When I say "imagination," I mean that in the current context of time. Projecting into the future to grab non-existant technologies, like a dyson sphere or what-

When I say "imagination," I mean that in the current context of time. Projecting into the future to grab non-existant technologies, like a dyson sphere or what-have-you, to try and resolve current energy demand roadblocks in photovoltaic and battery technology isn't looking at the current time frame we inhabitants of Earth share (with an ever so tiny bit of relativistic difference). If we start looking at pure physical energy and matter, I'm not sure how we get around laws of conservation of energy and matter, making the universe on the grandest of scales potentially zero-sum, but then we get into realms of physics we just don't quite have evidence for yet. But we really don't understand that much about space expansion or potential fate of the universe at all to even make intelligent guesses.