The Tragedy of the Moon

Where I'd simply enjoyed The Left Hand of the Electron, I found myself disagreeing with Asimov more (while still enjoying the read) in The Tragedy of the Moon.

The Moon and Earth

The book opens with an essay on the downsides of having a moon. There are startling errors – right on the first page, I suppose a typo, since he speaks of the moon being captured only 600 millennia ago, where his own telling of matters laters makes clear he was well aware the Moon was here back when life first crawled onto land, more than a hundred times as long ago as that – and details he didn't know that we've later worked out, like the fact that the Moon is the accumulated residue of the spatter from a collision between two bodies that merged to form the Earth fourish giga-years ago. These are by the by. He weaves a fine tale of how the Moon, obviously orbiting the Earth, made a geocentric understanding of the universe far more natural and thus harder to shake than it would have been without the moon, particularly if, instead, Venus had had a similarly prominent moon making it obvious that something went round something other than Earth. He makes a fair case that a culture, that worked out early on that Earth wasn't the centre, would be less mired in anthropocentric assumptions, taking for granted our own importance, and would thus have been better stewards of the one habitable world at our disposal. So that made for a fine essay and a fun read and I have no complaint, despite a few minor errors.

As I understand the modern formation story, without that early collision throwing off a large chunk of Earth's lighter parts, notably including a lot of water, the planet would have had a thicker crust mostly hidden under deeper oceans, so I suspect only aquatic life would ever have attained intelligence. Tectonic activity and vulcanism would surely throw up some land; but less of it would get through the ocean's surface and all of it would be transient, since ocean erodes far faster than wind and rain. This would limit life on land to amphibious forms, always able to return to the ocean once the land washed away. While an aquatic culture can learn a little metalurgy, it would never have much to do with fire; and the physics of movement under water would have made basic early tools (that got us hooked on the habit of making tools at all) considerably less useful. Plants don't need to make vast rigid structures to get at sunlight, so there'd be no trees and no wood, so no spears with which a clever and nimble-fingered species could defend itself against larger and more powerful predators. Without fire, there are none of the accidental discoveries from which we get pottery and (more than very basic) metallurgy. With life operating in three dimensions, it's much harder to herd food animals. For these and many similar reasons, I thus think aquatic intelligences are less apt to develop technology. They might well develop language, poetry, art, music, song and story-telling; but they would never have glass, pottery, steel or bronze, nor would they spend long nights watching over their flocks with little to do most of the time but stare at the sky (and thus, over time, come to understand the patterns of movement of the dots of light that litter it). So I doubt that aquatic cultures produce the kinds of technology that would make a space program possible. Still, Asimov knew nothing of this, so I won't take him to task over it; so I'll let him have a world with comparable amounts of land to ours and, consequently, the ability to produce life like us.

The second chapter, contrasting with the first, is titled The Triumph of the Moon and tells the positive side of the story. As his first of thsee, he takes life's colonisation of land, which was surely assisted by the lunar tides – which were larger back then, due to the Moon being closer, while the Earth spun faster, than we're used to. I find this unconvincing, since life would surely make its way up-river and thus be subject to stranding on land when floods washed it out into pools that dry out; indeed, he acknowledges that this is how our own ancestors came to land. There would also have been modest solar tides, which would do some similar stranding, at least in the places where the land slopes gently down into the sea, such as near river-mouths, where silt makes the soil fertile and life can be expected in abundance. So, given his assumptions, I'm fairly sure life would have made it onto land just as surely (though perhaps not as swiftly) as with the help of the Moon's tides.

His second chosen moment when the Moon helped us along was when humans learned to count the months in a year and days in a month so as to better know the future. Here, I think, he is on somewhat better ground, although I think we would have learned to count our sheep and recognise patterns of stars and their positions in the sky at the right seasons for various activities. Our ancestors were nomadic; which does not mean the wandered at random, they surely followed a seasonal tour, aiming to be in right places at right times to benefit from particular seasonal bonanzas – the ripening of particular fruits and the migrations of edible beasts. So I think we would have learned, using the stars, to anticipate the seasons and use this fore-knowledge to gain control of nature. We would have developed a calendar, based on positions of constellations at particular times of night, and we would soon enough have learned to count the nights between particular points in that calendar. I've no doubt the nice easy pattern of the Moon's phases did help us do that, for all that it also put is a bit skew thanks to the Lunar cycle not being a simple fraction of Solar one of the seasons; but I do not think the help was inevitable or decisive.

