From Derek Bolton, Sydney, Australia
The proper resolution of the conceptual puzzle raised by Loschmidt’s demon is instructive. Imagine a glass sphere floating in space shattered by a bullet. To an observer seeing the fragments flying apart, it would be evident that they had come from the same locality at more or less the same time, but it would take far more data and analysis to discover that reversing their motions would unite them into such a simple object. The positions and motions of the diverging fragments are vastly more special than would be realised by the observer (13/20 December 2025, p 46).
As the physicist Ludwig Boltzmann appreciated, in a fully deterministic universe, the gain in entropy consists of the configuration of the debris being effectively indistinguishable from billions of others that, on reversal, would not so neatly combine.
