Dear PF Forum Can I ask something quoted from a closed thread? In a closed thread: https://www.physicsforums.com/threads/predicted-heat-death-of-the-universe.824652/ This quote was presented by a Brian Cox. A scientist? And if he is, I'd like to ask this question. Is it technically possible that in the heat death of the universe, when all stars are black dwarfs, black neutron star and black holes, that there can't be a single atom left? The atoms aren't necessarily swept up by the black holes or celestial bodies, right. The black holes/black dwarf/black neutron star can still orbitiing the centre of the galactic while there are still interstellar medium? Even if their orbits are deterioting and entering SMBH event horizon, the interstellar/intergalactic medium are still there right. Or the scattered atoms just swept to the galactic core? In the far future, technically will all celestial body in a galaxy be joined the SMBH at the centre of the galaxy? If that is true, will all the SMBHs join to form just a single black hole for the universe? When will the time end? As long as the single black hole evaporates, the entropy is still increasing, right? If that is true, will this single black hole evaporate (by Hawking Radiation) and ceased to exist? And after that, what?