Take the Galileo Challenge

An Earth-Centered System?

Galileo and His Observations

Galileo was one of the first and most important observers of the Sun. Why do you think these observations were important to Galileo and to the people of his time? If you have trouble with some of the questions, try exploring the Galileo sites.

Galileo Quiz

What was European science like during Galileo's time (the early 1600s)?

Science hadn't been invented yet.

Good scientists thought hard about problems and theorized how the world might work.

Good scientists made experiments and observations about how the world worked.

What did the Europeans of Galileo's time think about the celestial bodies?

They thought the starry sky was perfect and unchanging.

They thought the Sun, Moon, planets, and stars all revolved around the Earth.

They believed Copernicus' theories that the Earth went around the Sun.

Did Galileo invent the telescope?

Yes

No

How did Galileo show that the heavens were not perfect and unchanging?

He found craters and what looked likes seas on the Moon

He found spots on the Sun

He observed a supernova explosion in the sky.

How did Galileo prove the Earth was not the center of the universe?

He carefully plotted the path of the Sun and planets in the sky.

He observed the moons of Jupiter.

He observed the phases of Venus.

In the Are Those Spots on the Sun? activity, we saw how Galileo proved that the sunspots were actually on the Sun, not small planets circling it. Would you have believed Galileo's proof? Do you think the Christian Church leaders at the time believed him?

Yes

No

What eventually happened to Galileo?

He was put in prison.

He was burned at the stake.

He was put under house arrest.

When did the Catholic Church finally admit they were wrong about what they had done to Galileo and what he believed?

1650

1992

They never did

How Would You Prove the Earth Travels Around the Sun?

There are a few fundamentalist religious sects today who still believe the Earth is flat and that the Sun travels around the Earth. These people rarely travel far from home, so have no experience with airplanes flying around the world. Nor do they know much about satellites, space shuttles, or space stations. But they can go outside and observe with their own eyes that the Sun travels around the Earth every day.

How would you go about convincing them otherwise? If both their eyes and their religion told them the Earth was flat and the center of the universe, do you think they would believe your arguments? Ask your parents or a teacher to pretend they belong to one of these religious sects, and then try out your arguments. Were they convincing?

These sects truly believe their religion says that the Earth is flat and the Sun goes around the Earth. Should you, or should you not, try to convince them otherwise?

About Galileo Galilei

About Galileo

Rice University has a wonderful hypertext source of information on the life and work of Galileo Galilei (1564-1642) and the science of his time.

Galileo's Fight with the Roman Church

For more detailed information about Galileo's charges, read the discussion by Owen Gingerich, a noted astronomer and historian.

To Other Pages

This page is http://solar-center.stanford.edu/gal-challenge/challenge.html
Last revised by DKS on July 29, 1997