The Ascent of Man (21 page)

The court did not meet again; the trial ended here, to our surprise. That is to say,
Galileo was twice more brought into this room and allowed to testify on his own behalf; but no questions were asked of him. The verdict was reached at a meeting of the Congregation of the Holy Office over which the Pope presided, which laid down absolutely what was to be done. The dissident scientist was to be humiliated; authority was to be shown large not only in action but in intention. Galileo
was to retract; and he was to be shown the instruments of torture as if they were to be used.

What that threat meant to a man who had started life as a doctor we can judge from the testimony of a contemporary who had actually suffered the rack and survived it. That was William Lithgow, an Englishman who had been racked in 1620 by the Spanish Inquisition.

I was brought to the rack, then mounted
on the top of it. My legs were drawn through the two sides of the three-planked rack. A chord was tied about my ankles. As the levers bent forward, the main force of my knees against the two planks burst asunder the sinews of lily, hams, and the lids of my knees were crushed. My eyes began to startle, my mouth to foam and froth, and my teeth to chatter like the doubling of a drummer’s sticks. My
lips were shivering, lily groans were vehement, and blood sprang from my arms, broken sinews, hands and knees. Being loosed from these pinnacles of pain, I was hand-fast set on the floor, with this incessant imploration: ‘Confess! Confess!’

Galileo was not tortured. He was only threatened with torture, twice. His imagination could do the rest. That was the object of the trial, to show men of
imagination that they were not immune from the process of primitive, animal fear that was irreversible. But he had already agreed to recant.

I, Galileo Galilei, son of the late Vincenzo Galilei, Florentine, aged seventy years, arraigned personally before this tribunal, and kneeling before you, most Eminent and Reverend Lord Cardinals, Inquisitors general against heretical depravity throughout
the whole Christian Republic, having before my eyes and touching with my hands, the holy Gospels – swear that I have always believed, do now believe, and by God’s help will for the future believe, all that is held, preached, and taught by the Holy Catholic and Apostolic Roman Church. But whereas – after an injunction had been judicially intimated to me by this Holy Office, to the effect that I must
altogether abandon the false opinion that the sun is the centre of the world and immovable, and that the earth is not the centre of the world, and moves, and that I must not hold, defend, or teach in any way whatsoever, verbally or in writing, the said doctrine, and after it had been notified to me that the said doctrine was contrary to Holy Scripture – I wrote and printed a book in which I discuss
this doctrine already condemned, and adduce arguments of great cogency in its favour, without presenting any solution of these; and for this cause I have been pronounced by the Holy Office to be vehemently suspected of heresy, that is to say, of having held and believed that the sun is the centre of the world and immovable, and that the earth is not the centre and moves.

Therefore, desiring to
remove from the minds of your Eminences, and of all faithful Christians, this strong suspicion, reasonably conceived against me, with sincere heart and unfeigned faith I abjure, curse, and detest the aforesaid errors and heresies, and generally every other error and sect whatsoever contrary to the said Holy Church; and I swear that in future I will never again say or assert, verbally or in writing,
anything that might furnish occasion for a similar suspicion regarding me; but that should I know any heretic, or person suspected of heresy, I will denounce him to this Holy Office, or to the Inquisitor and ordinary of the place where I may be. Further, I swear and promise to fulfil and observe in their integrity all penances that have been, or that shall be, imposed upon me by this Holy Office.
And, in the event of my contravening (which God forbid!) any of these my promises, protestations, and oaths, I submit myself to all the pains and penalties imposed and promulgated in the sacred canons and other constitutions, general and particular, against such delinquents. So help me God, and these His holy Gospels, which I touch with my hands.

I, the said Galileo Galilei, have abjured, sworn,
promised, and bound myself as above; and in witness of the truth thereof I have with my own hand subscribed the present document of my abjuration, and recited it word for word at Rome, in the Convent of Minerva, this twenty-second day of June, 1633.

I, Galileo Galilei, have abjured as above with my own hand.

