Therefore, if the Earth were flat, we could explain terrestrial
physics by saying: bodies fall downward because
there is a white wall 3 × 1015 meters away sitting over-
head in the heavens which is pushing off them. Moreover,
for example, we could test General Relativity by sending a
light signal upwards to the sky, and receiving it six months later.
Interesting papers.Spin_Network said:
This resource letter by R. M. Wald for teachers of general relativity is very interesting. Wald has come around to the point of view that it's OK to teach undergraduate general relativity courses that don't cover tensors or the Einstein fild equation. Undergraduate courses should concentrate on mining (via, e.g., Lagrange's equations) given (not derived as solutions to Einstein's equation) metrics for physical information. This way, much more time can be spent on quantitative aspects of interesting topics like black holes and cosmology.