Galileo Galilei (1564 - 1642), Italian scientist who proved that objects with different massesfall at the samevelocity. He was one of the first persons to use a telescope to examine objects in the sky. Authorities of the Roman Catholic Church forced Galileo to renounce his belief in the model of the solar system proposed by Nicollaus Copericus. Galileo had to assert that the earth stands still, with the sun revolving around it. —SHSBC Binder 3 Approved Glossary