On 2 July 2014 09:33, meekerdb <[email protected]> wrote: > On 7/1/2014 1:32 PM, David Nyman wrote: > >> On 1 July 2014 19:24, meekerdb <[email protected]> wrote: >> >> I think you have created a strawman "exhaustively-reducible physical or >>> material ontology". Sure, physicists take "forces" and "matter" as >>> working >>> assumptions - but they don't say what they are. They are never anything >>> other than "elements of a mathematical model which works well." And what >>> does it mean to work well? It means to explain appearances - exactly the >>> same thing you put forward as a uniquely different goal of comp. >>> >> Firstly, I'm not really persuaded by your contention that forces and >> matter, to use your example, are merely "elements of a mathematical >> model which works well". Rather, in terms of that very model, such >> elements are precisely those that (at least in principle) are supposed >> to comprise a fully-sufficient bottom-up ontology for the theory as a >> whole. The point, again in principle at least, is that nothing *above* >> the level of the basic ontology need be taken into account in the >> evolution of states defined in terms of it; put simply, there is no >> top-down causality. >> > > Actually, causality, except in the no-spacelike influence, doesn't enter > into fundamental physics. Models are generally time-symmetric. >
I agree. As Victor Stenger mentions in "The Comprehensible Cosmos" causality is just another word for the 2nd law, and the 2nd law is an emergent result of the universe being in a special state - namely expanding. The expansion determines an arrow of time via various processes where initially time-symmetric systems "freeze out" into bound states (quarks, nuclei, stars etc). This has the effect of allowing the entropy ceiling to rise so a system that was originally at thermodynamic equilibrium is able to move away from it as it cools / expands. So the question boils down to whether the expansion is a result of fundamental physics, or incidental / local. Eternal inflation seems to suggest it's fundamental - or does it? Can someone more knowledgeable correct me on that, if necessary? -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
