Saturday, December 4, 2021

Galileo, the Father of Science

Portrait of Galileo Galilei (Justus Sustermans, 1636)
Note the telescope in his hand

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Galileo Galilei (1564-1642) was an Italian scientist who worked in many fields: physics, math, engineering, astronomy, and philosophy. He was a true Renaissance Man. He gained many nicknames through the ages, but one of the greatest was simply: the Father of Science.

This is all the more surprising in that his main achievement was not his own thought, but confirmation of the idea of another person.

The Polish mathematician and astronomer Nicolaus Copernicus (1473-1543) had published a new theory in the year he died: that the earth goes around the sun, and not the other way around. This "Copernican Revolution" would shock the world: we were not at the center of things.

Copernicus died before his theory--based on mathematics--was proven. It was left for Galileo and Johannes Kepler (a student of Copernicus) to confirm his insight.

For this, Galileo used a "secret weapon": a telescope he had improved himself. With it he was able to view phases on Venus much like those of the moon, and observe four moons orbiting Jupiter. The former was only possible if Venus orbited the sun; the latter proved that not everything circled the earth.

The Roman Inquisition was a kind of religious court in the Roman Catholic Church, and in 1615 it said that any teaching of the earth going around the sun--including such teaching by Galileo--was forbidden.

But in 1632 Galileo wrote his most important work, the Dialogue Concerning the Two Chief World Systems. The older system was the Ptolemaic, known as "geocentrism" (putting the earth at the center). It was taught by Claudius Ptolemy, a Greek living in Alexandria, Egypt, around 90-168. The newer was, of course, the Copernican system of "heliocentrism" (putting the sun at the center).

For this act, Galileo was tried in court in 1633 and put under house arrest for the final nine years of his life, where he continued to work and write until his death.

The court also required Galileo to recant, or take back, his support of heliocentrism. Popular legend says that after standing up and recanting, he turned away and said quietly, "Eppur si muove"--in English, "Nevertheless, it moves"--where "it" refers to the earth's motion around the sun. Legend it may be, but the story shows the spirit of Galileo's stubbornness in support of scientific truth.

Galileo facing the Roman Inquisition (Cristiano Banti, 1857)


Vocabulary: Match the words to their meaning. Correct answers are in the first comment below.

  1. astronomy
  2. forbidden
  3. geo-
  4. helio-
  5. house arrest
  6. inquisition
  7. insight
  8. legend
  9. orbited
  10. recant
  1. withdraw a statement
  2. went around, circled (as the moon does the earth)
  3. the study of the stars and planets
  4. a made-up story that may contain some truth about a famous person
  5. not allowed
  6. an understanding, a discovery
  7. a prefix meaning "earth"
  8. having to stay in one's home, like in a prison
  9. an official investigation, especially one that's political or religious
  10. a prefix meaning "sun"

Questions to Answer: Answer the following questions in your own words. Suggested answers are in the first comment below.

  1. What "crime" did Galileo commit?
  2. Did Galileo make the discovery for which he was convicted?
  3. Why didn't Copernicus promote his own theory?
  4. Who else promoted Copernicus's theory?
  5. What "secret weapon" did Galileo use to support Copernicus's theory?
  6. What were the "two chief world systems" described in Galileo's work?

Questions to Think About: These questions do not have "right" or "wrong" answers. They only ask your opinion.

  1. Do you think the Church (or religion and religious people in general) should control the teachings of science? Does this still happen today?
  2. Copernicus, Kepler, Galileo: What can we learn about the process of science from the story of these three men?
  3. Copernicus was a theorist; Galileo supported his theories by observation. How important are these two sides of science, idea and evidence?

1 comment:

  1. Answers:
    Vocabulary: 1. C; 2. E; 3. G; 4. J; 5. H; 6. I; 7. F; 8. D; 9. B; 10. A

    Questions to Answer (suggested answers; yours may be written slightly differently)
    1. Galileo was convicted of teaching that the sun, not the earth, was the center of the solar system. (OR that the earth goes around the sun, and not vice versa.)
    2. Galileo did not discover heliocentrism; he just promoted the theory of Copernicus.
    3. Copernicus died shortly after his discovery, so he was unable to promote it himself.
    4. Copernicus's student, Johannes Kepler, also promoted Copernicus's theory.
    5. Galileo used a telescope to support Copernicus's theory.
    6. The Ptolemaic (geocentrism) and Copernican (heliocentrism) were the "two chief world systems" in the title of Galileo's book.

    Questions to Think About do not have any single correct answer. However, any answers you give should be supported by what you read or by things you know ("I think... because...").