Paradoxer

A Joke Nobody Gets

2011-11-15T03:04:00.000Z

OK, this is based on a chicken joke I saw on FB (Jenny's Think Tank and Holistic Comedy Bar - drop in sometime if you can find it.) It's a concept joke, I hope it gets around. But instead of just telling you, I'm making it a riddle.
An entangled particle said to its partner across the lab, "how do I get to the other side?"
What did the other particle say back?

Why?

2011-09-11T03:17:00.000+01:00

9/11 ... Sigh. I had a strange dream the night before. I was looking at that kind of art kids make from cutting and pasting different colors of paper to a board. I saw a dark rectangle in front of me against a lighter background. Then something ripped a big tear across it, a bit above the middle. I felt bad enough the next day hearing what happened, but especially creepy to see that footage of one of the planes tipping sideways and leaving that big gash in the tower.

Thank you FQXi, but I have concerns ...

2011-06-12T13:32:00.003+01:00

My essay "Our Non-Deterministic Reality Is Neither Digital Nor Analog: Experimental Tests Can Show That Decoherence Fails to Resolve the Measurement Problem" was accepted for the FQXi Essay Contest "Is Reality Digital or Analog," and I am grateful to them for that. My previous post about the article, focussed primarily on the scientific content I presented, generated many comments. There were various prizes offered, and I did not win any (announced June 4.) OK ... I realize readers may therefore take my critique of the process with a grain of salt, but what I have to say ultimately stands or falls on its own. On June 1 I sent an email about my concerns to FQXi Administrator Brendan Foster. I also told him I planned to reprint it unless told not to. I am taking no response as tacit approval, but reprinting it here instead of as a comment at my Essay or the discussion thread. (I did link here from the contest forum noted below.) The content is quoted below. I have not yet received a reply, which is also disappointing (yet I realize that administrators are busy at the end of the contest.)

I also made some comments at the forum for discussing the contest in general. I and some other commenters expressed some disappointment about there not being award/s for non-professional or amateur submitters (a possibility expressed in the rules for the contest.) However, my concerns go well beyond those issues, as seen below. So, tell me what you think, suggestions, etc. (I am trying to separate discussion of the scientific issues from Essay Contest issues, but I realize they might intermingle: especially since one of my concerns was the inadequate credit given papers - like mine - that proposed experimental tests, the few of them standing out "like sore thumbs" in a field of arm-chair fancy.

Brendan Foster and colleagues,
FQXi

Dear Brendan, all;

I sadly write to you as a disappointed contributor, with a posted essay in your contest "Is Reality Digital or Analog." ( http://fqxi.org/community/forum/topic/949 , "Our Non-Deterministic Reality Is Neither Digital Nor Analog: Experimental Tests Can Show That Decoherence Fails to Resolve the Measurement Problem" ) I surely should have written earlier, but I hesitate to challenge administrators. However, I finally felt the need to make some constructive critique about the way the contest went, and for me in particular as a matter of principle whatever the final results. Note: I corresponded with Mr. Foster in mid-February about some submission issues, which were resolved to my satisfaction. Indeed, I thank him heartily for letting me make corrections, and re-submit after the deadline.

First, I applaud the concept and mission of FQXi, and welcome the opportunity in principle offered by your contests. I applaud your openness to amateurs and semi-professionals lacking institutional support, and your giving a forum to challenging ideas and to those who produce good work but have trouble pushing submissions through the journal refereeing process, etc. What disappoints me is how this contest turned out so far (I haven't time to study previous contests for comparison.) Most relevant, perplexing and saddening to me, is the prevalence of low community ratings. There is something wrong when most essays in such a contest rate 3-5, and the "best" essay pegs a flabby 5.4! (On the Depth of Quantum Space by Daniele Oriti 76 posts ... Feb. 16, 2011 @ 14:23 GMT Community Rating: 5.4 (34 ratings) Public Rating: 6.0 (22 ratings)) That's like an "F" grade. What are the community raters looking for, that they didn't find?

Note that since essay submitters become community raters, and relative rankings determine success, then the least responsible CRs sadly have a conflict of interest: to give low ratings to other submissions that may be a threat, or that they dislike intuitively regardless of merit, etc. At least we should see separate ratings from fellow authors, compared to standing FQXi members. I don't even know, did the former pull down the latter's ratings, or vice versa? If the authors: why should their judgment as raters be any better than the papers that got low average ratings? Perhaps it would be better for applicants to just not rate each other except as public raters. Their comments can show what the consensus is.

My situation: instead of offering a new theory or challenge to accepted physics, I critiqued a popular alternative to traditional quantum theory. I also proposed a way to empirically test that interpretation. Few essays offered practical tests of any theory, most were very speculative. I received many supportive comments, and some from significant figures in physics like T. Dorigo. Not all commenters agreed with my thesis, yet none offered a correction to my technical points, my line of reasoning, said I did a poor job, or rebutted my claims as to the experimental outcome (even if not convinced of its implications), etc. Even so, my community rating was a mere 3.6 (Public = 6.5.) Why didn't any of the low raters explain what bothered them? Isn't that part of their job, formally or informally as the case may be? Most raters should at least have been impressed by someone proposing an eminently practical experimental test of what has just been a philosophical argument.

In any case, ratings need to be justified, not just a click and forget. I can see that applicant raters need to be anonymous to prevent retaliation, etc. However, perhaps standing FQXi members should (as in Olympic competition etc.) openly give grades and explain their ratings. The current system just does not work since raters are apparently too swayed by impulse attractions or distastes (after all, the decoherence theory I critiqued is a popular way to evade measurement paradoxes.) I realize that the expert judges will add further and could shift ratings around, but I can't see at FQXi website what they have accomplished. Also, the rules say the EJs will be "peers" of the applicants - how will you find "peers" for professed or presumed amateurs? Furthermore, if EJs don't revisit promising papers not among the finalists, what valuable work might be missed that wasn't appreciated in the community ratings? Is there a way to appeal to someone, "look at this again"?

Also: your contest has a category for "non-professional and/or non-academic," yet you don't seem to have a clear-cut process for identifying amateurs. I see no defined list. Is it assumed from the submitter not providing a professional affiliation? Isn't that subject to misinterpretation? I stated in my "Author Bio" that I count as an amateur (note: the term is defined in social context) and am not aware of any other posted submitter saying so directly in their Bio. (I did not make thorough check and some implied, or in comments.) Furthermore, if amateurs are a special group does that mean such a submitter still has a chance of that recognition, even if not among the general "finalists"?

Others have expressed similar concerns to mine here and there. See for example critique regarding amateur status, public ratings etc. in comment to my essay, "basudeba wrote on Mar. 20, 2011 @ 06:14 GMT." This author/s may have contacted you already. (I set aside my concerns about public ratings, since e.g. there are common criticisms.) Please distribute my comments widely, and among FQXi members, the applicants, judges etc. I want my concerns to be considered and responded to. I hope FQXi will post my letter so that everyone involved can see what sorts of concerns entrants have. Perhaps it can start a post for discussion. There is a valid case that although FQXi essay contests are a helpful effort in principle, their manner of administration needs clarification and reform. In any case I continue to support your trailblazing and egalitarian mission.

PS: I plan to enter this letter as a comment to my essay. If you object, please tell me and explain. Thank you for your interest and concern.

Best Regards,

Neil Bates

The Born Ultimatum

2011-06-07T01:28:00.004+01:00

Hello folks, I'm going to try something different here. The immediate purpose is to provide an outlet for those who want to continue the debate from Chad Orzel's post on the Born Rule in quantum mechanics. A very good reason for continuing elsewhere: comments there are closed now! This post is also for anyone just interested in that subject, and in particular whether we can properly derive the BR from the many-worlds concept.

