Review: A Very Short Introduction to Galileo

Review: A Very Short Introduction to Galileo
Galileo: A Very Short Introduction

Galileo: A Very Short Introduction by Stillman Drake

My rating: 4 of 5 stars

There is not a single effect in Nature, not even the least that exists, such that the most ingenious theorists can ever arrive at a complete understanding of it.

One of the most impressive aspects of the Very Short Introduction series is the range of creative freedom allowed to its writers. (Either that, or its flexibility in repurposing older writings; presumably a version of this book was published before the VSI series even got off the ground, since its author died in 1993.) This is a good example: For in lieu of an introduction, Stillman Drake, one of the leading scholars of the Italian scientist, has given us a novel analysis of Galileo’s trial by the Inquisition.

Admittedly, in order to contextualize the trial, Drake must cover all of Galileo’s life and thought. But Drake’s focus on the trial means that many things one would expect from an introduction—for example, an explanation of Galileo’s lasting contributions to science—are only touched upon, in order to make space for what Drake believed was the crux of the conflict: Galileo’s philosophy of science.

Galileo Galilei was tried in 1633 for failing to obey the church’s edict that forbade the adoption, defense, or teaching of the Copernican view. And it seems that he has been on trial ever since. The Catholic scientist’s battle with the Catholic Church has been transformed into the archetypical battle between religion and science, with Galileo bravely championing the independence of human reason from ancient dogma. This naturally elevated Galileo to the status of intellectual heroe; but more recently Galileo has been criticized for falling short of this ideal. Historian of science, Alexandre Kojève, famously claimed that Galileo hadn’t actually performed the experiments he cited as arguments, but that his new science was mainly based on thought experiments. And Arthur Koestler, in his popular history of astronomy, criticized Galileo for failing to incorporate Kepler’s new insights. Perhaps Galileo was not, after all, any better than the scholastics he criticized?

Drake has played a significant role in pushing back against these arguments. First, he used the newly discovered working papers of Galileo to demonstrate that, indeed, he had performed careful experiments in developing his new scheme of mechanics. Drake also points out that Galileo’s Dialogue Concerning the Two Chief World Systems was intended for popular audiences, and so it would be unreasonable to expect Galileo to incorporate Kepler’s elliptical orbits. Finally, Drake draws a hard line between Galileo’s science and the medieval theories of motion that have been said to presage Galileo’s theories. Those theories, he observes, were concerned with the metaphysical cause of motion; whereas Galileo abandoned the search for causes, and inaugurated the use of careful measurements and numerical predictions in science.

Thus, Drake argues that Galileo never saw himself as an enemy of the Church; to the contrary, he saw himself as fighting for its preservation. What Galileo opposed was the alignment of Church dogma with one very particular interpretation of scripture, which Galileo believed would put the church in danger of being discredited in the future. Galileo attributed this mistaken policy to a group of malicious professors of philosophy, who, in the attempt to buttress their outdated methods, used Biblical passages to make their views seem orthodox. This was historically new. Saint Augustine, for example, considered the opinions of natural philosophers entirely irrelevant to the truth of the Catholic faith, and left the matter to experts. It was only in Galileo’s day (during the Counter-Reformation) that scientific theories became a matter of official church policy.

Drake’s conclusion is that Galileo’s trial was not so much a conflict between science and religion (for the two had co-existed for many centuries), but between science and philosophy: the former concerned with measurement and prediction, the latter concerned with causes. And Drake notes that many contemporary criticisms of Galileo—leaving many loose-ends in his system, for example—mirror the contemporary criticisms of his work. The trial goes on.

Personally I found this book fascinating and extremely lucid. However, I am not sure it exactly fulfills its promise as an introduction to Galileo. I think that someone entirely new to Galileo’s work, or to the history and philosophy of science, may not get as much out of this work. Luckily, most of Galileo’s own writings (translated by Drake) are already very accessible and enjoyable.



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Review: Sidereal Messanger

Review: Sidereal Messanger

Sidereus Nuncius, or The Sidereal MessengerSidereus Nuncius, or The Sidereal Messenger by Galileo Galilei

My rating: 4 of 5 stars

A most excellent a kind service has been performed by those who defend from envy the great deeds of excellent men and have taken it upon themselves to preserve from oblivion and ruin names deserving of immortality.

