Ishi Crew
Ishi Crew
Aug 31, 2018 · 3 min read

Ishi Finds Out, while out and about, About the Arrow of Time (tho still entertains doubt, and whoever shows up in the Redought)

I had lost my phone, i thought at a free music show ‘cease fire, don’t smoke the brothers’ down the street — -our local version of hiphop called GoGo music (because it goes on and on — they only play 2 songs/show but each song may be 2 hours long).

It turned my phone had been left at someone’s apartment so i picked it up.

Then i went to the discussion on ‘time’ ( a popular physics discussion — -they don’t really do the rigorous stuff). Nice place — -private home — -free good health food, free high quality beer, and I wasn’t even sure i could get in there — -but somone i’ve met recognized me and said ‘hey ishi’, and a little girl opened the door for us, and said we were going to her neighbor’s home (its a co-operative).

The owner had a cast of tracks from the first hominids or humans found in 1976 by the Leaky’s in Africa — -he asked me if i knew what they were — -i guessed and got it correct.

So we were supposed to discuss ‘time’ — they have all the popular books written by experts (Smolin, Sean Carrol, Rovelli, didn’t have Barbour (but Smolin cites him), Hawkings and Roger Penrose, Max Tegmarck, R Muller — there are actually more than that).

The discussion was fairly informed, but its possible unless you go through the math details you don’t really get it right. You just get confused and reaffirm your prejudices (experts do this too — they develop factions — eg Einstein vs Bohr).

Some evident biases was this sort of view that a) physics explains everything but b) physics doesn’t explain subjectivity so it leaves something out. They don’t like ‘entropy’ and think shannon entropy (or information) somehow differs from that (it does by a negative sign and boltzmann’s constant , but that is it, and is applied to nonphysical systems).

I told them this debate has been going back for like 150 years, and its Boltzmann versus Gibbs, or the canonical versus microcanonical ensemble in technical terms. Those ensembles are the same — boltzmann is just a sample of gibbs.

In Gibbs time doesn’t exist. Entropy is constant. In Boltzmann it does — its a local phenomena. Entropy increases — called the most probably distribution.

The subjective view (Boltzmann, tho one can view it differently) say time arises from ‘coarse graining’. This is like looking at the computer i’m looking at now. I see letters, sentences, and shapes. But thats a ‘convention’ (in words of henri Poincare).

If i look closer all i see is ‘pixels’. This is the Gibbs view. There are no letters, or shapes or time. Just microdots on a screen — -bunch of photons. To get time out of that you may (almost surely) need quantum theory — -you have to say these photons ‘collapse’ into letters and time (Born’s rule) — also called GRW theory in quantum mechanics.

So you have a choice of interpretations — -either the objective universe makes time, or the subjective experience does. You call the former ‘collapse’, and the other ‘coarse graining’. Either way, my impression is the math is the same — a coarse brained (boltzmann) entropy increases, and time goes forward. Some would say that’s Bayesian updating.

I dought this clarification makes sense to anyone but Ishi.