New Pathways to Quantum Spring: Can Information About States Be Made More Democratic? by Neil Bates

Neil Bates

Peter, I will take a close look at your paper as I can see from Abstract it is about a subject dear to my heart and similar to that explored in my own essay: quantum states and whether there are novel experimental tests that can reveal new truths about them. I had gotten a bit depressed and lost much interest in this contest after seeing so many "speculative" papers without specific proposals, and seeing my own effort sink rather low in the ratings. Somehow I had forgotten that ours is instead, like mine in proposing testable new perspectives: "New experiments comparing single-photon pairs are proposed, ..." Indeed! That deserves some cogent comments and I will get back to you before day is done.

Neil Bates

(Erratum: "yours" - lol no your paper was your own and not a joint effort.)

Paul Borrill

Neil - Enjoyed your essay and gave it a good rating. I particularly liked your proposal on how to distinguish supposedly "indistinguishable" mixtures. I came up with something similar - the principle of "retroactive indiscernability", and would love to hear your comments on it:

http://fqxi.org/data/forum-attachments/Borrill-TimeOne-V1.1a.pdf

(sorry if the fqxi web site splits this url up, I haven't figured out a way to not make it do that).

Kind regards, Paul

Neil Bates

Paul, I will take a look this evening. BTW these comment forms don't use HTML the way that ordinary blogs use since on LaTeX. I use shortcut of "/1610" so people know how to find my essay. Cheers.

Michel Planat

Dear Neil,

I am not an expert of weak measurements but your excellent work needs a boost I am happy to offer. My topic is very close to quantum information and quantum computing. May be you have a chance to look at it before the end of the contest.

http://fqxi.org/community/forum/topic/1789

My very best regards,

Michel

Vladimir Rogozhin

Dear Neil,

I am pleased to read your essay in the spirit of Descartes, with very deep radical ideas on the theme of the contest, the evidence and conclusions.

Especially liked: "..tangible angular momentum is clearly not incidental to what we can know about quantum objects"..."We still won't really understand wavefunction collapse, despite various controversial attempts to explain it."

Please look at my essay and vote ideas.

Good luck in the contest,

Best regards,

Vladimir

Sreenath N

Dear Neil,

Thanks for visiting my site. I have downloaded your essay and now you immediately contact me at, bnsreenath@yahoo.co.in , for further details.

best,

Sreenath

Christian Corda

Dear Neil,

As I promised in my Essay page, I have read your intriguing Essay. Here are my comments/questions.

1) As I told in my Essay page, your Essay is connected to my one. In fact, finding a way to distinguish quantum mixtures of the same density matrix this is also of fundamental importance for the black hole information paradox.

2) Your statement "There is more to "it" than democratically available as "bit"" is beautiful.

3)The basic asymmetry in possible knowledge for observers was one of the reasons because Einstein rejected quantum mechanics. This is a issue that also gets under my skin.

4) I like your statement that "Observers who create a particle are able (at best) to know its complete wave function - the complete quantum specification of that particle". In fact,in quantum physics all the information is encoded in the wave function.

5) By "postulating that photon interactions transfer spin (at least cumulatively) based on the original expectation value (average measured value) rather than final apparent detection type" you are, in a certain sense, making quantum mechanics deterministic.

6) Although I like your humble declaration that "Most of the proposals here are impractical" I agree with you that being possible even in principle is of theoretical interest in order to have further insights on various limitations of quantum mechanics.

7) Do you think that your statement on the dominance of "it" over "bit" is compatible with my one "Information tells physics how to work. Physics tells information how to flow"?

In general, I find your essay very pretty as reading it gave me lots of fun. Then, I will give you an high score.

Cheers,

Ch.

Neil Bates

Dear Christian,

First of all thank you for your enthusiastic comments here and at your own essay (/1856.) I am flattered to get kudos and recognition from the current top-rated essayist. (That BTW is not surprising to me, considering that your essay most resembles a journal paper proposing an advance.) Sadly I have a bit of visual trouble reading your essay, perhaps my older pdf SW did not render it right (it has the scratchy look for me of "Ghostview" altho I downloaded the file itself.) [I left a long comment at Dr. Corda's essay.]

To answer your points:

1) Thank you for recognizing what I was attempting, and the importance of distinguishing supposedly "indistinguishable" mixtures in a novel way.

2) Thank you, this is a foundational insight for us all to appreciate.

