Free Radicals - Michael Brooks [20]
The free-thinking Galileo must have been pleased when Maffeo Barberini became Pope Urban VIII in 1623. Caravaggio’s portrait of the man has a playful air, and the new pontiff was reportedly something of a Renaissance man. He had been a supporter of Galileo’s scientific efforts, and enjoyed discussing Galileo’s ideas. One of the matters under discussion was Copernicus’s heliocentric model of the universe, in which the Sun, not the Earth, was the hub of the cosmos. Galileo was keen to prove Copernicus right, and Urban VIII was keen to hear a convincing argument. The tides held the proof, Galileo said, and he proposed to the Pope that he write a book entitled Dialogue on the Tides. Urban saw the bigger picture, and insisted the book be called Dialogue Concerning the Two Chief Systems of the World.
The theory of the tides comes in the fourth chapter of the Dialogue, and provides what Galileo considered to be his most forceful and conclusive proof of the motion of the Earth through the heavens. His argument centres on two facts: if the Earth moves as Copernicus had suggested, then it has both rotational motion (through its spin on its axis) and linear motion (along a path through space). Any point on the Earth’s surface therefore moves rather like a point on the rim of a cartwheel: around and along. This combination of movements produces an ever-changing speed of motion. And an ever-changing speed, as anyone who has carried a cup of ale in a horse-drawn cart knows too well, causes sloshing. Here, Galileo said, is the cause of the back-and-forth motion of the tides.
Except that it isn’t. The mathematics of Galileo’s theory creates one tide per day, and as any of his Venetian friends could have told him, there are two. Also, high tide should happen at the same time every day according to Galileo’s calculations. It doesn’t, as every sailor knows. Perhaps most heinously, Galileo makes no attempt to account for the Moon’s involvement with the tides, even though its influence was well known at the time. Johannes Kepler had made this point three decades earlier, in a 1609 treatise called Astronomia Nova. Galileo, unwilling to let the Moon destroy his precious idea, resorted to mocking Kepler’s openness to ‘puerilities’ about the Moon’s ‘occult properties’. The idea that the Moon had any influence on the tides was a ‘useless fiction’, he said.
It is stretching anyone’s credulity to suggest that Galileo was not aware of the mismatch between his theory and what was then common knowledge about the tides. It seems he simply ignored inconvenient data. He was convinced – rightly – that the Earth moved, and he was prepared to try to convince others, by any means necessary.
Isaac Newton tried something similar. He is arguably the greatest genius that ever lived, and had ‘a strength of mind almost divine’, according to his monument in Westminster Abbey. He was the first man of science to be granted a state funeral, and his eminence and scientific brilliance were bright enough to cause Alexander Pope to pen these famous words:
Nature and Nature’s laws lay hid in Night.
God said, ‘Let Newton be!’ and all was Light.
Pope says nothing, however, about Newton’s dark side. He was a man with few friends and many bitter enemies – especially among those who dared to dispute his scientific claims. Dissenters were met with a barrage of insults and ferocious attacks on their character and work. Later in life, Newton took on the role of Master of the Royal Mint, and showed further disregard for the notion of truth. He was singularly vindictive in his bid to curb forgeries. Counterfeiting was then a treasonable offence,