Well, quantum mechanics is weird so this post will work in a weird way: I first just make this basic outline of the purpose. Then, as time goes on, I will update the post substantially (not just the customary corrections and minor addenda.) So, it will grow along with comments and the development of my thoughts. However, I will put and retain a demarcation line below to show where my initial contribution ended.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Well, since the world kept on going ...

2011-05-22T03:18:00.002+01:00

So forget those traditional fundies, I want everyone to see what religion really ought to be about:

The "great smoky dragon"

2011-04-23T19:14:00.001+01:00

I consider this fabulous critter residing (sadly, impermanently) on my arm to be "the great smoky dragon" of the quantum wave function, as John Archibald Wheeler called it. Great job by Val "Daisy" Tutson of "A Mile Of Smiles."

"Everything I Know I Learned From 'Dancing With The Stars'"

2011-04-12T02:02:00.000+01:00

I didn't, but my GF is planning a book with that title. I put this post here to lock in priority of her claiming use of the entire title with the show name included. I wish her the best.

Can We Distinguish Supposedly "Indistinguishable" Quantum Mixtures?

2011-03-21T13:55:00.002Z

Here is a perplexing thought experiment (albeit sadly impractical, but more as a matter of reasonable duration than anything else.) It serves as “intuition pump” about possible knowledge in quantum mechanics, and the limitations of the density matrix. This TE suggests maybe we can distinguish between supposedly "equivalent" (experimentally non-distinguishable) quantum mixtures. Say, we want to distinguish between a continuing, random stream of mixed circular-polarized individual photons (equal mix of |R⟩ and |L⟩ states, Case I) versus a stream of mixed linear-polarized (Case II.) These mixtures are considered “indistinguishable” and have the same DM representation. There are several, in-line components so I hope a diagram is not needed (but I will out of courtesy when time permits.)

First, the photons pass through two half-wave plates in series. Each HWP is free to rotate and serves as a detector of angular momentum (as per the Beth experiment etc.) These plates can't detect the angular momentum from passage of a single photon, but at some large number n (maybe in the millions, depends on sensitivity and note that ħ is very small) we will know that a given number of circular-polarized photons have passed. Important: even though HWPs increment angular momentum from CP photon passage, they do not "collapse" those photons into a mixture of RH and LH. A HWP preserves the amount of circularity of light but reverses its sign. Hence RH becomes LH and vice versa, and e.g. a linear state exits as linear (but orientation angle may change.) The photons then encounter a filter CF that passes only left-circular light, followed by a general photon counter D as detector. Filter CF is about as sensitive as the HWPs and we can measure its angular momentum changes too.

In Case I, sometimes (albeit rarely) we encounter a run of n right-photons in a row, where n is large enough to measurably affect angular momentum. All of this run are absorbed by CF, so a run of “no counts” is correlated with a subsequent find of increment by nħ in the angular momentum of CF. The HWPs show increment by 2nħ and -2nħ respectively (remember, the first one showed direct effect from the RH photons and reversed them, so HWP2 has a negative AM change.) In a case of n LH photons, we should get switched results from the HWPs, no change in CF (all passed it), and n counts at D. Of course, we need to know when to wait for enough angular momentum to accumulate for a measurement. This is hard, since we need to set aside a block of n photon shots and hope we're lucky to have such a run. It won't happen often!

However, a run of no counts in Case II can only come from some linear photons just happening to be absorbed in CF “as if” they were |R⟩ photons. One's intuition from QM is to expect originally linear photons absorbed at CF to be effectively detected "as" LH with the same effect there, but there are problems.The lost set of n linear photons had no net angular momentum expectation value, so it seems we violate conservation of angular momentum if CF increments as before. Also, the HWPs are not supposed to "anticipate" what will randomly happen later to photons that are still linear (superposed R and L states.) During this run, they should not increment AM like they would for genuine RH photons. (I think including HWPs is crucial to driving home the perplexing nature of the situation.)

Yet if CF is not affected as before, we can distinguish Case I from Case II (eventually!), which is supposed to be impossible. Furthermore, distinguishing the Cases means that the DM is an inadequate representation. This is a paradox, and it’s hard to know what would happen if tried. In any case, it shows the limitations of not considering special subsets of random collections – a shortcoming of much thinking about quantum (and other venues of?) statistics.

Ke$ha - We R Who We R

2011-03-10T01:43:00.000Z

My FQXi Essay About the Quantum Measurement Problem is Now Available!

2011-02-17T18:32:00.006Z

The Foundational Questions Institute (FQXi, the "X" is there perhaps to represent the unknown, or maybe extra effort to try and find out what this is all about) promotes independent research into the ultimate scientific "why" questions. One of the reasons we need FQXi is given below from their summary, from http://fqxi.org:

EXPLORING THE FOUNDATIONS AND BOUNDARIES OF PHYSICS AND COSMOLOGY

FQXi catalyzes, supports, and disseminates research on questions at the foundations of physics and cosmology, particularly new frontiers and innovative ideas integral to a deep understanding of reality, but unlikely to be supported by conventional funding sources.

The money quote as they say: "... but unlikely to be supported by conventional funding sources." Such sources are not likely to be much help to those like me who are"amateurs" in practical terms, whatever their abilities. (I do note there are other helpful groups, like the Society for Amateur Scientists.) One of the ways FQXi supports quality inquiry that is open regardless of professional affiliation, is through their periodic essay contests. The current FQXi Essay Contest wants answers to the question: "Is Reality Digital or Analog?" My submission to this contest was just accepted. The title: Our Non-Deterministic Reality Is Neither Digital Nor Analog: Experimental Tests Can Show That Decoherence Fails to Resolve the Measurement Problem. The paper itself is IMHO too long and maybe hard to format into this space, but here's the abstract and a link to the article (pdf download):

Is reality best described in digital or analog terms? In proper context, we are asking: what type of math is best for that purpose? However, I argue that our universe is genuinely non-deterministic, as conventional notions of quantum mechanics imply. Since mathematics is by nature deterministic, reality is not fully describable by any true mathematical model. The best answer to the original question is then, “neither – reality transcends mathematics.” It is argued that some popular attempts to avoid the quantum measurement problem, such as the decoherence interpretation, are flawed. The logical case for DI is flawed by the circular argument at its core. More importantly: some experiments are described, which could falsify the DI. If successful, they would show that we can recover superpositions supposedly lost to decoherence. Hence our finding definitive experimental outcomes instead of superposed results is not due to the effects of decoherence. Those definite, exclusionary results show a genuinely indeterminate character of the universe.

The complete paper is available here.

Previous visitors to this blog will recognize that this paper deals with one of my controversial pet peeves: the idea that decoherence helps solve the quantum measurement problem. My previous post about the subject, Decoherence Interpretation Falsified?, generated lots of intense discussion. Please, hop on over to FQXi and tell me what you think.

A Note About the Fundamental Relationship Between SRT, GRT and the Equivalence Principle, and QM.

2010-10-25T01:55:00.001+01:00

Much effort is put into "deep" thinking to show the relationships between various aspects of theory and our world. Sometimes it can be done rather simply. Years ago I conceived the following little thought experiment in "comparative physics" (imagining the implications of laws being otherwise.) I don't have any idea who else might have also etc. Let's suppose light propagated "ballistically" like in the Ritz theory. (That means c' = c + v, so the speed of light is like a bullet in classical physics. It clearly would not be a constant for all observers, nor like the ether theory where c is relative to a pervasive, fixed medium.)

