Jacob Bronowski: The Starry Messenger

The following is based on part six of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). It is about astronomy up to the time of Galileo (pictured):

Cultures all over the world have some knowledge of astronomy – if only to know when to plant. But often it never goes beyond that.

The Mayans, for example, had the number zero before Europe did and a much better calendar too, yet they did not study the motions of the stars.

Easter Island was the same: people came there by accident but had no way of leaving because they had no model of the heavens. They were stuck there as the stars passed overhead, their secrets unread.

It seems the New World lacked a model of the heavens because they lacked the wheel. The Greeks built their model on the wheel: wheels within wheels, forever turning. It was Ptolemy who wrote down that  model in all its glory in about the year 150. It stood for over a thousand years.

In 1543 Copernicus put the sun, not the earth, at the centre – for sound Renaissance reasons. To the man in the street it seemed unnatural.

Then in 1609, a lifetime later, all that changed when Galileo in Venice, Italy pointed a telescope at the stars. What he saw proved Copernicus right.

The Catholic Church at the time was battling against the Protestant heresy. Taking a hard line, it believed that faith should rule. Galileo believed that truth should persuade.

In 1611 the Vatican starts to keep a file on him. In 1616 they tell him he can no longer hold or defend the Copernican system as proven fact.

Galileo waits till a more intellectual pope came to power, Pope Urban VIII in 1623. He is the one who hired Bernini to work on St Peter’s. But he is also the one who had the birds in the Vatican gardens killed because he did not like the noise.

In 1624 Galileo came to those gardens and had six long talks with the pope. He asked the pope if he could teach Copernicus. The pope said no. But Galileo continued to believe the pope was on his side. He was profoundly mistaken.

Galileo returned  to Florence and wrote “The Dialogue on the Great World Systems” (1632). Because the book did not present Copernicus as fact but merely debated his ideas, Galileo thought he was safe. But just to make sure he got four imprimaturs from Church censors.

It did not work. The pope stopped the presses and tried to buy back all the copies. Then in 1633 he called Galileo before the Inquisition. They threatened him with torture, twice, and forced him to state that Copernicus was wrong. Silencing him, the Church banned his book for over 200 years.

That all but killed science in Catholic countries. Now the cutting edge of science moved to the Protestant north. Indeed, in the year that Galileo died, in 1642, on Christmas day was born Isaac Newton in England.

See also:

• Jacob Bronowski: The Music of the Spheres – part five
• Galileo
• Copernicus
• Ptolemy
• Catholic
  • pope
  • heresy: Protestant
• Newton