Recent content by kasperm

This makes sense. So this is why people say energy is conserved on a local scale but not on large scales? @yogi: Interesting, I wasnt aware of that idea. Will check it out.

Im sorry, my question might have been a bit unclear. Consider this: Two stars a unit distance apart has a well defined potential energy in their gravitational field, or equivalently, a well defined amount of work needs to be done against the field to move each of them from the center of mass...

How is energy conserved in an expanding universe? As space expands between, say, stars in a galaxy, don't they gain potential energy in the gravitational field of the galaxy? Which mechanism lessens the total kinetic energy?