[Dave Lane]

Originally Posted by Fish

Honestly, we probably can't really expand this any further until we have a grand theory that satisfies both relative theory and quantum theory at the same time. There are 4 natural forces(we know of) in the universe. Gravity, weak force, strong force, and electromagnetism. Our physics explains how these 4 forces work in the universe.

Relative theory explains very well the motion of what we consider large bodies focusing on the force of gravity. But when you try to apply the theory of relativity(gravity) to very small scenarios, some things happen that relativity cannot explain. To simplify, gravity acts weird at really really small scales, and relativity breaks down. Inversely, quantum theory does very well at explaining things that happen on a very small scale, by looking at the natural forces other than gravity. Electromagnetic, weak, and strong forces in nature. These forces have great effect at very small scales where gravity is essentially insignificant. But these 3 forces are so weak at large scales that the physics again breaks down. Quantum mechanics in turn cannot explain some things that happen on very large scales, mostly because gravity is the dominant force there.

Which is also why quantum mechanics could actually serve as a better model than relativity for explaining the Big Bang because it's describing the universe as a tiny singularity where quantum physics works better. Gravity doesn't have much if any affect in a singularity, which is why the Big Bang theory doesn't necessarily violate relativity.

That said.... we need a new model that explains all 4 natural forces simultaneously.

When we finally discover the "Theory of everything" that can explain physics correctly at all scales of reference, we'll have another explosion of knowledge and information even bigger than when we proved the relativity and quantum theories. And it will happen eventually. Hopefully in our lifetime. It may very well be that we need to include another force(s) other than the 4 that we know. Perhaps it will require new physics to include what we now know as dark energy/matter/weakly interacting massive particles. That's my guess.

Thanks fish for a great post. It's entirely too much typing for me however I agree and I do think that dark energy or matter is going to play a role with tying the theories of the small and the large together.