[Malsua]

I haven’t read the “ringworld” and haven’t really done a calculation, but it seems very unintuitive that building a ring around the Sun would take materials worth of hundreds of planets.

Do you have some calculations handy?

I do admit that I have read bad sci-fi novels.

Larry Niven's science fiction, including Ringworld is not "Bad" science fiction. In fact, he's probably one of the most authentic hard science fiction writers that actually tries to stick to real science and extrapolate forward.

That said, he claims he did the math and the stress on the "floor" of the Ringworld exceeds the capacity of any known substance to withstand the tidal forces. He simply labeled it "Scrith", a substance with some pretty amazing properties that simply can't exist, but has to for the story.

[Krosan]

I took off my lazy hat and did some math myself. It is written out above in this thread. My math showed that dismantling Earth alone brings enough material to build 230 rings that are 50 km wide and 100m thick.