Energy In a Dying Universe
Everyone knows that energy that goes into a black hole is trapped forever. Slipping past the event horizon, falling infinitely into an infinitely empty, infinitely deep, and yet still infinitely dense well, concentrated in an infinitely small pebble at the bottom. We all know this energy is trapped forever… or is it?
It turns out there is a way to power any number of civilizations, or any number of living things, until the death of everything, the universe included. We might also even create the biggest bomb any living thing could ever hope to make. we can do all this for 1 simple reason: black holes are spinning.
Before we get to constructing massive bombs, why black holes are relevant, or why them spinning is relevant, let’s talk about why black holes are spinning. When a really massive star’s core collapses into a black hole, a lot of mass gets squeezed into an infinitely small space. A fundamental rule of our universe, as stated by Newton, is that spinning things don’t want to stop spinning. A big thing that’s spinning only spins faster when it gets smaller. Black holes are the smallest anything can get in this universe. So when a supermassive star spinning incredibly fast collapses into a black hole, the black hole keeps spinning, inconceivably fast.
A spinning black hole, just like a non-spinning one, has an event horizon and a singularity, where all of its mass is. a singularity is usually described as a singular, infinitely small point with no surface area. Interestingly, points can’t rotate, so for spinning black holes, it isn’t a singularity, it’s a ringularity. A ringularity is a ring with a thickness of zero and no surface area, spinning incredibly fast, with all of the mass of the black hole concentrated within it. Such black holes are spinning so incredibly fast that they warp space and time. It literally drags spacetime with it, such is its power. This forms a new zone around the black hole, called the Ergosphere. If space and time are completely broken inside the event horizon, they are only half-broken in the ergosphere. You can imagine falling into a normal black hole like falling into a spinning hole–like falling down a spinning deadly drain. This is where we can cheat the universe.
The black hole transfers this energy to you by rotation. the ringularity will make you go around even if you don’t want to. You have to move faster than the speed of light to even stand still here, which is impossible.
Here is the cheat: we can steal this energy, and there is a lot of energy to steal.
The easiest way to steal this energy, oddly enough, is to drop something in. We know that the ringularity forces its energy upon us. You can imagine this as being in a whirlpool, and swimming in the same direction the water flows to gain speed. In practice, this means sending a rocket into the ergosphere, giving it some mass-energy, and stealing massive amounts of kinetic energy. This requires a lot of “food.” Fortunately, black holes will eat anything. An advanced civilization would probably harvest asteroids for this purpose. Interestingly, there is a better way to get this energy, and, oddly enough, it builds the biggest bomb ever.
All we need to begin the harvest is a large spinning black hole and a mirror. The mirror would have to be fairly light, completely sealed, and able to withstand a lot of energy. This megastructure resembles a Dyson sphere. link to that here: https://esteemstream.news/48441/engineering/space/dyson-sphere/.
If we make the mirror 10cm thick, a large asteroid would probably suffice for a black hole with the mass of our sun. All we would need to do after that is to fire electromagnetic waves at the black hole. You can imagine it like this: throwing a bouncy ball at a wall, and it coming back faster than a bullet. A small amount of the electromagnetic waves fall past the event horizon, lost forever. A much larger portion gets much stronger, and begin the process of superradiant scattering, or in simpler terms, getting exponentially stronger, and very, very fast. By opening tiny holes, we can collect this energy as fast as it builds, which for all practical purposes, means free, clean energy for what is essentially forever.
One day, in the far-flung future, in the last gasps of humanity as the universe enters its heat death phase, we may live around a black hole, living in its last gasps of light, on the very edge of the death of the universe. The last living being in existence might one-day end their life around a black hole, which is equally chilling, and uplifting.