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Griffith University academics just published a radical paper based on the existence of, and interactions between, parallel universes.

In a paper published in the 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, attempt to 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 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 twist 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.

From the 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.

“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.”

Of course, and this really should go without saying, it must be emphasized that this is just a new proposal that could lead to other interesting and fruitful conclusions.


 

Provided by Griffith University.  Journal access.


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