Now let's apply ballistic light to the equivalence principle: we have a source at the bottom of an accelerating chamber, at some frequency ν. Since the light is ballistic, each pulse takes the same time delay to catch up to the accelerating "top" end. That means there is no Doppler shift of frequency, even though there would presumably (depending on just how the Ritzian theory handles light) be a loss of energy equivalent to the change in gravitational potential. This situation may be acceptable in terms of classical physics, but it won't do for quantum physics: if each pulse or photon carries a certain energy, and the energy is diminished by climbing up the relative g field, then the frequency should be slowed the same proportion according to U = hν. Note: I tend to use "U" for energy because I like to save "E" for electric field.

Hence we see that SRT, GRT/EP, and QM form a sort of triangle of consistency. We (or Nature) are not free to just, say, substitute classical velocity addition for light and expect things to stay the same in other areas.

Why Petraeus Spoke - The Daily Dish | By Andrew Sullivan

2010-09-10T22:55:00.000+01:00

Why Petraeus Spoke - The Daily Dish | By Andrew Sullivan

Jaron Lanier Inspires This Takedown of AI, via Modal Realism

2010-09-02T20:14:00.004+01:00

There is a glaring problem with the idea that all human mental processes (not just thinking as such) can be modeled in terms of computational intelligence, etc., like computer programs.  Computations work with numbers in effect, and can't represent anything that isn't some sort of mathematical structure. Well, as modal realists have explained: the very idea of substantial existence ("real stuff" being distinct from Platonic forms) cannot be coherently defined and explained in strictly logical terms. We not only can't explain why some possible worlds, have a special trait called "really existing" and others don't, we can't even explain what the distinction consists of to start with. Indeed, we speak of the "existence" of defined configurations of numbers and shapes. Hence thinkers like David Lewis said all such worlds "exist" with equal standing.

This leads to the IMHO hilarious irony for "materialist" (?) thinkers like Dan Dennett: if our minds are only computational, then we can't even conceive a "material universe"! (Part of Dennett's assault on ideas like qualia and phenomenal sense-data is to tease their ostensible realness by saying they're made of "figment."  Well, as a tweak to Dennett I will  use the term "mysterial" for the alleged special property or "stuff" that imbues mathematical models in the MUH ultimate ensemble and makes them "really exist" - like ours is intuited as - instead of just being "models" like for if I wonder what physics is like if space had 23 dimensions.

Note that the thinking done in a model simulation is just like that in a "real world" -  if both are defined in AI terms.  Hence, the AI entity can't even frame the thought, "I am a material being and not just part of a program simulation or  Platonic structure of math (as in MUH.) It is ironic, that those who believe in AI concepts of human thought *have to be modal realists* to be honest and can't even be genuine "materialists." They implicitly don't believe in a way to conceive of substantial worlds being distinct from the mathematical process itself (although most don't realize it and continue to pretend they can make the distincion.)  Hence, all such worlds exist and there is no point in "physics" or materialism per se.  Even all cartoons would be real worlds.

Jaron Lanier, philosopher of mind and cybernetics, made a similar point (awaiting cite here).  His was more on the order of, a mind wouldn't need to be embodied since the Platonic representation would be equivalent.  If so, then all those minds have the same thoughts and experiences we do just "as the same math."  It is sort of like the brain in a vat, except this time the question is: are my thoughts happening in a "real material brain" (at all, anywhere!) or am I just the pure thoughts themselves?  I take this to the next level: not only would the mind not know or be able to find out whether it was a material manifestation or not, it could not even have the intelligible thought of what the difference meant or consisted of!  I suggest checking Lanier's new book You Are Not a Gadget.

Note that we have Bayesian expectation problems about own in such a case: we'd be more likely to be in a world that  was just coherent enough to create us, but no better (and not inclined to stay that way - since changes are of course "describable" features of a concept world too!)  See below re Marcello Gleiser.

Neither can we logically define "real flowing time" as a special way for reality to be, distinct from simply there being a configuration of points and lines (world-lines) in a "space" of four-dimensions. Yes, we *represent* time events in math, but there is no definition of it as a distinct entity, no mathematical way to point to the "t" in dx/dt and say, "That is some special, qualitatively different trait and not just another axis in a coordinate system; in kind like the "x". Yet somehow our minds grasp or profess these distinctions, as they do the idea of "consciousness" being special.  I don't think that's a coincidence.

And if a CI/AI proponent is going to gripe that our minds are computational and that "consciousness" can't be logically defined or explained, then neither can "real flowing time" or even the idea that for example our thoughts happen in "real material brains" and not just some Platonic math structure - as I explained in amplification of Lanier's point.  I call this dilemma "the brain as a fact" (as mere computations  distinct from "incarnation") in comparison to the old conundrum, how does any of us know he or she isn't really a brain in a vat being fed simulations Matrix-style.

Now, this argument doesn't prove that either AI/CI or MR/MUH is wrong, it just ties them together in ways that may not be palatable for e.g. conventional materialists who believe in AI (Dennett?)  My final word on this, as a non-believer in either of those perspectives:
I feel, therefore I (really) am!

PS if you have access to Facebook, check out the discussion at William Hodge's thread.  It's based on this
web article by Antonio Damasio at bigthink.com

I'm working on some format issues and may twiddle this post as per my custom.

This Time It's About You ...

2010-08-05T01:59:00.000+01:00

Why not a post for people to comment about what they want to? No worry about being OT, since you make your own topics. Have at it.

Zandar Versus The Stupid: It's Over, They Lost, Go Home

2010-07-08T20:23:00.001+01:00

Zandar Versus The Stupid: It's Over, They Lost, Go Home

Agree, disagree ...
One of my few non-physics posts, a link to another blogger about a social policy issue.

Many-Worlds Incoherence

2010-06-28T16:23:00.001+01:00

First, I understand how thinkers felt driven to MWI to avoid what they considered an otherwise insoluble (?) quantum measurement problem. But MWI is IMHO grossly fallacious and full of hand-waving snow-jobbery. The honest way is to admit we can't solve something, not to put forth a fallacious pretense because many thinkers just can't stand the alternatives. The key difficulty is in way things "split" and the attitude towards why and how we find quantum statistics. What we find is statistics, not a superposition of states. The statistics are based on squared amplitudes.*

So how does MWI deal with that? Well suppose there are two states, showing amplitudes: 0.6i |1> + 0.8 |2>. (Sometime I'll get around to improving the symbols here.) When we look we find either |1> or 2>, at respective probabilities 36% and 64%. But we started with two states, and no statistics. In WMI, neither states just "goes away" and the true outcome in the mulitverse has no preference - hence no genuine statistics of e.g. a real card game (heh, well a "real card game" as we imagine it in a classical world or collapsian world!) But there "are" only two states, even if we keep both and just somehow decouple them from each other. How oh how to get 36% of one outcome and 64% of the other? A mere split wouldn't do the trick, since I'd have equal chance of ending up in either outcome. After all, the amplitudes are just intensities, not actual sets of things. (And if they were, how many would there be in each set? Some arbitrary number? But if infinite such as Aleph null, no way to have the ratio.)

So the MWIers double-talked their way into some mystical, inexplicable sort of thickness of the wavefunction that somehow stands in for real statistics (like, authentic frequentism) that they call "measure." Everett imagined that one's "subjective probability" of ending up in a world depending on this "depth" (which BTW is not the amplitude, but its square.) We see an illustration on p. 172 of the silly and fawning book Schrödinger's Rabbits by Colin Bruce. Huh? That's just doubletalk. What the heck is that? If there's no unique self but both states |1> and |2> continue to evolve, then it isn't like the chance that one "self" will end up in world A or world B. They can't explain what they mean by that. Real quantum experiments do build up patterns the same as are generated by classical sources of unique outcomes.

