> We don't see it because we can't; we don't have the technology. Why are radio telescopes insuffient? Given what we know, humans building a Dyson sphere woul

> We don't see it because we can't; we don't have the technology. Why are radio telescopes insuffient? Given what we know, humans building a Dyson sphere would be pretty obvious to anyone looking, simply by the waste heat. We'd have to take specific measures to actively avoid detection. It's not even clear how that's possible, given the second law of thermodynamics. Positing that civilizations are everywhere but hiding seems the more extraordinary claim. It just takes one "person" sending one message to Earth for the veil to be broken.