Galileo's life and scientific contributions

Galileo was certainly one of the most formative and important figures in the history of science -- among the inventions and contributions to science attributable to him are the refinement of lens-grinding and telescope making technologies as well as the creation of the scientific method in any real and meaningful form, and, certainly neither last nor least among his discoveries, the discovery of four of Jupiter's moons and their retrograde-motion which served to him as one of the many proofs and evidences suggesting that the Copernican hypothesis about the solar system was the correct one. Indeed, his continuing popularity and pervasiveness as a scientific and intellectual figure is only further evidenced by the fact that his life has been recently dramatized in the imaginary memoir, Galileo's Daughter: A Historical Memoir of Science, Faith, and Love by Dava Sobel, in which Sobel attempts to recount the thoughts of Galileo's daughter and details her reactions to their correspondence in this impressive and imaginative work. For these reasons the details surrounding Galileo's own increasing conviction of the correctness of the Copernican version of the design of the solar system as well as the Catholic Church's response by accusing him of and trying him for heresy, as well as his eventual and evasive abjuration, all continue to be of an importance than transcends the category of mere historical interest. Indeed, Galileo's trial reveals much about the very founding principles of science and shows us much about how we think today by showing us how much the way that we think about the world has evolved and changed since his lifetime.

Galileo, of course, is known not only as the father of the telescope and the scientific method, but also as someone who not only endorsed quietly, but, in fact openly supported a model that was radically different from the classical Ptolemeic model that was also the model that was used by the church and which held that the earth was, in fact, the center of the universe and that all of the stars and planets and other element sin the evening sky were part of the nine celestial spheres that orbited around the earth regularly, resultant in what we often hear described as the "celestial music." Indeed, this sort of approach to astronomy was digressed upon at length by a number of thinkers and artists extremely important to the history of the church -- not only were such questions hotly debated by medieval philosophers who viewed their astrological viewings and works as one that had both scientific and theological resonance, but also poets of the day, such as Dante, for example, expounded upon the beauty of the celestial sphere in his enormous section of the Divine Comedy known as Paradiso. Indeed, Galileo held to this belief in the course of his life (although he renounced such a belief after a fashion in order to avoid death by the inquisition) for many reasons. Perhaps the most famous of these reasons was his observation of the retrograde movement of bodies in the night sky that turned out to be the moons of Jupiter. Nonetheless, his reasoning also was supported by other ideas, specifically, he had a groundbreaking theory about the causation of the tides of the earth:

He noticed that whenever the barge's speed or direction altered, the freshwater inside sloshed around accordingly. If the vessel suddenly ground to a halt on a sandbar, for instance, the water pushed up towards the bow then bounced back toward the stern, doing this several times with ever decreasing agitation until it returned to a level state.

Galileo realized that the Earth's dual motion -- its daily one around its axis and its annual one around the sun -- might have the same effect on oceans and other great bodies of water as the barge had on its freshwater cargo. The key, as Galileo saw it, was that even though we don't sense it, different parts of our planet move at different speeds depending on the time of day. it's as if the Earth were a barge, which sped up, slowed down, and periodically changed direction.

Tyson)

The interesting, of course, is that Galileo was exceptionally wrong in this particular idea. There were, even from the get-go a whole slew of theoretical and observational problems that seriously and terminally plagued his hypothesis, but regardless of those phenomena, Galileo felt that his answer was more correct than the going idea, which had been supplied by the mathematician and astronomer Johannes Kepler. Indeed, Galileo's ideas, for example should have predicted only one high tide per day, when in fact there are two, and Newtonian physics would eventually vindicate the Kepplerian idea of tidal motion (Tyson). Part of the reason for his objection to the Keplerian notion that the moon created tides through some form of "attractiveness" was that, by adhering to the scientific method, Galileo refused to believe in forces that could not be empirically observed and thus, since this antedated Newton's explanation of gravity the lunar explanation of the ides as offered by Keppler seemed to Galilieo as if they were "occult" beliefs rather than scientific and empirical facts about the world (Tyson). If nothing else this is an excellent illustration of the fact that correct method does not always lead to correct answers and that sometimes even those preceding by an incorrect argument that is not yet wholly formed may still arrive at a notion that approximates the truth. Nonetheless, Galileo persevered with his own idea and even though it argued persuasively for the correctness of the Copernican vision of the scheme for the design and movement of the solar system (Tyson).

