Heat Death of the Universe

This fate of the Universe (note 5) begins 100 trillion years from now when stellar formation has come to a halt.  Over the next 10^30 years, planets, stars, and eventually galaxies will decay gravitationally and start to flow freely in space.  From 10^30 to 10^40 years, all protons will decay and all matter will be converted into photons and gamma rays.  All that remained after this era was black holes.  As the age of the Universe soars to a googol (10^100) years Black holes will evaporate due to Hawking Radiation and all the will remain are gamma rays and the occasional photon.