| There are 3 main proofs (I know of) that the Earth orbits the Sun: 1. Stellar parallax: Stars will appear at slightly different positions in the sky due to the changing position of the Earth during its orbit. Many astronomers from the 1500s to 1800s hoped to measure parallax, and it was finally measured by Friedrich Bessel in 1838. This is the work that first made Bessel famous. 2. Stellar Aberration: Stars appear at slightly different positions during the course of the year due to the finite speed of light relative to the (changing) velocity of the Earth. This was first explained and carefully measured by James Bradley in 1729, making him the most famous scientist of the 18th century according to scientists of the time, including Laplace. 3. The Foucault pendulum: Pendulums on Earth precess. This is not so much proof that the Earth orbits the Sun, but that the Earth rotates in place. The fact that the sun appears to rise/fall/go around us is an illusion due to this rotation. First demonstrated by Foucault in 1851. I disagree with you on the reference frame/general relativity argument. It is true that, by GR, the actualy picture of spacetime is more complicated. However, there is an intuitive notion of 'orbiting' which is very useful which applies in classical/SR, which applies in inertial reference frames, and in that ase the above observations make clear that the Earth orbits the sun. Also: >it's still an open question if bacteria evolve or not > If the earth ever starts orbiting the sun...as the resulting acceleration would affect magma flow This is silly. |