Many Interacting Worlds?

[JB80]

I stumbled across this today and  thought it looked interesting.

http://www.eurekalert.org/pub_releases/2014-10/gu-gsp102914.php

Griffith University academics are challenging the foundations of quantum science with a radical new theory based on the existence of, and interactions between, parallel universes.

In a paper published in the prestigious journal Physical Review X, Professor Howard Wiseman and Dr Michael Hall from Griffith's Centre for Quantum Dynamics, and Dr Dirk-Andre Deckert from the University of California, take interacting parallel worlds out of the realm of science fiction and into that of hard science.

The team proposes that parallel universes really exist, and that they interact. That is, rather than evolving independently, nearby worlds influence one another by a subtle force of repulsion. They show that such an interaction could explain everything that is bizarre about quantum mechanics

Quantum theory is needed to explain how the universe works at the microscopic scale, and is believed to apply to all matter. But it is notoriously difficult to fathom, exhibiting weird phenomena which seem to violate the laws of cause and effect.

As the eminent American theoretical physicist Richard Feynman once noted: "I think I can safely say that nobody understands quantum mechanics."

However, the "Many-Interacting Worlds" approach developed at Griffith University provides a new and daring perspective on this baffling field.

"The idea of parallel universes in quantum mechanics has been around since 1957," says Professor Wiseman.

"In the well-known "Many-Worlds Interpretation", each universe branches into a bunch of new universes every time a quantum measurement is made. All possibilities are therefore realised – in some universes the dinosaur-killing asteroid missed Earth. In others, Australia was colonised by the Portuguese.

"But critics question the reality of these other universes, since they do not influence our universe at all. On this score, our "Many Interacting Worlds" approach is completely different, as its name implies."

Professor Wiseman and his colleagues propose that:

• The universe we experience is just one of a gigantic number of worlds. Some are almost identical to ours while most are very different;
• All of these worlds are equally real, exist continuously through time, and possess precisely defined properties;
• All quantum phenomena arise from a universal force of repulsion between 'nearby' (i.e. similar) worlds which tends to make them more dissimilar.

Dr Hall says the "Many-Interacting Worlds" theory may even create the extraordinary possibility of testing for the existence of other worlds.

"The beauty of our approach is that if there is just one world our theory reduces to Newtonian mechanics, while if there is a gigantic number of worlds it reproduces quantum mechanics," he says.

"In between it predicts something new that is neither Newton's theory nor quantum theory.

"We also believe that, in providing a new mental picture of quantum effects, it will be useful in planning experiments to test and exploit quantum phenomena."

The ability to approximate quantum evolution using a finite number of worlds could have significant ramifications in molecular dynamics, which is important for understanding chemical reactions and the action of drugs.

Professor Bill Poirier, Distinguished Professor of Chemistry at Texas Tech University, has observed: "These are great ideas, not only conceptually, but also with regard to the new numerical breakthroughs they are almost certain to engender."

http://www.engineering.com/3DPrinting/3DPrintingArticles/ArticleID/8829/Do-Parrallel-Worlds-Interact-with-One-Another.aspx

Abstract

We investigate whether quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but finite, number of classical “worlds,” and quantum effects arise solely from a universal interaction between these worlds, without reference to any wave function. Here, a “world” means an entire universe with well-defined properties, determined by the classical configuration of its particles and fields. In our approach, each world evolves deterministically, probabilities arise due to ignorance as to which world a given observer occupies, and we argue that in the limit of infinitely many worlds the wave function can be recovered (as a secondary object) from the motion of these worlds. We introduce a simple model of such a “many interacting worlds” approach and show that it can reproduce some generic quantum phenomena—such as Ehrenfest’s theorem, wave packet spreading, barrier tunneling, and zero-point energy—as a direct consequence of mutual repulsion between worlds. Finally, we perform numerical simulations using our approach. We demonstrate, first, that it can be used to calculate quantum ground states, and second, that it is capable of reproducing, at least qualitatively, the double-slit interference phenomenon.