Of course, there was no particular discovery that could possibly have had a more smashing, effective, and massive effect on Galileo's perception that the Ptolemeic version of the design for the solar system was incorrect and that the Copernican schema for the construction of the Universe was correct that his discovery of the moons of Jupiter, which enabled him to discover an exception that flew so massively in the face of the received notions about how the solar system was constructed that he was forced to part irrevocably from the original conception of the solar system that was the reigning model of Galileo's day. Indeed, Galileo did observe the existence and then the eventual orbiting of four of the moon so Jupiter, being Io, Europa, Ganymede, and Callisto, all of which were some of the most important discoveries in the history of astronomy. What he noted moreover, about these planets was that the moved in retrograde fashion -- meaning that sometimes their motion appeared to occur in reverse of the motion of the rest of the objects in the solar system. After contemplating this retrograde motion of Jupiter's moons, Galileo was eventually able to attribute the irregularity to the development of a theory in which he hypothesized that the objects he observed were not knew heavenly bodies orbiting the earth, per se, but rather moons which were orbiting the larger Jupiter. Once Galileo realized that there were other bodies in the solar system that did not orbit the earth as the center pointing its orbit, it was very easy to see that the Potelmeic model of the heavens was very probably incomplete, and, more specifically, probably in error. Indeed, he wrote a letter in which he enclosed a brief summary of his findings and also explained the most rudimentary elements of his conclusions, as well:

should disclose and publish to the world the occasion of discovering and observing four Planets, never seen from the beginning of the world up to our own times, their positions, and the observations made during the last two months about their movements and their changes of magnitude; and I summon all astronomers to apply themselves to examine and determine their periodic times, which it has not been permitted me to achieve up to this day... On the 7th day of January in the present year, 1610, in the first hour of the following night, when I was viewing the constellations of the heavons through a telescope, the planet Jupiter presented itself to my view, and as I had prepared for myself a very excellent instrument, I noticed a circumstance which I had never been able to notice before, namely that three little stars, small but very bright, were near the planet; and although I believed them to belong to a number of the fixed stars, yet they made me somewhat wonder, because they seemed to be arranged exactly in a straight line, parallel to the ecliptic, and to be brighter than the rest of the stars, equal to them in magnitude...When on January 8th, led by some fatality, I turned again to look at the same part of the heavens, I found a very different state of things, for there were three little stars allwest of Jupiter, and nearer together than on the previous night.

Galileo, as quoted in Baalke)

This initial passages clues us into the basic thought process that Galileo was undergoing at the time in which he effectively made this discovery. Indeed, we can see here his own initial wonderment and the very simple excitement that he felt upon making a series of discoveries that, aside from being exciting, were clearly of exceptional and lasting scientific significance and would certainly earn Galileo a reputation as one of the most important astronomical observers of his time if not in all of history. However, we can also see how this initial awe quickly turned into logical questioning after Galileo underwent the observation of a great deal of further data culminating in the observed retrograde motion of the moons, which lead him to a state of extreme and earnest puzzlement about the state of the solar system.

Indeed, this state of puzzlement was understandably not long-lived, however, and Galileo again quite understandably brought to bear the not inconsiderable powers of his mind to the task of parsing the confusing string of data that his astronomical observations had yielded with regard to the retrograde motion of these new "planets" that his telescope had enabled him to discover. After a series of intriguing thoughts, reflections, and considerations, Galileo eventually came to the conclusion that the provenance of this strange retrograde motion was attributable not to some strange "occult" device but to the simple fact that these "planets" were like the moon orbiting earth except for the fact that they were instead orbiting Jupiter. Indeed, this conclusion excited him to no end:

therefore concluded, and decided unhesitatingly, that there are three stars in the heavens moving about Jupiter, as Venus and Mercury around the Sun; which was at length established as clear as daylight by numerous other subsequent observations. These observations also established that there are not only three, but four, erratic sidereal bodies performing their revolutions around Jupiter.

