Galileo: Watcher of the skies
Yale University Press £25
Church Times Bookshop £22.50
HUMANS with a sense of wonder have always gazed at the heavens and tried to understand them. Aristotle (384-322 BC) believed that the sun and the planets circumnavigated the earth in circles and that they were perfect, crystalline spheres. That was modified because of the naked-eye observation that some planets seemed occasionally to go backwards. Ptolemy (AD 90-170) proposed that the planets did not all follow circular orbits in the same direction, but that some followed smaller “epicycles” going the other way.
Johannes Kepler (1571-1630) proposed that the orbits were ellipses, not circles. It seemed essential to the Church to believe that the earth was the centre of the universe and was stationary; but it would have preferred circular orbits, because circles were thought to be perfect — never mind observation.
Tycho Brahe (1546-1601) came up with a sort of compromise: the planets revolved around the sun, but the sun revolved around the earth. Galileo (1564-1642) upset those ideas with his telescope, the best there was. He saw planets revolving around Jupiter and rings around Saturn, and that the moon had mountains and craters.
Galileo had been pipped at the post. Nicolaus Copernicus (1473-1543) had argued that the centre of the solar system was the sun, and that the earth and the main planets revolved around it. Galileo accepted Copernicus, but knew from observation that the earth and some other planets had moons of their own.
Wootton writes a fascinating book about family, friends, colleagues, and opponents. He writes it as biography — an odd category for a historian, but he justifies that at length. I am glad he did. An oddity in the book was an apparent misunderstanding (twice) of Aquinas’s use of substance and accidents and their relation to transubstantiation; and a correct understanding (once). But, as a whole, the book is absolutely first-rate, and well worth reading and re-reading.
Wootton’s account of Galileo’s appearance before the Inquisition is factual, but he implicitly invites thought about whether theology should dictate scientific results — any more than science ought to try to decide whether God exists. He refers to the experimental evidence of 1729 that the earth moves; Rome forbade its followers to think about that for another 90 years.
We might get up to date and wonder whether Rome needs to rethink its theological objection to the Nobel Prize awarded to Professor Robert Edwards for his work on in vitro fertilisation.
The Revd Jeremy Craddock was a forensic scientist.