We tried the "no material consumption" thing for a few hundred thousand years. It was slightly unpleasant. This material consumption thing though, it's got its

We tried the "no material consumption" thing for a few hundred thousand years. It was slightly unpleasant. This material consumption thing though, it's got its pluses. We probably need to feed higher up on the energy food chain, now lower. Fission, fusion, and whatever is above that.