Furthermore, this sort of "measure" is not the authentic probability measure in statistics. Maybe that fools readers about MWI into thinking a sort of inherent, hand-waving mystical equivalent of real probability (of how many of one v. the other) is mathematically rigorous and kosher. But I can't see any way to explicate the phony MWI "measure" and explain what's it's proponents claim is going on. For example, in Rabbits we see this quote:
"He has his own take on the question, does measure require large, maybe infinite numbers of each world-line to generate the correct probability ratios. For him, measure has no more meaning than it is postulated to have. You could perhaps (very loosely) think of it as a kind of tag attached to each world-line with a percentage value written on it, but certainly not in terms of huge stacks of each world-line."
Huh? A "tag" in which you just wave a wand and say "there aren't really more of one than the other, but it's as if there were." How?! This is an abomination, it's intellectual irresponsibility.

Another big complaint I have about MWI is about where in the chain of events, does the separation of states come about? Briefly here, I may have more later: In MWI, observation is not special. So, that juncture should not be the specific instigation of the separating of the states. Now consider a Mach-Zehnder Interferometer with photon entering and "splitting" at BS1. So shouldn't the photon state "separate" at the first beamsplitter instead of after recombining at BS2? Why not? That's supposedly a choice between taking the lower leg or the upper leg, isn't it? But if that happened, then the lower and upper paths are "separated" - so why should they be able to interfere later? Yet we know there's interference. I realize that issues of of decoherence complicate that, but it's food for thought. (I also have big gripes about the idea that decoherence explains collapse. Read more elsewhere on this blog, or Google for decoherence + "circular argument."

Schrödinger's Cat is still wanted, dead and alive. Reports of his liberation from uncertainty are greatly exaggerated. Is there an answer? I don't think so. I believe the universe is just not always amenable to our modeling hopes and capabilities. We should have the humbleness to accept that could be the case. It sure beats coming up with disingenuous "models."

*(Well, squared moduli, but the complex numbers just show relative phase. We can represent phases between real AC currents with complex numbers if we want to, it doesn't suggest anything about how "real" the currents are or not. So it's a canard to say "the WFs aren't real, because they "are represented" by complex numbers. Uh, no - not "are represented", that's just a choice. And if the WFs aren't real, what the hell is really there?)

Marcelo Gleiser Has a Point

2010-06-27T17:54:00.003+01:00

This post is based on my comment at Backreaction, under Marcelo Gleiser's guest post explaining it may be a mistake to pursue a final theory of "the" universe (or at least, to think it must be simple/beautiful etc.) I think Marcelo has a good point. Here I delve into the relevant and deep philosophical problems about "why is there something instead of nothing" and "why is it like this and not otherwise." (We should add: is "something" even clearly defined - a point well made by the modal realists.)

We don't have any a priori notion of why "reality" should be like this or otherwise. For deep logical reason I've noted before, I don't see how we can. There is nothing in logical analysis that can "bless" some mathematical constructs with a "right to life" over others - ie, to be incarnate in the special manner we feel that we are. To be, as Madonna put it, "living in a material world." (I like to say, it's like number 23 specially existing also as brass numerals "just because", despite being just another number ...)

Many thinkers cogently argue we can't even make that distinction. I think that collides with our basic feeling of being alive etc. but it is near impregnable as a strict logical critique of material realism being coherently distinct from abstractly descriptive and totally unselective modal realism.

Hence some believe in MUH: that all structures in the Platonic mindscape exist (logically wide-open, a far bigger set than even the wildest string-theory landscape etc.) If so there is little point in looking for a fundamental theory that makes sense or is beautiful etc, because we are just in a possible world that allows us to exist.

However, that presents deep Bayesian expectation problems. If that were true, our greatest expectation would be living in a universe just orderly enough to get us in this condition and to this point, and no more so (because there are so many more ways to do that than to be very neatly consistent, with identical electrons and laws that don't change over time etc. in various odd ways.)

So no one knows what's going on or why it should be or be like this. I think there's some "management" in the sense some ultimate reality has some intrinsic goals or even purposes like beauty and life-friendliness, but it would be wrong to impose that as a working assumption. BTW that would not have to be like a person, FWIW. So: find a TOE that works if you want, but be aware of the logical problem of justifying it existentially.

How to Get "Free Energy" Out of an Expanding Universe, Maybe for Real

2010-03-04T18:50:00.000Z

This may come as a big surprise to some folks, but it is acknowledged that energy is not necessarily conserved in large-scale GR. I once thought of a paradox about that: Have either an infinite or closed hyperspherical, now-expanding universe. Let's say it is filled with a bunch of devices (acting like "galaxies" in cosmology) in a closed Cartesian array (i.e. like integers in x, y, x.) Have them connected together (as "given") with elastic bands. Since the elastic forces on each object cancel out, the spatial standards of the universe and these objects can retreat from each other without being "held back." It's as if no bands, just gravity, right? But as this universe expands for awhile, the bands can accumulate whatever amount of elastic energy they can hold from W = (1/2)ks^2 (for some duration.) Note that if we want to avoid complications from elastic stress terms, we can imagine connecting cords used to turn generator rotors around as the cords unwind, etc.
(Similar recently posted in comments at "Gravity is Entropy is Gravity is..." Sorry to Bee, I should have linked to here instead of spilling it there.)

This makes a problem of sorts about energy conservation. It may already be accepted that such things are possible, given the acknowledged issues with CoE in GR, but wouldn't you be surprised if this could work? It seems so much like that crank stuff that just is supposed to be possible.

How the word "interference" causes confusion

2010-02-10T13:43:00.000Z

It is good to check on whether some terms used in physics are "well posed" and do their jobs right. I believe one of the unfortunate, sloppy semantic habits in physics is use of "interference." The word came from observation of light and dark fringes in e.g. double-slit experiments. This can be explained by superposition (amplitudes add linearly) and squaring of summed amplitudes to get intensity. The classic experiments reveal a vivid depiction of this principle, but led to careless semantics that were wrongly tied down to the original context and to superficial demands of visible manifestation. For example, if the phases between waves changes around for various reasons, or they can't match up in a well-ordered or stable way (different frequency or polarization etc.) people loosely say "the waves don't interfere anymore." But of course the waves still superpose everywhere, the result just isn't a stable or evident pattern over time and space.

And as for polarization: yes, x and y polarized light do "interfere" in the genuine technical sense, properly enlarged to mean vector addition and not just "amplitude" as a scalar. Add x and y light in phase: we get a definite 45 degree wave. If added at pi out of phase, they make a 135 degree wave; or circular etc. in other phases. We can even get a pattern of varying polarization type on a screen from little x and y sources acting like slits, but it all has the same amplitude. Should we call them "state-fringes" or "type-fringes"? (And yet, we could pull back a bit and choose to pick out the x or y with filters. That seems to offer 'which way' information in a contradictory way, reminiscent of issues raised by the Afshar experiment.) But since that isn't the historically conditioned intensity fringes, this led to careless and misleading talk that "orthogonal polarized states don't interfere."

This confusion about "interference" plays a major role in the fallacious claims that "decoherence" resolves the puzzle (to whatever extent) of collapse of the wave function by in some sense converting superpositions into mixtures. There are many faults with that interpretation. Briefly, it is a circular argument since it introduces at the outset what it is trying to explain: collapse is required as unacknowledged "selector" to introduce quantum statistics into the density matrix along with the classical statistics. Then such a hybrid DM is used to seem to explain the collapse it already incorporated.

