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FQXi FORUM
May 25, 2012

ARTICLE: Readers' Choice: The Many Lives of Hugh Everett III [back to article]
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Lawrence B. Crowell wrote on Oct. 6, 2010 @ 03:10 GMT
I tend to agree that the many worlds interpretation is contentless, as are so called nonlocal hidden variable theories. These may be useful in solving different types of problems, but there are not experimental prospects for testing them.

Cheers LC

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T H Ray wrote on Oct. 6, 2010 @ 22:03 GMT
Einstein might have liked the hypothesis as assurance that the moon is still there whether one looks at it or not. After all, who's to say that a one-way peek from another "world" is not dual to the uncollapsed wave function that we experience as a continuous flow of time in this one? It takes no leap of faith to reconcile a classical experience of time with discrete perceptions so long as one has no investment in that frozen moment; i.e., no fixed frame. In every world of the many universes, any moment is the least of all possible moments of that world. Therefore, time symmetry that remains a local property of our world is impossible in the evolving many-worlds.

Tom

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Philip Janes wrote on Oct. 7, 2010 @ 06:30 GMT
The Sep 3, 2008, talk by David Albert in the Perimeter Institute Recorded Seminar Archive goes into some depth about Everett's Many Worlds Interpretation.

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paul valletta wrote on Oct. 7, 2010 @ 12:51 GMT
Should not Everett be able to continue his work in another Universe?...or is his existence/death here in this Universe, multi_Universal?

If one can die in this Universe, then all Universe's that you split into must calibrate thier wavefunctions to this effect.

In standard shroedinger cat box experiments, what is the difference in weight before observation and after observation?

If shroedingers cat does not exist inside the box (dead), then if the box is placed on an accurate weighing system, the moment you open the box there should be a corresponding increase in the systems weight?

The simple probable outcome, QM speaking, is if one is alive in this Universe, then the probable outcome of you being alive in all other Universe's is zero.

Alive or dead, entangled or seperated?..to be alive in any Universe must be matched with being dead in all other Universe's?

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Lawrence B. Crowell wrote on Oct. 7, 2010 @ 17:02 GMT
Tom,

I think you got it backwards, time symmetry may exist in the many worlds, but along one eigen-selected path time asymmetry is locally apparent.

I think MWI has some working basis with respect to multiverse situations. The grand AdS spacetime, in 27 dimension in the Jordan 3x3 matrix algebra, or maybe 57 dimensions, in an E_{8(8)} model, time is symmetric. However, local regions have within the time arrow direction, say a Z_2 cyclic group of 2 letters, a time direction that is frozen into the local region. Each of these local regions are decoherent sets, similar to what induces the eigen-branching of the Everett MWI.

However, outside of spacetime physics or cosmology I question whether MWI has much content. At least with multi-verse situations there might be metric back reactions associated with generating a nascent cosmology. This would be horrendously difficult to detect, but in principle it could be. Gravity has this classical field realization, which has features not existing in other field interactions. So a standard many world eigen-branching is probably without measurable content.

MWI does imply that we all live a vast number of lives, which I estimate to be around 10^{70}, where this assumes only fluctuation branching inherent in the quanta which make us up. If we include the entire universe things are enormous. This would be 10^{22} quantum collapse events per atom in a thermal context, time 10^{80} atoms in the observable universe, time 10^{23} for the much larger extent of the universe, times the 10^{10} seconds we all live. This might be a grand total of 10^{135} possible life tracks. So this might mean that death is just a sort of restart button on the grand video computer game called the universe, we start over with the first quantum collapse event involved with our conception.

There are also alternate tracks to history, such as where Germany won WWII, the Cuban missile crisis turned into a nuclear conflagration, and General Lee planted the Confederate Stars and Bars over Lincoln’s Whitehouse. There are also alternative evolutionary tracks, such as large therapod dinosaus similar to T-rex still live and so forth. None of use can likely exist in any of these alternatives.

This might be extended some if there is some universal contextuality to consciousness. So we might in some nonlocal fashion all be part of one MWI conscious track. Then maybe this is extended to extraterrestrial intelligence elsewhere. Then what about animals? This begins to sound like some Hindu fantasy.

Cheers LC

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T H Ray replied on Oct. 7, 2010 @ 18:30 GMT
Lawrence,

I am looking at MWI as something different than n-dimensional Euclidean space. Because worlds are forbidden to communicate, we can't say anything about time symmetry in any other world than ours. We can say, however, that from a one-way perpective into other worlds, a perspective which other worlds also have of ours -- (i.e., we're all loooking at the same moon) -- event trajectories cannot reverse; time symmetry is local. MWI has to exist in other than a simply connected space.

