In philosophy class last night we discussed the Copernican revolution. As you’ll recall, his 16th-century theory that the Earth was not, in fact, the centre of the universe was the source of much controversy. It was the source of even more controversy (and condemnation) later, when it was supported by observations and models from Galileo and Kepler. In the end, of course, this was the first big defeat of an area of religious knowledge by a scientific one.
We had a fun exercise last night. We had to break up into small groups and come up with ten reasons why one might believe in a geocentric model for the universe; then ten reasons why one might believe in a heliocentric model for the universe; then come up with other models that the evidence might support. The first task saw most teams come up with similar ideas: it feels right that the Earth should be the centre of the universe because it feels biggest, because the other heavenly bodies appear to move around us, because we don’t feel like we’re moving, because we’re the reason God created everything, etc. The reasons for abandoning this model and adopting a heliocentric view produced a little more variety: the phases of the moon, lunar eclipses, the changing seasons, other planets and how the number of moons they have appears to change, etc. We didn’t come up with too many other models of the universe, but my favourite was that perhaps the earth is stationary and a new Sun, Moon, and set of stars are created fresh for us to observe each day.