3) Yeah, it is unsettling and of course Einstein was human, too. I think I have chipped away at some of that peculiar asymmetry, as you have.

4) Yes, the info is encoded in the WF but a random "observer" out there normally can't "map" that WF if she doesn't already know what's there. That phrase "quantum tomography" of a WF is really about an ensemble, not the characterizing of e.g. the complete polarization state of a single photon. Yet I have found a way that at least offers hope for finding more about such individual states, as well as ensembles - leading right into 5):

5) That much, is sort of determinism since we can find a given ellipticity and not just "here is a chance of this or that being recorded."

6) Thanks for your appreciation of the significance of thought experiments.

7) I am still reflecting on this, not sure. I think we still have to admit to a basic idea of it-to-bit "working" but then a free-spirited "flow" imposed on that, which is simply not all reducible to exact formulas and predictions - like the basic knowledge that water will go into various channels etc as it flows down, but we can't be sure just what ripples and splashes will happen. To the extent that is what you mean, it sounds similar.

I am glad too, my essay could be considered "fun." I was worried my title was a bit pretentious but the political analogy appealed to me.

Cheers.

George Kirakosyan

Hi dear Neil,

It is enjoyable to read your nice essay! However my comments I will send

after some time. I have rated your work properly!

Best wishes,

George

Neil Bates

Belated thanks, George. I think your essay was interesting and congrats on it reaching a high ranking. Good luck.

Neil Bates

Briefly, Hoang: "No" ;-)

Neil Bates

James, I thought your essay was rather clever in integrating the human element and our own relevance to the cosmos as conscious beings, not just pure disembodied physics. It was also enjoyable to read, like an essay by Medawar or other "interdisciplinary writer." BTW does your title mean, we are the "kings" of reality?

Neil Bates

Some notes. First, I've had Internet issues for the last couple days and avoided commenting. I apologize too for not commenting much at other essays until the final few days (typical procrastinator and often busy), and will try to make some more comments from now on. Indeed, with ranking out of the way it can be more relaxed and productive. This is no time to just wait for prizes etc. and give up on the discussions. Don't be afraid to remind me to leave some assessments of your essay if you asked and I didn't get to it. In some cases I wanted to reflect rather than saying some fluff for the sake of a gesture. Finally does anyone know of blogs, articles etc. that are discussing this contest or planning too? Thanks.

Neil Bates

Perhaps the following draws some needed attention towards a significant more basic insight that we can test with existing equipment (riff on Beth experiment.) My essay meandered a bit so I will cut to the core quantum measurement issue. Yes it's nice to distinguish previously indistinguishable mixtures, but that is impractical and a byproduct of a more fundamental insight into quantum measurement. The original spin hypothesis states, that an absorbed photon imparts spin equivalent to its expectation value (equal to (a^2 - b^2)hbar where a,b are coefficients for R and L components) rather than per its measured status (sometimes the same.) That amount is doubled for transmission through a HWP, and more complex effects are possible. The distinction is only truly meaningful for cumulative measurements.

My main hypothetical example was runs of apparent R or L detections applied to originally linear photons. This is very difficult so consider the flip side (so to speak) I noted briefly in the essay: circular photons detected "as linear" would continue to transfer the spin expected from conservation of AM and as predicted by OSH. Note that R or L are superpositions of H and V etc. Hence SQT implies that detection as either of the latter should "collapse" the WF into "being a" H or V photon - with no spin transfer!

There are two ways to do this test. The easier way is to have a series of e.g. R photons pass through a measurable HWP and thence to a fixed H/V linear detector. Well the latter will get a series of something like VHHVVVHVHH... etc. SQT would presumably "retrodict" and redact the detection-made linearity into the HWP, so no spin transfer. OSH says that 2nhbar is found transferred to the HWP. Now, how many thinkers can really say they expect the angular momentum of all those R photons to not put a spin on a HWP, just because a "linear detector" is put after it?

A more difficult method is to detect AM change of the linear detector itself (with or without an initial HWP.) We can either keep the LD within a reasonable orientation and still be able to detect change of AM to withing hundreds of hbar if need be, or just consider that the angle of apparent linear detection doesn't matter since any angle means "no spin." Again, it is unlikely such a detector can prevent the original nhbar angular momentum of the series of R photons from being transferred to the system. If it can't, then quantum theory already needs a fresh look and we don't need to find the very improbable runs of the reverse kind.

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