Profiles in Courage: Galileo

Dateline: November 04, 1998

In more ways than one, Galileo can be considered the first truly modern scientist. He brought Copernicus' ideas to practical fruition. He went a long way in melding together theory and empirical observation. His works read easily even today, and most modern readers can feel comfortable with them. He was on the receiving end of much religious persecution, even to the point of living out his last years under house arrest, forbidden from writing and publishing. He was, however, lucky to escape the terrible fate of Giordanno Bruno. The conflicts between religion and science as they played out in the case of Galileo serve today - and will continue to serve - as a paradigm of how fearful sectarian leaders can exercise their power over the lives of those who express inconvenient and uncomfortable ideas.

Like Copernicus before him, Galileo advocated the independence of science from traditional, political, and ecclesiastical authorities. This attitude he likely acquired for his father who wrote in his work Dialogue on Ancient and Modern Music:

It appears to me that they who in proof of any assertion rely simply on the weight of any authority, without adducing any argument in support of it, act very absurdly. I, on the other hand, wish to be allowed to freely question and to freely answer without any sort of adulation, as well becomes those who are sincerely in search of truth.

Galileo could well have used this statement as a motto aptly describing his life and his work - and should probably thank his father for inculcating this intellectual attitude in him. If I had a nickel for every theist who came to me in an attempt to convert me via assertions based on authority without supporting arguments, I'd be a very rich man by now. Unfortunately, this was the path followed by Galileo's later inquisitors - authority over logical argument.

Early Rumblings

But in the meantime, the attitude of preferring sound arguments to tradition and authority served to get him in other, more minor forms of trouble. His conduct at the University of Pisa earned him the nickname the "Wrangler" as he proceeded to dispute the conclusions drawn by various faculty and argue the merits of scientific statements made by the ancients. He respected the achievements of Aristotle, but not his exaggerated authority and did not for a minute let that prevent him from questioning Aristotle's claims, something which very nearly bordered on blasphemy in a University setting. Needless to say, he managed to produce a real disturbance in his classes and among his colleagues, even as a student - an apt beginning to his career, I think. Galileo always spoke his mind, and always gave material the critical examination it deserved, no matter who authored it. He did not wish to merely memorize lectures and parrot it back later - he was more interested in discussing a subject and engaging in careful critique.

During his second year, he was exposed to mathematics and geometry - subjects which seemed to have hit him very strongly, causing him to alter his course of studies and spend a great deal of time working with math. Due at least in part to example of Archimedes, who used an experiment to discover that the crown of King Hiero was not solid gold, Galileo made a conscious effort to combine mathematics with laboratory testing in order to discover the nature of the world and matter around him. By recognizing and promoting this basic principle, one could regard him the founder of modern physics.

Perhaps one of the most famous stories told of Galileo was of his dropping two balls of different weights from the Tower of Pisa in order to demonstrate that they would fall at equal speeds. This effective and soundly refuted the venerated Aristotle, who claimed without any experimentation that objects fell at speeds proportional to their weight. Unfortunately, there is no good evidence that this event indeed took place, and at any rate this proof had already been done by Simon Stevin, a Dutch scientist. However, Galileo went further than this, developing a way to slow down the rate of "fall" (rolling balls down an incline) such that it could be observed in close detail, thus allowing him to discern the basic mathematical principle underlying the event. Through this, Galileo discovered the principle of velocity and inertia, the most basic principles of moving bodies, thus opening the door for Newton's later work building the main structures of modern physical science.

Early Teaching

In the meantime, he managed to obtain a position as chair of mathematics at Pisa, and as he made these discoveries, he did not hesitate to discuss them in the lectures he was giving. Obviously, such raw, unabashed contradictions of the great Aristotle were not received well by the other faculty, even though his popularity among the students remained quite high. In addition, the chair of mathematics was considered lowest among the faculties, and no one liked him stepping out of his territory to make pronouncement in other fields. Unfortunately, hisses and disturbances during his lectures continued to rise and, in 1592, he was forced to resign his chair at Pisa, although he later took the chair of mathematics at Padua with the help of an influential friend, and where his popularity and influence continued to expand. William Harvey studied there from 1598 to 1602, and was likely exposed to the widespread discussions on the new discoveries of motion, liquids, and pumps - perhaps priming his mind for his later discoveries about how the heart moves blood through the body. Galileo's audiences were always growing such that the great hall, which held 1000, was sometimes inadequate and he was forced to give his lectures in the open air.

