moons the size of Triton, down to moons the size of Neptune’s second largest satellite, Proteus, there is a liminal zone: moons in this region tend toward sphericity, but they can be deformed by other forces into distorted shapes. Moreover, at their small sizes, surface features often visibly interrupt their shapes, which no longer appear to the observer as neat circles.

Titania, Rhea, and Oberon — the largest of these mid-sized moons — are quite round, but Iapetus, only slightly smaller than Oberon, is not; some unknown trauma far back in its history has severely distorted its shape, flattening it on one side. It is the largest really irregular body in the solar system, not counting the gaseous planets, whose flattening is regular and predictable.

Smaller than Iapetus are Charon, Pluto’s moon, which has not been well-imaged; then Umbriel, Ariel, Dione, and Tethys, all rather similar in size; the larger Kuiper Belt Objects that have been discovered are estimated to be about the same size, but their exact size and shape are unknown.

The next largest object in the solar system is Ceres, the largest asteroid, orbiting between Mars and Jupiter. Images of Ceres are not very precise; it is nearly spherical, but may be slightly irregular. Smaller asteroids like Pallas and Vesta are at best elliptical (Vesta is actually a very squashed spheroid, more so even than Iapetus).

Among the moons, we have the mini-spheres Enceladus, Miranda, and Mimas. Enceladus, for its size, is remarkably round; Miranda, Uranus’ smallest moon, is generally round, but has such variable surface features as to seriously distort it shape. Mimas, the smallest body in the solar system that could be reasonably called round is actually somewhat egg-shaped.

Even larger than Mimas is Neptune’s Proteus, a thoroughly irregularly-shaped moon, with no round lines at all. Below Proteus, shapes are pretty much random, sometimes long and narrow, sometimes oblong, or compact potato-shapes. This includes the immense majority of objects in the solar system — though all together they count for an insignificant portion of its mass.

These facts bear on the question “what is a planet”?, which has especially been asked with regard to the outermost planet, Pluto — which some people would like to reclassify as the largest known Kuiper Belt Object — in effect, a very big asteroid.

It has sometimes been suggested that a planet is a body orbiting the Sun that is “large enough to be round”. But it is evident that the correlation between size and “roundness” is by no means exact, and a substantial body of objects exists in the twilight zone between the clearly spherical or spheroidal, and smaller and definitely irregular objects. A generous definition would require us to include Ceres and several Kuiper Belt Objects as planets. This is not in itself inadmissible — Ceres was considered a planet for many years after its discovery; but reminds us of how arbitrary our classifications are. Each of the nine recognized planets is very different from all the others, and no one definition easily encompasses them, except for this: they are the nine largest bodies orbiting the Sun. Why draw the line at nine, instead of lower or higher? There is no particular reason, but as it has been done, it might as well remain that way. The working definition of a planet might as well be “any body orbiting the Sun which is the size of Pluto or larger.” This tautologously keeps Pluto in the family of planets, but if Pluto is jettisoned, we might as well go on to drop Mercury from the list, or even Mars. But the time we finish, even the Earth might not count as a world.

Images are just being made available of the surface of Titan, showing a beautiful lacy network of what can only be rivers — not rivers of water, of course (Titan is too cold for that) but perhaps of liquid methane. It is stunning — managing to be simultaneously both alien and earthly. Thinking back to what John Wilkins used to define a “world” in the 1630s — mountains, seas, rivers, atmosphere, clouds — it may be that in Titan we have found, for the first time, a “world” other than Earth.

After Pythagoras’ ideas came to be accepted among the Greeks, a variety of ideas were proposed for the larger-scale construction of the universe. All of them still assumed a heavenly sphere, but varied in the contents placed within it. For a while, there was a great deal of controversy. Some people, like Heraclides of Pontus, supposed that the diurnal revolution of the heavens could be accounted for by supposing that the Earth spun like a top. Aristarchus of Samos was even more radical, arguing that the Earth not only spun, but moved in a huge circle around the Sun together with other planets.

