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Lesson 2-Galileo and his Telescope
Learning Objective:To understand the importance of the development of the telescope in Galileo's direct observation of heavenly bodies.
DA-Define heliocentric and geocentric.
Lesson 2-Galileo and his Telescope
Learning Objective:To understand the importance of the development of the telescope in Galileo's direct observation of heavenly bodies.
DA-Define heliocentric and geocentric.
Galileo.pdf | |
File Size: | 203 kb |
File Type: |
From the pdf above, describe in detail what you see; how Galileo's publisher wished to present him.
Read as a class and discuss: In 1608 Hans Lippershey, a Dutch optician, is believed to have made the first refracting telescope (with lenses, rather than mirrors, like our large modern telescopes) which he called a spyglass. Lippershey was unable to obtain a patent on his invention as is done today. Thus, a year later, in 1609, the Italian astronomer and mathematician Galileo Galilei (1564–1642), heard about Lipper- shey’s invention, and built his own improved model. Galileo, who was a professor of mathematics at the University of Padua, used his own home-made telescope to make some startling new discoveries. He proved, along the way, that the heliocen- tric theory of Copernicus was correct. Galileo was the first person to see and write about the imperfections of celestial bodies. He observed the mountains and craters of the moon, the rings of Saturn, and the sunspots on the sun. In 1613, he also discovered four of the moons of Jupiter, which was the discovery that gave him hard evidence to prove Coper- nicus’ heliocentric theory that all heavenly bodies do not revolve around the Earth. He had seen, through his telescope, objects orbiting another planet! Galileo published his startling findings in many letters and books, including his Starry Messenger of 1610 (in which he wrote about the Earth’s moon and the moons of Jupiter and his History and Evidence about Sunspots, written in 1613. He appealed to his readers to validate for themselves his findings by observing the very things he himself had seen, by using the device of a telescope. His appeal was to the knowledge available by the empirical evidence through sensory perception and logical analysis, rather than the reliance on accepted authority and canonical texts. In 1632, Galileo's masterwork, the Dialogue on the Two Great World Systems, was published in The Netherlands, a more tolerant and receptive country than his native Italy. This work discussed the Ptolemic and Copernican systems and Galileo favored the latter. He wrote the book in Italian, not in the Latin traditionally used for scholarly works, so that it would be accessible to more readers. Predictably, the Roman Catholic Church, whose authority on the heavens he had challenged, responded by called upon Galileo to make a complete retraction. Church doctrine had taught the perfection of the celestial spheres, in opposition to the imperfection of the earthly realm. Galileo’s findings showed clearly that the celestial realm was no different than the earth in its imperfections. He also showed that the earth was not the center of the universe, but only a small planet in a greater solar system. His empirical proof of such a basic reorientation of the universe upset all Biblical and ancient models which existed at that time. In 1633, he was brought before the Inquisition of the Roman Catholic Church, and after a lengthy trial, was forced to sign a statement saying that he did not really believe his findings, especially that the earth moved around the sun. Under threat of excommunication from the Church, Galileo retracted his beliefs in front of the Pope at the Vatican, but the story goes that as he was led away, he muttered, “Eppur si muove,” or “but it moves.” In spite of the fact that the Pope was a personal friend of his, Galileo’s discoveries were still deemed too danger- ous to be disseminated. He was arrested and then put under house arrest for the rest of his life in his villa outside Florence. Galileo died there, imprisioned at his own home, nine years later. But he was still able to continue his reasearch and writing. In spite of his banishment from the public to the private sphere, and the fact that the Church also put all of his works on their Index of Forbidden Books, (where they remained for the next 200 years), Galileo’s works reached a large audience, and influenced scientists and philosophers the world over. For example, by 1614, only five years after the Starry Messenger first appeared, a Jesuit missionary in Peking was publishing Galileo’s findings in Chinese. His ground-breaking work with the telescope was augmented by many other pioneering scientists and astronomers of the 16th- and 17th-century Scientific Revolution, and his discov- eries revolutionized the field of astronomy. Download the following document and break into three groups: |
All these primary sources are from Galileo's writings, and each one describes a different astronomical discovery.
HW:
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Documents A, B, C-1.pdf | |
File Size: | 230 kb |
File Type: |