DI proponents often say that "decohered states don't interfere anymore." That harks back to old, careless classical talk of vividly evident fringes, which are equivalent to the orderly statistics of ensembles with consistent phase relations. First, REM that classical interference wasn't about "statistics" at all, but amplitudes and their squares per se. The conceptual models of QM say the superpositions always exist together until "collapse" somehow both concentrates and isolates a given state, allowing for statistical outcomes. Second, it is misleading to talk of "interference" when comparing waves to each other that occur in different instances in an ensemble of trials. Superposition is about waves existing and adding together here and now, not a collective. Third, once we understand the universality of superposition, we realize that claim of non-interference is actually false. Instead, decohered states do "interfere" in the technically correct sense of following the superposition principle. If the phase difference is phi1 one time and phi2 another time, so what. The states still would superpose accordingly each time. That is regardless of whether the overall patterns made either by their squared sums in any one case, or by the statistics from collapse applied to ensembles of such superpositions was coherent and orderly; versus whether the patterns (merely) simulated the behavior of genuine mixtures.

Proposal summary: can we find circularity of a single photon along a range of values?

2010-01-31T00:45:00.003Z

Suppose a photon is a superposition of e.g. 0.8|RH> and 0.6 |LH>. Standard QM says we can only test for the 64%/36% chance of getting full "RH" or "LH" as projected eigenstates. But let's use mirrors to send a single photon round and round many times through a pair of half-wave plates ("pair", to revert the photon to original state for entry.) HWPs flip the rotation of polarized light. They accumulate angular momentum thereby (Beth experiment 1936 etc.) That AM is proportional to the circularity of the light times the number of photons. Hence it shows intermediate values for elliptical light etc.

From particle indistinguishability: the same photon going through each HWP many times (being reverted to original state each pass through two HWPs) should have the effect of the same number of like photons, going through once each. Hence, I argue, we should get a range of results for circularity (intermediate for elliptical, no net AM change for linear, etc.) for one photon as for many. But that contradicts standard theory, so what happens?

Decoherence Interpretation Falsified?

2009-12-31T22:00:00.113Z

[Note: this post has been revised here and there, off and on. I gave up specifying each change in []s; just NB that it's been changed. The essential point is the same, but with a major new caveat about just where the conversion from superposition to "mixture" is imagined to take place. See also note below about the controversy provoked at another blog. Perhaps most important: I am defending orthodox QM from the Decoherence Interpretation, not challenging it with some alternative theory etc. Traditional QM says that wave functions continue to evolve together in superposition until some mysterious measurement process selects and localizes an eigenstate - as per the projection postulate. Hence, we have no idea why Schroedinger's Cat doesn't stay both alive and dead. DI enthusiasts like W. Zurek say that decoherence gives an "natural" explanation (in some sense which is often unclear) of why we don't find such macro superpositions. I propose that my experimental setup would distinguish the two ways of imagining the evolution of wave functions. Hence, they would no longer be mere "interpretations" - but readily subject to experimental testing. I continue to refer to DI as "interpretation" for convenience and by tradition. I also just posted similar to sci.physics and sci.optics.]

"Decoherence" is both a real phenomenon, and part of an interpretation purporting to tell us why don't observe macroscopic quantum superpositions like Schroedinger's Cat. ("Explanation" is too strong, often avoided even by supporters.) Some would say, the DI avoids the paradoxical quantum measurement problem of "collapse of the wave function." This supposedly comes about because, roughly, decoherence and entanglement of the phase relations between superpositions (like "dead" + "alive") effectively converts them into mixtures (like classical particles, roughly speaking.) Some say the unactualized alternative slips into another universe. (All easy to find online.) I don't agree, making rebuttal at other posts here and elsewhere. I am heartened that Roger Penrose made similar complaints at e.g. Shadows of the Mind, and critics like N P Landsman have picked at various loose ends and problems. Yet few DI advocates are swayed by critics. As Landsman writes: "Like capitalism, decoherence seems here to stay."

I thought of an experiment we could do to demonstrate the weakness of the DI. It shows we can recover information that would have been lost if indeed "decoherence converts a superposition into a mixture" as some have IMHO too-boldly proclaimed. That's better than just arguments per se against DI. Briefly, it shows that true but decohered superpositions would produce one set of results in this system, but a true mixture (or anything, by definition, "indistinguishable" from a mixture) would (if present where detectors are usually deployed) produce a different set of results. Hence they can't both describe the situation. Since I gather there is agreement ("conventional QM") that the first outcome is the correct result, that causes difficulties for the DI. (Note: the importance of this argument may go beyond DI, if such information "should" simply have been "lost" period, apart from any interpretative framework.) The predicted outcomes are already derivable through known quantum optics, so I assembled a case from existing knowledge. (It still should be empirically verified.) I hold therefore that the "quantum measurement paradox" remains unresolved, perhaps the deepest mystery about the nature of our world.

My proposal is fairly easy to describe. (The math is less simple but not hard to work through.) I use some ASCII conventions for now from tech issues, so "*" for multiplication where needed etc. Synopsis: even if we completely scramble their relative phases over a history of instances, and then recombine split waves; we can recover their original amplitudes when the secondary outputs are recombined again in a subsequent beamsplitter. This would not be possible from a genuine mixture, as opposed to an apparent one as the case below is revealed to be. Hence decoherence does not always convert a ensemble of superpositions of random phase into a mixture.

Consider a Mach-Zehnder interferometer (as shown above) with a first beamsplitter BS1 that does not [was "need not"] divide intensity equally. For sample values we'll use intensity along bottom leg L1 = 64% and top leg L2 = 36%. Hence, relative amplitudes are: a = 0.8 and b = 0.6. We use a 90 degree (i) phase change at each half-silver and treat full reflections and transmissions as not changing phase (per custom of Roger Penrose, OK as long as consistent.) We can represent what happens to a single photon entering BS1 as: transmitted state a|1> goes along the bottom, and reflected state ib|2> along the top.

However, suppose some interaction/s introduce a new phase shift φ to the wave in L2, as complex angle. [Shift φ was "u" before font change, and added cleanup of this section.] That changes the phase in L2 to iφb|2>. Then we recombine the beams at BS2, which is a 50/50 splitter/recombiner. It combines relative phases as did BS1, with output from the lower face of BS2 called channel CA2; and from the other face: channel CB2. (This keeps numbering consistent and allows easy reference to original output from BS1.) I will just use "s" for sqrt(0.5) ~ 0.7. A half-silver mirror reduces intensity to 1/2 and thus multiplies amplitude by s. Hence [equations adjusted to new phase standard, pardon some earlier untidiness],

(1) CA2 superposition = s[(ia|1> + iφb|2>],
CB2 superposition = s[(a|1> - φb|2>].

We find intensity (and photon statistics if we collected at this point) by inserting into

(2) I = A^2 + B^2 + 2AB cos theta,

showing involved net (superposed) amplitudes A and B that are comprised from combinations of |1> and |2>. If a = b and u = 0 and thus net phase between legs is i, then the intensity out of CA2 = 1/4 + 1/4 + 1/2 = 1, and out of CB2 = 1/4 + 1/4 - 1/2 = 0. That is equivalent to bright and dark fringes. If a = 0.8 and b = 0.6, we get CA2 = 0.32 + 0.18 + 0.48 = 0.98 and CB2 = 0.32 + 0.18 - 0.48 = 0.02. Hence, lower contrast fringes. If there is a further phase difference introduced between |1> and |2>, then the relative intensities change accordingly as can be calculated (but still must add to one of course.) If we introduce photons one by one into such a device, the statistics of detection are the same. To make the argument and experiment about "the wave function of a single photon," that is what we'd do. (Despite some states of unclear photon number, an effective "one photon at a time" *can* be introduced into such a device. It means basically, one net "click" from arrays of ideal photon detectors covering all avenues of escape.)