One serious blow to traditional authorities came in 1604 with the sudden appearance of a brilliant new star (a supernova). This directly contradicted the traditional and fiercely held opinion that the skies were eternal, perfect and unchanging in their nature. This star, however, was new and changed in brightness. And unlikely the theories of Copernicus which tended to be restricted to discussion among learned academics, this was plainly visible to any person who wished to look up at the night sky. This was one bit of knowledge which authorities could not restrict or prohibit discussion on. With it, Galileo and others found it easier to come out publicly in favor of Copernicus' heliocentric theory.

Another achievement which Galileo is often credited with is the telescope - an instrument who's value at the time cannot be underestimated. But contrary to popular stories, Galileo did not in fact invent the telescope - that glory must go to others. He did, however, manufacture some of the best telescopes, and his work on them was not equaled until much later in the mid 17th century. His use of the telescope is also an important story, as this instrument allowed him to make startling discoveries about our solar system - discoveries which guaranteed both his place in human history and his place in the sights of ecclesiastical authorities hunting for heresy.

Spotting the Sun

The first conflict arose over the issue of sun spots. Today, sun spots are a familiar subject - they are cooler spots on the sun which appear black in relation to the rest of its surface, but which we know are nevertheless still super hot. Their regular effects on radio waves are known, their possible effects on our long-term planetary weather are unknown and only just starting to be discerned. But in Galileo's time they were unknown and, in fact, philosophically excluded. Just as the principle of the eternal, unchanging perfection of the heavens excluded the possibility of any new stars, the principle of an eternal, unchanging, and perfect sun precluded the possibilities of spots. But that wasn't all - Galileo's studies of sun spots revealed that they, and thus the sun itself, were rotating. None of this went over very well with the Catholic Church, and especially among the Jesuits. Enemies of Galileo and the ideas which he advocated began to gather, and monks in Florence (where he had since moved) gave harsh sermons against the Copernican heliocentric theory and any ideas which denied church dogma on celestial bodies.

Quote of the week: Throughout the 1970s I had been mainly studying black holes, but in 1981 my interest in questions about the origin and fate of the universe was reawakened when I attended a conference on cosmology organized by the Jesuits in the Vatican. The Catholic Church had made a bad mistake with Galileo when it tried to lay down the law on a question of science, declaring that the sun went round the earth. Now, centuries later, it had decided to invite a number of experts to advise it on cosmology. At the end of the conference the participants were granted an audience with the pope. He told us that it was all right to study the evolution of the universe after the big bang, but we should not inquire into the big bang itself because that was the moment of Creation and therefore the work of God. I was glad then that he did know the subject of the talk I had just given at the conference -- the possibility that space- time was finite but had no boundary, which means that it had no beginning, no moment of Creation. I had no desire to share the fate of Galileo, with whom I feel a strong sense of identity, partly because of the coincidence of having been born exactly 300 years after his death! Stephen Hawking, A Brief History of Time (New York: Bantam, 1988), pp.

Galileo was rather impatient of anything he thought to be nonsense - and just as this served to cause him trouble as a student, it served to would cause him to suffer now. He was neither particularly diplomatic nor particularly harsh - he simply worked from the assumption that evidence and logic would speak for themselves. If one is dealing with rational and reasonable people, this would not need defense. Unfortunately, we rarely have the pleasure of dialogue with people who are completely rational and reasonable - especially when that dialogue involves contradicting traditional and deeply held beliefs. Ideally, a rational person would accept an idea if they were unable to formulate reasonable and convincing arguments against it based upon at least as much evidence and logic as the idea itself is - and this is likely what Galileo would have appreciated. But when people have a vested interest in contrary ideas, logic quickly gives way to emotion - a dangerous prospect when dealing with powerful and jealous individuals.

