> Isnt the purpose of a Dyson sphere to keep all Energy inside? No, because that would be both impossible (see "black body radiation") and useless. The purpose

> Isnt the purpose of a Dyson sphere to keep all Energy inside? No, because that would be both impossible (see "black body radiation") and useless. The purpose is to use all energy produced by the star. But "using" energy doesn't mean it's gone (see conservation of energy) or that you have to trap it. What it really means is you want to use the low entropy inherent in a concentrated source of energy to perform work.