To: huw@mail.usyd.edu.au 10/16/2002

From: "Paul J. Werbos" <

Subject: issues re polarizer

Cc: luda.werbos@verizon.net,Huw.Price@ed.ac.uk

Bcc:

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Hi, Huw!

I think I need to "put on hold" one of the points I was groping towards in the two-pager.

The longer paper, being mainly theorem-and-proof, is pretty solid. (Maybe today I would

tune down some of the adverbs regarding hopes of backwards-time effects in the laboratory...

I hope I stressed "conceiveable possibility" rather than promising... The astronomical area

is one thing, but it's way too early to know exactly what can be done on a more local

scale.)

When I was typing the paragraph about the polarizer... I knew it was a bit fuzzy. I am glad I did not

show it to a wide range of people, and stressed it was only a discussion starter.

As I think more...

I did spend about a week checking out the need for a0*delta+a1*cos**2 in order

to explain the

and no interaction between them.

But the time-symmetry of p(in,out) of the polarizer.... my heuristic reasoning was a bit of a stretch.

Really not convincing at this point. The a0*delta+a1*cos**2 Bell-Theorem argument does NOT

in any way require strict time-symmetry... only a modest deviation from strict time-forwards behavior.

IN effect, what we really have are p(photon in, polarizer in, photon out, polarizer out), in a physical set-up.

It is conceivable that ambient temperature effects could break the symmetry here, via e(-kH/T) kinds

of effects, in a way that sets up astronomical ratios... in fact, the ratio between the probability

of absorbing an optical photon and spontaneously emitting one... might ACTUALLY be astronomical,

even without accounting for other boundary conditions; if ambient thermodynamic conditions should have that kind

of effect, then the observed behavior would not depend a great deal on the temperature of the polarizer, so

long as the temperature is in the normal zone.

This doesn't mean I have changed my mind, exactly. It means that I do not feel a firm conviction or clear image of the

entire situation with polarizers, and need to work towards greater clarity.

===

In the end... the MRF formalism is quite general, and would include even the Aharonov extreme as a special case.

So that part is solid. The practical challenge is to build up reasonable models -- slightly more complex than

one might use in quantum optics experiments, for example.

If I am not 'way off base... I
believe that the

is different from the usual time-forwards version in any case. And then, given some new components available...

it then becomes more reasonable to study more systematically what can be done with such components.

There is no good reason as yet to believe that Eberhardt's theorems ruling out faster-than-light experiments

would apply in general to such systems, even if the arrow of time generally runs forwards in the entire universe.

The claim is NOT that FTL effects are possible. The claim is that the previous arguments for it being impossible

almost certainly fall apart, leaving us with a question mark, a kind of logical possibility which may or may not

hold up under further study. Revised measurement-component models will be necessary in order to begin the

mathematical analysis of whether or how FTL effects are possible.

---

A further consequence. The proposed astronomical experiments do not rely on polarizers. Therefore, it

should be possible to discuss that sort of possible experiment even before we feel any final clarity about the polarizer side.

The arguments about free energy all hold in a very general sort of way, without any need to make strong assertions at this time about

polarizers.

---

There is something strange about feeling puzzled about how polarizers work. These are such simple-looking objects one can hold in

one's hand, and buy for a small sum... (Ludmila and I may buy a few soon for our four-year old who

has expressed an interest in such things.) Yet I remember how strange it seemed to be so puzzled about

the functioning of the brain, when, after all, it is so close at hand and available for direct observation...

Best,

Paul