On the face of it, it's a hard thing to take seriously. A currency backed by nothing and based only on the energy expended to generate hashes? We've seen this b

On the face of it, it's a hard thing to take seriously. A currency backed by nothing and based only on the energy expended to generate hashes? We've seen this before, in 1992, as hashcash. It didn't go anywhere then, there was no reason to think Bitcoin would be different.