Wahrnehmung galileo biography

The philosophical thread that runs through Galileo's intellectual life is a strong and increasing desire to find a new conception of what constitutes natural philosophy and how natural philosophy ought to be pursued. Galileo signals this goal clearly when he leaves Padua in to return to Florence and the court of the Medici and asks for the title Philosopher as well as Mathematician.

Wahrnehmung galileo biography: Galileo explores the relative merits of

This was not just a status-affirming request, but also a reflection of his large-scale goal. What Galileo accomplished by the end of his life in was a reasonably well articulated replacement for the traditional set of analytical concepts connected with the Aristotelian tradition of natural philosophy. Selections in LindbergOsler Some scholars might wish to describe what Galileo achieved in psychological terms as an introduction of new mental models Palmieri or a new model of intelligibility Machamer c.

However phrased, Galileo's main move was to de-throne the Aristotelian physical categories of the one celestial the aether or fifth element and four terrestrial elements fire, air, water and earth and their differential directional natures of motion circular, up and down. In their place he left only one element, corporeal matter, and a different way of describing the properties and motions of matter in terms of the mathematics of the equilibria of proportional relations Palmieri that were typified by the Archimedian simple machines—the balance, the inclined plane, the lever, to which he added floating bodies and the pendulum Machamer b, Machamer and Hepburn In doing so Galileo changed the acceptable way of talking about matter and its motion, and so ushered in the mechanical tradition that characterizes so much of modern science, even today.

But this would take more explaining DijksterhuisMachamer et al. As a main focus underlying Galileo's accomplishments, it is useful to see him as being interested in finding a unified theory of matter, a mathematical theory of the material stuff that constitutes the whole of the cosmos. Perhaps he didn't realize that this was his grand goal until the time he actually wrote the Discourses on the Two New Sciences in Despite working on problems of the nature of matter from onwards, he could not have written his final work much earlier thancertainly not before Starry Messenger ofand actually not before the Dialogues on the Two Chief World Systems of Beforehe did not have the theory and evidence he needed to support his claim about a unified, singular matter.

He had wahrnehmung galileo biography deeply about the nature of matter before and had tried to work out how best to describe matter, but the idea of unified matter theory had to wait for the establishment of principles of matter's motion on a moving earth. And this he did not accomplish until the Dialogues. Galileo began his critique of Aristotle in the manuscript, De Motu.

The first part of this manuscript deals with terrestrial matter and argues that Aristotle's theory has it wrong. For Aristotle, sublunary or terrestrial matter is of four kinds earth, air, water, and fire and has two forms, heavy and light, which by nature are different principles of natural motion, down and up. Galileo, using an Archimedian model of floating bodies and later the balance, argues that there is only one principle of motion, the heavy gravitasand that lightness or levitas is to be explained by the heavy bodies moving so as to displace or extrude other bits of matter in such a direction that explains why the other bits rise.

So on his view heaviness or gravity is the cause of all natural terrestrial motion. But this left him with a problem as to the nature of the heavy, the nature of gravitas. In De Motuhe argued that the moving arms of a balance could be used as a model for treating all problems of motion. In this model heaviness is the proportionality of weight of one object on one arm of a balance to the weight of another body on the other arm of the balance.

Galileo realized quickly these characterizations were insufficient, and so began to explore how heaviness was relative to the different specific gravities of bodies having the same volume. He was trying to figure out what is the concept of heaviness that is characteristic of all matter. What he failed to work out, and this was probably the reason why he never published De Motuwas this positive characterization of heaviness.

There seemed to be no way to find standard measures of heaviness that would work across different substances. So at this point he did not have useful categories to replace the Aristotelian ones. Still, he has no good way to measure or compare specific gravities of bodies composed of different materials; his notebooks during this early 17 th century period reflect his trying again and again to find a way to bring all matter under a single proportional measuring scale.

He tries to study acceleration along an inclined plane and to find a way to think of what changes acceleration brings. In this regard and during this period he attempts to examine the properties of the percussive effect of bodies of different specific gravities, or how they have differential impacts. Yet the details and categories of how to properly treat weight and movement elude him.

