A Biography of Galileo Galilei

There have been many frontiers throughout the history of the world. There have been huge accomplishments, especially in the field of science. Yet, none have even come close to the amazing accomplishments of Galileo Galilei. Galileo provided a frontier in history because of his improvements in the field of science, his discoveries, his many inventions, and his intelligent theories. Galileo was not very supported by anyone when he started, but he soon began gaining popularity as he ascertained different things and started proving that he was right and some ideas of the past were erroneous.

In the summer of 1609, Galileo’s inspiration of improving the telescope was launched. A friend of his, Paolo Spari of Venice, wrote to him, asking him to try and figure out how the invention of the spyglass worked (MacLachlan 46). In his letter, he wrote that Lippershey of Holland had discovered that two lenses, if placed if front of one another, would enable great distances to be seen three to four times closer than usual, but they would only be able to be seen upside down (Levinger 75). Galileo accepted the challenge immediately after he read the note, attempting to discover the principle behind the spyglass, reproduce it, and then finally improve it (Rosen 119). Galileo soon discovered that light rays from the object go through the converging lens and eyepiece at the end of the tube, enabling him to create his own spyglass (Bernadini 49). The model of the new and improved “spyglass” took less than a day to create (Rosen 120). However, the actual “spyglass” took much longer to construct (Rosen 121).

His new model was able to be seen right side up, after he added a third lens, and could magnify objects up to nine times their actual size (MacLachlan 46). After his first spyglass was completed, Galileo climbed up on his roof to test it. After adjusting the tubes of the spyglass together, a tree bean forming from the blur he first had seen. At that time, he put the spyglass down and looked in that direction. All he could see on the horizon was a blurred, wavy, black line (Rosen 121). His spyglass was successful! He presented it to Doge Leonardo Donato (the leader of the Venetian Republic at the time). It was passed around to all the people in the court, who marveled at how far they could see and how amazing and fun it was (Rosen 126). Soon after, crowds of all classes began to gather in front of his house to get a chance to see what was being considered a phenomenon (Levinger 76).

After making his improvements on the telescope, Galileo wanted to test it out to see how far he could see into outer space. Therefore, he first began with the Earth’s moon. As he examined the surface of the moon, he realized that its surface was rough and uneven and was covered with valleys and craters that had many shadows (Rosen 134). Galileo also observed many other interesting facts, such as the many isolated peaks, one of which he calculated to be abut four miles high (Bernadini 54). This discovery proved to be very important since it disproved Aristotle’s famous theory that the “heavenly bodies” (objects in space) were perfect (Bernadini 55). In fact, the moon was much like the earth in that it was not exactly spherical (Levinger79). Next, he observed the stars. He noted a few attention-grabbing discoveries. For instance, there were many, many more stars than ever thought before. He also noticed that the Milky Way was not just a hazy patch (as previously thought).

Instead, it was clusters of myriads of stars (MacLachlan 45). Galileo made another discovery: that there were over eighty stars to be found in Orion’s belt and sword. Finally, he began observing Jupiter daily. At first Galileo thought, there were two stars, then a few days later, he realized there were three. The next day was very cloudy and he grew impatient. Subsequently, after further observation, he realized that there were four stars, and that they had changed their position over a period of a few days. At first, Galileo wondered if the planet had moved, but it was actually the stars. Then, he realized the truth. These weren’t stars, but moons (Levinger 80)! This challenged another theory of Aristotle: that the earth was the center of the universe. If everything revolved around Earth and nothing else could be the center of rotation, how could anything revolve around the planet Jupiter? He did not prove that the sun was the center of the universe, but instead merely speculated that it could be a possibility. However, this caused a great response in the science community. Copernican’s followers loved Galileo for helping to prove his theory of planetary motion and theory of the true center of the universe. Aristotle’s followers loathed Galileo for proving that even Aristotle, the great mastermind, could be wrong.