However, calm, conservative heads (like Plato and Aristotle) won the day and these radical theories were placed in the rubbish heap. The consensus was that the earth stayed stable in the very center of the cosmos and the celestial bodies moved around it; proving that there was one law of circular motion for all regions from the Moon up, and another of motion toward the center of the Earth for the sublunary regions. Beyond the Moon moved the planets — not, as we now think of them, solid spheres, but as they are observed with the naked eye — brilliant specks (or in the case of the sun, a brilliant circle).

There were different ideas about how to place the planets in their distance from Earth; eventually the consensus order was that postulated by Claudius Ptolemy, who placed them in this order: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn — with the slower-moving ones farther away. But from a mathematical point of view, the distance did not matter and, so long as Earth was assumed to be at the center of the system, even relative distances could not be calculated, only angles. Each planet, including the Sun and the Moon, was placed within a transparent Orb or Sphere, which shared in the overall motion of the outermost sphere of stars, and also had its own proper motion, which caused it to move relative to the starry background.

Some confusion has arisen from the fact that, as was discovered via telescope, Mercury, Venus, Mars, Jupiter, and Saturn are actually more or less sphere-shaped. When the ancients spoke of the “orb of Mars” or the “sphere of Saturn”, they did not mean the shape of the physical planets — which, as mentioned above, they only knew as minuscule but brilliant points of light. Rather, they meant the entire transparent spherical shell, surrounding the whole earth, whose rotation caused the movement of the planet embedded in it. The renaissance notion of the “Music of the Spheres” uses the term “sphere” in this sense.

Although the Ptolemaic structure, thus drawn, looks something like our current model of the Solar System (with Earth and Sun switched) it should not be forgotten that the presuppositions of the two were very different. Our model is a description of physical relations in space, which can be interpreted to give us a picture of what the sky looks like at any given time. The Ptolemaic system, on the other hand, had become a set of mathematical conventions for predicting the appearance of the sky, with no guarantees that it accurately described the physical layout. Indeed, since the heavens were understood to lie on the boundary between the metaphysical and the physical — since the divine heavens and the visible heavens were not clearly distinct — then perhaps a purely abstract description was best? There was no assurance that the heavens obeyed physical or even geometrical laws anything like those observed on Earth.

The same indefatigable Claudius Ptolemy who, in his Almagest plotted the positions of the stars and accounted for the heavenly movements, also plotted the positions of the nations of the world within the Orbis Terrarum, the Circle of the Lands. The word orbis in this sense has multiple meanings; it could mean an “orb” or sphere, referring to the shape of the earth, but also to the situation of the terræ, the dry lands surrounded on all sides by the seas. Before the discovery of the American continents, medieval sketch-maps of the whole world showed the world as consisting of the three great continents of Europe, Asia, and Africa, compacted within a circle (orbis) and surrounded by the ever-flowing Ocean Sea.

These maps were, however, a step back from the geographical achievements of Claudius Ptolemy. On a practical level, his geography was not perhaps very great; a comparison of the maps in his Cosmographia with the maps in a world atlas of today doesn’t argue too well for his accuracy in detail. Only Europe, North Africa, and the Nearest East (the lands belonging to the Roman Empire) are even broadly accurate; to the east, south, and further north, the delineations appear to be those of some bizarre fantasy world. The Caspian and Aral Seas are merged into a single “Hyrcanian Sea”; India is flattened out, and Ceylon swollen to immense size; the Himâlayas don’t exist, but other mountain ranges unknown to modern geographers run across inner Asia; even the region of Alexandria, Ptolemy’s own city, is not very well drawn out.

However, it was as a theoretical geographer that Ptolemy excelled. He realized that there was a problem to be dealt with in describing the layout of lands on a spherical earth, and put his mathematical skills to work on it. He set up the grid of latitude and longitude that we still use today — though his zero-longitude went through the “Fortunate Isles” (more or less = the Canaries), and not through Greenwich. He devised methods for plotting sections of a sphere onto a flat page; these are for the most part not followed today, but he certainly pioneered the science of map projection. With the use of the latitude/longitude grid to map, first the Moon, then Mars and other globes in our Solar System, Ptolemy’s work has surpassed Earth itself.

Ptolemy’s geographical work went, unfortunately, largely unrecognized throughout most of the Middle Ages, and more sketchy geographical treatises took its place. In the fourteenth century the Cosmographia was “rediscovered”, or at least repopularized, at about the same time that Portuguese, Castilian and Catalan sailors were redrawing the map of the Mediterranean and of the Atlantic coasts.

