Daily Archives: October 9, 2011

sidereal

When I was a boy genius, I naturally thought it befitting for me to take an interest in science and especially astronomy. It was, as were nearly all my interests, dilettantish and bookish; I did not spend hours at a telescope. But I did spend hours daydreaming. Space is fit fodder for fantasy: humans had walked on the moon; other planets were in reach; could the stars be much farther? As H.G. Wells wrote at the end of The War of the Worlds, “Dim and wonderful is the vision I have conjured up in my mind of life spreading slowly from this little seed bed of the solar system throughout the inanimate vastness of sidereal space.”

I also spent hours reading and watching movies. I watched the Star Wars movies and others avidly, of course. And I acquired and read (or at least read about two-thirds of, before my attention was seized by something else) Isaac Asimov’s The Universe: From Flat Earth to Quasar. I think it was that book in which I think I first encountered the word sidereal.

I was reminded of sidereal yesterday when making one of my several annual excursions to Collingwood: launching myself (and my wife and her mother) for a day or two on the side to one of the more distant points that are in stationary orbit of the Centre of the Universe, as Torontonians jokingly call their town. The scenic country route we prefer rolls up hill and down under enormous skies (and at times in the later hours the moon hangs low at the horizon). And every so often you cross an intersection with a sideroad: there is a post with a sign reading County Sideroad 10, for instance, or what have you. They are the fixed marks, the meridians crossing the countryside; when you go and return, they are still there, avenues to other places.

It was, as you may have imagined, the word sideroad that made me think of sidereal. Ah, sidereal, a word that can make you think you are veering off into a side reality, a digression, a divergence from the constitutive quotidian, perhaps a launch into orbit and back or perhaps a right turn and off into a different perspective altogether. What if we measured our days not by the sun that is before us but by the distant stars that call to us in their faint celestial choir?

Why, that would be sidereal time, of course. A day as measured from when a given star crosses the meridian to when it again crosses the meridian is a sidereal day. Given that if the star is at its zenith at midnight – thus directly opposite the sun – on, say, the spring equinox, it will be at its zenith at noon – directly behind the sun – a half year later on the fall equinox, we can see that a sidereal day loses half a solar day in half a year. A sidereal day is about 23 hours, 56 minutes long. And this also means you fit in an extra sidereal day every solar year. It’s like having an extra day on the side that no one else gets.

Sidereal isn’t formed from side and real, though, and it isn’t pronounced like side real. It’s a bit more like “sigh deer eel”: /saɪ ‘di ri əl/. It’s from Latin sidereus, from sidus “star, constellation”. So when I see sideroad, I amuse myself by thinking /saɪ ‘di ro æd/ and imagining it’s some sidereal excursion or measure – or right turn to the stars.

But of course my wanderings are entirely planetary (fittingly, planet comes from Greek for “wanderer”). I spend some time with family in that distant detached world two hours north, and then come back to my centre of gravity, my rental vehicle more of a space shuttle than an interstellar ark.

Our interstellar explorations have receded farther into the future since my childhood, too. We content ourselves with fantasies. My dreams of being in the stars, like my later dreams of being a star, seem like messages from beyond that turn out to have been destined for someone else. And I recall that the sentence I quote from Wells above is followed by “But that is a remote dream. It may be, on the other hand, that the destruction of the Martians is only a reprieve. To them, and not to us, perhaps, is the future ordained.”

But before I throw up my hands and sigh “Deary!” I’ll remember that there are many excursions one may make within ready reach. New things are being discovered every day about the world we live in, and even about the words we live with. Every book is a new world, and every word a new star. And each blog post that goes by marks a sidereal sideroad, a chance to turn the head and look away from the main road of discourse down a lane that leads to a different set of horizons.