The Big Freeze

The most widely accepted fate is heat death, also called the Big Freeze. The universe keeps expanding, galaxies drift apart, and stars gradually burn through their fuel. Over trillions of years, star formation ceases.

After the last stars die, the universe becomes a dark graveyard of black holes and cold stellar remnants. Even black holes do not last forever — they slowly evaporate, and in time nothing massive is left. What remains is a thin soup of photons drifting near absolute zero.