This book (more of a pamphlet, really) is proof that you do not need to write many pages to make a lasting contribution to science. For it was in this little book that Galileo set forth his observations made through his newly improved telescope. In 50-odd pages, with some accompanying diagrams and etchings, Galileo quickly asserts the roughness of the Moon’s surface, avers the existence of many more stars than can be seen with the naked eye, and—the grand climax—announces the existence of the moons of Jupiter. Suddenly the universe seemed far bigger, and stranger, than it had before.

The actual text of Siderius Nuncius does not make for exciting reading. To establish his credibility, Galileo includes a blow-by-blow account of his observations of the moons of Jupiter, charting their nightly appearance. The section on our Moon is admittedly more compelling, as Galileo describes the irregularities he observed as the sun passed over its surface. Even so, this edition is immeasurably improved by the substantial commentary provided by Albert van Helden, who gives us the necessary historical background to understand why it was so controversial, and charts the aftermath of the publication.

Though Galileo is sometimes mistakenly credited with inventing the telescope, spyglasses were widely available at the time; what Galileo did was improve his telescope far beyond the magnification commonly available. The result was that, for a significant span of time, Galileo was the only person on the planet with the technology to closely and accurately observe the heavens. The advantage was not lost on him, and he made sure that he published before he got scooped. In another shrewd move, he named the newly-discovered moons of Jupiter after the Grand Duke Cosimo II and his brothers, for which they were known as the Medician Stars (back then, the term “star” meant any celestial object). This earned him patronage and protection.

Galileo’s findings were controversial because none of them aligned with the predictions of Aristotelian physics and Ptolemaic astronomy. According to the accepted view, the heavens were pure and incorruptible, devoid of change or imperfection. Thus it was jarring to find the moon’s surface bumpy, scarred, and mountainous, just like Earth’s. Even more troublesome were the Galilean moons. In the orthodox view the Earth was the only center of orbit; and one of the strongest objections against Copernicus’s system was that it included two centers, the Sun and the Earth (for the Moon). Galileo’s finding of an additional center of orbit meant that this objection ceased to carry any weight, since in any case we must posit multiple centers. Understandably there was a lot of skepticism at first, with some scholars doubting the efficacy of Galileo’s new instrument. But as other telescopes caught up with Galileo’s, and new anomalies were added to the mix—the phases of Venus and the odd shape of Saturn—his observations achieved widespread acceptance.

Though philosophers and historians of science often emphasize the advance of theory, I find this text a compelling example of the power of pure observation. For Galileo’s breakthrough relied, not on any new theory, but on new technology, extending the reach of his senses. He had no optical theory to guide him as he tinkered with his telescope, relying instead on simple trial-and-error. And though theory plays a role in any observation, some of Galileo’s findings—such as that the Milky Way is made of many small stars clustered together—are as close to simple acts of vision as possible. Even if Copernicus’s theory was not available as an alternative paradigm, it seems likely to me that advances in the power of telescopes would have thrown the old worldview into a crisis. This goes to show that observational technology is integral to scientific progress.

It is also curious to note the moral dimension of Galileo’s discovery. Now, the Ptolemaic system is commonly lambasted as narcissistically anthropocentric, placing humans at the center of it all. Yet it is worth pointing out that, in the Ptolemaic system, the heavens are regarded as pure and perfect, and everything below the moon as corruptible and imperfect (from which we get the term “sublunary”). Indeed, Dante placed the circles of paradise on the moon and the planets. So arguably, by making Earth the equal of the other planets, the new astronomy actually raised the dignity of our humble abode. In any case, I think that it is simplistic to characterize the switch from geocentricity to heliocentricity as a tale of declining hubris. The medieval Christians were hardly swollen with pride by their cosmic importance.

As you can see, this is a fascinating little volume that amply rewards the little time spent reading it. Van Helden has done a terrific job in making this scientific classic accessible.

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Review: Dialogue Concerning the Two Chief World Systems

Review: Dialogue Concerning the Two Chief World Systems

Dialogue Concerning the Two Chief World SystemsDialogue Concerning the Two Chief World Systems by Galileo Galilei

My rating: 4 of 5 stars

I should think that anyone who considered it more reasonable for the whole universe to move in order to let the earth remain fixed would be more irrational than one who should climb to the top of your cupola just to get a view of the city and its environs, and then demand that the whole countryside should revolve around him so that he would not have to take the trouble to turn his head.

It often seems hard to justify reading old works of science. After all, science continually advances; pioneering works today will be obsolete tomorrow. As a friend of mine said when he saw me reading this, “That shit’s outdated.” And it’s true: this shit is outdated.