I'm more sympathetic to his third triumph of the Moon: unlike everything else in the sky, it wasn't simply a uniform light. It varies in shape and has distinct markings, that we can readily construe as geography on a spherical world, illuminated by the Sun from one side. To be sure, it took a while before folk understood it in those terms, but the evidence was easy enough to see. Asimov omits one piece of evidence I suppose some ancients must have noticed: the unseen dark portion of the moon does hide stars as it passes in front of them, thereby revealing its presence. He also doesn't mention that understanding the Moon as a sphere may have helped folk to consider the possibility that the Earth is also a sphere. None the less, as he points out, this conception of the Moon as a world like ours took hold long before we saw the phases of Venus and Mercury (that needed a telescope) or the non-uniformity of Jupiter's (and later of Mars's) surface appearance; which, furthermore, we would have seen on different planets (Venus is quite uniform, the irregularities of Mercury were not easy to see with early telescopes; and neither Mars nor Jupiter shows phases). So I accept his conclusion that the Moon helped us to recognise the other planets as worlds like ours earlier than we would have done. Finally, of course, the Moon has also provided us with a nearby destination in space: one we were able to reach with technology far short of what it shall take to reach any other planet. Indeed, it may fairly be said that sending humans to other planets is folly – they are deserts at the bottoms of gravity wells – whereas a staffed moon-base shall actually make sense, by virtue of being close to home yet in a far shallower gravity-well. Even without bases on the Moon, its Lagrange points shall serve as useful places for any future space-faring civilisation.

He then embarks on a discussion of calendars and a proposal for calendrical reform. This is one of those fine ideas that's utterly pointless, at least when (as he does) you decide that some days shall not be any day of the week – these intercallary days make it possible to describe the year in terms of the day, despite their durations not being tidily commensurate, but they ensure that your calendar will get out of step with the ones being used by various major religions, who aren't about to play along. Fortunately, folk like me make software that can sort out the conversion between calendars (ultimately by mapping them all to a thing called the Julian day number) straightforward, so that the fiddly quirks of our established calendars (even including Easter) become harmless and easy to bear. Isaac was rather concerned with the business of printed calendars; but now we all have our calendars on our personal electronic devices and only buy paper ones for the sake of pictures on them or the things we're going to scribble on them to remind the rest of a household about upcoming events, neither of which would be well served by a perpetual calendar, whose chief virtue would the lack of any need to buy another each year (as long as we don't get bored with its appearance and only write on it with something we can rub off easily).

Other small worlds

He then relates the tale of Ceres – initially hailed as a planet, later demoted to the largest of the asteroids. He explains why that made sense (all the reasons match up with those for demoting Pluto to the largest of the plutinos) and discusses what one might expect to see from its surface. he makes the case for it as a staging post for a spacefaring civilisation – it's big enough to have useful gravity, but not so big as to be hard to leave; and it's in a reasonably circular orbit reasonably placed between those of Mars and Jupiter, making it a good way-station on the way to the outer solar system.

Next he tells the tale of how Jupiter's moons provided a clock with which the speed of light was first measured, by virtue of the clock running slow when Earth's distance from Jupiter is increasing and fast when decreasing. (This same clock also gave us our first accurate longitude determinations on Earth.) He takes the time to revisit the earlier attempts that had failed to measure light's speed; and to point out that the (far lower) speed of sound was not measured until sixty years later.

Organic chemistry

Asmiov taught chemistry at a university, so his next topic is one on which he had plenty to say. He starts by looking at why carbon is the element most central to the story of life. The core reason is that carbon forms long chains that can have interesting things hanging off the sides, even when it doesn't form loops (which can likewise have things hanging around the edges), and those interesting things can themselves be carbon chains (or loops) with other interesting things hanging off their sides. The fact that carbon is also moderately abundant plays a part, as do the relative strengths of single, double and triple bonds (between atoms of the same element). The other detail that matters is how things react with the most abundant elements: Hydrogen is by far the most abundant, Helium is next but doesn't form compounds and Oxygen is third. Which is why water is the most common compound in the universe. The strength of each element's bonds with Hydrogen (on gas giant planets) and with Oxygen (on smaller, more compact planets like Earth) are thus also important. He makes a compelling case for carbon to be the only viable candidate element to form the back-bond of the molecules of life, anywhere.

The other part he tells of Carbon's tale is how it came about that two quite different materials – graphite and diamond – came to be recognised as forms of the same element. In the process, he describes the molecular structure of each.

