At the end of time will the universe consist of dark matter, dark energy and black holes (if the galaxies are gobbled up by their 'parent' black hole)?
- The fate of the Universe far, far into the future is not certain. Dark matter and dark energy have been given the labels 'dark' for a good reason – we don't understand what they are and hence how they will influence the Universe in the future. Putting those aside for the moment, we can say that star formation will end in a few trillion years when all the hydrogen has been used up. Even the smallest of stars, the most long-lived, will die a few trillion years after that. All that will be left is black holes and photons of radiation. Eventually, all the black holes will evaporate. The largest, the supermassive black holes, evaporate very slowly and so it might take a googol years for this to happen (1 googol = 10 to the power 100).
Bringing dark energy back into the mix, if it continues to increase the way it is doing at present (which is by no means certain) then the expansion of the Universe will continue to accelerate. This expansion will rip apart galaxy clusters, and then individual galaxies, and then stars, and eventually all matter. One way or the other, the far future of the Universe looks much less interesting than the present.
"Eternity is a very long time, especially towards the end."