Search FQXi


RECENT FORUM POSTS

Lee Bloomquist: ""…Rovelli’s interpretation of quantum theory is hard to overlook." (F...." in The Spacetime...

Jonathan Dickau: "Thanks for this intro Ed, and hello all.. There are several points of..." in FQXi Essay Contest 2016:...

dieu le: "Finding Dark Matter Our research so far lacks any concrete details of..." in Alternative Models of...

Lee Bloomquist: "Algorithms produce information. Then inferring from G. 't Hooft's..." in Painting a QBist Picture...

Rajiv Singh: "Hi Lorraine, This time, before submitting, I noted that the web page did..." in FQXi Essay Contest 2016:...

sussan betcher: "Such ventures helping to raise public awareness and interest in theoretical..." in Multiversal Journeys —...

sabir rao: "We are looking for the ways how to hack instagram password online and..." in Purifying Physics: The...

sabir rao: "If you don't know a little bit about the free psn plus codes then here is..." in Towards a Goal — Two...


RECENT ARTICLES
click titles to read articles

Bohemian Reality: Searching for a Quantum Connection to Consciousness
Is there are sweet spot where artificial intelligence systems could have the maximum amount of consciousness while retaining powerful quantum properties?

Quantum Replicants: Should future androids dream of quantum sheep?
To build the ultimate artificial mimics of real life systems, we may need to use quantum memory.

Painting a QBist Picture of Reality
A radical interpretation of physics makes quantum theory more personal.

The Spacetime Revolutionary
Carlo Rovelli describes how black holes may transition to "white holes," according to loop quantum gravity, a radical rewrite of fundamental physics.

Riding the Rogue Quantum Waves
Could giant sea swells help explain how the macroscopic world emerges from the quantum microworld? (Image credit: MIT News)


FQXI ARTICLE
May 1, 2017

Does Quantum Weirdness Arise When Parallel Classical Worlds Repel?
Quantum mechanics could derive from subtle interactions among unseen neighboring universes
by Steven Ashley
FQXi Awardees: Howard Wiseman, Michael Hall
April 15, 2016
Bookmark and Share


Howard Wiseman
Griffith University
If quantum physics didn’t work so incredibly well, nobody would take it all that seriously. As Albert Einstein wrote in 1912, "The more success the quantum theory has, the sillier it looks." After all, quantum experiments tell us that particles can exist in two places at once and tunnel through insurmountable barriers.

Now, however, a trio of physicists is striving to take the silliness out of quantum theory by developing a model that can explain away its strangest effects—by invoking the existence of multiple parallel classical worlds. Each world, they posit, is filled with particles that can exert a group force on their nearby clones in our universe, creating quantum effects.

The theory of quantum mechanics has proved to be amazingly successful at describing events at the smallest scale—enough to fully revolutionize modern electronics and computers. In return, however, it has unsettled the conventional notions of physical reality held by scientists and laymen alike.

It has long seemed that physicists must just accept that the intuitive everyday "classical" laws of physics that govern macroscopic objects do not apply in the microscopic realm. But the new model of Many Interacting Worlds (MIW) developed by Howard Wiseman, a quantum physicist at Griffith University, in Brisbane, Australia, and colleagues may offer an explanation for these bizarre phenomena that relies only on common-sense classical rules. With the help of an FQXi grant of almost $104,000, they are now investigating how interference from these other universes may affect our own—and whether there is a way to find proof of the existence of parallel realities in the lab.

"We prefer to follow Einstein (and like-minded others) in seeking a more realistic theory," Wiseman says. "We’ve taken a fresh perspective involving a fundamental shift from previous quantum interpretations."

When Parallel Worlds Interact

Howard Wiseman describes the Many Interacting Worlds model to Zeeya Merali.

LISTEN:

Go to full podcast

The standard interpretation of quantum theory eschews the idea that there is an objective reality at all. Instead, it says that before scientists scrutinize the properties of a quantum object by measuring them, those properties—such as its location—are not set. Quantum equations can predict with stunning accuracy the probability of getting certain results over many thousands of runs of the experiment; but they cannot tell you with certainty exactly which answer you will get in any single test.

Another famous interpretation, first laid out in the 1950s by American theorist Hugh Everett III suggests that when such measurements are carried out they force a split in reality, creating multiple parallel quantum universes—one for each possible experimental outcome that could be realized. (See "The Many Lives of Hugh Everett III.") The new theory of interacting classical worlds should not be confused with Everett’s theory, however. Where Everett’s universes arise as a result of the seemingly strange laws at play at the quantum level, Wiseman and his colleagues, Michael Hall, also at Griffith University, and Dirk-André Deckert of Ludwig-Maximilians-University in Munich, Germany are searching for a description of reality that rejects quantum weirdness entirely.

Multiple Worlds

With that goal in mind, a few years back, Wiseman began to ponder what would happen if multiple worlds not only existed, but could influence each other. Within these worlds even objects on the smallest scales obey the plain old rules that Isaac Newton devised to explain force and motion. A classical law is also used to describe the forces that the parallel worlds exert on each other. "Ours is a new picture of reality at the atomic scale," Hall says, adding that they believe it to be "both elegant in principle, and useful for calculations in practice."