Well, for one thing, understanding the history of the development of a theory often aids in the understanding of the theory. Look at any given technical discipline today, and it’s overwhelming; you are presented with such an imposing edifice of knowledge that it seems impossible. Yet even the largest oak was once an acorn, and even the most frightening equation was once an idle speculation. Case in point: Achieving a modern understanding of planetary orbits would require mastery of Einstein’s theories—no mean feat. Flip back the pages in history, however, and you will end up here, at this delightful dialogue by a nettlesome Italian scientist, as accessible a book as ever you could hope for.

This book is rich and rewarding, but for some unexpected reasons. What will strike most moderns readers, I suspect, is how plausible the Ptolemaic worldview appears in this dialogue. To us alive today, who have seen the earth in photographs, the notion that the earth is the center of the universe seems absurd. But back then, it was plain common sense, and for good reason. Galileo’s fictional Aristotelian philosopher, Simplicio, puts forward many arguments for the immobility of the earth, some merely silly, but many very sensible and convincing. Indeed, I often felt like I had to take Simplicio’s side, as Galileo subjects the good Ptolemaic philosopher to much abuse.

I’d like to think that I would have sensed the force of the Copernican system if I were alive back then. But really, I doubt it. If the earth was moving, why wouldn’t things you throw into the air land to the west of you? Wouldn’t we feel ourselves in motion? Wouldn’t canon balls travel much further one way than another? Wouldn’t we be thrown off into space? Galileo’s answer to all of these questions is the principal of inertia: all inertial (non-accelerating) frames of reference are equivalent. That is, an experiment will look the same whether it’s performed on a ship at constant velocity or on dry land.

(In reality, the surface of the earth is non-inertial, since it is undergoing acceleration due to its constant spinning motion. Indeed the only reason we don’t fly off is because of gravity, not because of inertia as Galileo argues. But for practical purposes the earth’s surface can be treated as an inertial reference frame.)

Because this simple principle is the key to so many of Galileo’s arguments, the final section of this book is trebly strange. In the last few pages of this dialogue, Galileo triumphantly puts forward his erroneous theory of the tides as if it were the final nail in Ptolemy’s coffin. Galileo’s theory was that the tides were caused by the movement of the earth, like water sloshing around a bowl on a spinning Lazy Susan. But if this was what really caused the tides, then Galileo’s principle of inertia would fall apart; since if the earth’s movements could move the oceans, couldn’t it also push us humans around? It’s amazing that Galileo didn’t mind this inconsistency. It’s as if Darwin ended On the Origin of Species with an argument that ducks were the direct descendants of daffodils.

Yet for all the many quirks and flaws in this work, for all the many digressions—and there are quite a few—it still shines. Galileo is a strong writer and a superlative thinker; following along the train of his thoughts is an adventure in itself. But of course this work, like all works of science, is not ultimately about the mind of one man; it is about the natural world. And if you are like me, this book will make you think of the sun, the moon, the planets, and the stars in the sky; will remind you that your world is spinning like a top, and that the very ground we stand on is flying through the dark of space, shielded by a wisp of clouds; and that the firmament up above, something we often forget, is a window into the cosmos itself—you will think about all this, and decide that maybe this shit isn’t so outdated after all.

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Quotes & Commentary #51: Montaigne

Quotes & Commentary #51: Montaigne

I set little store by my own opinions, but just as little by other people’s.

—Michel de Montaigne

Although nobody is free from self-doubt, I have long felt that I have this quality to an inordinate degree. The problem is that I can’t decide whether this is a good or a bad thing.

On the one hand, doubting yourself is one of the keys of moderation and wisdom. If you think you already know everything you cannot learn. If you are sure that your perspective is right you cannot empathize. Dogmatism, selfishness, and ignorance result from the inability to doubt the truth of your own opinions.

There are no such things as self-doubting fanatics. The ability to question your own opinions and conclusions is what prevents most people from committing atrocities. I couldn’t kill somebody in the name of an idea, since there is no idea I believe in strongly enough.

And yet, this tendency to doubt my own beliefs and conclusions so often makes me hesitating, indecisive, and occasionally spineless. Never mind killing anyone: I don’t even believe in my political ideals enough to stand up to somebody I find offensive. I doubt the worth of my dreams, the reason of my arguments, the virtue of my actions; and I am not terribly sure about my professional competency or my literary skill.

