On 7 January 2014 08:36, meekerdb <[email protected]> wrote: > On 1/6/2014 8:16 AM, John Clark wrote: > > On Sun, Jan 5, 2014 at 4:11 PM, LizR <[email protected]> wrote: > > On 6 January 2014 06:47, John Clark <[email protected]> wrote: >> >>> >>> >>> Bell's theorem holds only under a certain set of assumptions, >>>> >>> >>> >>True. As I've said many times Bell made exactly 3 assumptions: >>> 1) High School algebra and trigonometry works. >>> 2) Things are local. >>> 3) Things are realistic. >>> >> >> > In fact Bell made a fourth assumption, although he didn't realise he >> was making it until later. Namely, he assumed that time is asymmetric. >> > > I won't bother to argue if Bell made this assumption or not because it > doesn't matter, time is asymmetric. > > > 4) Time is asymmetric not just at the level of everyday experience, >> but also at the quantum level >> Bell's 4th assumption seems to me quite a reasonable one to drop, >> given that most physics contradicts it. >> > > That is incorrect, most physics does NOT contradict time's asymmetry, > thermodynamics and cosmology certainly don't. Yes Quantum Mechanics seems > to be time symmetrical but even if Quantum Mechanics tells the whole story > (and we know for a fact that it doesn't because it doesn't include gravity) > time could still be asymmetric because how a system evolves over time > depends not only on the rules of the game (Quantum Mechanics) but also on > the initial conditions. > > > But if QM without collapse is fundamental, then the dynamics are time > (really CPT) symmetric and all the observed asymmetry is a statistical > effect due to starting in low entropy initial conditions. Bell derived his > inequality assuming QM with collapse, i.e. he assumed this time asymmetry > was fundamental, not a mere statistical effect related to the low entropy > of the initial conditions of the experiment. >
Well if Bell assumed collapse (which is I agree a fundamental time asymmetry) then he built in time asymmetry, just as I said. It is, indeed, his 4th assumption. I know of only one CPT violation, and if we assume no-collapse then everything else in the universe appears to be either a (rather unlikely) knock-on effect of kaon decay or a statistical result of the entropy gradient, which is in turn derived (most likely) from universal boundary conditions like the cosmological expansion. PS It *would *have been nice if you'd started what you said "And" rather than "But" just to show that you were agreeing with me :( -- 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/groups/opt_out.
