`A good exposition. It doesn't address the questions of the alignment of thermodynamic,`

`radiation, and spacetime expansion though. This paper may be of interest:`

## Advertising

Arrows of Time in the Bouncing Universes of the No-boundary Quantum State

`James Hartle <http://arxiv.org/find/hep-th/1/au:+Hartle_J/0/1/0/all/0/1>,Thomas Hertog`

`<http://arxiv.org/find/hep-th/1/au:+Hertog_T/0/1/0/all/0/1>`

`(Submitted on 9 Apr 2011 (v1 <http://arxiv.org/abs/1104.1733v1>), last revised 16 Apr 2012`

`(this version, v3))`

We derive the arrows of time of our universe that follow from the no-boundary theory of its quantum state (NBWF) in a minisuperspace model. Arrows of time are viewed four-dimensionally as properties of the four-dimensional Lorentzian histories of the universe. Probabilities for these histories are predicted by the NBWF. For histories with a regular `bounce' at a minimum radius we find that fluctuations are small at the bounce and grow in the direction of expansion on either side. For recollapsing classical histories with big bang and big crunch singularities we find that the fluctuations are small near one singularity and grow through the expansion and recontraction to the other singularity. The arrow of time defined by the growth in fluctuations thus points in one direction over the whole of a recollapsing spacetime but is bidirectional in a bouncing spacetime. We argue that the electromagnetic, thermodynamic, and psychological arrows of time are aligned with the fluctuation arrow. The implications of a bidirectional arrow of time for causality are discussed. http://arxiv.org/pdf/1104.1733v3.pdf Brent On 12/4/2013 3:37 AM, Alberto G. Corona wrote:

Yes there is no loss of information/at the lowest level,/ that is at the quantum level .But at the lowest level, there is NO notion of HEAT. only speeds and momentums ofelementary particles. HEAT and temperature and entropy are statistical parameters,words used in the macroscopical laws to define sum of energies and mean energies ordisorder of particles because the energy of each particle is not know at the human scalebut each particle carry all the information intact.THe post is talking about the loss of information contained in a macrostate consistingof a phisical bit of information stored in a macroscopical object. For example a gate.The conservation of information on the laws of physics refers to the information of themicrostates. not macrostates, whose information can be lost. and loss of information ina macrostate generate increase of entropy by the following reason:in terms of state, an increase of entropy is produced when we pass from a macrostatewith less possible microstates to other with more possible microstates. At thebeginning we have one macrostate , for example 1 formed by all the possibleconfigurations of electrons in a gate when it stores a 1. when erased, we have amacrostate that may be one of the possible configurations of electrons that may be in agate with a 1 OR a 0 or a neutral state. So the entropy has increased because the newmacrostate (erased) has more microstates than the original. the disorder has increased.How that entropy increase is produced in the erase depend on the process. It may be bymeans of a short circuit in the gate. The electrons circulate and hit the atomsproducing heat. the potential electric energy of attraction produces cynetic energy inthe atoms and heat.The microstate-macrostate transition is the same case that happens when we have a gas ofdifferent types confined in a room and other room empty. When we communicate the rooms,the gas expand and fill both rooms, the entropy increased because the final macrostateadmits more possible configurations speeds and positions of particles in the two rooms. Something similar, not equal, happens with gas of electrons in a gate. Measured intermodinamical terms, the temperature decreased and the entropy measured intermodinamical terms delta Q/T has increased. Q is the thermal energy or heat.However the process is different. in the first case, potential energy is dissipated andthere is increase of Q, in the other the potential energy is dissipated against thevacuum and produces reduction of T. Q/T seems to be proportional to the number ofmicrostates in a macrostate.The availability of information in the form of macrostates when entropy is low is whatpermits living beings to compute in order to anticipate the future and survive. That canonly happen in the direction of entropy increase. I wrote something all of this here:http://www.slideshare.net/agcorona1/arrow-of-time-determined-by-lthe-easier-direction-of-computation-for-life

-- 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/groups/opt_out.