DOI: http://dx.doi.org/10.1103/PhysRevX.4.041013

Popular Summary

Quantum mechanics provides our most fundamental description of nature, but there is a long-standing and passionate debate among physicists about what all the math “really” means. We provide an answer based on a very simple picture: The world we experience is just one of an enormous number of essentially classical worlds, and all quantum phenomena arise from a universal force of repulsion that prevents worlds from having identical physical configurations. Probabilities arise only because of our ignorance as to which world an observer occupies. This picture is all that is needed to explain bizarre quantum effects such as particles that tunnel through solid barriers and wave behavior in double-slit experiments.

Our “many-interacting-worlds” approach hinges on the assumption that interactions between deterministically evolving worlds cause all quantum effects. Each world is simply the position of particles in three-dimensional space, and each would evolve according to Newton’s laws if there were no interworld interactions. A surprising feature of our approach is that the formulation contains nothing that corresponds to the mysterious quantum wave function, except in the formal mathematical limit in which the number of worlds becomes infinitely large. Conversely, Newtonian mechanics corresponds to the opposite limit of just one world. Thus, our approach incorporates both classical and quantum theory. We perform numerical simulations and show that our approach can reproduce interference with a double slit. As few as two interacting worlds can result in quantumlike effects, such as tunneling through a barrier.

Our approach, which provides a new mental picture of quantum effects, will be useful in planning experiments to test and exploit quantum phenomena such as entanglement. Our findings include new algorithms for simulating such phenomena and may even suggest new ways to extend standard quantum mechanics (e.g., to include gravitation). Thus, while Richard Feynman may have had a point when he said “I think I can safely say that nobody understands quantum mechanics,” there is still much to be gained by trying to do so.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.4.041013

http://arxiv.org/abs/1402.6144

[ollypenrice]

This is all genuinely interesting but my gut feeling is that all these hypotheses are like Ptolmeic (and indeed Copernican) epicycles. They are, metaphorically, elaborate devices for turning circles into ellipses - because we have failed to grasp that the planests move in ellipses. These great lumbering clockworks, and that of Copernicus was arguably worse than that of Ptolemy, only come into being because we have missed one fairly simple but fundamental concept.

Whether anyone will ever pop up with an 'ellipse' that will suddenly dismiss all the contradictions and seeming absurdities of quantum theory remains to be seen, of course.

Olly

Edit, I am using ellipse metaphorically in my last remark as well.

[Qualia]

Aye, a great read and one not to treat lightly. 

In a sense, the 'battle ground' is still the same Plato was disputing over 2,500 years ago; that between Materialists and Idealist. In this sense, the Many Worlds interpretation per se fits into the former category whilst the Copenhagen School per se, with the latter.

Those in the Copenhagen School would more than likely dismiss all questions about what a quantum object is “really like” outside of observation. The notion would be a priori untestable and therefore meaningless. In this sense, to ask about the state of some entity before observation/measurement is a meaningless question; all that is meaningful is to state the properties of an entity after measurement. Thus the Copenhagen School says that QM science is not about noumena, but the phenomenal. QM is just about what we can experience and describe. In that I'd say Copenhagen is very Kantian.

Many Worlds does the following: it restores realism to the world by introducing Many Worlds (MW). Under MW, quantum objects really do have classical style properties before any observation and are thus independent of any and all minds. It also helps restore classical determinism to physics, because there never takes place any sort of wave function collapse that exhibits an inherently random outcome. In this way, the wave function is itself a physical object. It encodes every possible location and property state of a quantum object under consideration and does so before, during and after a measurement; the wave function collapse is illusory because when Observer A sees an electron at location x, his counterpart, Observer B, sees the electron at location y in a parallel universe, or other world. If this interpretation is apt, Many Worlds seems like a hyper sort of Realism or Materialism — every way that a material object can be, is a way that it is, somewhere, in a multiverse.

I'm not sure how far the investigators will move from or within this battlefield, but to the battlefield they march

I would have only two related comments on all this.