 

Dangerous Letters

Combining both his impatience with nonsense and his faith in the power of a reasonable argument, Galileo proceeded to get himself into even more trouble by writing a letter in 1616 on what he considered to be the proper relationship between science and scripture. First, he set down that human interpreters can err in their readings of scripture and that it would be impossible to know for sure who exactly might be divinely inspired in their interpretations. This might sound obvious to us today, but it was insanely radical theology for the time, especially when directed against a Catholic Church struggling with Protestants saying similar things. Based partly on this, he went on to argue that since both scripture and nature are divine creations, then it is impossible for an interpretation of scripture to be correct if it contradicts what we observe in nature. Galileo advised forbidding the quotation of scripture to support "...what our senses, or demonstrated proof, may manifest to the contrary."

Galileo then proceeded to argue that therefore science should remain of ecclesiastic control or boundaries set by religious dogma, since "Who can set bounds to the mind of man? Who dares assert that he already knows all that in this universe is knowable?" In a further statement on the proper, independent role of scientific investigation, Galileo sounds very modern in his attitude:

But I do not think it necessary to believe that the same God who gave us our senses, our speech, our intellect, would have us put aside the use of these, to teach us instead such things as with their help we could find out for ourselves, particularly in the case of these sciences, of which there is not the smallest mention in the Scripture, and, above all, in astronomy, of which so little notice is taken that the names of all the planets are not mentioned.

In this explosive letter, Galileo implied the fallibility of the Church, the fallibility of church leaders, and one of the main principles of Protestantism: personal interpretation of scriptures. Needless to say, they panicked. Galileo's intentions were good, but his attitude too naive. Unfortunately, a copy found its way to Rome, and the Inquisition "invited" Galileo to Rome to explain his opinions. He expected a fair hearing and a chance to persuade them of his ideas, but he had no idea of what forces were arraigned against him. His ideas were judged erroneous and heretical, and anyone advocating anything along the lines of Copernicus was to be corrected or prohibited. Before he left, he was informed that he was not to hold or defend Copernican theories - however, a secret minute of the admonishment included that he was also not to teach them. This would eventually cause problems.

Judgment

In 1623 a friend of his, Cardinal Barberini, was elected Pope Urban VIII and Galileo had high hopes that his situation might change, since Barberini had long been sympathetic to him and his Copernican ideas. Galileo decided to take advantage of the perceived friendly atmosphere by distilling more then forty years of work and research in astronomy and science into his great Dialogues Concerning the Two Principle Systems of the World, the manuscript for which took a full 6 years to prepare. The dialogues are conducted by three characters: Sagredo, Salviati and Simplicius. The latter defends the Ptolemaic system and comes in for a great deal of ridicule.

Unfortunately, the Pope's attitude toward Galileo had changed dramatically over time, possibly caused by the influence of his Jesuit advisors. A secret commission was set up to investigate Galileo's book, and all known to have any favorably feelings towards him were deliberately excluded. It was here that the crucial issue of "teaching" Copernican theories came into play, since Galileo's book obviously had that effect, something which he was prohibited from doing. Galileo pled ignorance of this prohibition, and he was tried in secret, as was customary. The judgment was of heresy for daring to think and teach that the sun might be the center of the solar system, and so the aged and ailing scientist was forced to kneel before the Inquisition tribunal and recite a long and detailed recantation, in which he was forced to declare that he

...must altogether abandon the false opinion that the sun in the centre of the world and immovable, and that the earth is not the centre of the world and moves...

In the end, he was forced to live out the rest of his life under house arrest, ever under surveillance. He lived alone and was not allowed to receive general visitors, but at 70 years old and in pain, he nevertheless prepared his next work, Dialogues Concerning Two New Sciences, containing the foundations of the sciences of motion and materials. It wasn't quite as dramatic as Two Systems, but perhaps more important. He managed to have it smuggled out of Italy to be printed in Holland and later feigned that it had been printed against his will. Only after 1638, after he became totally blind, was surveillance relaxed and more visitors permitted. When he died in 1642, the Inquisition prohibited the Court and citizens of Florence to give him a public funeral or to erect a marble mausoleum for his grave.

Although we have much to learn from the natural truths he discovered about our universe, we also have just as much to learn from the more "spiritual" truths about courage and dedication which he and his life exemplified.