Readers' Choice: The Many Lives of Hugh Everett III

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

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

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

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

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 AmritAttachment #1: 1_Time_measured_with_Clocks.pdfAttachment #2: Time_measured_with_Clocks__cover_letter.pdf

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

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

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

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 is at least in principle detectable.

In fact this connects up with solitonic physics on the gravitational brane (D3 or D4 brane) with an underlying quantum physics, but a largely classical structure to spacetime. In other words gravity is not quantized, but is a semi-classical and classical physics which emerges from an underlying quantum field theory. The structure of this type of theory and has connections with 2-dimensional systems like graphene. Much of this stems from well understood physics.

The k = -1 curvature manifold in two dimensions, the Poincare disk, half-plane or hypersphere, describes by the Gauss-Codazzi a wave motion governed by the sine-Gordon equation

∂_{tt}φ - ∂_{xx}φ = sin(φ)

which is a fascinating equation. This is usually written as

∂_{uv}φ = sin(φ),

for u = (x + t)/2, v = (x - t)/2. This describes the motion of a particle with the line element

ds^2 = du^2 + dv^2 + 2cos(φ)dudv

which is the AdS_2 spacetime for the hyperbolic replacement cos(φ) - -> cosh(φ) with the sinh-Gordon equation ∂_{uv}φ = sinh(φ).

Exact quantum scattering matrix for this sine-Gordon equation was discovered by Alexander Zamolodchikov, which is S-dual to the Thirring model. This is a theory of fermions in two dimensions with the Lagrangian,

L = ψ-bar(γ^a∂_a - m)ψ - g(ψ-bar γ^aψ)(ψγ_aψ),

which is a fermionic theory of bosonization -- similar to superconductivity. Zamolodchikov solved this theory and removed the UV divergence with the Bethe hypothesis. The solution is S-dual to the sine-Gordon equation. This points to very deep relationships with respect to gravitation. Gravitation has as its underlying quantum theory a fermionic quantum system with bosonization (a quantum critical point), where gravitation itself is not really quantized.

This fermion theory, which might be the underlying quantum theory of gravitation (gravitation might not need to be quantized directly beyond a few loop level) is the graded portion of the anyonic field on the two dimensional surface. This is described by a Chern-Simons Lagrangian, which in a more general setting of the 3ﾃ--3 Jordan algebra describes associators with 3 octonions or E_8 groups. This is the possible connection between graphene and these M-theoretic foundations.

The above fermionic Lagrangian has a bosonization according to Bogoliubov functions. This is a bosonization similar to superfluidity or superconductivity. The interpretation with respect to the emergence of gravity is the onset of decoherent quantum fields in curved spacetime. The emergence of spacetime might then be a phase transition, where the parameter of "disorder" is the scale of quantum fluctuations. This plays the role of temperature if the iHt/ħ is wick rotated i - -> 1 and equated to the Boltzmann term E/kT so the Euclidean time t = ħ/kT serves as the "β" term. So this means the set of quantum fluctuation of the Ferm-Dirac field have a critical point or "attractor," similar to the condition for a Fermi surface, where there is a bosonization.

Graphene exhibits structure similar to this, and suggests a sort of universality to this sort of physics. In other settings this is also apparent with the quantum phase transition in heavy metal http://arxiv.org/abs/0904.1993 and http://arxiv.org/abs/1003.1728

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

Steve,

Dude, chill.

Tom

Yes, perhaps the extra spatial needs of a nonperturbative theory will turn Goethe's demand for "more light!" into "more room!"

Tom

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

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

You'll have to speak for yourself, Steve. I know that I'm here to laugh and have fun. Life wouldn't be worth it otherwise.

Tom

hihihi indeed you are right , after all let's laugh.

ps fun can be rational ! and of course it exist a time for all, the serious about sciences are important also in my humble opinion.

Steve

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

In some sense we might think of this as a case where one has QCD in spacetime, and there is an addition dimension. We then think of the additional dimension as an AdS spacetime which repels particle fields from its boundary. There is then a black hole in this AdS_5, and the CFT physics lies on the boundary in 4 dimensions. The conformal structure there is equivalent to spacetime isometries. Then the paths leave this domain of massless fields and approach the black hole. Here mass kick in and this renormalization group flow ends. There the AdS_5 breaks into AdS_3xR^2. The AdS_3 is dual to QCD in two dimensions or an SL(2, C) ~ SU(2) QCD-like theory. If we reduce dimensions further we have AdS_4 reduced to AdS_2xR^2, where AdS_2 is conformal structure on the two plane, or the C* plane.

Cheers LC

Well.

The ads cft link is just a false extrapolation of the string theory.

Thus of course that has no sense.Perhaps only for Princeton, Mr Witten and his team.

Well I am continuing.

This correspondance at bounderaies are just falses.

First a BH is a sphere and its mass is so important.

The gravitational effect my friends.

Yang muills no but we dream or what???

This holographic principle..........Susskind a Hooft are falses, we understand thus why some people work these stupidities at Utrecht also.

Dear scientists...it doesn't exist an equivalence between the strings and the jauge.......be rational^please.You can use maths but please use them well.

We have no proof and we shan't have proof .R 4 and yang mills supersymmetry no but we dream or what all that is false.

The referential and the gravity is in 3D .....????

A real circus all that.and they continue furthermore.

That's all for the moment

Steve