Use the text to compare and contrast Nicolaus Copernicus and Galileo Galilei. For centuries, most people believed that the sun orbited Earth. Astronomer Nicolaus Copernicus disagreed. Copernicus believed that all planets, including Earth, orbited the sun. He used math to support his theory. Like Copernicus before him, Galileo Galilei also used math to support the idea that all the planets orbited the sun. But Galileo went a step further and came up with new ways to prove this theory. While most religious leaders allowed Copernicus to continue his work even when they opposed his beliefs, religious leaders of Galileo's time were not so tolerant. They put Galileo under house arrest for his work. Today, it's accepted knowledge that the planets orbit the sun, not Earth.