The Black Hole Bomb and Black Hole Civilizations
Why Hacker News recommends it
Linked as a nice summary of how civilizations could harvest black hole energy.
What it is
Kurzgesagt explains the black hole bomb and how far-future civilizations might extract energy from spinning black holes, including Dyson-sphere-style ideas.
Recommended by 2 HN commenters across 2 different months, 2018 to 2021.
What Hacker News said
Recommends Malic · 2018-06 · on “What life could be like for civilizations 1 trillion years from now”
Kurzgesagt had some nice summaries of: 1) Why white dwarves might be the last home for life in the universe - [LINK] 2) ...or maybe it will be black holes - [this video]
Recommends kadoban · 2021-08 · on “What if Planet 9 is a Primordial Black Hole? (2019)”
There's also the Penrose process which is theoretically useful on spinning black holes. I also watched this in the past, which has some fun ideas (that are probably a little fanciful?) [this video] tl;dw: put a mirror around it and shine light in, get back lots of energy and/or blow up your whole solar system. I'm not sure if any of that would apply to a ~planet mass black hole spinning with ~planet sized angular momentum, or how solid the physics even is, but it sounds cool anyway.
Cites ainar-g · 2019-04 · on “Saudi Arabia threatens to ditch dollar oil trades to stop 'NOPEC'”
I used to play with an idea of a science fiction novel, where the united Earth's currency is essentially kcal/kJ. The problem is that if you have a flammable and radioactive material, do you count the energy you get from it by burning it, or the energy from throwing it into a nuclear fission reactor, or the energy of throwing it into a black hole in a particular angle[1]? [1]: [this video]
Cites Qub3d · 2021-08 · on “A Dyson sphere around a black hole”
Kurtzgesagt made a video explaining some possibilities. In short, you can throw mass or radiation at a spinning black hole and "steal" rotational energy from it. [this video]