  We speculate whether the second law of thermodynamics has more to do with
Turing machines than steam pipes. It states the logical reversibility of
reality as a computation, i.e., the fact that no information is forgotten:
nature computes with Toffoli-, not NAND gates. On the way there, we correct
Landauer's erasure principle by directly linking it to lossless data
compression, and we further develop that to a lower bound on the energy
consumption and heat dissipation of a general computation.
