Galileo Galilei (1564-1642): Science and Religion – Part III: Galileo – Science and the Bible of Nature

The Torah begins with a cosmological metaphorical account of the creation and character of the universe. One can get caught up in the literary and religious meaning, but it is important to recognize that the initial cosmological story is a claim that the universe is a bible of nature and that the understanding of that bible precedes any understanding of the various historical and political accounts of human behavior.

If you do not understand and grasp the bible of nature, you will not understand the condensed tales of the behavior of all of humanity and then of the origin and development of the nation of Israel. That there might be a correspondence between what we observe at a behavioral level, at the level of the human microcosm and then the level of the macrocosm has been a conceit of astrology. Galileo turned a literary notion of that conceit (astrology was a literary rather than scientific conceit dressed up in pseudo-scientific garb) into a natural one. Radically different orders of experience had to be grounded in a common conception of nature, and that accomplished by paying close attention to what we grasp with our senses to a microscopic degree and what we deduce from reason and mathematics abstracted as much as possible from experience itself.

For Galileo, both science and religion were preoccupied with the “marvels kept hidden in obscurity for all previous centuries.” The point of both science and religion is to make the unknown known and for both to bracket what could not be known at this time given the developments of our skills and knowledge. Further, on the alleged dichotomy between science and religion, Galileo’s eldest daughter’s letters, “recognized no such division during his lifetime.” (Sobel 12)

Galileo’s aptitude for mathematics and science came early. There is the tale that he used the Tower of Pisa to test his theory that material objects fell at virtually the same degree of acceleration regardless of their weight though differentiated by air resistance. If Galileo had used the anecdotal feather versus a cannon ball to prove his theory, he would have been laughed out of the academy. Instead, according to established Aristotelian belief that material objects fell at a speed relative to their weight, Galileo showed mathematically that a cannon ball would have to reach the ground ten times faster than a musket ball one-tenth the weight when the latter, in fact, as he demonstrated physically, reached the ground very shortly after the cannon ball did. Reason and experimentation were necessary to validate a theory. The traditional explanation was patently absurd.

Galileo was a prodigious inventor as well as a scientific and mathematical genius. He invented a device for irrigation, a marine compass, an improved telescope, a way for ship pilots to navigate, the way to determine longitude at sea, a way to improve military fortifications, an early pocket calculator, all enormously valuable to the mercantilist nobility of Tuscany. He revealed the mathematics behind the lever, developed lenses with twice the magnifying quality of those made by the Dutch, a significant benefit to sailors at war watching enemy ships and maneuvers through an eyeglass. He invented the pendulum clock. But his greatest initial achievement was his validation of the Copernican theory of the movement of the heavenly bodies. That depended on his increased improvement of lenses that eventually had a magnifying power of twenty and that were used in telescopes to show that heavenly bodies were anything but perfect spheres. The moon was not spherical at all.

Nicolous Copernicus was born ninety years before Galileo and had long before published his classic, De revolutionibus. In 1543, this Polish cleric had argued that the Earth was not the centre of the universe. Even its sun was not. As we would learn, there are 200 billion other stars in the Milky Way galaxy to which the sun belongs. The Milky Way is also not the centre of the universe. There are 200 billion galaxies. 200 billion stars in this galaxy and 200 billion galaxies – I cannot imagine numbers that large let alone the number of stars in all the galaxies. And to think just 400 years ago, the vast majority of people on this earth believed that the earth was the centre of the universe.  It was Galileo who established that the distant stars only appeared immoveable because of their great distance. Talk about a revolution in thought!

The scientific revolution was taking place throughout Europe. Already in the sixteenth century, Andreas Vesalius had disproven the belief that men had one less rib than women by simply counting them and showing that both genders had 12 pairs. (On the Fabric of the Human Body) He also demonstrated that the earth was just one of a finite number of planets that circled the sun. A contemporary of Galileo, Johannes Kepler, published the first two laws of planetary motion. In 1628, William Harvey disproved Aristotle’s ebb and flow theory of blood and established that blood circulated by means of the heart as a pump. By tracing the nerves to the brain, Harvey also established that the heart was not the centre of the nervous system.

The cosmological world view, the anatomy and physiology of the body, the physics of motion to which Galileo would contribute so much, the geography of the earth and its spherical shape and motion through the solar system, all provided a brand new sense of the world around us. Galileo was perhaps the greatest contributor to that revolution, not only because of his theories, but because he established the basic principles of the scientific method dependent on repeated and repeatable observations married to abstract theories from which predictions could be made. Further, he showed that advances in technology were often necessary prerequisites to advances in science.

Galileo became obsessed with the heavens at the age of 40 in 1604 when a new star appeared, much to the consternation and concern of the intellectual world at the time since stars were not supposed to come into being or die; they were supposedly fixed in the heavens for eternity. When Galileo himself began to teach at the University of Padua in 1592, he himself had taught that the earth was the centre of the universe. In the new century, Galileo began to question this long held and widespread belief.

