(c) Anthony K. Grafton 2003

Galileo Galilei

Few scientists have, by themselves, significantly changed the entire landscape of human understanding as did the man named Galileo Galilei. It was through his efforts, and against much opposition, that people came to understand that the Earth was not the center of the Universe.

Galileo lived and worked in Italy 400 years ago. Although he accomplished many things in his life, he is best known for his work perfecting the telescope and using it to observe the planet Jupiter. Jupiter has four bright moons, and Galileo was the first person to see them. By studying them, he was able to show that these moons orbited around Jupiter, and not around the Earth.

Galileo’s work provided direct evidence to support the Copernican theory (named for Copernicus, the man who first proposed it) that the planets, including Earth, orbited around the Sun. Unfortunately, this idea was in direct opposition to the view held by the dominant Catholic Church that the Bible showed that Earth was the center of the Universe, and so the Sun, as well as all other planets and moon, must move around the Earth.

Because Galileo defended an idea that opposed scriptural interpretation, he was denounced by the Church, which banned some of his writings and forced him to declare publicly that his data and theories were “errors and heresies”. Nearly 400 years later, in 1992, the leader of the Catholic Church, Pope John Paul II, said “From the Galileo case we can draw a lesson which is applicable today in analogous cases which arise in our times and which may arise in the future. ... It often happens that, beyond two partial points of view which are in contrast, there exists a wider view of things which embraces both and integrates them.”

Scientists study nature in a very careful and controlled way. Sometimes, ideas that emerge from scientific study can disturb our comfortable thinking and they can even frighten us. But this shouldn’t be the case. As Pope John Paul II reminded everyone in 1996, “truth cannot contradict truth”.

Of course we now know for certain that the Earth orbits the sun, and not the other way around. There have been other ideas throughout history that challenged established thought and were later proved to be true. Can you think of any?