Re: physics for ex-farmers

Thus spake Oz <Oz@xxxxxxxxxxxxxxxxxxxx>
Oh No <notI@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> writes

Certainly I am expected classical positions. It's a matter of whether
Doppler shows anything non-classical. Cassini, for example, did not
pick
up anything in measurements of bending of light around the sun. The
measurements were so precise that an anomalous Doppler shift should
have
shown.

I haven't come across this one.
Can you give a simple experimental setup and results?

I'll email a pdf of this:

Letters to Nature

Nature 425, 374-376 (25 September 2003) | doi: 10.1038/nature01997

A test of general relativity using radio links with the Cassini
spacecraft

B. Bertotti1, L. Iess and P. Tortora

Also a graph of the prediction if the effect were visible for the Mars
Rover, and Erik's comments.


But if the inner solar system defines classical reference frame,

there should be no anomalous Doppler, so that actually makes sense too.

No, I don't like this. You are picking and choosing which is BAD.

I think there is a difference between picking and choosing, and
specifying, which is necessary.

As far as I can see you are predicting an effect of an expansion in time
for the light moving from emitter to observer. This expansion is not
currently modelled.

That's right. But if you remember, my original thought was that for
classical motions the wave function is continuously collapsing, and the

reference frame continuously defines length scales, and that under such

circumstances the effect does not appear. This applies in the inner
solar system. The continuous collapse is the limit of fig4b in the
paper, and gives classical motions.

My thought then, which you attacked and found wanting, was that it does

not apply to Pioneer, because it is a bound motion. I was forced to
revise this view for a number of reasons, one of which is that the
effect is observed in the Milky Way, which is also bound. I was led to
think the effect probably is apparent in the inner solar system, but
that maybe we have missed it because we weren't looking for it. However

That seems wrong, because there are a number of Doppler measurements of

great accuracy done regularly in the solar system, and I now don't
think
it could have been missed.

So this has lead me back to the original problem I was struggling with,

to specify the conditions under which the effect is observed. Going
back
to fig4, the answer to that is that the effect is observed when there
are no intermediate collapses and rescalings of coordinates between
emission and absorption. Then the question becomes "what instigates
collapse and rescaling"

Now I had thought that any measurement of position would instigate a
collapse. But I found this a little difficult to stomach, because
really
it ought to be "measureable in principle" rather than in practice.
Would
a radar measurement of Pioneer (which seems possible in principle, if
not in practice) really force a collapse and reset the drift to zero? I

find that one difficult to stomach, also.

However I have thought of a more stringent criterion, though I am still

having trouble putting it into words. This is to do with the fact that
for the teleconnection I relaxed gtr by specifying parallel
displacement
of momentum only in the direction of motion from the origin. For an
affine connection parallel transport is possible in any direction. In
classical physics any point can be taken as an origin, and you can
parallel displace a classical rod in any direction. This requires an
affine connection. But the teleconnection works in the quantum domain,
and you only have an initial state and a final state, so the relaxation

seems valid. But in a lab, or in the inner solar system we can
continuously measure everything from all angles, so we need an affine
connection, in which no shift is observed.

But at a certain point pioneer moves out of this classical reference
frame, and we can only measure it one dimensionally, so to speak, with
e.m. from there to here. I would say this is the point at which the
teleconnection comes into play, and the shift is found.

.

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