By the time that new star appeared, Shakespeare, who had been born the same year as Galileo, had written his greatest classics. In the 1580s he had already become not only the greatest playwright of his time, but the greatest playwright of all time. Who claims that mathematicians and scientists come into their greatest productive and creative period in their twenties while artists take a much longer period of gestation to mature?

Galileo was highly productive after he turned forty. In 1610, when Shakespeare had already written 38 plays, Galileo discovered the planet Jupiter with his improved version of the Dutch Hans Lippershey’s 1608 creation of the refracting telescope which he had used to discover and describe mountains on the moon in 1609. Galileo published The Starry Messenger. As a result of his prodigious number of inventions and his experimental and mathematical proofs, in 1610 he was made what we now call a research professor with no teaching duties and a salary sufficient that he no longer had to depend on renting quarters to students.  A year later, he was named to the Lyncean Academy that had been founded only eight years earlier and quickly became the most famous institution for academic networking at the highest level for its time.

However, by then, Shakespeare had written Hamlet (1601), Othello (1605), Macbeth (1606) and The Tempest in 1612. Galileo was a late bloomer in comparison. But what a tempest he produced when, by the same year Shakespeare’s play of the same name appeared on stage, Galileo had established empirically that the surface of the moon was rough, with mountains, valleys and craters, that other planets had their own moons, that at least Venus travelled around the sun, and that the sun itself was imperfect with many dark spots, spots that came into being and decayed, did so with irregularity, changed shape, but were nevertheless enormous and, depending on their number and size, could impede sunlight from reaching earth. Galileo even invented a system whereby the portraits of the sun each day could be projected on paper on which he could draw the daily location and sizes of those sunspots.

In 1612, he published his erroneous theory of the tides in Bodies That Stay Atop Water or Move Within, though the work very successfully demonstrated why ice floated on water and clearly demonstrated that the sun did not have a perfect body. However,instead of the tides resulting from the gravitational attraction of the moon, Galileo then contended that they were the result of the rotation of the earth and the movement of the earth around the sun much as water piles up on one side of a basin when it is moved.

He held onto that theory and published an elaborated account in 1616, Theory on the Tides, even though it later directly contradicted his own explanation for why we and other animals never experienced the earth’s rotation. In 1613, Galileo published his Sunspot Letters about the shifting position of black spots on the sun with pictures with near photographic quality that established that the sun rotates on its own axis and, further, proving that the earth rotates around the sun rather than vice versa. However, his dismissal of comets as mere illuminations proved erroneous.

However, I must jump ahead to the end of Galileo’s life after he had been condemned by The Inquisition when he returned to his very early interest in motion and his developed interest in the strength of different materials. In 1633, Galileo penned his most important work, not his Discourse dealing with Copernican theory, but returned to his work on motion which he had begun to explore thirty-five years earlier when he was a very young professor at the University of Pisa before he even moved onto Padua.

He had begun with the study of the speed of falling bodies, but went on to describe the swinging of a pendulum in accordance with a mathematical scientific law. His mathematical calculations for the rate of acceleration of a falling body arose from repeated observations of the rate of travel of a bronze globe down an inclined trough. That study of motion yielded the mathematical law of the rate of acceleration for bodies on earth, 32.2 feet per second per second. Prior to then, traditional science dictated that the acceleration of a falling body would be proportional to its mass — that is, a 10 kg object was expected to accelerate ten times faster than a 1 kg object. Galileo demonstrated the absurdity of such a claim.

Instead of making determinations about the physical world in terms of a telos, a final cause, an end to which an object wanted to go as if it had a built-in inner intention, Galileo focused on how an object behaved. That focus included observation, experimentation and the development of mathematical formulae in terms of which predictions could be made about the motion of bodies. While Aristotle had held that mathematics belonged to the immaterial world, Galileo demonstrated its applicability to the material world. In terms of a thrown object instead of one in free fall, Galileo demonstrated with mathematical precision that the object always followed the arc of a parabola.

Galileo was not only interested in the motion of bodies, but in their malleability, how they bend and break. His new dialogue, Two New Sciences, revived his characters, Salviati, Sagredo and Simplicio, from his Discourses. It was set in a Venetian shipyard where precise measures had to be made when a new ship was launched lest it be crunched by its own weight.

The title page of the Leiden, Holland 1638 edition read:





Concerning Two New Sciences

Pertaining to

Mechanics & Local Motions

by Signor

Galileo Galilei, Lyncean

Philosopher and Chief Mathematician to His Serene Highness

The Grand Duke of Tuscany

With an Appendix on the center of gravity in various Solids

I want to end this blog with a metaphor rather than science. In Galileo’s last book, he had broken down the motion of a hurled projectile into two vectors, its forward motion and the downward acceleration of an object in free fall. For a quarter century, his scientific achievements traveled a similar parabola, between two vectors, the forward projection of his science initially towards the heavens and the downward repression by the Inquisition that ended with the science of local motion and of the strength of solids falling to earth. Ironically, these two new sciences were, in part, the product of repression and not free fall, for in his house arrest, Galileo found the time to complete his original scientific work. Earth was precisely where those two sciences belonged. From the soil of Italy, the Dutch would resurrect and lift on high this last illustrious scientific product. The last blog will cover the latter vector of religious repression.


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