1577 – Denmark
‘The heavens are changeable, and the comets move through space. The Earth is the centre of the universe, and round it rotates the moon and the sun. The planets orbit the sun’
Up to now it had been believed that planets were carried on ‘heavenly spheres’ that fit tightly around each other.
Brahe dissented from the Copernican doctrine and accepted the dogma that the Earth stood still. His real contribution to astronomy was as an observer, rather than as a theorist. He accurately measured the position of 777 stars, a remarkable achievement considering it was done without a telescope. He also measured the movement of planets, but was unable to determine their orbits.
His observations paved the way for the discoveries of his assistant, Kepler. After Brahe’s death Kepler inherited Brahe’s vast accumulation of data on planetary observations.
Brahe’s observation of the supernova of 1572 and the comet of 1577 convinced him that the universe was not unchangeable as was believed by philosophers of his time. The notion of celestial spheres was not possible because comets moved through these spheres. But he still placed the Earth at the centre of the universe. His contemporary, the Italian philosopher Giordano Bruno (1548-1600), believed in the sun centered Copernican system and for these heretical beliefs was burned at the stake.