No matter what I do, I have this nagging feeling that, somewhere out there, there are people who could make me appear ridiculous by comparison. So often I feel out of the loop. I hesitate to submit my writing anywhere because I think a professional editor would cut it to pieces. I hesitate to put forth arguments because I think a real expert could see right through them. I hesitate to commit to a profession because I doubt my own ability to follow through, to perform difficult tasks, and to do my duties responsibly.

My nagging self-doubt is more of a feeling than a thought; but insofar as a feeling can be expressed in words, it goes like this: “Well, maybe there’s something big out there that I don’t know, something important that would render all my knowledge and standards inadequate.”

The odd thing is that I have no evidence that this fear is justified. In fact, I have evidence to the contrary. The more I read and travel, the more people I meet, the more places I work, the less surprised I am by what I find. The contours of daily reality have grown ever-more familiar, and yet this fear—the fear that, somehow, I have missed something big—this fear remains.

The perilous side of self-doubt is that it can easily ally itself with baser qualities. I can argue myself out of taking risks because I am unsure whether I really want the goal. I can argue myself out of standing up for what I believe is right by doubting whether it really is right, and whether I could prove it. Self-doubt and fear—fear of failure, fear of rejection, fear of being publically embarrassed—so often go hand-in-hand.

I can’t say why exactly, but the thought of writing a flawed argument, with a logical fallacy, an unwarranted assumption, or a sloppy generalization, fills me with dread. How mortifying to have my mental errors exposed to the world! Maybe this is from spending so much time in a school environment wherein the number of correct answers was used as a measure of my worth. Or maybe it is simply my personality; being “right” has always been important to me.

This fear of being wrong is particularly irrational, since some of the greatest minds and most influential thinkers in history have been wrong—Galileo, Newton, Darwin, Einstein, all of them have erred. Indeed, the fear of being wrong is not only irrational, but counterproductive to learning, since it sometimes prevents me from exposing my thoughts, increasing the likelihood that I will persist in an error.

Despite the negatives, I admit that I am often proud of my ability to doubt my own conclusions and change my opinions. I see it as a source of my independence of mind, my ability to think differently from others and to come to my own conclusions. After all, doubting yourself is the prerequisite of doubting anything at all. As Plato illustrated in his Socratic dialogues, from the moment we our born our minds are filled with all sorts of assumptions and prejudices which we absorb from our culture. The first step of doubting conventional opinion is thus doubting our own opinions.

But just as often as my self-doubt is a source of pride, it is a source of shame. I am sometimes filled with envy for those rare souls who seem perfectly self-confident. In this connection I think of Benvenuto Cellini, the Renaissance artist who left us his remarkable autobiography. Cocksure, boastful, selfish, prideful, Cellini was in many ways a despicable man. And yet he tells his story with such perfect certainty of himself that you can’t help but be won over.

Logically, self-confidence should come after success, since otherwise it isn’t justified. But so often self-confidence comes beforehand, and is actually the cause of success. In my experience, when you believe in yourself, others are inclined to believe in you. When you are confident you take risks, and these risks often enough pay off. When you are confident you state your opinions boldly and clearly, and thus have a better chance of convincing others.

Confidence is often discussed in dating. Self-confident people are seen as more attractive, and tend to have more romantic success since they take more risks. The ability to look somebody in the eye and say what you think and what you want—these are almost universally seen as attractive qualities; and not only in romance, but in politics, academics, business, and nearly everything else.

The charisma of confidence notwithstanding, this leads to an obvious danger. Many people are confident without substance. They boast more than they can accomplish; they speak with authority and yet have neither evidence nor logic to back their opinions. The world is ruled by such people—usually men—and I think most of us have personal experience with this type. I call it incompetent confidence, and it is rampant.

As Aristotle would say, there must be some ideal middle-ground between being confidently clueless, and being timidly thoughtful. And yet, in my experience, this middle-ground, if it even exists, is difficult to find.

I suppose that, ideally, we would be exactly as confident as the reach of our knowledge permitted: bold where we were sure, hesitating where we were ignorant. In practice, however, this is an impossible ideal. How can we ever be sure of how much we know, or how dependable our theories are? Indeed, this seems to be precisely what we can never know for sure—how much we know.

For the world to function, it seems that it needs doers and doubters. We need confident leaders and skeptical followers. And within our own brains, we need the same division: the ability to act boldly when needed, and to question ourselves when possible. Personally, I tend to err on the side of self-doubt, since it easily allies itself with laziness, inaction, and fear; but now I am starting to doubt my own doubting.