The first is that I would agree with Kant that we don't seem to have any kind of epistemic access to the "real world" - if such a concept really is. That is, no matter what we try to do, if such a world does exist, it will always be hidden behind the complex filters of our biology and psychology.

The other which merely adopts the charitable stance of falsification, is that we shouldn't mistake our current models of observed phenomena, which is what science is in the business of doing, as being the absolute description of reality in itself.  

What science is advancing is its ability to predict observed phenomena, but any elements of that reality that lie outside of our abilities will necessarily appear mysterious. I don't see this as any warrant for assuming a hardcore Idealist stance, since it would seem easier for me to just assume I don't have the working models to access this part of reality, than to try and postulate how reality is somehow dependent on a mind. But in equal measure, I can also dismiss Hyper Materialism, for it just seems far more simplistic to count on my own incapacity than to try and postulate Many Worlds that would for all intents and purposes lie outside my ability to test .  

Poor Ockham so often gets abused, but I think he still makes a good rule of thumb

[Cath]

What immediately comes to mind is that 'fumbling around in the dark" feeling.

Interesting though!

[JB80]

This is all genuinely interesting but my gut feeling is that all these hypotheses are like Ptolmeic (and indeed Copernican) epicycles. They are, metaphorically, elaborate devices for turning circles into ellipses - because we have failed to grasp that the planests move in ellipses. These great lumbering clockworks, and that of Copernicus was arguably worse than that of Ptolemy, only come into being because we have missed one fairly simple but fundamental concept.

As far as analogies go I feel that one is more descriptive than many would like to admit.

Whether anyone will ever pop up with an 'ellipse' that will suddenly dismiss all the contradictions and seeming absurdities of quantum theory remains to be seen, of course.

That is all part of the fun though, until then I am finding myself more and more enthralled by it. Mind you I don't envy those trying to figure it out.

[JB80]

Aye, a great read and one not to treat lightly. 

In a sense, the 'battle ground' is still the same Plato was disputing over 2,500 years ago; that between Materialists and Idealist. In this sense, the Many Worlds interpretation per se fits into the former category whilst the Copenhagen School per se, with the latter.

Interesting, In a way I agree that there is a sense of Idealism and Materialism however I think the lines have been redrawn. I'm not entirely certain I would say that MW is materialistic on fact I would lean to the opposite being a truer statement, at the least when comparing Copenhagen to MW.

However there have certainly been those that have tried to make the leap to materialism or close to it with the Many Minds interpretations which I don't feel does much service to the original basis of realism that Everett pioneered.

Those in the Copenhagen School would more than likely dismiss all questions about what a quantum object is “really like” outside of observation. The notion would be a priori untestable and therefore meaningless. In this sense, to ask about the state of some entity before observation/measurement is a meaningless question; all that is meaningful is to state the properties of an entity after measurement. Thus the Copenhagen School says that QM science is not about noumena, but the phenomenal. QM is just about what we can experience and describe. In that I'd say Copenhagen is very Kantian.

They definitely have dismissed and to this day still do but I at least some are willing to take new things on board and it should be noted that they are not separate theories but interpretations and both are consistent with current observations and none of them as yet makes experimentally testable or falsifiable predictions which differ from the other.

I find Kantian an interesting description too, possibly a correct description and also exactly why there is a movement against it.

Many Worlds does the following: it restores realism to the world by introducing Many Worlds (MW). Under MW, quantum objects really do have classical style properties before any observation and are thus independent of any and all minds. It also helps restore classical determinism to physics, because there never takes place any sort of wave function collapse that exhibits an inherently random outcome. In this way, the wave function is itself a physical object. It encodes every possible location and property state of a quantum object under consideration and does so before, during and after a measurement; the wave function collapse is illusory because when Observer A sees an electron at location x, his counterpart, Observer B, sees the electron at location y in a parallel universe, or other world. If this interpretation is apt, Many Worlds seems like a hyper sort of Realism or Materialism — every way that a material object can be, is a way that it is, somewhere, in a multiverse.