Tom

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T H Ray wrote on Oct. 8, 2010 @ 12:32 GMT
I'm not satisfied with the way that I said that last. I mean that because MWI is based on branching probabilities, irreversibility is built into the event trajectory at any node leading to the many-worlds set -- while preserving time symmetry in our classical universe. If this were not true, continuous information loss would deny us the appearance of the stable universe that we observe. Observers from any of the many worlds should also see the same stable universe as we, through the same one-way mirror that we view it. So as noted, the moon really is there when no one is looking, as Einstein had it.

Tom

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Lawrence B. Crowell wrote on Oct. 8, 2010 @ 12:57 GMT
The eigen-branching in MWI is due to observer bias, for fundamentally the universe remains in a superposition of all these branching probability amplitudes. This is what Tegmark says is the “bird’s eye” view, where on a fundamental level the world is in a pure quantum state. Yet real observers see the world from a “frog’s eye” perspective, and what part of a pure state we observe is in complicated entanglements with parts of the world we have little or no knowledge of. From there the observer bias sets in and the dice outcomes are read. This is the meaning of the eigen-branching of the world. However, on a deep or fine grained level (what the bird’s eye sees) the world actually does not branch.

Cheers LC

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T H Ray replied on Oct. 8, 2010 @ 14:00 GMT
Actually, Lawrence, for MWI to hold, the probabilities do have to actually branch, even though the wave function does not collapse. We may read the results of the dice at any arbitrary moment, IOW, but we cannot say anything about a birds-eye view which is inaccessible to us. The observer bias (choice, branching probability) is as real as anything that physics can describe.

Tom

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Lawrence B. Crowell wrote on Oct. 8, 2010 @ 22:54 GMT
I suppose there is a different meaning to the use of the word "branch." In the bird's eye view a system becomes entangled with a reservoir of states and so the local observation of some superposed set of states is reduced. This local observation is what we call the collapse. However, the branching is not one where one branch is ontologically real and the others are not. I suppose this is the sense in which I am using the term branching. From a frog's eye perspective one one of the branches is observed, which is a local observation that has the appearance of a collapse. However, if your system has been entangled with some other set of states that entanglement still actually remains.

Cheers LC

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T H Ray replied on Oct. 9, 2010 @ 07:11 GMT
Lawrence,

Aren't we saying the same thing? The branching probability (entangled state) is real though not observed, and that's all we can make of it.

Tom

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Lawrence B. Crowell replied on Oct. 9, 2010 @ 11:18 GMT
It sounds as if we are meaning the same thing. If we had a superposition of two states in a wave |ψ> = a(1)|1> + a(2)|2>, then a measurement is just the coupling of some other set of states, say |+> and |-> as spin states that act as a needle so

|ψ> - -> a(1)|1>|+> + a(2)|2>|->,

so the superposition is replaced by an entanglement. So this is a form of branching, and of course this can branch further, for this spin state might has a magnetic moment that couples to a Josephson diode ring, inducing a current (another entanglement) which is then amplified by some electronic (more entanglement) and so forth. Of course this leads ultimately to the Schrodinger cat problem, for we read this out and we do not see the entanglement, but a single outcome. So we are moved along one of the eigen-branches.

I saw the PBS NOVA program on Hugh Everett, which featured his son who heads up a rock band “The Eels,” a bit of an art rock group. I came away with the impression that Hugh worked on the matter of nuclear war almost with an MWI sense of things. It appeared as if he wanted to understand what the eigen-branching was with respect to “war or no war,” and our prospects for survival. If the world is ultimately quantum mechanical there is then some world on the grand Markovian eigen-branching tree where the Cuban missile crisis turned into a nuclear war. Maybe Hugh had an interest in making sure we understood what the options were and what the dice throw probabilities were so we might avoid the worst outcomes. The whole program had this sense of melancholy and estrangement to it.

Cheers LC

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T H Ray replied on Oct. 10, 2010 @ 10:59 GMT
We agree.

One of the facts I see almost never discussed is that our measurement conventions are between mass points. This gets us perturbative results that we can call a continuous function; however, the continuous wave independent of discrete mass points leaves room, however infinitesimal, for events that are real yet beyond measurement. So I tend to agree -- if Hawking did ever actually say the words -- that MWI is "trivially true."

A non-perturbative theory would bring classical sense back to continuous reality, but there will never be enough "room" for it in our one 4-dimensional world, in principle. Or at least, the principles that current mathematics allows.

Tom

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amrit wrote on Oct. 9, 2010 @ 06:07 GMT
Each quantum option is satisfied—the cat both lives and dies—just in two parallel worlds.