Now, what if we introduced complete decoherence into the picture, in a manner like Chad Orzel uses (and similar in effect to found elsewhere) to model decoherence in e.g the post at http://scienceblogs.com/principles/2008/11/manyworlds_and_decoherence.php ? (We had quite a debate there and elsewhere. I admit being testy sometimes but think I'm in the right in the end. [I add, that Chad seems not to be an advocate of the strongest claims about DI. Commenters suggested also http://www.ipod.org.uk/reality/reality_decoherence.asp by Andrew Thomas.] Now we have to integrate over a range of randomly varying φ, and divide by that full range to get the mean value. This is easy for a uniform distribution of phase differences, since

(3) integral (Eq. 2) d theta = (A^2 + B^2)theta + 2AB sin theta + C.

We pick a range that completely scrambles the phases ("complete decoherence") such as between +/- pi, substitute into the integral, and divide by the range 2pi. Then (since sine of each limit = 0) we find the result out of either channel is simply A^2 + B^2 = (a^2 + b^2)/2. This destroyed the statistical interference pattern of photon hits, even in the case a <> b. The output acts like a "mixture" of photons each exiting BS2 from either CA2 or CB2 with 50/50 chance, but not "both at the same time." [fixed poor wording]

A strong DI follower would say (following an ensemble interpretation): what would have been a coherent superposition is now a mere "mixture" despite being comprised from interacting waves. They would follow an essentially positivist yet post-modern tack that "we couldn't tell the difference, so the output should be regarded as being the same as a 'real' mixture." Hence, somehow we don't have to worry about why a hit occurred at the CA counter instead of the CB counter, when under old-fashioned (!) QM there are still wave amplitudes (usually) at both counters - and a mysterious collapse was still needed to sweep the whole big mess into one little atom that absorbed it all. Their argument sounds circular (what causes any "statistics" in the first place instead of distributed amplitudes, to allow comparing one set of stats to another etc.), and I'm fortified by seeing similar misgivings from e.g. Roger Penrose. But DI is popular because it lets the perplexed brush off their worries about paradoxical features of reality. I can't blame them for wanting to try, but Nature is what it is ...

So, is the DI view really apt - even in its own terms? I think not - but [added] that depends on a crucial distinction. Instead of intercepting photons and collecting statistics right out of BS2, let's instead recombine outputs CA2 and CB2 into BS3. Since amplitudes are again reduced by s and reflection multiplies angle by i, the new output that combines the beams is like this:

CA3 = s[iCA2 + CB2] = s[s[(a|1> - φb|2>] + s[(-a|1> - iφb|2>]] = -φb|2>
CB3 = s[CA2 + iCB2] = s[s[(ia)|1> + iφb|2>] + s[ia|1> - iφb|2>]] = ia|1>

Note that since φ is just a variable complex angle, the amplitude ratios are the same each trial from BS3, and therefore the final average over a range of φ will reflect this as well. So, from BS3 we recover the respective original amplitudes a and b (and hence, same original statistics) that came out of BS1! Of less importance IMHO is that we can later recover the phase relation, that entered BS2. That information was hidden in the relationship between the wave outputs from BS2. It would not show in a raw statistics of hits if we used detectors right around BS2 instead of letting the wave continue on through BS3.

This result could not happen from a mixture that came out of BS2, since photons that came from either CA2 or CB2 but not "both at the same time" would just scatter as individuals from BS3. Their statistics from BS3 would be 50/50 output instead of a^2, b^2. [However, if we imagine that "a mixture" enters BS2 instead, then there is no discrepancy.] This does demonstrate the continued wave nature of the output from BS2, despite total mixing of phases which in some perspectives destroys the superposed character of the photon wave function. The recovery of BS1 exit amplitudes from BS3 shows that. Does one of the deep mysteries of reality remains a challenge?

IMHO, Bye bye decodance! [snark snipped for peaceful purposes!]

--
Regards, and Happy New Year (and New Decade, so they say !)

Neil Bates

[Notes: My post provoked an unfortunate reaction at another blog. It was acerbically critiqued at, with key comment here: Neil Bates Owes Me $160. In that comment Prof. Chad Orzel of Uncertain Principles sci-blog admitted that my math was not wrong as he had claimed. He still doesn't think it proves any good point about quantum measurement, and he may be right (not that it's always clear what the implications of a quantum experiment are anyway!) But readers should decide that for themselves.

Even though him checking some things could have avoided misunderstandings, I don't blame him for most of that. First, my presentation was not adequately clear for various reasons. Also, it was not fair for me to fish for a response from him (in the hope of garnering attention and "publicity") as even some part of referencing his former posts. I didn't mean to anger anyone or make a feud. Sadly it did, and I apologize for that. My main reason for noting his MZI example was it corresponding to how I could show there is a distinction between superpositions and mixtures at the critical juncture. Also, it or similar is in his new book which is selling well and deservedly so.

As to where the "mixture" is to be imagined found. If we can tell the difference between a real mixture and the actual superpositions, even after decoherence - then the claim "there's no way to tell the difference" is wrong. Chad Orzel used the similar phrase "since the end result is indistinguishable from a situation in which you have particles that took one of two definite paths" in the above link.

However, he was imagining a mixture occurring even before we recombined into BS2. Now we have to ask: in which treatments of this problem, would the output from BS2 be considered a mixture? Well, in order to have any significance to the measurement problem in the case of detectors just past BS2 - the mixture would have to be present outside BS2. But then, the result (50/50) would not agree with this experiment. OTHO - (and this is a supreme irony) - if you take the mixture as present before entering BS2, then entering photons would turn back into a superposition anyway! In that case we'd get my result, but it wouldn't help show selection at detectors. So DI either fails to be relevant to detection issues, or it is factually wrong.

BTW I wish no continuing "feud" as such, just fresh looks at this problem. tx!]

With Regards to Rudolph

2009-12-26T01:03:00.003Z

My mother recently wrote this poem. She was expecting a "yes" vote on HCR but not positive of the outcome or time of vote. Well, it went through. It's IMHO debatable just how "good" it is, but indeed it is historic.

(BTW, belated Merry Christmas to all, interpreted in the manner of your choice.)

With Regards to Rudolph

by Joanne Bates

Barack, our first black President,
Figured he was Heaven sent.
Vowed not to follow the norm,
But to pull off Health Care Reform.

Obama, with your brain so bright,
Won't you lead us in this fight?

On a snowy winter's night
Flakes were falling fast and light.
Demos snagged the 60th vote,
Now Repubs can't rock the boat.
But will the abortion concession
Reconcile with House legislation?
A final vote on Christmas Eve
May decide what gifts we'll receive.

Obama is happy but wary,
Hoping to finish work in January.

We are weary of this drama
But one thing is sure, President Obama.
With Health Care Reform victory
You'll go down in history.

Happy St. Puketricks Day or St. Pooka-tricks Day!

2009-03-17T19:38:00.004Z

Hello all, however few of you there may be!
Depending on your proclivities, please have a Happy St. Puketricks Day or St. Pooka-tricks Day!
Well, to be more straightforward and "normal" (ugh) I could just say "Happy St. Patrick's Day" to everyone.

Enjoy/celebrate; don't drink too "liberally" I beseech ...

PS: Look up pooka/pookah/púca on the Internet etc. for fun ...

Open forum: dish against or defend many-worlds and decoherence theories

2008-11-23T16:05:00.004Z

Over time I've left many remarks (and many very recently) critical of many-worlds and decoherence theories at blogs such as Uncertain Principles, Quantum Pontiff, etc. I can be at bit of an irritant so I don't want to wear out the OPs that I criticize, many of whom indeed don't have time to follow up on my depredations. Here's a forum to discuss the problems of such theories, especially if you were debating with me at another blog. Do also check the previous post about "quantum stupefaction" which is sort of silly, yet may have actual implications for MW concepts and related.