Hmm yes and no!

I feel that what MW does more than to give quantum objects classical properties it gives classical objects quantum properties. Tomato's or tomatoes I know.

It does away with observation altogether(which personally I think sounds sensible). In a way that all classical objects a superposed all the time.(? It's late I may be off on this, vino tinto!)

Re: determinism bit, I think that sounds right.

I'm not sure on observers A & B though. Observer B would see the same as A as has been pointed out location y is untestable and therefor according to Everett not of a great deal of concern yet physically real.

Hyper realistic? Probably, materialistic? just an offshoot of the realism. If that makes sense. I don't think it does but by nature of the philosophy it is all things, idealistic included but that again is to be found on the various infinite branches and possibly not ours. 

I'm not sure how far the investigators will move from or within this battlefield, but to the battlefield they march

Not sure either but this Many Interacting Worlds interpretation on face value looks like a leap if the claims of testability come to fruition.

The first is that I would agree with Kant that we don't seem to have any kind of epistemic access to the "real world" - if such a concept really is. That is, no matter what we try to do, if such a world does exist, it will always be hidden behind the complex filters of our biology and psychology.

The other which merely adopts the charitable stance of falsification, is that we shouldn't mistake our current models of observed phenomena, which is what science is in the business of doing, as being the absolute description of reality in itself.  

What science is advancing is its ability to predict observed phenomena, but any elements of that reality that lie outside of our abilities will necessarily appear mysterious. I don't see this as any warrant for assuming a hardcore Idealist stance, since it would seem easier for me to just assume I don't have the working models to access this part of reality, than to try and postulate how reality is somehow dependent on a mind. But in equal measure, I can also dismiss Hyper Materialism, for it just seems far more simplistic to count on my own incapacity than to try and postulate Many Worlds that would for all intents and purposes lie outside my ability to test .  

Poor Ockham so often gets abused, but I think he still makes a good rule of thumb

I don't object to much of those paragraphs except maybe this...

 just seems far more simplistic to count on my own incapacity than to try and postulate Many Worlds that would for all intents and purposes lie outside my ability to test

Just because I somehow think it is a simpler version and poor old Ockham is the chap  responsible for it because unbelievably, less of it sounds like nonsense and guess work.

All in all I'm still reading up on it  and haven't even got to the implications of decoherence on the later models which are far more robust and this new Interaction postulate is very interesting which I hope to keep an eye on at the very least.

I'm not dismissing any interpretation though, just find it fascinating.

[Ronnie67]

This is something we discussed as a teenager, myself and my friends had a debate many years ago on the same topic, we each believed that alternative earths exist somewhere out there, a bit like a mirror image of our own, but each with its own story,. It reminds me of Stargate SG1.

But who knows trillions of planets are out there and we are definitely not the only planet to sustain life, oh no that means there's hundreds of me out there ha ha ha.

[Ruud]

Does all this mean that every time I type a letter, I create many different universes in which I type different letters, leading to all sorts of spelling mistakes?

Where does the energy come from? Typing doesn't involve enough work to create a universe. Or were these alternative universes already there, just waiting for me to start typing?

I'm happy with the universe I'm in. At least I don't make too many typing errors.

[Qualia]

Great questions, Rudd

I think the basic problem is the correct or most accurate metaphysical interpretation of the measurement problem. The Copenhagen School may argue that random collapse or mind causes the wave function collapse.

Many Worlds may argue that wave function collapse never happens because the particles involved and the observer are already in multiple states. So in something like the double-slit test you’d have the two states: photon goes right and observer sees it go right and photon goes left and observer sees it go left. Both states exists.

I really do not know enough to answer your questions (perhaps the next book I read will be on QM) but yes, I think according to Many Worlds those other states you mention do exist.

The main problem I have with Many Worlds is purely philosophical. If there really is such a thing, it follows that Copenhagen Worlds must by definition also exist And furthermore, this world could be just one of them

[Ruud]

It's turtles, all the way down.