Parallel Universes: Do They Exist? - A Galaxy Insight (VIDEO)

"The multiverse is no longer a model, it is a consequence of our models.”

~Aurelien Barrau, particle physicist at CERN

The Hollywood blockbuster, The Golden Compass, adapted from the first volume of Pullman's classic sci-fi trilogy, "His Dark Materials" portrays various universes as only one reality among many, but how realistic is this kind of classic sci-fi plot? While it hasn’t been proven yet, many highly respected and credible scientists are now saying there’s reason to believe that parallel dimensions could very well be more than figments of our imaginations.

"The idea of multiple universes is more than a fantastic invention—it appears naturally within several scientific theories, and deserves to be taken seriously," stated Aurelien Barrau, a French particle physicist at the European Organization for Nuclear Research (CERN).

There are a variety of competing theories based on the idea of parallel universes, but the most basic idea is that if the universe is infinite, then everything that could possibly occur has happened, is happening, or will happen.

According to quantum mechanics, nothing at the subatomic scale can really be said to exist until it is observed. Until then, particles occupy uncertain "superposition" states, in which they can have simultaneous "up" and "down" spins, or appear to be in different places at the same time. The mere act of observing somehow appears to "nail down" a particular state of reality. Scientists don’t yet have a perfect explanation for how it occurs, but that hasn’t changed the fact that the phenomenon does occur.

Unobserved particles are described by "wave functions" representing a set of multiple "probable" states. When an observer makes a measurement, the particle then settles down into one of these multiple options, which is somewhat how the multiple universe theory can be explained.

The existence of such a parallel universe "does not even assume speculative modern physics, merely that space is infinite and rather uniformly filled with matter as indicated by recent astronomical observations," Max Tegmark, a cosmologist at MIT in Boston, Massachusetts concluded in a study of parallel universes published by Cambridge University.

Mathematician Hugh Everett published landmark paper in 1957 while still a graduate student at Princeton University. In this paper he showed how quantum theory predicts that a single classical reality will gradually split into separate, but simultaneously existing realms.

"This is simply a way of trusting strictly the fundamental equations of quantum mechanics," says Barrau. "The worlds are not spatially separated, but exist as kinds of 'parallel' universes."

Partly because the idea is so uncomfortably strange, it’s dismissed as sci-fi by many critics. But there are also many credible, respected proponents of the theory—a group that is continuously gaining new adherents as new research unveils new evidence. Some Oxford research—for the first time—recently found  a mathematical answer that sweeps away one of the key objections to the controversial idea. Their research shows that Everett was indeed on the right track when he came up with his multiverse theory. The Oxford team, led by Dr David Deutsch, showed mathematically that the bush-like branching structure created by the universe splitting into parallel versions of itself can explain the probabilistic nature of quantum outcomes.

The work has another strange implication. The idea of parallel universes would apparently side-step one of the key complaints with time travel. Every since it was given serious credibility in 1949 by the great logician Kurt Godel, many eminent physicists have argued against time travel because it undermines ideas of cause and effect. An example would be the famous “grandfather paradox” where a time traveler goes back to kill his grandfather so that he is never born in the first place.

But if parallel worlds do exist, there is a way around these troublesome paradoxes. Deutsch argues that time travel shifts happen between different branches of reality. The mathematical breakthrough bolsters his claim that quantum theory does not forbid time travel. "It does sidestep it. You go into another universe," he said. But he admits that there will be a lot of work to do before we can manipulate space-time in a way that makes “hops” possible. While it may sound fanciful, Deutsch says that scientific research is continually making the theory more believable.

"Many sci-fi authors suggested time travel paradoxes would be solved by parallel universes but in my work, that conclusion is deduced from quantum theory itself."

The borderline between physics and metaphysics is not defined by whether an entity can be observed, but whether it is testable, insists Tegmark.

He points to phenomena such as black holes, curved space, the slowing of time at high speeds, even a round Earth, which were all once rejected as scientific heresy before being proven through experimentation, even though some remain beyond the grasp of observation. It is likely, Tegmark concludes that multiverse models grounded in modern physics will eventually be empirically testable, predictive and disprovable.

Posted by Rebecca Sato

Related Galaxy posts:

New Proof from Oxford: Parallel Universes Exist
Cosmic Pentimento: Beyond the Great Void May be a Great Something
Weird Science: Can Time Move Backwards?

links:
http://www.dailygalaxy.com/my_weblog/2007/09/n--one-of-the-m.html

http://physorg.com/news118241154.html

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/09/21/sciuni121.xml

Comments

[SiliconJon]

No.

I can't come up with any good argument other than I find it to be a silly idea for science, but a fair movie theme.

[claudio]

I do not have difficulty in believing that the dimension that we perceive and we live into is NOT the only one available.

Fortunately for us the parallel universes or the more complex multidimensions 'multiverses' are NOT easily accessible to us Human beings.

Then the matter becomes extremely complex and relates to the famous principle of Eisenberg about elementary particle location : fully undetermined...in addition to the quantum theory and to the experiments of CERN and of Fermi LAB....and to a lot math.

Rather nice a controversial theories...and sorry for the classic Physics that predicates that 'what is NOT obdervable directly or indirectly does Not really exist ....in physics' , BUT too many math models seems to indicate that these multistate universes do exist.

What to say more ??? The problem it is NOT what we perceive or believe the reality is...but how many reality observable nd unobservable truly exist...and I bet we and them do NOT yet know exactly.

Regards to the pure physics researches MATH-SUPPORTED.

[Dave]

A lot of people will have a hard time with this one. And will dismiss it without even a consideration.

It's because people's minds have been made especially for this universe and set up physics etc. So they find it almost impossible to think outside the box that their mind has always been inside.

I's a shame.

It's the same reason people have such a hard time grasping the concept of no time or space existing before the big bang or that objects can exist simultaneously in two states.

Because it's so foreign people believe it's just a fairy tale. But really, you shouldn't be expecting anything LESS than completely foreign when you look completely outside our conventional everyday universe.

[Marty Ferguson]

Thank goodness the jerk who calls himself 'Yo mama' didn't leave a message. He's so far removed from this level of physics and science that he might as well be a Neanderthal (probably a gang-banger with no science 'sense' at all).

M

[Harrrie]

I believe without a doubt that our universe is surrounded by an infinite number of universes. These universes have the same properties our universe has (the properties we know and don't know about), including gravitation, and all of these universes are attracted to each other to different degrees, depending where they are in their evolution. Eventually, the mass from our universe, in all directions, will merge with the mass of other universes. Then all this merged mass, some here and some there, will eventually contract, and there will be new big bangs going off all over the place (of course at different times). If we could see beyond our universe edge, we would see other universes merging, some doing the big bang, some spreading out like ours, etc. It's too simple to not be true. And there is no reason that our universe has to be the only one.

[Joe]

A lot of people think these parallel universes are adjacent to our own. n00bs. The parallel universes are right here, in your own room, just hidden. So why do I live in this shitty universe and not the one where I'm a millionaire? Because the way the universe is set up, all possibilities are contained in the 10th dimension, so the choices I make carve out which path I join. Think about it: all the possibilities are out there- you just choose how to get there. The ways I can get to being a millionaire are infinite. If I choose to play the lottery and win it, then I've only gone down one possible path to that end. This "parallel universe" model actually just follows simple logic.