Galileo, as quoted in Baalke)

Indeed, it is important to consider briefly here the strength of Galileo's language, in which he above states that the conclusion he has reached that the satellites that he has observed are not heavenly bodies orbiting the earth at all, but rather four distinct bodies all of which were instead orbiting the much larger Jupiter, was one the Galileo reached, according to this own words, "unhesitatingly." Indeed, not only was this a conclusion, but something that, again according to his own words was "decided" for him. He had crossed from territory of working hypothesis to the realm of theory and then even further into the strata of fervent belief that these new objects were moons of Jupiter. Once Galileo had crossed the boundary, he had violated the current presiding principle about the shape and construction of the universe, which held that the earth was the center of the universe about which all other things orbited, because he had proven that other bodies orbited points other than the earth. Once this central principle was thrown out the window, there was no need to hold to the standard view whatsoever, and, thusly, Galileo began to embrace the Copernican view, which held that the planets orbited the sun -- which was a view that Galileo felt that the preponderance of the current evidence supported in a full and rationally considered, as well as scientific and methodologically sound, fashion. After this course of thinking, he understandably sided himself with the Copernicans, but, he also knew that, given the fact that the Copernican view was not only openly dismissed by the Church and the other powers that be of his day, but also that Copernican views were actively punished by threat of excommunication and death, Galileo attempted to tread lightly on the subject in his monograph in a fashion that might enable him to avoid coming under the suspicious investigation of Church powers. Nonetheless, as we all well know, he was, in fact, completely unable to do so, and, since the church felt him to be in violation of one of its ordained heresies, being, in this case, the heresy of holding the Copernican view, it brought him to trial for these crimes, and, in order to save his own life and spare himself so that he might do further research in astronomy and observe new and ever more important phenomenon, Galileo recanted, although he did so after a fashion that was uniquely his own.

Indeed, that the Church found Copernican views of the cosmos heretical and sought to prosecute and discourage them at every given turn in history is greatly evidenced by the very trial that they conducted of Galileo in which the evidence that they laid out against him consisted almost entirely of accusing him of the Copernican heresy and laying out a case against him within those heretical terms:

following the hypothesis of Copernicus, you include several propositions contrary to the true sense and authority of the Holy Scriptures; therefore (this Holy Tribunal being desirous of providing against the disorder and mischief which were thence proceeding and increasing to the detriment of the Holy Faith) by the desire of his Holiness and the Most Emminent Lords, Cardinals of this supreme and universal Inquisition, the two propositions of the stability of the sun, and the motion of the earth, were qualified by the Theological Qualifiers as...

1.) the proposition that the sun is in the center of the world and immovable from its place is absurd, philosophically false, and formally heretical; because it is expressly contrary to Holy Scriptures. 2.) the proposition that the earth is not the center of the world, nor immovable, but that it moves, and also with a diurnal action, is also absurd, philosophically false, and, theologically considered, at least erroneous in faith.

Indictment of 1633")

Indeed, we can see here in very simple terms that the logic of the Church was one that was clearly and ironically not to be moved or altered by either logic or scientific empiricism. Indeed, the chief charge against both the claims that the Sun is the center of the world and against the idea of Galileo's that the Earth is not the center of the world is laid out in simple and non-negotiable terms which claim that Galileo's claimed empirical observations do not run in accordance with what is written in the scriptures and therefore must be understood and perceived as heretical. Indeed, what is at issue here is one that is much and considerably larger than the simple issue of astronomical observance and the precedence of the scientific method. At its base, this investigation and the entirety of the clash between Galileo and the Church was, at its core, an argument over the bases of epistemology and a debate about the locus of gnosis, for Galileo, really was, in his adherence to the scientific method making a distinct claim about truth that did and would continue to threaten the Church's dominion and domain. Indeed, the Church saw only one font of truth: God, and the will and ideas of God were discoverable by two sources and two sources only, one of which was the Bible whose scriptures provided instruction and guidance in the ways of the world, and the second of which was the Pope, who was God's living intermediary on the Earth and who provided instruction regarding how the scriptures were to be interpreted and guidance concerning the other issues not enumerated in the scriptures. Galileo, however, was quite literally arguing for a different base for epistemology and for a different locus for the primacy of truth. Whereas the Church believed that God was the location of all truth, Galileo placed his belief in truth as it was revealed through the scientific empiricism of the scientific method. Thus, this debate should not be viewed as a simple clashing over a disagreement about the finer point of a relatively obscure and essential unimportant theological matter that was merely an academic matter and nothing else. No, this debate was fundamentally a disagreement about the very nature of knowledge, where the basis of knowledge existed, and what authorities had the right to claim its understanding.