My pet theory is that the universe isn't expanding. Rather, all the objects in the universe are shrinking. If your ruler is shrinking then it looks like space is expanding. /:-)
Maybe I am wrong, but isn't it the same?
I mean, if everything is shrinking (excepted the distances between galaxies), then it is exactly the same as if the galaxies were spreading in the universe... only the point of view changes right?
Expanding consumes energy. Shrinking releases energy. When object is pooled to another object by gravitation, energy is released, so these objects must shrink to obey law of energy conservation!