While a student at Pisa, Galileo developed his first invention. It was later know as a pendulum, but to Galileo it was a pulsilogia (named after the way it kept in time with a person’s pulse). He developed the pendulum because of his interest in vertical fall and wanting to explain it. The idea for the pendulum was created when Galileo performed an experiment to find ways to slow vertical fall. He was inspired to begin such an experiment while studying in a cathedral and saw one of the lamps swinging (Rosen 43). He figured out a formula for the proportion of the swing of the pendulum (the square root of the length of the pendulum), which helped him to determine how to create different types of pendulums. He furthermore showed his exemplary math skills by figuring out a fixed numerical relationship between the time of the fall, and the time of the swing. The pendulum could keep perfect time and had many uses. It was used in the warfare navigation, and field of medicine. In warfare, it was used to predict the ranges of cannons. Pendulums were helpful in calculating longitude in navigation. In medicine, the pendulum was used to help determine how sick patients were by comparing their pulse to the pendulums’ (MacLachlan 36).

Galileo also developed a new and improved compass that was a two-hinged instrument with flat arms. It was one inch wide, one foot long, and a very useful mechanical device. It was used in military operations and was very popular since it could also be used for many other things such as figuring out the square roots and cubes of numbers, equalizing money, mechanical drawing, and enlarging maps (MacLachlan 30). One of Galileo’s achievements was an improvement on a previous invention he claimed rights to and that was the thermometer. Galileo wondered why heat and cold weren’t previously measured, so, he decided to create something that would tell the exact temperature. The previous thermometer he had invented used water and was not as accurate, so he decided to use mercury. He used a thin tube made of glass and discovered that when the heat rose, the mercury did also, and when the heat dropped, the mercury dropped (Rosen 114).

Galileo had many theories on many topics, but his most important ones were the theory of the falling bodies, the floating bodies, and his theory on planetary motion. The theory of the falling bodies dealt mostly with mathematics and applied to the motion of bodies (Rosen 63). His theory of the falling bodies concurred with Archimedean in that it stated that the speed of falling bodies was proportional to the density of the objects. Galileo once again disagreed with Aristotle, who believed that the speed of falling bodies was proportional to the weight of an object. Galileo experimented, and concluded that if two homologous bodies were dropped at the same time, it would make no difference whether or not they were separate or united with one another and that they rate at which they fell was pretty close (Bernadini 24). In fact, he believed that if there were no air, the objects would fall at the exact same rate.

He also published a book on this theory entitled Two New Sciences in which he actually uses scientific fact to prove it, describing in detail exactly how and why he did each experiment (Bernadini 118). On the theory of the floating bodies, Galileo agreed with Archimedes in saying that water exerts an upward thrust on an object immersed in it and the upward force is equal to the weight of the water the object relocates. An object with the same density as water will float on the water’s surface. Another theory of Galileo’s was on planetary motion, and stated that the earths daily as well as yearly motion caused tides and that the reason for this was because the earth was angled on its axis (MacLachlan 32). This, as usual, was against the ideas of Aristotle and his followers, yet was in total agreement with Copernican and Ptolemy who believed that the sun was the center of the universe and that the earth and other planets revolved around it. The book he published, entitled The Starry Messenger told how Galileo believed that the reason for the moon’s illumination was due to sunlight that was being reflected off of Earth (MacLachlan 58).

Galileo Galilei was not only a physicist, but he was a role model in addition. He paved the way for other scientists and helped people who could not get as fine an education as the rich. For example, he had many of his books published in Italian. At the time, most books were published in Latin, and only those with an expensive education could afford them. Galileo said that he wanted to encourage young men who did not have a chance to go to college. Galileo stood up for what he believed in, and that was that people should not always follow what they are taught, especially if there is not any proof behind it. Galileo only made claims of theories when he had proof and he inspired many people to find out things on their own, and not to rely on what others tell you. He was an inventor, physicist, mathematician, and scholar, but most of all, he was a frontiersman and a teacher.

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