We do not agree with above: cat is alive or dead in the same 4D space.

This is how we see the whole idea of paralel worlds: they do not exist.

Yours Amrit

attachments: 1_Time_measured_with_Clocks.pdf, Time_measured_with_Clocks__cover_letter.pdf

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Lawrence B. Crowell wrote on Oct. 11, 2010 @ 02:10 GMT
Tom,

Clearly nonperturbative theory requires superspace considerations. This is where MWI does manage to have some possible context. With multiple cosmology (multiverse) considerations there are at least some nonlinear gravitational aspects to this. In this setting MWI might have some measurable context, as the eigen-branching might be associated with a unique metric back reaction, which...

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T H Ray replied on Oct. 12, 2010 @ 10:51 GMT
Yes, perhaps the extra spatial needs of a nonperturbative theory will turn Goethe's demand for "more light!" into "more room!"

Tom

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Lawrence B. Crowell replied on Oct. 12, 2010 @ 11:27 GMT
That might have a ring of truth to it, if this requires many degrees of freedom. Of course the number of degrees should be conserved. Solitons do have an infinite number of symmetries, but these are largely Pfaffian structures, which are not observables in the proper sense. These symmetries are structures imposed on the group velocity of a linear wave which deforms these waves into nonlinear waves. Which ever is the case the number of degrees of freedom must be within the Bekenstein bound.

Cheers LC

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T H Ray replied on Oct. 14, 2010 @ 12:06 GMT
It was thinking about the Bekenstein bound that, in part, led me to a complex plane analysis of the initial condition. I.e.:

We are used to thinking of the beginning as a point. We can keep that same idea with extension to the complex plane and C*, realizing that a complex point has infinite expansion as a line, a metric.

The Bekenstein bound defines its limit on the finite radius of a sphere. What I found is that if one considers two kissing spheres of infinite radius and zero thickness, the closest point of contact is _anywhere_ on the imaginary (Y) axis, and defines the C* (complex sphere) origin. Then, when we take the real (X) axis as the equator of the complex sphere, through the origin, we get flat Euclidean regions of arbitrarily finite area.

Then taking my specifically physical definition for "time" ("n-dimensional infinitely orientable metric on self-avoiding random walk") one may calculate boundary conditions as self-limiting, because time is now identical to physical information, in a dissipative system of n-dimension Euclidean kissing spheres.

I've always been puzzled at the lack of professional interest in the Hawking-Hartle imaginary time hypothesis -- which has been around since the 80s -- because I have found no reason for it in all that time, other than the simple belief that "time" is always a real metric. There is no particularly complicated mathematics in the idea of imaginary time, however, and we use Hilbert space complex calculations (absent a time metric) in quantum mechanical calculations, routinely.

Tom

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Steve Dufourny wrote on Oct. 11, 2010 @ 09:29 GMT
ARE YOU SERIOUS .....????

All that is pseudo sciences and even sciences fiction,

Well and perhaps after the Mtheory and the help) of princeton, really even the medals are falses .

Ahahaha the string theory and the universe and after what a time machine for the happy new year.

The strings are falses .And all that is a pure joke .

MWI and after what it exists an infinite what ....all that is for the second part of sciences community because an under sciences is inserted, the business.

That's all for the moment.

Steve

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Steve Dufourny replied on Oct. 11, 2010 @ 09:32 GMT
Well Massachussets...it's time to be serious about sciences ,because your are going to be really bad respected in the future .

Princeton has a real respectability thus at the board, please be rational and forget this under sciences.

New york new york ??? what are you doing, it's so corrupted , at this point ???? and FQXi of course the message is for you also, you are an innovant platform and you can be rational.

Regards

Steve

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T H Ray replied on Oct. 12, 2010 @ 10:48 GMT
Steve,

Dude, chill.

Tom

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Steve Dufourny replied on Oct. 13, 2010 @ 10:30 GMT
hihihi the truth is not always liked ....it's the earth and its false ironies.

Fortunally the universe is harmonious and its plan is universal.We are youngs at the universal scale, dude and the hours is serious.We are not here to laugh my friend.

The universe has a plan for this universe with or without your approvements.

I am universalist, humanist and scientist.

I want the well of humanity, I suspect that all aren't in this logic.

Your extrapolations are just for fun but not for our foundamentals.

Mr Witten is competent and is an interesting person but as I said before it exists bad and good people everywhere,

and of course around Mr Witten I suspect a business.It's logic when we see the state of NY for example.

The sciences are rationals and have the solutions, it's not a play dude.

If you like show us your vanity, you loose your time.

