This isn't the "reversible computing" I covered at school. To me, a reversible computer was one that could absorb energy to perform a calculation that could be recorded. Then the machine would reverse, releasing the energy as it returned to a ground state. This would effectively mean calculations would happen without energy consumption. The whole thing bordered on perpetual motion, calculations happening without energy loss.

Electronic computers would not be good at this. They churn up too much heat. The only practical path would be something mechanical, powered by gravity... or a quantum object bouncing through a tiny rat's maze to solve a problem before returning to the ground state.