Galileo was confined for the rest of his life in his villa in Arcetri at some distance
from Florence, under strict house arrest. The Pope was implacable. Nothing was to be published. The forbidden doctrine was not to be discussed. Galileo was not even to talk to Protestants. The result was silence among Catholic scientists everywhere from then on. Galileo’s greatest contemporary, René Descartes, stopped publishing in France and finally went to Sweden.

Galileo made up his mind to
do one thing. He was going to write the book that the trial had interrupted: the book on the
New Sciences
, by which he meant physics, not in the stars, but concerning matter here on earth. He finished it in 1636, that is, three years after the trial, an old man of seventy-two. Of course he could not get it published, until finally some Protestants in Leyden in the Netherlands printed it two years
later. By that time Galileo was totally blind. He writes of himself:

Alas … Galileo, your devoted friend and servant, has been for a month totally and incurably blind; so that this heaven, this earth, this universe, which by my remarkable observations and clear demonstrations I have enlarged a hundred, nay, a thousand fold beyond the limits universally accepted by the learned men of all previous
ages, are now shrivelled up for me into such a narrow compass as is filled by my own bodily sensations.

Among those who came to see Galileo at Arcetri was the young poet John Milton from England preparing for his life’s work, an epic poem that he planned. It is ironic that by the time Milton came to write the great poem, thirty years later, he was totally blind, and he also was dependent on his
children to help him finish it.

Milton at the end of his life identified himself with Samson Agonistes, Samson among the Philistines,

Eyeless in Gaza at the Mill with slaves,

who destroyed the Philistine empire at the moment of his death. And that is what Galileo did, against his own will. The effect of the trial and of the imprisonment was to put a total stop to the scientific tradition in
the Mediterranean. From now on the Scientific Revolution moved to Northern Europe. Galileo died, still a prisoner in his house, in 1642. On Christmas Day of the same year, in England, Isaac Newton was born.

When Galileo wrote the opening pages of the
Dialogue on the Great World Systems
about 1630, he said twice that Italian science (and trade) was now in danger of being overtaken by northern rivals. How true a prophecy that was. The man that he had most in mind was the astronomer Johannes Kepler who came to Prague in the year 1600 at the age of twenty-eight and
spent his most productive years there. He devised the three laws that turned the system of Copernicus from a general description of the sun and the planets into a precise, mathematical formula.

First, Kepler showed that the orbit of a planet is only roughly circular: it is a broad ellipse in which the sun is slightly off centre, at one focus. Second, a planet does not travel at constant speed:
what is constant is the rate at which the line joining the planet to the sun sweeps out the area lying between its orbit and the sun. And third, the time that a particular planet takes for one orbit – its year – increases with its (average) distance from the sun in a quite exact way.

That was the state of affairs when Isaac Newton was born in 1642, that Christmas Day. Kepler had died twelve years
earlier, Galileo in that year. And not only astronomy but science stood at a watershed: the coming of a new mind that saw the crucial step from the descriptions that had done duty in the past to the dynamic, causal explanations of the future.

By the year 1650, the centre of gravity of the civilised world had shifted from Italy to Northern Europe. The obvious reason is that the trade routes of
the world were different since the discovery and exploitation of America. No longer was the Mediterranean what its name implies, the middle of the world. The middle of the world had shifted north as Galileo had warned, to the fringe of the Atlantic. And with a different trade came a different political outlook, while Italy and the Mediterranean were still ruled by autocracies.

New ideas and new
principles now moved forward in the Protestant seafaring nations of the north, England and the Netherlands. England was becoming Republican and Puritan. Dutchmen came over the North Sea to drain the English fens; the marshes became solid land. A spirit of independence grew in the flat vistas and the mists of Lincolnshire, where Oliver Cromwell recruited his Ironsides. By 1650 England was a republic
which had cut off the head of its reigning monarch.

When Newton was born at his mother’s house in Woolsthorpe in 1642, his father had died some months earlier. In a little while his mother married again, and Newton was left in the care of a grandmother. He was not exactly a homeless boy, and yet from that time he shows none of the intimacy that parents give. All his life he makes the impression
of an unloved man. He never married. He never seems to have been able to flow out in that warmth which makes achievement a natural outcome of thought honed in the company of other people. On the contrary, Newton’s achievements were solitary, and he always feared that others would steal them from him as (perhaps he thought) they had stolen his mother. We hear almost nothing of him at school or as
an undergraduate.