One of Galileo's problems was that the Archimedean wahrnehmung galileo biography machines that he was using as his model of intelligibility, especially the balance, are not easily conceived of in a dynamic way. Except for the inclined plane, time is not a property of the action of simple machines that one would normally attend to. In discussing a balance, one does not normally think about how fast an arm of the balance descends nor how fast a body on the opposite arm is rising though Galileo does in his Postils to Rocco ca.

The converse is also true. So it was that Galileo's classic dynamic puzzle about how to describe time and the force of percussion, or the force of body's impact, would remain unsolved, He could not, throughout his life, find systematic relations among specific gravities, height of fall and percussive forces. In —9, Galileo worked long at doing experiments on inclined planes and most importantly with pendula.

The pendulum again exhibited to Galileo that acceleration and, therefore, time is a crucial variable. Moreover, isochrony—equal times for equal lengths of string, despite different weights—goes someway towards showing that time is a possible form for describing the equilibrium or ratio that needs to be made explicit in representing motion. It also shows that, in at least one case, time can displace weight as a crucial variable.

Work on the force of percussion and inclined planes also emphasized acceleration and time, and during this time ca. We see from his work during this period that Galileo's law of free fall arises out of this struggle to find the proper categories for his new science of matter and motion. Galileo accepts, probably as early as the draft of Le Mecanichethat natural motions might be accelerated.

Wahrnehmung galileo biography: the article deals with the

But that accelerated motion is properly measured against time is an idea enabled only later, chiefly through his failure to find any satisfactory dependence on place and specific gravity. Galileo must have observed that the speeds of bodies increase as they move downwards and, perhaps, do so naturally, particularly in the cases of the pendulum, the inclined plane, in free fall, and during projectile motion.

Also at this time he begins to think about percussive force, the force that a body acquires during its falling motion that affects the strength of its impact. For many years he thinks that the correct science of these changes should describe how bodies change according to where they are, their position, on their paths. Specifically, it seems that height is crucial.

Percussive force is directly related to height and the motion of the pendulum seems to involve essentially equilibrium with respect to the height of the bob and time also, but isochrony did not lead directly to a recognition of time's importance. The law of free fall, expressed as proportionality to time squared, was discovered by Galileo through the inclined plane experiments Drakev.

His later and correct definition of wahrnehmung galileo biography acceleration as dependent on time is an insight gained through recognizing the physical significance of the mean proportional relation Machamer and Hepburn ; for a different analysis of Galileo's discovery of free fall see Renn et al. But let us return to the main matter.

In Galileo begins his work with the telescope. Many interpreters have taken this to be an interlude irrelevant to his physics. The Starry Messengerwhich describes his early telescopic discoveries, was published in Perhaps the most unequivocal instance of this is Galileo's analogizing the mountains on the moon to mountains in Bohemia. Moreover, if there is only one kind of matter there can be only one kind of natural motion, one kind of motion that this matter has by nature.

So it has to be that one law of motion will hold for earth, fire and the heavens. This is a far stronger claim than he had made back in In addition, he described his discovery of the four moons circling Jupiter, which he politically named the Medicean stars after the ruling family in Florence, his patrons. In the Copernican system, the Earth's having a moon revolving around it was unique and so seemingly problematic for a system where the Earth was just one planet among others.

His experiments proved this theory to be false. InGalileo constructed his first telescope, an optical system consisting of convex and concave lenses, and began systematic astronomical observations. This marked the rebirth of the telescope, which had been virtually unknown for nearly twenty years, and became a powerful tool for scientific inquiry.

Therefore, Galileo can be considered the inventor of the first telescope. He quickly improved his telescope, and according to his own words, "built an instrument so perfect that objects appeared almost a thousand times larger and more than thirty times closer than when observed with the naked eye". Galileo turned his telescope towards the sky on the night of January 7, What he saw there — the lunar landscape, mountain ranges and peaks — led him to believe that the Moon resembled the Earth and had mountain systems.

This discovery contradicted religious dogma and Aristotle's teachings about the special position of Earth among celestial bodies. Galileo also discovered four moons of Jupiter, which also contradicted Aristotle's teachings. He established that the Sun rotates on its axis. Based on his observations, Galileo concluded that rotational motion was inherent to all celestial bodies and that the heliocentric system proposed by Copernicus was the only true one.

