Daily Archives: June 27, 2017

comet

Speaking of things beautiful and strange, comely and kimet, let us look to the comet.

No, I don’t mean look out the window. There certainly isn’t one to be seen while I’m writing this. Perhaps at some later date there will be, and if you’re reading this then you’ll know. But consider the celestial body, the long-haired nine days’ wonder that will come t— I was going to say come to be seen, but it was gone already.

Or not. The comets are always out there. There are more than 5000 of them swinging around our Sun, and countless many more around the countless other stars. Every alien civilization on a distant planet has arisen under the periodic portents of comets. But you only see them when they’re close to the light. And even then, you don’t really see them. You see what they leave behind.

A comet is a dirty snowball in space, or sometimes an icy dirtball. It is dark: it has low albedo; it reflects only about 3–4% of the light that hits it. But it is also light: a comet is only about 60% as dense as liquid water, and only 2/3 the density of ice (which is 92% as dense as liquid water, generally). And while it’s bigger than a snowball, it’s not really bigger than a big city – even Halley’s comet, which is large as they go, is only 15 km by 8 km by 8 km. Oh, yeah: they’re oblong and odd-shaped because they’re too small for gravity to round them out.

But that is the dark and dirty part of them, the part that’s always there, the part without which they would not exist, but not the part that we see. What we see and seek in comets is the sublime. Or, more to the point, the sublimation: the solids becoming gases under the heat of the sun. It’s not all water steam – there are various volatile compounds. But it takes up a sweep of space, and it glows. And that glow catches our eyes and imaginations – and anxieties and myths, perhaps. It has taken a long time to learn the truth about comets, and we’re still discovering new things, thanks to such expeditions as the Rosetta spacecraft.

What is it we see when a comet awakens from its sleep, or should I say from its coma? We see its coma, and its tail, like long sweeping white hair drawn through a pool.

Out of coma and into coma again? Thereby hangs a tale. The coma that means ‘deep sleep’ comes from Greek κῶμα, which means ‘sleep’. The coma that you see on a comet – or around glowing objects in an imperfect lens, or around some plant heads, flowers, or seeds – is from Greek κόμη, ‘hair of the head’. And it is from κόμη that we get κομήτης, ‘long-haired’, which came to name a long-maned celestial body, and thence into Latin cometes and now our comet.

And all of that appears just when there is light and heat to make it visible. But comets are still there the rest of the time. It’s like the famous people you see on TV: they don’t just hang them on hooks in warehouses when they’re not glowing before you. They aren’t Schrödinger’s kittens, indeterminate until a gaze fixes them. Turn off the lights on a comet and you have a dark, light, cold, dirty, uneven object. Turn them on and you have a glowball that may be bigger than the earth, a tail that may be longer than the distance between us and the sun. Until it gases off all its gassable bits and becomes just another eccentric asteroid.

But ah, what discoveries the light of attention brings. I can’t see the sun set on this word until I direct you to the Wikipedia page for comet, and specifically to the long mane of languages down the left side. There are many tongues there, an article on comets in each of them. There are languages there that I guarantee you have never heard of before. There are languages there that I had been unaware of. Scroll down and see what you light on, and click to read about it in Bân-lâm-gú, Livvinkarjala, Qaraqalpaqsha, Seeltersk, Vahcuengh, Winaray, Žemaitėška, or any of many others, all languages that have grown up under the same sky seeing the same celestial sweeps and talking about them in their own ways. These languages have been there all along but you’re only now noticing them – or their digital traces – and perhaps you’ll forget about them again in a few days or as soon as your attention moves on. And sure, you don’t understand what they’re saying, but you know what the topic is, and you know it’s all pretty much true and yours to discover over time if you wish. Wikipedia is your own Rosetta Stone.