And after a hundred generations of this there will be no fusible material left. We can extract energy from rotating black holes until they stop, and then the universe is dead.
replySo solar energy is renewable over a human lifetime, not renewable over a stellar lifetime, renewable over a stellar formation cycle, not renewable over the lifetime of a universe, and renewable if universes turn out to be cyclical. And all but the first are pendantry in the context of renewable energy conversations.
reply