A lot of thought has gone into far-future uses of black holes: - Black hole starships [1] - Weaponizing black holes [2] - Colonizing black holes [3][4] - Bl

A lot of thought has gone into far-future uses of black holes: - Black hole starships [1] - Weaponizing black holes [2] - Colonizing black holes [3][4] - Black hole computers [5] Black holes may be the most efficient forms of batteries and power generators yet conceived. If our model of the Universe is mostly correct then the Univese will have an era of stars that will ultimately burn through all the fuel and we'll just be left in the dark with black holes that will evaporate over an extraordinarily long period of time, many orders of magnitude than the stellar era. For propulsion, this ultimately comes down to photons have momentum. We can use them to move things. This is the idea behind the solar sail. Black hole propulsion revolves around how you use the momentum from an evaporating black hole into motion for a ship. There are a bunch of factors to balance out here. Too small and the black holes dies too quick (and is too energetic). Too large and it's too hard to move and has a lower output and so on. Turns out there's a sweet spot for all this of about a million tons, which is in the realm of what we call Kugelblitz black holes. I personally think using stellar output to accelerate and decelerate ships it he most likely outcome for a spacefaring species. If fusion ever becomes viable this may be an alternative for when you're not near a star. Ultimately black holes may replace that but there are significant theoretical and engineering challenges to that like how you'd even make a small (a million tons of small) black hole and how you'd feed it more mass (since it would be the size of an atom). If we could ever find a material to reflect and lase gamma ray (a "graser") then it might be possible but that's far from certain. [1]: https://www.youtube.com/watch?v=oAocMzxPjjo https://www.youtube.com/watch?v=oAocMzxPjjo [2]: https://www.youtube.com/watch?v=zTMxO1nJaA4&list=PLIIOUpOge0Lv3LmdudQ6aPFzEvJarKF2J&index=3 https://www.youtube.com/watch?v=zTMxO1nJaA4&list=PLIIOUpOge0... [3]: https://www.youtube.com/watch?v=pxa0IrZCNzg&list=PLIIOUpOge0Lv3LmdudQ6aPFzEvJarKF2J&index=2 https://www.youtube.com/watch?v=pxa0IrZCNzg&list=PLIIOUpOge0... [4]: https://www.youtube.com/watch?v=Qam5BkXIEhQ&list=PLIIOUpOge0Lv3LmdudQ6aPFzEvJarKF2J&index=4 https://www.youtube.com/watch?v=Qam5BkXIEhQ&list=PLIIOUpOge0... [5]: https://cse.buffalo.edu/~rapaport/111F04/lloyd-ng-sciam-04.pdf https://cse.buffalo.edu/~rapaport/111F04/lloyd-ng-sciam-04.p...