Amber Robot: I thought cosmological redshift was not the Doppler effect, even though it has a similar outcome.

dcl: Cosmological red shift is definitely Doppler effect. It occurs because the distance between the light source and the light detector is increasing because of the expansion of the space between them. It is independent of whatever local motion either the source or the detector may have with respect to its immediate surroundings.

Drunk Vegan: There are two basic theories. The first states that if this principle where ever to be fully understood, it would result in the Universe immediately being replaced by something even more bizarre.
The second theory states that this has already happened.
mugaliens: Corollary: And this keeps happening, repetitively, every 5.39121 x 10^(-44) seconds.

dcl: Drunk Vegan and mugaliens: There can be no plausible bases for your statements.

astromark: Does a SMBH ever reach a point where it just collapses. Becoming energy only. Next question: What is energy?
dcl: By "SMBH", I assume you mean "supermassive black hole." The answer to your question about whehter it will ever collapse is "no". It is expected to be one or the very last objects to remain to the end of the Universe. Energy is formally defined in physics as the ability to do work, and work is defined in physics as the product of force and the distance through which it is exerted. For more on the technical meanings of "force" and "energy", I suggest you look up those words in Google.