Sure, you won't reach 100%. But say you reach 99.9% - the Dyson sphere should radiate infrared at 0.1% of a normal star, right? It wouldn't necessarily be bright.

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (2 children)

They must be mining a lot of bitcoin to need 99.9% of a star’s energy.

Or else to power one of those Kurtzgestat space lasers that will melt us anyway.

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (1 children)

Even if that level of efficiency were possible, 0.01% of a star's output is still a substantial amount of heat. You would still have to radiate it away otherwise it would melt your mega structure, and you would have to radiate it out equally in all directions otherwise you'd knock it off its orbit with the thrust generated from the radiating of the heat on one side.

[–] [email protected] 1 points 7 months ago

Yeah, it’s interesting to think about IR powered thrust.

I wonder if moving a star by cooling one side could ever happen? Like in a some weird future tech way obviously.

[–] FooBarrington 1 points 7 months ago

Maybe they are just fabricating matter. That takes a surprising amount of energy!

[–] [email protected] 1 points 7 months ago

Not all heat can be converted to work by the second law of thermodynamics. Now the question is, how hot can the star be for it to sustain life? Can most of its light be UV with very little visible? https://courses.lumenlearning.com/suny-physics/chapter/15-4-carnots-perfect-heat-engine-the-second-law-of-thermodynamics-restated/