(urth) OT: Christian relativity - in which I manglephilosophyof science

[Iorwerth Thomas]

>From: "Dan'l Danehy-Oakes" <danldo at gmail.com>
>Heh. Back in my days at Berkeley, one of their Nobel winners in
>Physics insisted on sitting on all doctoral defenses. He would
>inevitably ask "What is the definition of force?" and similar
>questions -- if you couldn't come up with F=MA, you were hosed.
>Some of the candidates, who hadn't touched "that stuff" in ten
>years or more, had to cram before their oral
>

Ouch...

>Okay I didn't know that there was a canonical version of quantum
>gravity yet... I clearly need to catch up on my science mags. (There's
>a huge pile by the bed...)
>

Canonical quantum gravity is just the term for what Stephen Hawking does 
(i.e. take GR and second quantise it); it isn't hugely successful...

> > The degree to which Bell's inequalities affect relativistic causality is
> > somewhat up in the air, because you can't transmit information
> > faster than light,
>
>Ummm ... I have this idea that you can, by exploiting exclusion.
>
>Consider three points, A, B, and C. B is between A and C,
>but one light-microsecond closer to A. B emits photon-pairs
>towards both A and C, at regular intervals.
>
>At C, you set up a device to detect photons coming from B as
>waves.
>
>At A, I measure every other (odd-numbered) photon as a particle. If
>I'm understanding exclusion and the inequality correctly, this means
>that you can't measure these photons as waves, so your wave-
>measuring doodad misses every odd-numbered photon, which gives
>us a kind of synchronization. Then I measure the even-numbered
>photons as waves for 1 and as particles for 0. You will only be able
>to detect the ones paired to the ones I measure as waves. So no
>matter how far A and C are from each other, the information I
>encode in this way will reach you in one microsecond.
>
>True? False? I'm not sure -- I don't have the maths to understand
>why I'm wrong, if I am.
>

I'll have to think about that...  I suspect that it may be an ill posed 
problem :) (that is, there's a catch, but I'm buggered if I know what it 
is).

> > >I'm pretty sure that the whole point of relativity is _not_ to have
> > >a preferred frame of reference. But, ZPF theory may mess that
> > >up pretty good (if it ever amounts to anything).
> > >
> >
> > Well, yes...  But in the case of the universe you get a
> > Machian 'background of fixed stars' effect (I think); I'm not sure
> > Lee Smolin is happy with that but he's a bit of a purist in this regard.
>
>Mmmm. I see the point while not conceding it -- if I move an
>inch, my position relative to the farthest actual star _has_
>changed, even if the change is below any conceivable threshold
>of measurement. I don't think this creates an actual preferred
>frame of reference, but a difference of scales in which certain
>effects become smaller than quanta and effectively disappear.

I think it's a little more fundamental than that (and my refernce to Mach 
may be slightly misleading).  Maybe it's a property of the particular 
space-time metric cosmologists use?

> > ZPF theory?
>
>Zero point field theory, which (aside from offering a nifty source
>of hypothetical free energy, at least in science fiction) seems
>to propose an actual reason why inertial mass is related to
>gravitational mass.
>

Ah yes, I think I've heard of that (vaguely), though I don't know much about 
it; most of my particle physicist watching at the moment constists of 
observing the general kerfuffle as string theory dies a messy death for the 
_third_ time...