The thought of turning a map of a sphere drawn on paper into a map drawn on a model sphere seems like an obvious one, but in fact it was quite late in coming. The first extant earth globes date only from the end of the 15th century — just prior, in fact, to the voyages of Christopher Columbus, whose discoveries would upset everyone’s geographical knowledge. But those discoveries would also make globes indispensable for understanding the true nature of the Earth; the old world-map had only occupied half the sphere, but the new lands showed that the whole sphere had to be taken into account.

Five hundred years later, so thoroughly have the ideas of “Earth”, “world”, and “globe” become meshed, that the standard shorthand figure for the earth is a circle crossed with curves in the shapes of lines of latitude and longitude.

One of the things that everyone knows about the world, our Earth, is that it is round, a ball rolling through space, almost if not quite a sphere. We’re surrounded by globes and maps that presume a spherical shape; the planetary globe is an icon of the modern world. If you search for images representing the word “world”, you will find pictures of the globe.

But in the overall history of knowledge, this insight into the shape of the world is a unique event. The spherical nature of the earth was unknown to the pre-Columbian Native Americans, to Australian aborigines, and remained unknown in parts of the Far East down to times within living memory. The knowledge that the earth is a sphere was, in the Middle Ages, found only in those parts of the world that had been touched by the astronomy of the Greeks, namely Europe and throughout the Islamic world.

The proximate source for their understanding of the shape of the world was the writings of Aristotle (de Cælo, etc.) — this being one of the rare occasions on which he got a physical fact mostly right. Aristotle’s prestige was such that his opinion was bound to be accepted throughout the Euro-Islamic world without question. But although Aristotle had certain good justifications for his claim, the theory went back before him to Pythagoras and the Pythagorean school.

Pythagoras (fl. 500 BCE) is probably best known for his theorem about the mathematical relationship between the sides of a right triangle. He was something of an oddball, whose ideas went beyond geometry into philosophy, music, and diet, and who was revered by his followers (who had a quasi-monastic lifestyle) almost as a religious leader. For Pythagoras, mathematics had a mystical element, teaching one about the ultimate nature of reality, and that through it one can rise to divine contemplation.

The curious thing about his discovery of the shape of the earth is that he almost certainly did not have enough evidence to support it. One can only hazard a guess at how he arrived at his conclusion.

The observation of the heavens shows that the heavenly bodies, including the sun, moon and stars, arise in the east and, after appearing to make circles about the North Star, they set in the west. Unless one is prepared to assume that these bodies are recreated every day in the same patterns, one is forced to assume that the world is finite in extent and that it is surrounded by the circles that these bodies make. If one assumes (erroneously) that they are all about the same distance from the Earth, and if one takes literally the circles they describe through the sky, one will get the picture of the earth being surrounded by a great sphere, in whose body the sun, moon, and stars move.

Having established that the heavens were spherical in shape (as we know, in error, but this would not be discovered until the 17th century), it remained to determine the shape of the earth. The shape of the heavens, as reasoned out, does not tell us that, but only demonstrates that the world is finite. Within the heavens, the world could be a flat plate of various shapes or any number of regular or irregular solids.

Given that our experience is that the earth appears to extend in all directions without bound, and that all things fall in a single ‘down’ direction, the natural assumption would be that the world is a very, very large plane. Of course, that begs the question of what such a plane would rest on in the middle of the heavenly sphere, if everything must fall down, but one might well reason that things fall toward the earth but the earth has nothing to fall toward. In the Far East, before contact with the West, this is about as far as cosmographical thought got.

The Greeks, however, had a bit more information than most other peoples. Like the Phœnicians, they were great travellers, and sailed throughout the Mediterranean; their voyages could take them from the Sea of Azov in the north to the Gulf of Sidra in the south. This is a bit less than 20° of latitude, but it’s enough for navigators keeping their eye on the North Star to notice that it would vary in height; from 30° above the horizon to more than 45°, a fairly substantial amount. What can you conclude from this? One possibility is that as one moves north one is drawing closer to the North Star, and as a result it appears to be further overhead. The problem with this analysis is that a basic geometry problem will show that if the angle of the North Star changes 15° over a distance of about 1035 miles then the North Star cannot be only about 1500 miles distant from the northernmost point of observation, and only about 1100 miles run from there to the northern edge of the world itself. Well, the Greeks knew from their explorations that the world was a lot larger than that.

