On Fri, Nov 07, 2014 at 12:59:28PM +1100, Bruce Kellett wrote: > LizR wrote: > >On 7 November 2014 12:32, Bruce Kellett <[email protected] > ><mailto:[email protected]>> wrote: > > > > I have not seen your arguments for this, being new to the list, but > > the expansion of the universe is a universal consequence of general > > relativity. So it is built into the laws of physics, and has nothing > > to do with whether or not there ever was a period of rapid inflation. > > > > > >Expansion or collapse is a consequence of GR, certainly. However I > >was thinking on a larger scale with the EI comment, since EI seems > >to necessitate the existence of expanding universes. Not sure that > >it can be counted as a TOE though, so it's still in need of > >ultimate explanation.. > > > > The AoT comes from the third law of thermodynamics and has little to > > do with the expansion of the universe. Entropy increases in the same > > direction as the expansion solely because the universe 'began' in a > > state of very low entropy. (The Past Hypothesis). > > > >I didn't realise there was a 3rd law, but anyway - saying the U > >began in a low entropy state begs the question - why did it? The > >big bang fireball was more or less in thermodynamic equilibrium as > >far as I know, and if it had stopped expanding it would have > >rapidly reached that stage. My point is to explain the > > > Sorry -- typo. I meant the second law, of course. > > I agree that the past hypothesis, while it explains the > thermodynamic AoT, itself stands in need of explanation. This is the > great unsolved problem of cosmology -- at least according to many > cosmologists. The initial big bang might be assumed to be in > thermodynaic equilibrium, but that is essentially the same > assumption as the assumption of low entropy. The question remains as
Thermodynamic equilibrium is at maximum entropy. This leads me into commenting on your post slightly earlier in this thread - expansion of the universe is coupled to th second law in that it allows a universe initially at maximum entropy (thermodynaic equilibrium) to evolve into a universe not at maximum entropy, but never have entropy decrease, so satisfying the second law. The equation is S_max = S+C, where S_max grows as the universe expands, and S=S_max indicated thermodynamic equlibrium. The value C indicates complexity, or information content of the universe, and is the bit we find interesting. I think this is Dewar's equation - but it may also possibly be attributable to Brillouin, who pointed out that C could be considered to be Shroedinger's "negentropy". The point being that we can have both dS/dt > 0 (2nd law) and dC/dt > 0 (evolution of complexity), but only in an expanding universe dS_max/dt > 0. > to why it was in equilibrium. Generic creation events might > actuallybe expected to produce extremely lumpy universe down to the > smallest scaels. I.e., state with very high entropy. > > Bruce > > -- > 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. -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au Latest project: The Amoeba's Secret (http://www.hpcoders.com.au/AmoebasSecret.html) ---------------------------------------------------------------------------- -- 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.