Galileo began to advocate more boldly for Copernican theory.

Wahrnehmung galileo biography: Galileo Galilei refers to Kepler's achievements

Further, in Day Four, when he is giving his proof of the Copernican theory by sketching out how the three-way moving earth mechanically moves the tides, he nuances his matter theory by attributing to the element water the power of retaining an impetus for motion such that it can provide a reciprocal movement once it is sloshed against a side of a basin.

We saw it in De Motu inwith submerged bodies, but more importantly he learned much more while working through his dispute over floating bodies Discourse on Floating Bodies In fact a large part of this debate turned on the exact nature of water as matter, and what kind of mathematical proportionality could be used to correctly describe it and bodies moving in it cf.

Palmieri,a. The second science, discussed so to speak in the last two days, dealt with the principles of local motion. These have been much commented upon in the Galilean literature. But the first two days, the first science, has been much misunderstood and little discussed. This first science, misleadingly, has been called the science of the strength of materials, and so seems to have found a place in history of engineering, since such a course is still taught today.

However, this first science is not about the strength of materials per se. See MachamerMachamer and Hepburnand the detailed work spelling this out by Biener Galileo realizes that before he can work out a science of the motion of matter, he must have some way of showing that the nature of matter may be mathematically characterized. Both the mathematical nature of matter and the mathematical principles of motion he believes belong to the science of mechanics, which is the name he gives for this new way of philosophizing.

Remember that specific gravities did not work. So it is in Day One that he begins to discuss how to describe, mathematically or geometricallythe causes of how beams break. He is searching for the mathematical description of the essential nature of matter. He rules out certain questions that might use infinite atoms as basis for this discussion, and continues on giving reasons for various properties that matter has.

The most famous of these discussions is his account of acceleration of falling bodies, that whatever their weight would fall equally fast in a vacuum. The Second Day lays out the mathematical principles concerning how bodies break. He does this all by reducing the problems of wahrnehmung galileo biography to problems of how a lever and a balance function.

Something he had begun back inthough this time he believes he is getting it right, showing mathematically how bits of matter solidify and stick together, and do so by showing how they break into bits. The second science, Days Three and Four of Discorsidealt with proper principles of local motion, but this was now motion for all matter not just sublunary stuff and it took the categories of time and acceleration as basic.

Interestingly Galileo, here again, revisited or felt the need to include some anti-Aristotelian points about motion as he had done back in Then, he says, join the bodies together. In this case the lightness of the small one ought to slow down the faster larger one, and so they together fall as a speed less than the heavy fell in the first instance.

Then his punch line: but one might also conceive of the two bodies joined as being one larger body, in which case it would fall even more quickly. So there is a contradiction in the Aristotelian position Palmieri His projected Fifth Day would have treated the grand principle of the power of matter in motion due to impact. He calls it the force of percussion, which deals with two bodies interacting.

He has a new science of matter, a new physical cosmography, and a new wahrnehmung galileo biography of local motion. In all these he is using a mathematical mode of description based upon, though somewhat changed from, the proportional geometry of Euclid, Book VI and Archimedes for details on the change see Palmieri It is in this way that Galileo developed the new categories of the mechanical new science, the science of matter and motion.

His new categories utilized some of the basic principles of traditional mechanics, to which he added the category of time and so emphasized acceleration. But throughout, he was working out the details about the nature of matter so that it could be understood as uniform and treated in a way that allowed for coherent discussion of the principles of motion.

Thereafter, matter really mattered. The end of the episode is simply stated. In Januarya very ill Galileo made an arduous journey to Rome. Finally, in April Galileo was called before the Holy Office. This was tantamount to a charge of heresy, and he was urged to repent Shea and Artigas, f. Specifically, he had been charged with teaching and defending the Copernican doctrine that holds that the Sun is at the center of the universe and that the earth moves.

Galileo was called four times for a hearing; the last was on June 21, The next day, 22 June, Galileo was taken to the church of Santa Maria sopra Minerva, and ordered to kneel while his sentence was read. Galileo was made to recite and sign a formal abjuration:. Galileo was not imprisoned but had his sentence commuted to house arrest. In December he was allowed to retire to his villa in Arcetri, outside of Florence.