But if, instead, you assume that the North Star is in a fixed position, and that its actual distance from the observer does not change significantly, then the surface of the earth has to be curved. But there are lots of possible curved surfaces. The observations of the change in angle could be accounted for if the Earth had a cylindrical shape, as the philosopher Anaximander believed. Other, irregular shapes, ovoids and so on, could also be envisaged. Pythagoras was having none of that. If the earth was indeed curved, then its form ought to be that of the most perfect solid shape, the sphere, of which all points were equidistant from the center. Pythagoras’ insight was therefore based less on science than on the mystical vision of the geometric perfection of the universe. As it happens, he was more or less right.

[To be continued]

The Cassini spacecraft has swung by the Saturnian moon Iapetus, taking close-up pictures far better than the best that Voyager was able to provide, and the results are both pictorially stunning and planetologically surprising.

Those who have read Arthur C. Clarke’s novel 2001: A Space Odyssey will remember Iapetus as the site where David Bowman discovers the alien monolith. There are not actually any monoliths on Iapetus, but the true Iapetus may be stranger than the fictional one.

Iapetus (named after one of the Titans in Greek mythology) has always been a lunar oddball. It is not a small moon; its surface area is approximately equal to that of Australia. It is the twenty-first-largest object in the solar system (unless some of the larger Kuiper Belt Objects, out beyond Pluto, are slightly larger) and the tenth-largest moon, and it is the third-largest moon of Saturn (after Titan and Rhea). But of Saturn’s seven large moons, six orbit in tight circles close to Saturn and parallel to Saturn’s equator, just like Saturn’s rings. Iapetus, however, orbits much farther out, and its orbit is extremely tilted with respect to Saturn, suggesting that it was not formed together with Saturn, but was an errant object that was captured by Saturn’s gravitational field.

This much has been known from telescopic observations since Giovanni Domenico Cassini discovered the moon in1671. Later telescopic details added to the puzzle, as it was discovered that Iapetus was a piebald moon, about half of it shiny white, the other half ashen black. This discovery led to a still unresolved ‘zebra question’: is Iapetus a black moon frosted with white, or a white moon dusted in black?

The new close-ups don’t immediately answer the existing puzzles, but they show previously unseen characteristics which raise even more questions. These include:

An enormous multi-ringed impact basin, and several other extremely large craters.

A bizarre ’seam’ running along Iapetus’ equator, which changes from a broad fault or fracture to the highest range of mountains in the solar system, so large that the disruption in the limb (the edge of the moon seen against space) is clearly visible from a distance. By contrast, Earth’s largest mountains are microscopic ridges on its surface.

The entire body of Iapetus is not, it turns out, near-spherical like other moons of comparable size, but distinctly ovoid or egg-shaped. This makes it the largest irregularly-shaped body in the solar system.

I can’t even begin to suggest explanations for any of these bizarre facts, other than the obvious one that Iapetus has been hit by an uncommonly large and forceful cloud of space debris. The rest of these facts point to something even stranger going on earlier in its evolution. The creepiest of all of them is the equatorial mountain range, which makes Iapetus look as if it had been sliced apart exactly throught the middle and then sewn up again. I’ve never seen anything like it. In many respects, this solar system we live in is stranger than we can imagine.

One of the most exciting scientific sites I’ve found on the web is Tree of Life, a site that charts, in a tree format (still being filled in), the relationships of all living things on earth.

The old-style biology, which I can still remember being taught, grouped living things according to rather superficial similarities (single-celled vs. multi-celled, sessile vs. motile, without vertebrae vs. with, finned vs. legged) creating large groups that actually had no particular relationship with each other. These groups were arranged in a rather rigid and arbitrary hierarchy: Kingdom, Phylum, Class, Order, Family, Genus, and Species.

