On 8 November 2014 11:40, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> LizR wrote: > >> On 7 November 2014 22:30, Bruce Kellett <bhkell...@optusnet.com.au >> <mailto:bhkell...@optusnet.com.au>> wrote: >> >> No, my main problem with identifying the expansion of the universe >> as the origin of the arrow of time is that the expansion of the >> universe really has essential zero impact on the everyday physics of >> our experience, but we see a consistent AoT associated with >> increasing entropy in every phenomenon of our everyday experience. >> Sure, what happened in the early universe has had lasting >> consequences for our everyday life, but any connection with the >> expansion is too remote to provide a plausible explanation of the >> consistency of our experience of time. So the increase of entropy >> itself -- whose universality is easily understood -- is itself the >> origin of the AoT. >> >> >> So you don't think that the creation of bound states in the BB fireball >> is a significant contribution to the entropy gradient? >> > > No, and I don't really understand what you are trying to get at with this. Well, the best thing to do if you don't understand something is to ask for clarification! (I do that a lot...) The point is that the existence of an AOT is partly derived from the existence of bound states like nuclei. In a quark-gluon plasma at equilibrium at a few trillion degrees, it is safe to say there is no discernible AOT. All interactions occur with equal probability in either time direction. But if you cool and spread out the plasma to the point where nucleons can form, then you have objects which can participate in entropic processes. So you have started to build the components necessary for the existence of an AOT. Similar comments can be applied at lower temperatures. Several things are needed for an AOT. One is objects like atoms, which can be arranged into low entropy states. Another is objects like nuclei that are able to undergo energy-releasing processes. Nuclei are effectively frozen chunks of negative entropy - a big contribution to the AOT which didn't exist when they were a q-g plasma. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
