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A Dyson sphere around a black hole

(arxiv.org)
214 points SkyMarshal | 1 comments | 19 Aug 21 03:40 UTC | HN request time: 0.201s | source
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ardit33 ◴[19 Aug 21 08:55 UTC] No.28231727[source]▶
The whole concept of a Dyson sphere is kinda idiotic. Any civilization that is capable to build one, it is probably able to work out fusion energy very efficiently.

There is no point to go and harness energy around a star or a black hole, when you can just produce it locally with a lot less resources/waste and materials. The sun itself is actually very inefficient in producing energy.

There is no need to harness the sun million of km away, when you can recreate it in your home planet. The only way to produce a dyson like of sphere, is to tame an over-heated sun, and reflect away un-needed energy. But there is no point to build one to just harness it.

It makes great sci-fi stories, but that's about it. Scientifically, it just doesn't make sense.

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JohnJamesRambo ◴[19 Aug 21 15:08 UTC] No.28234793[source]▶
How do people expect to-

A.) Keep it in place and not hit the star/black hole.

B.) Avoid it being demolished by intercepting every piece of space trash, comet, asteroid in a solar system?

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1. jjk166 ◴[19 Aug 21 18:44 UTC] No.28237646[source]▶
A realistic dyson sphere is not a single structure held up by mechanical forces. Instead it's an incredibly large number of independent, sail-like panels where the radiative pressure pushing the panel away from the star is equal to the gravitaional pull towards the star, allowing the panel to sustainably "hover." Panels would need some method of active positioning for initial alignment and dealing with variations in radiative pressure, so they can potentially move out of the way of debris. Alternatively, since you have the infrastructure in place for making truly mind boggling numbers of these, you just let them get destroyed and replace them.