The last couple of decades have seen the victory of cladistic analyses that are intended to show how closely related any two living beings are. All living beings can be considered related in some way; but some are more closely related than others. The most closely related are now grouped together in low-level “clades”, more distantly related ones are grouped together in higher-level clades; the relationships can be shown in a tree-like “cladogram” in which the most recent branching is lowest down. There is no limit to the number of clades that can be defined between the root of the tree and the individual species, so the terms ‘family’, ‘order’, ‘class’ are not much used any more.

The defining of “relationship” is the tricky point; evolutionary development is not simple, and defining relationships based on similar genetic sequences, or upon shared morphologies derived from a common ancestor (synapomorphies), can occasionally result in somewhat different results. Nonetheless, the overall picture that is emerging is stable, and is very different from what was taught in my high school biology class.

One of the objections made, when cladistic analysis first began to be discussed, was that it created “counterintuitive” groupings. “How can you create a clade,” it was asked, “that groups together cows and cœlacanths, when the latter are clearly fish?” (Lobe-finned fishes and terrestrial vertebrates are grouped together as Sarcopterygii; other “fish” are paraphyletic, belonging to several different groups whose only common ancestor includes obvious non-fish — like cows — as descendants, but the most familiar types, goldfish, tunas and the like (but not sharks) belong to the Actinopterygii, ray-finned fishes.

Of course, the reason for classifying plants and animals in the first place is to reveal relationships among them that are not obvious at first glance and may run counter to “intuitive” groupings like “fish” — which may still have some practical use, but are adequately represented in ordinary language. A paraphyletic “Class Pisces” that just corresponds to everything we call “fish” is not very enlightening; whereas realizing that cows and apes and cats and people and cœlacanths are more closely related to each other and share certain characteristics not found in tuna and goldfish actually does tell us something new.

Tree of Life is full of such revelations; the entire taxonomy of living things has been revolutionized in the past few decades. I would never have guessed that mushrooms (formerly lumped together with a lot of other things as “non-flowering plants”) are more closely related to monkeys than they are to maples: fungi and animals (metazoa) form a single clade, Opisthokonta. Nor would I have supposed that vertebrates are more closely related to echinoderms (starfish and so on), as members of the clade Deuterostomata, than they are to insects and mollusks. Equally surprising to me, though perhaps less sensational, is the fact that annelids (like earthworms) are more closely related to squids and slugs than they are to ants and crayfish; the notion that the segmentation of segmented worms corresponded to the segmentation of arthropods has been overthrown.

All of the above are part of an immense clade called Bilateria that includes all animals that are bilaterally symmetrical and have a centralized nervous system and (at one time anyway) anterior sense organs. Some bilaterians, like starfish, appear to be radially symmetrical, but actually have bilaterally symmetric larvæ; the radial symmetry is a later development.

The bilaterians, despite being the most widespread type of macroscopic animal, are actually a relatively recent development, appearing around 600-650 million years ago. The common ancestor of all bilaterians, nicknamed Urbilateria, would have been a small, soft-bodied, worm-like animal, unlikely to leave fossils (which it hasn’t). But it appears to have radiated into a wide variety of types over a short period of time, with its descendants soon (i.e., by the beginning of the Cambrian) becoming the most dominant type of large animal, which of course they still are today. Some people have guessed that this radiation is closely related to a period of intense cold and a high level of ice cover occurring around 600 mya; perhaps environmental stresses wiped out competitors and created opportunities for a (relatively) clever animal to succeed and proliferate.

The idea of evolution has been around for almost 150 years; but although it’s had a strong impact on some types of literature (particularly science fiction) it’s one which many people have not come to terms with. Some simply reject evolution (without understanding it); others give lip service to the idea, but have not realized how much it could or should affect our thinking about our position here on earth.

Homo sapiens is an exceedingly vain animal, inclined to view his own form as the most beautful and excellent in the world; he has tended to downplay or disregard his relationship with the rest of the living world, preferring to consider himself a degraded angel rather than even the best of beasts. One of the things, however, that a close consideration of the various manifestations of life, both in its living and fossilized forms shows is that there are no crystal clear lines between man and beast; between intelligence and unintelligence; even, perhaps, between sentience and insentience, or life and nonlife. These things have emerged gradually, and there are always intermediate stages which one can never quite clearly characterize.

