Dyson Spheres
Why Hacker News recommends it
HN references it in threads on megastructures, Kardashev civilizations and Dyson sphere detection, and recommends the channel for in-depth futurist content.
What it is
Isaac Arthur examines Dyson spheres and swarms, including common myths and misconceptions. He covers uses such as interstellar travel, black hole generation, and computing large enough to simulate universes.
Recommended by 1 HN commenters across 1 different months, 2017 to 2022.
What Hacker News said
Recommends digitalronin · 2022-02 · on “Upper limits on partial Dyson spheres in the Milky Way”
There's plenty. The vast majority of the 'shell' would be solar concentrators - basically aluminium foil or something like it. You can make a LOT of that by dismantling a few asteroids, never mind a planet or two. Isaac Arthur's youtube channel goes into this in some depth (and is generally excellent, IMO). Here's an episode on Dyson Spheres: [this video]
Cites stcredzero · 2017-07 · on “A Simulated Stable Planetary System with 416 Planets in the Habitable Zone”
As huge as 416 Earths sounds, this is actually paltry for what's possible for a Kardashev 2 level civilization: [this video]
Cites stcredzero · 2018-03 · on “A Simulated Stable Planetary System with 416 Planets in the Habitable Zone”
If you're going to be using artificial habitats to have more living space, 416 is a very small number. [this video]
Cites cletus · 2019-03 · on “Rotating Black Holes May Serve as Gentle Portals for Hyperspace Travel”
See [1] and [2] where the idea of hiding a Dyson sphere is covered in depth. It essentially means breaking the laws of thermodynamics, specifically entropy. Hit and object with light from a star and it heats up. It radiates away that heat in a predictable way. [1] [LINK] [2] [this video]