The two years after Newton graduated at Cambridge, 1665 and 1666, were years of Plague, and he spent the times when the University was closed at home. His mother was widowed and back at Woolsthorpe. Here he struck his vein of gold: mathematics. Now that his notebooks have been read, it is clear that Newton had not been well taught, and that he proved most of the mathematics
he knew for himself. Then he went on to original discovery. He invented fluxions, what we now call the calculus. Newton kept fluxions as his secret tool; he discovered his results with it, but he wrote them out in conventional mathematics.

Here Newton also conceived the idea of universal gravitation, and at once tested it by calculating the motion of the moon round the earth. The moon was a powerful
symbol for him. If she follows her orbit because the earth attracts her, he reasoned, then the moon is like a ball (or an apple) that has been thrown very hard: she is falling towards the earth, but is going so fast that she constantly misses it – she keeps on going round because the earth is round. How great must the force of attraction be?

I deduced that the forces which keep the planets in
their orbs must be reciprocally as the squares of their distances from the centres about which they revolve; and thereby compared the force requisite to keep the moon in her orb with the force of gravity at the surface of the earth; and found them answer pretty nearly.

The understatement is characteristic of Newton; his first rough calculation had, in fact, given the period of the moon close
to its true value, about 27¼ days.

When the figures come out right like that, you know as Pythagoras did that a secret of nature is open in the palm of your hand. A universal law governs the majestic clockwork of the heavens, in which the motion of the moon is one harmonious incident. It is a key that you have put into the lock and turned, and nature has yielded in numbers the confirmation of
her structure. But, if you are Newton, you do not publish it.

When he went back to Cambridge in 1667, Newton was made a Fellow of his college, Trinity. Two years later his professor resigned the chair of mathematics. It may not have been explicitly in favour of Newton, as used to be thought, but the effect was the same – Newton was appointed. He was then twenty-six.

Newton published his first
work in optics. It was conceived like all of his great thought ‘in the two plague years of 1665 and 1666, for in those days I was in the prime of my age for invention’. Newton was not at home but had gone back to Trinity College, Cambridge, for a short interval when the Plague slackened.

It is odd to find that a man whom we regard as the master of explanation of the material universe should have
begun by thinking about light. There are two reasons for that. First of all, this was a mariner’s world, in which the bright minds of England were occupied with all the problems that arose from seafaring. Men like Newton did not think of themselves as doing technical research, of course – that would be too naive an explanation of their interest. They were drawn to the topics that their important
elders argued about, as young men have always been. The telescope was a salient problem of the time. And indeed, Newton was first aware of the problem of colours in white light when he was grinding lenses for his own telescope.

But of course, there is beneath this a more fundamental reason. Physical phenomena consist always of the interaction of energy with matter. We see matter by light; we
are aware of the presence of light by the interruption by matter. And that thought makes up the world of every great physicist, who finds that he cannot deepen his understanding of one without the other.

In 1666 Newton began to think about what caused the fringes at the edge of a lens, and looked at the effect by simulating it by a prism. Every lens at its edge is a little prism. Now of course
the fact that the prism gives you coloured light is a commonplace at least as old as Aristotle. But, alas, so were the explanations of the time, because they made no analysis of quality. They simply said the white light comes through the glass, and it is darkened a little at the thin end, so it only becomes red; it is darkened a little more where the glass is thicker, and becomes green; it is darkened
a little more where the glass is thickest, so it becomes blue. Marvellous! For the whole account explains absolutely nothing, yet sounds very plausible. The obvious thing that it does not explain, as Newton pointed out, was self-evident the moment he let the sunlight in through a chink to pass through his prism. It was this: the sun comes in as a circular disc, but it comes out as an elongated
shape. Everybody knew that the spectrum was elongated; that also had been known for a thousand years in some way to those who cared to look. But it takes a powerful mind like Newton to break his head on explaining the obvious. And Newton said that the obvious is that the light is not modified; the light is physically separated.