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Asia-Pacific
Forum on Science Learning and Teaching, Volume 6, Issue 2, Article 8
(Dec., 2005) Ke-Sheng CHAN Exploring the dynamic interplay of college students' conceptions of the nature of science
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Asia-Pacific
Forum on Science Learning and Teaching, Volume 6, Issue 2, Article 8
(Dec., 2005) Ke-Sheng CHAN Exploring the dynamic interplay of college students' conceptions of the nature of science
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Appendix II: Galileo and the Moon's New Clothes
In 1611, an Italian man in his late 40s wrote a letter to Kepler, the leading astronomer of Europe at the time, complaining: “You are the first and almost the only person who, after a cursory investigation, has given entire credit to my statements...... What do you say of the leading philosophers here to whom I have offered a thousand times of my own accord to show my studies, but who, with the lazy obstinacy of a serpent who has eaten his fill, have never consented to look at the planets, or moon, or telescope?”
Stop the story here and ask your students the following question. Wait for students’ answers before continuing the story.
Who do you think wrote this letter? Why was he so upset about his contemporary leading philosophers?
The man writing the letter was Galileo Galilei (1564-1642), a famous scientist who lived at the end of the Renaissance. Born in Pisa, Italy in 1564 (the year of Shakespeare's birth and Michelangelo's death), Galileo lived at a time when most leading philosophers followed Aristotle's teaching faithfully and believed that anything that contradicts Aristotelian philosophy must be wrong. In particular, most of his contemporary philosophers believed that the Earth was at the center of the universe and that the surfaces of all heavenly bodies - the moon, the planets and the stars - were smooth, uniform and perfectly spherical. Although Galileo suspected that they might not be right about this, he did not have enough scientific evidence to disapprove it until 1609 when he constructed his own “home-made” telescope and pointed it toward the heavens.
With the help of his telescope, Galileo found that “...the surface of the moon is not smooth, uniform, and precisely spherical as a great number of philosophers believe it to be, but is uneven, rough, and full of cavities and prominences, being not unlike the face of the Earth, relieved by chains of mountains, and deep valleys.” This evidence was so directly opposed to the Aristotelian notion of a perfect moon that Galileo thought his telescopic discoveries would soon cause everyone to realize how absurd the Aristotelian notions were and abandon them altogether.
To his surprise and disappointment, however, many of his contemporaries refused to accept the scientific validity of his telescopic discoveries and still insisted that the moon was smooth, uniform and perfectly spherical. Some argued that the evidences of the telescope could be due to distortions, citing the fact that all glass lenses were known to change the path of light rays. Others said that even if telescopes seemed to work for terrestrial observation, nobody could be sure they worked equally well when pointed at these vastly more distant celestial objects.
One of Galileo's opponents, Colombe, although admitted that the surface of the moon looked rugged, maintained that it was actually quite smooth and spherical as Aristotle had said, reconciling the two ideas by saying that the moon was covered with a smooth transparent material through which mountains and craters inside it could be discerned.
Stop the story here and ask the students to analyze the story and consider the following questions about the nature of science raised by the story. Accept all sensible answers and do not indicate whether they are correct or not, for there are no “right” answers.
How and why do you think Galileo and his opponents were able to reach different conclusions based on the same observational data?
Can observation alone give rise to scientific knowledge in a simple inductivist manner? Why do you think so?
How do you think we should decide whose theory is “correct”? Can they both be “correct”? Why do you think so?
Are imagination and creativity important for developing scientific theories? Why do you think so?
Faced with this kind of response from a leading scholar at that time, if you were Galileo, what would be your reply to your opponent's argument about the perfect moon?
Finish the story by presenting Galileo's reply to his opponent's argument.
Galileo (sarcastically applauding the ingenuity of this theory) offered to accept it gladly – provided that his opponent would do him the equal courtesy of allowing him to assert that the moon was even more rugged than he had thought before, its surface being covered with mountains and craters of this invisible substance ten times as high as any he had seen. He went on to say: “The hypothesis is pretty; its only fault is that it is neither demonstrated nor demonstrable. Who does not see that this is a purely arbitrary fiction that puts nothingness as existing and proposes nothing more than simple noncontradiction? One might equally well define Earth to include the atmosphere out to the top of the highest mountain and then say ‘the earth is perfectly spherical.’”
Stop the story for discussion. Possible questions include, but are not limited to:
Do you agree with Galileo's criticism of his opponent's theory? Explain why you think so.
What does this story tell us about science and how it progresses? Do you know any other similar case in modern science?
Copyright (C) 2005 HKIEd APFSLT. Volume 6, Issue 2, Article 8 (Dec., 2005). All Rights Reserved.