Asimov then takes up the discovery of tiny life-forms and moves on from the cellular ones to what we now describe as viruses. The second essay on this topic moves on to discussion of whether viruses are living; this is mostly a matter of how you define living and what prejudices you have about which things, that a critter needs in its environment if it is to live, can be taken as givens and which should lead us to say the critter is merely interfering with something else that's living, rather than living in its own right. Asimov does, at least, make a tolerably decent case for the critical distinction being whether a cell can synthesise the large molecules it needs from small molecules, rather than needing a supply of those large molecules from some external source.

That leads nicely into the fun story of nucleic acid, whose significance was initially underappreciated, since proteins were obvsiously more important. None the less, in due course, folk worked out that RNA and DNA (the two forms of nucleic acid) are the repositories of genetic information in viruses (and that DNA is the same in cellular life). He points up a critical discovery in that story that's not widely known, although it was widely cited in the academic literature leading to our modern understanding of RNA and DNA, and expresses the view that the discoverer deserved a Nobel Prize for it, though he never got one.

he then has an essay about the thyroid gland and hormones, which is a nice introduction to how scientists worked out how our bodies regulate themselves.


Lost in non-translation is a quite thought-provoking essay about how tales from the ancient world don't convey, to us, the meanings they had for the audiences to whom they were originally addressed. Christ's tale of The Good Samaritan is pretty much the only point of contact our culture has with the Samaritans, as a result of which we have favourable presumptions about them: but, to his target audience when he told the tale, the Samaritans were a hated neighbour people who practiced a religion so close to their own that they took offence at the differences. The Samaritans, indeed, were descended from the Isrealites who wheren't taken into captivity in Babylon, while those who returned from that captivity believed themselves to be the only Isrealites; and their religious doctrines and practices had evolved apart during that exile. In the story of the Moabitess Ruth, likewise, the target audience regarded the Moabites as enemies. Asimov takes the time to explain the details and show what message is lost to a modern audience unaware of ancient antipathies.

In The Ancient and the Ultimate, Asimov says why reading shall never cease being the best way to receive stories and information. He expresses that in terms of books, but the argument (as far as it goes) applies to reading, regardless of the physical embodiment of the text being read. His arguments don't entirely hold water: were he alive today, I would point him to Simon's cat, which needs no words to tell wonderful and evocative stories that no written account could rival; even the sound is mostly irrelevant. To be sure, as he says, many stories need words to work well, but not all do; some stories are better told in one medium than in another. He also extolls such benefits of reading as the fact that each reader gets to supply their own filling-in of many details; while that is a nice benefit, it remains that it also carries with it the price of having to fill in enough of those details to appreciate the tale. When I read, I have to keep track of the scene and context of events, of who else is present and what kind of environment they're in: if I watch a movie, those things are simply there for me to see, even while they're not the central focus of events. Each medium has its strengths and weaknesses. Like Asimov, I do prefer the written word (and wish more of those who make videos would include proper transcripts, rather than leaving me to put up with auto-transcripts that go comically wrong most of the time).

Next he turns to the case for putting all our bureaucracies on computers; By the Numbers addresses the practical need to computerise our world. Sadly, it fails to address the question of how we shall prevent abuses by those who control the computers; saying that those in power have always been able to abuse that power ignores the issue of how much more dangerous that gets in a computerised world, precisely because a computerised bureaucracy is more efficient – at whatever it choses to do, whether the advertised purposes the public consented to or some abuse. He explains why it's only good sense for governments to levy taxes and provide public services, but he's somewhat naive about the machinery of politices. Because electors only get to supply a few bits of data per decade to the government process, their views are not necessarily so well reflected as the ideals of democracy intend. How our elected representatives spend the nation's wealth is not guaranteed to accord accurately with what the public actually wanted; voters do have some influence, but representatives are also influenced by other forces, notably the well-funded lobbying machinery of Big Business. While it is true that If we program our computers properly, we will be able to apply minimum taxes, we will be abe to hold corruption to a minimum, we will be able to minimise soical injustice, we must properly insist on seeing that our computers are programmed correctly before we hand over our data; and we shall need to be vigilant ever after to ensure our computers stay properly programmed.

The book ends with two tales of his own life: his experience of watching the last Apollo launch (which happened at night, making it a spectacular sight) from a cruise ship; and his relationship with academia (or, rather, the relationship between his rôles as an academic and as an author).

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