[Tidal energy is not renewable | Hacker News](https://news.ycombinator.com/item?id=37383283)
[Tidal Energy - Not Renewable](https://cs.stanford.edu/people/zjl/tide.html)

[Matrioshka brain - Wikipedia](https://en.m.wikipedia.org/wiki/Matrioshka_brain)

[Kardashev scale - Wikipedia](https://en.m.wikipedia.org/wiki/Kardashev_scale)

[Computronium - Wikipedia](https://en.m.wikipedia.org/wiki/Computronium)