Kepler's Legacy

Early yesterday morning, I started reading John Banville's Kepler. It is a classically intense piece of biographical fiction which aims a heated spotlight on the life and times of Johannes Kepler, astrologer and mathematician, and his painful intellectual relationships with Nicolaus Copernicus (dead but whose ideas act like goads to Kepler) and Tycho Brahe (alive, but not for long).

While still in the first few pages, I glanced idly across the internet and discovered that, by some quirk of time and fate, May 23 was the day chosen by the Episcopalian church to commemorate the lives of Kepler and Copernicus. A skeptic would say that this was one of the many inevitable coincidences of life, only remembered because it was so randomly exact.

To me, it was a sign to think a little deeper about what I was reading. Kepler was a Lutheran holdout in a time of painful religious and political change. Obsessed with the idea of divine mathematics, he routinely cast horoscopes and made predictions that came out right again and again. He ardently believed in the music of the spheres; he claimed to hear it every now and then.

It was his struggle with Tycho Brahe's data on the orbit of Mars that brought him to the realisation that the area swept out by a body in orbit remained the same at any distance for the same period of time. Nearly a century later, Newton was able to build on Kepler and show that this was a consequence of gravitational behaviour.

I have suddenly discovered that I am in possession of Banville's Doctor Copernicus and The Newton Letter as well. What wonderful distractions! I cannot wait to move out from under the burden of educational globalisation and back into the history of science. And somewhere between those points, I hope to enjoy tracing out that arc of my own orbit.

Word of the Day: Ephemeris

This is another word related to time. The Greek hemera means 'day'; if you go to Greece you will hear people greeting each other with "Kalémera!" which comes from kalli- meaning 'good, beautiful' and hemera — that is, 'Good day!'

So what does 'ephemeris' mean?

The forms 'ephemera' and 'ephemeral' are probably more common. They come from the Greek preposition ep(i)- which means 'on' or 'on the surface of', and hemera. 'Ephemeral' therefore means '(only) on the day' and 'ephemera' literally means 'things that are (only) on the day'. Figuratively, they refer to things that are transient, that pass quickly and are gone, that touch us lightly and thus have less value in terms of durability and impact.

An ephemeris, however, is a book of days. Technically, it's an astronomer's guidebook which lists data related to known celestial bodies for a given day, and gives calculations and calculated information based on that data.

It's a lovely word, isn't it? You could call your diary an ephemeris if you were so minded. Until the next time, Kalémera!

Leonidae

From out of the constellation of Leo come many strange things eponymously named. One of those can be seen in mid-November every year: the famous Leonid meteor shower. To see a falling star is one thing; for people of the past to have seen many at one time must have been terrifying, provoking thoughts that the sky was falling. But the firmament remains.

It is the same with many things. Reagan was hailed as one of the greats, of Rushmorean eminence, for his part in taking down the 'Evil Empire' of which a certain Leonid was the last great exponent. But despite the falling of many stars in that crimson sky, Vladimir Putin appears to have somehow managed to jury-rig an apparatus that holds together.

Many strange things come out of Leo. It is a pre-eminent constellation in the northern sky starting a short time from now. It only remains to be seen what strange Leonids will bring awe, startlement and excitement to our mundane lives.