During this time he finished his last book, Discourses on the Two New Scienceswhich was published inin Holland, by Louis Elzivier. The book does not mention Copernicanism at all, and Galileo professed amazement at how it could have been published. He died on January 8, There is also controversy over the legitimacy of the charges against Galileo, both in terms of their content and judicial procedure.

It has even been argued Redondi that the charge of Copernicanism was a compromise plea bargain to avoid the truly heretical charge of atomism. Though this latter hypothesis has not found many willing supporters. Legitimacy of the content, that is, of the condemnation of Copernicus, is much more problematic. Galileo had addressed this problem inwhen he wrote his Letter to Castelli which was transformed into the Letter to the Grand Duchess Christina.

In this "wahrnehmung galileo biography" he had argued that, of course, the Bible was an inspired text, yet two truths could not contradict one another. So in cases where it was known that science had achieved a true result, the Bible ought to be interpreted in such a way that makes it compatible with this truth. The Bible, he argued, was an historical document written for common people at an historical time, and it had to be written in language that would make sense to them and lead them towards the true religion.

Cardinal Bellarmine was willing to countenance scientific truth if it could be proven or demonstrated McMullin But Bellarmine held that the planetary theories of Ptolemy and Copernicus and presumably Tycho Brahe were only hypotheses and due to their mathematical, purely calculatory character were not susceptible to physical proof.

This is a sort of instrumentalist, anti-realist position DuhemMachamer There are any number of ways to argue for some sort of instrumentalism. Duhem himself argued that science is not metaphysics, and so only deals with useful conjectures that enable us to systematize the phenomena. Subtler versions, without an Aquinian metaphysical bias, of this position have been argued subsequently and more fully by van Fraassen and others.

Galileo would be led to such a view by his concern with matter theory. Of course, put this way we are faced with the question of what constitutes identity conditions for a theory, or being the same theory. The other aspect of all this which has been hotly debated is: what constitutes proof or demonstration of a scientific claim? This argument, about the tides, Galileo believed provided proof of the truth of the Copernican theory.

Galileo argues that the motion of the earth diurnal and axial is the only conceivable or maybe plausible physical cause for the reciprocal regular motion of the tides. How could the moon without any connection to the seas cause the tides to ebb and flow? Such an explanation would be the invocation of magic or occult powers. Inhe published his observations of sunspots, which also refuted Aristotelian doctrine that the sun was perfect.

Galileo published a number of books throughout his career, including:. Dialogue Concerning the Two Chief World Systemsa discussion among three people: one who supports Copernicus' heliocentric theory of the universe, one who argues against it, and one who is impartial. Though Galileo claimed Dialogues was neutral, it was clearly not. The advocate of Aristotelian belief comes across as the simpleton, getting caught in his own arguments.

In addition to the telescope and his numerous mathematical and scientific discoveries, in Galileo constructed a hydrostatic balance for measuring small objects. That same year, he also refined his theories on motion and falling objects, and developed the universal law of acceleration, which all objects in the universe obeyed. He also devised a type of simple thermometer.

A simple glass-bulb thermometer known as a Galileo thermometer wasn't invented by Galileo, but was based on his understanding that the density of liquids changes based on its temperature. A thermoscope that Galileo designed or helped to design is similar to modern-day thermometers. Inside the thermoscope, a liquid rises and falls in a glass tube as the temperature of the liquid rises or falls.

After Galileo built his telescope inhe began mounting a body of evidence and openly supporting the Copernican theory that the earth and planets revolve around the sun. The Copernican theory, however, challenged the doctrine of Aristotle and the established order set by the Catholic Church. InGalileo wrote a letter to a student to explain how Copernican theory did not contradict Biblical passages, stating that scripture was written from an earthly perspective and implied that science provided a different, more accurate perspective.

The letter was made public and Church Inquisition consultants pronounced Copernican theory heretical. Galileo obeyed the order for seven years, partly to make life easier and partly because he was a devoted Catholic. He allowed Galileo to pursue his work on astronomy and even encouraged him to publish it, on condition it be objective and not advocate Copernican theory.

Church reaction was swift, and Galileo was summoned to Rome.