This programme on BBC 4 is a very lucid description of the life cycle of a star.  I was however, a little taken aback at the uncritical adulation awarded to Nicolas Copernicus for his “discovery” that the earth goes round the sun.  Students of history will realise that this presentation is a little simplistic.  For something to be discovered, we must have a pre existing idea that it is there.  It’s rather like the discovery of America by Columbus.  He had an idea that land would be there.  He thought it was India rather than America but he was still proceeding on a theory that the world was round and therefore he could sail to India without having to round the southern tip of Africa.

My confidence in Copernicus as a great scientist was thoroughly trashed by Arthur Koestler’s book “the Sleepwalkers”.  Now of course Koestler wrote his book in the 1950’s and he had an agenda; he wanted to show that “progress” is not a straight line but has travelled in ups and downs, through quirks of fate.  He writes that “The basic novelty of our age is the combination of this sudden, unique increase in physical power with an equally unprecedented spiritual ebb-tide”.

Now Koestler himself has undergone a process of personal denigration for failings of character and this has helped to undermine the value of his work.  All the same, Copernicus has not recovered in my opinion from Koestler’s damning opinion.  “The figure of Copernicus, seen from the distance, is that of an intrepid revolutionary hero of thought.  As we come close, it gradually changes into that of a stuffy pedant, without the flair, the sleepwalking intuition of the original genius; who, having got hold of a good idea, expanded it into a bad system, patiently plodding on, piling more epicycles and deferents into the dreariest and most unreadable among the books that made history.”  Koestler traces the path whereby the core idea for which Copernicus is famous, took hold amongst his successors.  It was an idea whose time had come, written by a man who was keen not to promote it too noisily.

Koestler credits Aristarchus of Samos, more than 2000 years ago, with setting out the principle that the earth rotates around the sun.  This he says was clearly understood by authorities such as Archimedes and Plutarch.  That the idea did not take hold was due to complex factors such as the availability of the books of Plato and Aristotle throughout the middle ages.  These men developed a cosmology founded on philosophy rather than observation or mathematics.  Plato needed the cosmos to be orderly; an idea that lived for many centuries afterwards.

In pursuit of Aristarchus and other cosmologists of the ancient world, I am off to St. Andrew’s University at the weekend.  There the classics department are exploring ancient cosmologies.  This should be good.