Otherworldly Influences
A repulsive force between particles in different worlds could explain
the odd trajectories taken in the double-slit experiment, and other effects.
The three theorists postulate that there are a huge but finite number of worlds, or universes. Each of these is categorized by their configurations—the list of the positions of all the particles in the world. Most worlds have very different configurations, they conjecture, but some are similar, with a few sharing almost identical configurations that feature only microscopic differences in the positions of some particles. It’s these almost identical worlds that exert the strongest influences over each other, creating a repulsive force between particles and their parallel clones (really, "almost-clones") that can influence the paths they take in experiments in one world.

Remarkably, in 2014, the team calculated that a repelling force of this type, acting between a large number of worlds, can be used to explain many puzzling effects of quantum physics (Michael J. W. Hall, Dirk-André Deckert, Howard M. Wiseman; Phys. Rev. X 4, 041013 (2014)).

Quantum Tunneling

Consider, for instance, how the MIW interpretation explains quantum tunneling—when a particle unaccountably surmounts an energy barrier that it should not be able to according to classical physics. "In our view, when a particle approaches a barrier that really means that there are parallel classical worlds with particles in each, each approaching the barrier from the other side," Hall explains. A repulsive interaction occurs between these particles; in one world, the particle gets pushed toward the barrier faster than average and so possesses enough energy to get over it. "Clones of the particle in other worlds are correspondingly slowed and reflected by the barrier," says Hall.

If you postulate these
worlds, then you can
reproduce the equations,
the phenomena, the
weirdness of quantum
mechanics
- Michael Hall
Additionally, in the MIW view, quantum-related probabilities arise from our ignorance as to which specific world we actually occupy. This explains why scientists cannot predict the outcome of an experiment with certainty. "If you postulate these worlds, then you can reproduce the equations, the phenomena, the weirdness of quantum mechanics," Hall says. (Listen to Wiseman describing some of the many quantum phenomena explained by MIW, in detail, including quantum tunneling, indeterminism, double-slit interference, uncertainty, zero-point and vacuum energies, quantised energy levels, and entanglement, in an extended interview on the FQXi podcast.)

Shelley Goldstein, a mathematician and quantum theorist at Rutgers University in New Brunswick, New Jersey, shares the team’s desire for a deterministic alternative to standard quantum theory, but worries that the cost may be too dear in the MIW interpretation. "They want to seem as classical as possible," he says. "The price for doing that is having all these interacting worlds, and it’s a pretty big price." One big technical concern, Goldstein adds, is that the model assumes particles and their parallel clones zip about in a regular way, whereas in real life, even gas particles in a box (obeying classical physics) tend to have more variation in their speeds than the model allows. Despite his skepticism, however, Goldstein notes that the model deserves further investigation.


Michael Hall
Griffith University.
With their FQXi grant, the team plans to do just that, with a hopeful eye to developing a way to test the model experimentally. It has been tough to think up experiments that can distinguish between many of the other proposed interpretations because they tend to make the same predictions for quantum experiments, by design. The MIW approach is different, however, because its predictions vary slightly depending on the overall number of classical parallel universes invoked by the model.

Ian Durham, a quantum physicist at St. Anselm College in Manchester, New Hampshire, is excited at the thought of potentially finding evidence of parallel universes. (Durham also discusses MIW on the FQXi podcast.) "Whether it’s true or not," Durham says, "I give them credit for formulating an interpretation that at least has the possibility of producing some testable predictions."

Comment on this Article

Please read the important Introduction that governs your participation in this community. Inappropriate language will not be tolerated and posts containing such language will be deleted. Otherwise, this is a free speech Forum and all are welcome!
  • Please enter the text of your post, then click the "Submit New Post" button below. You may also optionally add file attachments below before submitting your edits.

  • HTML tags are not permitted in posts, and will automatically be stripped out. Links to other web sites are permitted. For instructions on how to add links, please read the link help page.

  • You may use superscript (10100) and subscript (A2) using [sup]...[/sup] and [sub]...[/sub] tags.

  • You may use bold (important) and italics (emphasize) using [b]...[/b] and [i]...[/i] tags.

  • You may also include LateX equations into your post.

Insert LaTeX Equation [hide]

LaTeX equations may be displayed in FQXi Forum posts by including them within [equation]...[/equation] tags. You may type your equation directly into your post, or use the LaTeX Equation Preview feature below to see how your equation will render (this is recommended).

For more help on LaTeX, please see the LaTeX Project Home Page.

LaTeX Equation Preview



preview equation
clear equation
insert equation into post at cursor


Your name: (optional)



Important: In order to combat spam, please select the letter in this menu between 'P' and 'R':




Recent Comments


The word is enternal magic. Hope all secret never has answer will be out soon. Kab from ghe tatami


Calm and quietly now steve ,not like before when I was not well psychologically speaking due to personal problems.I am a little better and I am less parano even if I have many hackers,I am quiet and calm.So frankly they are bad Fallen because I will not stop and like I have lost in belgium don't forget that I can travel quickly.So now they must kill me.I don't fear.It is the life we all dies after all and we were, we are we shall be.I like now me this play.Them they begin to doubt.It is like...


This team agaisnt me has forgotten several foundamental parameters about me.They do not really know me and they are false about me.I am going to laugh if I am alive.Them no !!!!They have forgotten the entropy and the well.

read all article comments

Please enter your e-mail address:
Note: Joining the FQXi mailing list does not give you a login account or constitute membership in the organization.