"Quantum Stupefaction" pwns Many-Worlds!

2008-11-20T02:39:00.004Z

This is adapted from my comments to a thread about MW and morality going on at Uncertain Principles as well as a post to sci.physics, alt.fan.rawilson etc:

First, let me explain "quantum suicide" (c.f. quantum immortality, check Wikipedia. Later, I explain something even more perplexing.) If we imagine that only your conscious selves serve as possible carriers of what "you observe" as you split up into "many worlds", then you can do this: Set up the Schrödinger's cat experiment with yourself inside. That means, a radioactive nucleus decaying will cause HCN to flood the chamber, so the decay and you dying from it is a chance event and "not determined" by classical physics. In the many-worlds theory, each moment means the splitting of the universe into other universes representing possible outcomes (such as did or did not decay.) Robert Anton Wilson wrote about Everett-Wheeler MW theory, among other things, in the speculative/fabulist fiction work Schrodinger's Cat Trilogy.

Well, there is always a chance you will survive even after many half-lives of the death-dealing source. Hence there are always some "yous" which can enter some "branches" of MW. Sure, "you" die most of the time but the conscious survivors are the ones saying "Hey, here I still am after all this time." Hence you can never die! If you get into the chamber, you will always "still be there" wondering WTH happened and how you survived millions of half-lives of an unstable nucleus. You can even walk out later, by having a temporary period for the nucleus to be allowed to affect the death-dealing device.

BTW this does not depend on whether consciousness collapses WFs or is "weird" since any sentient being can only notice its survival, right? It is eerily reminiscent of the "multiverse" (that has differing physical constants like alpha) idea of explaining anthropic fine-tuning. However, I think that outcome ruins the whole "proportional" argument that sophistrizing MW advocates put out to imply that each of us has the same "expectation" of outcomes in MW as in ordinary collapse. (BTW I believe "decoherence" is a failed, circular argument for making "apparent" collapse work out OK. Note that use of "apparent" yadda is a warning sign of post-modern psychobabble.)

Note, it is quite possible to build this device. I challenge any supporter of MW to have the balls/etc. to actually get in one. We can even arrange a cash prize waiting outside of $10,000,000 or so, that you can only collect when the temporary danger period is over. Since we might set up a chance of only say 1:10,000,000 of a "you" getting out alive after the danger period, it is an eminently reasonable bet for the rest of us. But since you expect to experience surviving and winning, why not show your "faith" in MW and come out a multi-millionaire to boot? Not only that, but you can see the amazed expressions of the versions of us that see you walk out alive! We'd never live it down, heh.

Well, that's already rather weird, but let's take it further into the twilight zone: Suppose we change the quantum suicide scheme so it doesn't actually kill you if the agent nucleus decays. Let's say, it injects you with something causing total but temporary unconsciousness. Let's call this "quantum stupefaction" ;-) Well, the logic regarding "awareness" should work the same way at first. "I" expect to be one of the tiny minority that remains awake and knows it, for how can that be "experienced" any differently than if most of me actually died?

Yet after awhile, all the other me`s start waking up and there are so many more of them then those who never got put to sleep. So, now what? If "I" can "expect" to be able to say, "How fortunate, I didn't even have to become unconscious" what then takes over the expectations when the others wake up? So what do I really have to "likely" look forward to: not even being knocked out at all, or being put asleep and then waking up? The first option follows the original logic of quantum suicide, but the latter follows what we expect from the total chance of being put asleep and then waking up. Quantum [non-]Suicide was at least a potentially viable if wacky notion, but I think this further refinement makes the whole idea (and by extension, many-worlds "theory") look silly.

2008-06-03T19:57:00.001+01:00

Here's a paradox about work-driven buildup of mass and conservation of angular momentum. Give it a try.

In everyday mechanics, in order to redistribute mass we have to actually move it from one place to another. However, the equivalency of mass and energy complicates that issue. For example, we could convert the impact energy U (I use U so E can be a field) of a falling mass m1 hitting the floor into mass m2: m2 = m1gh/c^2. Hence potential energy can of course be converted into mass, not just actual energy. Note that we could violate conservation of angular momentum (sum of r cross p) if we could just shift mass effortlessly (no forces, like "teleportation") even if the total did stay the same. That's because in a frame of ref. where the mass is moving, its linear momentum vector would be shifted sideways to itself. (Thus changing the r cross p with no compensation.)

I am aware of various sorts of compensation etc. in apparently paradoxical situations, but I imagined a thought experiment that I can't solve to maintain CoAM. Have a line charge along "x." Have also two square "solenoids" S1 and S2 with same sense of current and sides equal to Y. All three lie in the same plane, with one solenoid centered at coordinate y1 and the other at y2 = -y1. (Being lazy at constructing ASCII diagrams has sharpened my verbal descriptions.) One one side of each solenoid , the current is being "pushed" in the direction of field E, and on the other, the current is fighting against E. It helps the following if you imagine not a literal current of electrons, but a mechanically driven belt of little charged bodies: On the side of each where E is favorable to the "current ", mass-energy builds up at a rate dm/dt = IEY/c^2. On the unfavorable side, mass-energy is lost at a rate dm/dt = -IEY/c^2 (if abs. vals used for the variables.) That already looks like a problem per the previous discussion, but we usually consider such issues solved by the AM etc. of the fields. (Note Feynman's paradox of the charged wheel, etc.) Some say there's an "energy current" between the sides (see Taylor/Wheeler, Spacetime Physics etc.) , but how does that really work?

However, the real test (?) of there being a problem is whether it is reversible. Hence, let's move S1 and S2 respectively away from the line charge at low velocity. Now, once they're accelerated, we have for the rate of change of angular momentum L: dL/dt = rv dm/dt, using proper signs in vector notation. If you check, you'll find that there's a net change of L as S1 and S2 move to a distance from the line (same sign of build ups at opposite sides as seen by observer looking at plane, times opposite r and v, gives same dL/dt for S1 and S2.) I can't find an influence on the wire from their motion that would compensate the right amount. Then, at a distance, you can switch the direction of current in the solenoids and again no net effect. Then, move S1 and S2 towards the line charge, and reversed dm/dt and reversed v makes the same dL/dt as before. Lather, rinse, repeat; I don't yet see how to foil it.

Give solving it a try, you may even get help from offbeat angles like stress corrections in the solenoids etc.

Happy Saint Patrick's Day!

2008-03-17T18:05:00.001Z

Have fun, but take care of yourself and everybody else ...

It's Talk Like a Physicist Day!

2008-03-15T00:33:00.004Z

Greetings ....

Well, (in my time zone, folks, and still in many others!) it's Talk Like a Physicist Day, Pi day, Bee writes about the PI gym (at the Perimeter Institute) albeit two days earlier, and Albert Einstein's 129th birthday! First, one cool way to talk like a physicist is to never refer directly to "zero" or "one." Instead, say the quantity is vanishingly small, or vanishes, and say "unity" instead of "one."

Second, here's the weird little story I heard years ago about someone who got in trouble for talking like a physicist, and was one as well (assuming it really happened ...): If you run a red light and it goes to court, beware of trying the apocryphal (?) tack of claiming that Doppler blue shift made the red light look green (or yellow.) Supposedly the physicist who posed that excuse some years ago faced a scientifically literate judge, to his dismay. The judge calculated that the driver had to be going around 100,000,000 mph, and fined him accordingly! It’s not always wise or clever to talk like a physicist, even if you are one.
(Does anyone remember when/where they head that one?)

