So I've been on a bit of a future bender lately, and I figured it would be interesting to take on possible ways to extend our civilizations capacity to survive after the universe has gone dark. As in when every sun has burnt out and all that is left is black holes small and large.
There are a few different ways to get this done, and one that springs to my mind is to feed in matter from another source which will generate photons as the matter is swirled around the accretion disk of the black hole and consumed by the singularity.
Basically as the matter swirls and crushes together on it's way into the black hole, it rubs together and is broken apart creating huge amounts of friction and heat.
Given that there is not many places for this heat to go, radiating heat in space is rather difficult as there is not much to transfer it along, the atoms in the accretion disk will get rather warm, lighting up and sending off photons you can capture.
This would work rather well I imagine in the distant dark future as not only a light source but as an energy source as well. Assuming that we have perfected solar panels, and I would think that quite a bit of power would be generated in terms of matter to energy conversion.
Another idea that comes to mind is that black holes have powerful electromagnetic fields around them, and not surprisingly like most things in our universe, they rotate quite quickly.
I imagine that given some kind of super-material it might be possible to encase a black hole in a cage of some kind, capturing this rotating electromagnetic field much like a stator (capturing structure) and rotor (black hole) in a typical generator.
Given the astronomical mass of the black holes, this rotational energy would be very long lived and a very good power source, and also in some ways renewable, as you could press matter together using lasers or some kind of thruster in order to create new black holes if the previous ones evaporate.
Yet another source could potentially be the relativistic jets that are emitted along the poles of the black holes, these jets travel at large percentages of the speed of light and are highly energetic, containing ionized matter.
You could quite easily tap these matter jets for the ions contained, or even use the jet as a direct drive for some kind of super galactic turbine.
These jets of ionized matter stretch for thousands to millions of parsecs so the energy contained within them is outright mind boggling, and would keep the lights on for a very very long time.
There may be other ways to capture the energy of black holes and if you can think of any that I may have missed, I would love to hear about them in the comments below.
Thanks for your attention dearest readers. I hope you have a wonderful day, much love. <3