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 this 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 court in the Roman Catholic Church, and in 1615 it said that any teaching of the earth going around the sun--including that 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 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, "Nevertheless, it moves"--"it" referring to the earth. Legend it may be, but the story shows the spirit of Galileo in support of scientific truth.

    Vocabulary: Which word above means:

    1. went around, circled (as the moon does the earth)

    2. a made-up story that may contain some truth about a famous person

    3. having to stay in one's home

    4. the study of the stars and planets

    5. not allowed

    6. understanding, discover

    ANSWERS: 1. orbited 2. legend 3. house arrest 4. astronomy 5. forbidden 6. insight