Over the last few decades, cosmologists discovered what the future of the universe may hold. That concludes the part of the post where we entertain a single shred of optimism since it seems that our future is bleak. On the biggest time scales, stars burn down to dark embers, life goes extinct, galaxies fly apart, and black holes will inherit a dark, cold universe until they too evaporate into nothing. In short and without mincing words, we’re screwed to the fullest possible extent. Nothing personal, it’s just a function of entropy that an open universe is going to expand in all directions until all the energy it contains spreads so thinly across such a vast distance, that everything chills to the same temperature and the processes we’re used to today become impossible in this icy, static realm trillions upon trillions of years from now.
It seems that studying areas of cosmology which focus on just how everything we know will ultimately end is a bit like being the undertaker in a old Western movie, sizing up the hero of the story for a casket as soon as he strolls into town. And this is the role embraced by astrophysicists Chas Egan and Charles Lineweaver who wanted to find out whether the supermassive black holes in the center of each galaxy were actually adding to the entropy of the universe and whether they have a final role to play as things slowly cool into nothingness. By measuring the total amount of energy the cosmos can use, or the entropy budget of the universe, they found that monstrous black holes actually increase entropy because they effectively lock up both matter and energy in their mysterious innards.
Even if black holes evaporate due to Hawking radiation, it would still take up to 10102 years for all that energy to be hurled back into the cosmos and at that point, it would only serve to increase entropy. Considering how they form and how strangely they behave, we shouldn’t be surprised that black holes are often thought to be cosmic entropy machines by a number of physicists. Matter and energy inside them are configured in some of the most bizarre and unexpected ways, the constant churning in their interiors creating utter chaos, especially in the singularity which is infinitely small and theoretically deduced to be ruled by quantum anarchy. Since the energy isn’t usable and does no meaningful work other than being savagely tossed around, it just adds to the overall entropy of the system and even after being freed by an evaporated black hole, it would simply cool and dissipate into the inert darkness.
See: C. Egan, & C. Lineweaver (2009). A Larger Estimate of the Entropy of the Universe, arXiv: 0909.3983v1