phasespace

He illustrates the second law by drawing a map of phase space, corresponding to some particular observer and what he is able to measure and what phasespace points he lumps together as macros.

Against Bounces Sean 2007

There is one absolute correct map of regions in phasespace.

Against Bounces Sean 2007

Are they? what he says in the November 2005 talk is very relevant. he draws phasespace, and different size blob regions on it representing the macrostates from perspective of some observer — - the coarse grains of phase space then he draws a squiggly line in phasespace and shows how it likely wanders into everlarger blobs (that is entropy likely increases) then he goes out to near “time-infinity” and, at the next to last slide, he takes the Reproductive Cosmology step of imagining a new big bang and there he says the coarsegraining map of the phase space TOTALLY CHANGES so that we dont have to worry about entropy — - there is a new perspective, as if a new observer with different significant measurments — so basically he assumes a radical discontinuity in entropy even though the squiggly line wandering in phapsespace is continuous, because that is moving in a space of fundamental degrees of freedom, which do not change (only the coarsegraining changes, at the moment of reproduction).

Against Bounces Sean 2007

At the end, Penrose makes the point that a large region in one observer’s phasespace can correspond to a small region in another observer’s phasespace

Against Bounces Sean 2007