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.
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.
Because all that energy contains heat as well, and you’ll need to balance the heat from your star along with the energy absorbed.
You’re never going to get to 100% efficient conversion, so you’ll have to radiate away the heat so your sphere doesn’t melt or something.
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.
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/
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.
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.
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.