A quantum measurement paradox: the reallocation by measurement problem

2007-09-27T20:06:00.003+01:00

I spend lots of time thinking about puzzling foundational issues in quantum mechanics (search for "quantum measurement paradox" and I often show in the top five), and do I have a deal for anyone else like me. I have been thinking of this problem for awhile, and the post Many Worlds, Many Headaches on Uncertain Principles stimulated me to post a version of it. If you want something really strange and "after the fact" about measurement, please consider my following proposal: In a Mach-Zehnder interferometer, insert a gray filter G into leg L2. Given a traditional stream of light, that alters the amplitudes delivered to the beam-splitter/recombiner R. With a 25% transmitting filter, the L2 amplitude is 0.5 of that in L1 (which itself is sqrt (0.5) of the original pre-split input.) Hence, with symmetrical R, we get an output mix rather than all A channel output. We can adjust R to a compensatory split so that output is again all A channel. Using individual photons, the statistics should be the same. FEL optical physicist Michelle Shinn of J-Lab agreed with me that's so, despite the weirdness of the photon's wave function in L2 being attenuated by the chance that it could have been absorbed, even if it wasn't (well, superposition of absorption and not-absorption in the dye molecules in the filter, etc, right?) Also, as G gets darker, this has to be the limiting factor approaching the results of an opaque stop in L2. But what happens if we can find out whether a photon has been absorbed in the filter?

Consider an opaque stop: the stop clearly "reallocates" the WF all into L1, in a manner akin to the Renninger negative result problem, even though no actual "measurement" is taken। But there, a photon will just never get through. However, G may or may not absorb a photon, something we can in principle check on (There are semi-transparent optical detectors, no? Just consider film for example.) Now, while G is still "deciding" (in a state of superposition) whether it will absorb or not, it makes sense to consider the L2 wave to be attenuated relative to L1. Maybe that's the normal time scale to allow interference in R before that happens. But, after a certain time, if we check G carefully to look for evidence of absorption, it should be settled: absorption or not. If it did, there's no paradox. But if we find "no absorption," why in the world should the L2 wave continue attenuated? The measurement result was "no" for G, so there is no longer "a chance" that the photon might end up there. The filter might as well have been clear glass, right? If so, then the interference at R would be different (it would follow normal equal-balance rules instead.)

The really weird thing is, that reallocation should take place as soon as the absorption/detection issue is settled. If so, we could manipulate the pattern of hits (with sequential photon shots) at the output by looking for evidence of absorption in the filter, which would start rearranging the WF as per Renninger etc. In principle, there's nothing to stop this from being a true FTL signal, since manipulating G (or perhaps the distance to R) causes noticeable effects (not distant signal correlations) at R. Sure, that's problematical, but you can't just blow off the supposed effect on the WF of the negative measurement in G, can you? Have fun.
(I also just put this up on sci.optics, sci.physics, etc.)

Not Even Wrong?

2006-06-29T03:07:00.000+01:00

Science In Crisis: Not Even Wrong

This is an interesting take on a "scientifically incorrect" jeremiad: that string theory/s are not really the it thing. (Well, have they produced testable predictions yet? Or rather, successfully tested predictions? Actually, the millimeter dimension theories did, but we didn't find the sub-mm deviations from Newton's 1/r^2.) Check out the post, and the book it's about (Peter Woit's new book, Not Even Wrong: The Failure of String Theory and the Continuing Challenge to Unify the Laws of Physics...) when it becomes generally available in a few months. While you're here, check out my synopsis of how I showed that space must have three large dimensions without needing string theory etc. - just self-consistency for extrapolated electromagnetism.

- NB

Why 3-D?

2006-05-06T03:02:00.000+01:00

Hello folks, and long-time no-be-seen.

I recently listened to an interview on Public Radio with physicist Lisa Randall. She is a top theorist on foundational theory of why the universe is the way it is. That means string, branes, and such. One of the venerable questions is: why is space three-dimensional? It may seem natural to have three dimensions of space and one of time, but mathematically there can be any number of dimensions (think of specifying points using 4, 10, etc. variables.) Physicists, including Lisa, say they can't see why space *had* to have three dimensions. (Check out http://arxiv.org/abs/hep-th/0506053 ) However, they have come up with reasons why three large-scale dimensions would be more likely to expand out of a larger set (usually thought of as 10 or 11) of original, perhaps tiny dimensions. Below follows a statement adapted from my post to http://www.radioopensource.org/the-holy-grail-of-physics/ in response to the interview, and outlining my own efforts to answer this question. (I’ll also find out if the automatic editing puts in links for me.) Also, happy Cinco de Mayo, late as it is!

I have been working myself on the question, why are there three *large* dimensions of space? (There are probably more, like a total of 10 or 11 space dimensions, but the rest are curled up very small or otherwise inaccessible.) After extrapolating electromagnetic interactions to spaces of other dimensions, I found at least two arguments:

1. In spaces with other than one or three dimensions, an oscillating charge does not project the same *average* field along the axis of oscillation as the rest value. That is due to two things: the combination of "projection" of its retarded distance - where it would be had it continued at the velocity it had when light left it - and the distortion of the field due to Lorentz contraction, which weakens it to
gamma^(1-N) the value it has at rest. N is the number of large space dimensions. (We also must take into account the Doppler shift of projection intervals. Heh, it’s not quite as complicated as it sounds.) Remember that the Coulombic electric field intensity is given as E = qr^(1-N) due to field spreading. This amplifies the effect of the oscillating charge’s apparent position being close (projected from approaching cycle) to a second “target” charge at rest. It increasingly swamps the weakening effect of the gamma factor as N goes above three and is incorrect when N = 2. That would impose a net force on a second "target" charge unequal to that on the oscillating charge, and violate conservation of momentum and energy. The one-dimensional case is ruled out due to infinite potential energy as is the 2-D case (why didn’t A. K. Dewdney realize that about the 2-D Planiverse?)

2. Let two charges be connected by a reasonably rigid rod. Then, accelerate the rod along its length. The combined force between the charges will be derived from the sort of considerations given in (1.), as the projected field of each charge catches up to the other charge. Then we must take into account the extra force created by the action of acceleration on the relativistic stress-correction to the momentum and energy of the rod. Only in three dimensions of space does that equal in net the effective inertia the charges should have given their potential energy. (In higher dimensions, taking the integral of f = q1q2/r^(N-1), that potential w.r.t. infinity is: -q1q2r^(2-N)/(2-N). )

I hope I can publish the full development of this before long. I don’t think anyone else has an explicit proof that N *must* equal three, only reasons it was more likely to form, or oddities like being unfriendly to life, distorted wave propagation (see Barrow and Tipler’s _The Anthropic Cosmological Principle_ for great discussion of this.)

Neil Bates

Welcome to Tyrannogenius!

2005-11-26T02:37:00.000Z

Hello, visitors!

My name is Neil Bates, and I welcome you to Tyrannogenius - the first post of my first blog. I'm just introducing myself here, and will have more to say later. However, to give you a taste...

1. I like scientific paradoxes, and I propose them too. Enter "quantum measurement paradox" into Google, and a thread I started on sci.physics.research (a quality, refereed newsgroup) comes up first. I'll describe the paradox in these pages later.

2. The great philosophical questions interest me greatly. I think that the unwit I call "Witlesstein" is one of the worst philosophers ever. Someday I will post a refutation of his undeservedly renowned "beetle-in-a-box" argument against private languages. (It's mostly an indulgence of logical positivism. Hey - can you logical positivists tell me what the operational meaning of "things continue to exist even while not being observed" is? Nor can we find out what happened yesterday because of quantum uncertainty, but we don't pretend things aren't a definite way to be today for the sake of the poor bastards of tomorrow who can't do a Laplacian track-back...)

Well, that's all folks 'til next time!