This fact raises questions which philosophers and theologians have not clearly addressed — questions which go well beyond disagreements with Genesis 1-2 or Suras al-Hijr and Sâd in the Qur’ân. If humanity is distinguished from “the beasts” by the possession of a soul, for instance, how, when, and by whom was this acquired? Did H. erectus have a soul? How about H. rudolfensis? A. afarensis? Was there some miraculous transformation of an entire species? Or can we be sure that there really is a qualitative difference between humans and great apes, who seem capable of manipulating ideas and expressing themselves through symbols and signs, approaching at least the rudiments of language? Could the characteristics which we proudly claim as uniquely human also appear, in slightly changed form, in other animals?

It is sometimes objected that, whatever the truth of humans’ relationship to other animals may be, if humans allow themselves to be classified with the beasts, they will as a consequence act bestial — i.e., violently, impulsively, without man-made laws and boundaries. It is difficult, however, to see how humans could act worse than they currently do. Many of the people nowadays who plot to explode buildings full of civilians and who conduct saturation bombings of cities are die-hard creationists, whose assumption of their own angelic nature has not stopped them from conducting mass execution of their fellow-humans. They are encouraged to do this, not discouraged, by the same laws and boundaries which theoretically keep humans’ ‘bestial’ tendencies in check.

Perhaps a greater sense of our existence as part of the natural world, not as something apart from and above it, would help us behave in a more charitable way to fellow-humans and fellow-beasts alike; remembering that they are, after all, our relatives.

Writers of the fantastic often provide their books with maps of nonexistent lands, in order to help coordinate (for the writer) and explicate (for the reader) the action taking place in the book. The maps range in quality from highly detailed and artistic to mere doodles. An excellent example of the former is the map of the three kingdoms (of Rerek, Meszria, and Fingiswold) that appears in E.R. Eddison’s Mistress of Mistresses, done somewhat in the style of the beautiful copperplate maps of the 17th and 18th centuries. The latter can be found inside the lurid front covers of any novel on the shelf of a B. Dalton’s f-sf section.

The relationship of these lands to those of our earth is pretty vague; either it’s an entirely other world, which just happens to resemble our world in numerous particulars, like C.S. Lewis’ Narnia; sometimes the relationship between the two worlds is explicitly set out (as Lewis did) but more often the question is glossed over. Other writers set their fantasy lands in the distant past (like Robert Howard’s Hyborian Age) or in the distant future (like Clark Ashton Smith’s Zothique). Only rarely do writers or their map artists trouble themselves about geological considerations, far less fitting their map to current geological knowledge of the time period in which the action is supposed to take place; exceptions being books like the glacial-era “pre-historical” novels of Jean Auel.
This is perhaps a little bit unfortunate, since the reconstructed geography of the earth of past epochs is both detailed and — despite being continuous in time with our modern geography — strikingly alien in its outline of lands, far more alien than the geographies that many fantasy-map artists come up with.

Ron Blakey’s paleogeography page contains maps, for many different periods of earth history, which are not only informative scientific charts, but works of art as well. This geography of the past has been under-exploited by fiction-writers, for a variety of reasons.

An obvious one is that the science on which these maps is based is new, of only the past forty years, and the maps are being continually revised and updated. It hasn’t always been easy to find maps on suitable scales, either. Another is that for most of the history of the planet there have only been animals of no great intelligence, which somewhat limits the kinds of stories you can write. Though, from the point of view of the fantastic, this is no great obstacle; H.P. Lovecraft imagined humans as only the latest, and not the greatest, of a series of civilizations stretching millions of years into the past; an interesting, though implausible conceit, which could be exploited by authors — quite without adopting any of the ideas or modes of Lovecraft’s genre.
In the late 19th and earliest 20th century, a fair bit of fiction depended upon the imagination of civilizations on now-sunken continents and land bridges which were the stuff of the geology of the day. Modern geology has no room for Atlantises and Lemurias, but its Laurasias and Gondwanalands are, in my opinion, even better substitutes. What, really, is weirder — a world in which continents slowly rise and fall, or one in which they slide around the surface of the earth bashing into each other? It’s unfortunate that so much of this imaginative fiction got trapped in an outdated geological model — more unfortunate, I think, that no one has emerged to satisfactorily express the new geology in a fictional form.