What I say is simple, the earth must be restabilized quickly and the biggest problems must be analyzed also very quickly.

For that the harmonization of chaotics systems is essential........for that the truth is important NO??? Even if some people are angry .

The problem TH is not the scientists but the team of businessman behind.

We recongnize always the real scientists and searchers of truth.

If you are a scientist you understand me,isn't it ?

Well I d like speak with Mr WITTEN HERE IF HE WANTS IN TRANSPARENCE.

I am persuaded he has very interestings ideas about our Universe.

Steve

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Lawrence B. Crowell wrote on Oct. 15, 2010 @ 11:30 GMT
If Steve D. puts some of his posts in rhyme with a bit of meter he could be the next Alan Ginsburg.

Cheers LC

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T H Ray replied on Oct. 15, 2010 @ 12:10 GMT
He's got the "howl."

Tom

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Steve Dufourny replied on Oct. 15, 2010 @ 17:06 GMT
hihihi I saw this mister Gisnburg on the web ahahah well tried I agree you have a big humor Mr L B Crowell Oh what a splendid humor it's well that you answer, you have others answers more rationals,hihihi I wait a rational answer dear Th and Lb.

These extrapolations I repeat are just for under sciences.These systems are all hypotheticals if my memmory is good.

It lacks a real perception of whole.

Indeed, our Universe has its intrinbsic laws and proportionalities.The thermodynamics prove this fact.

The real foundamental problem is the road taken at the base of this problem.

I have nothing against people, I insist, only against these theories and some ironies of our system.

I see skills and I am very troubled by these skills on these subjects.As both of you, Mr Witten,Hooft,Susskind.....It's purely not possible to focus on these stupidities when we see the whole.What are you doing ??? What is all these ironies ??? I am curious.

Ps if you want read my poems, learn french! ahahaha indeed it's a passion for me, I am going to write in french about your ideas and you if you are ok of course, hihihih That begins by Once upon a time(in english of course I translate)A string in the sky, two friends and their team, take a wisky, that rhymes no lawrence ,and they dream of a time machine,....I am better in french .Humbly of course....hihhi

hhhhhhowlllllllllllllll howlll howlllllllllll REVOLUTION hihii

Tive

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T H Ray replied on Oct. 19, 2010 @ 10:33 GMT
Okay, Steve. I guess if you don't understand time symmetry by now, you're not going to.

Tom

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T H Ray wrote on Oct. 20, 2010 @ 18:02 GMT
" ... one can prove that in any arbitrary volume the net outflow of energy across the boundary is equal to the time rate of decrease of energy within the volume." (p. 8)

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Steve Dufourny replied on Oct. 20, 2010 @ 18:26 GMT
Thanks but it's a work of a person and not about the theorem itself.

The interpretation is interesting that said.

I insist on the fact that never time is a dimension.That implies that conservation and symmetries are logics without time.

You misinterpret the theorem.The fact that the time rate is essential in thermodynamics do not stipulate that this time is reversible.That has no sense.

The time is a concept of duration with an international unity which permits to utilize correctly the transfert of E .It's different than a mirror of symmetry where time is a dimension.

The dimensions always shall rest in 3D, our fractals are in 3D.

And it's just a difficulty of perception of the fractalised mass in fact.It dosn't exist extradimensions.

Steve

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T H Ray replied on Oct. 20, 2010 @ 22:27 GMT
Steve,

I expect that you just don't grasp the mathematical meaning of continuous functions in classical physics.

Tom

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Steve Dufourny replied on Oct. 21, 2010 @ 10:48 GMT
AHAHAH I know my maths better than you.Your only answer is to try to conclude with maths but where are them TH ??? let's go here now , where are your maths.

Let's begin with analyze, algebras, geometry, dericvation, integration, limits, domains, ......

Show me your model

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Gordon Dyer wrote on Feb. 12, 2011 @ 21:45 GMT
Everett's view is compelling in providing an alternative to the "lets give up trying to explain what we observe" Copenhagen interpretation, but if the universe splits at every possible alternative quantim event then the number of realities becomes almost infinite and then we cannot analyze or predict the outcomes we observe, so again we are left with a meaningless non-physical theory. Roger Penrose is more likely to be on the right track...

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joseph baron pravda wrote on Feb. 13, 2011 @ 20:01 GMT
Well done; I've written a three act play about this unique life, and its progeny---both literal and otherwise (his kids are prinicipal players).

Unlike Dr. Strangelove, I rather see him as a buddhistic fellow, contemplating the truest nature of 'reality', within the very Tree of Knowledge, trapped in its least interesting 'branch'.

J.B. Pravda

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