Parallel universes and extra dimensions

[shakeNbake06]

found this documentary really interesting . It's about the theory of parallel universes and how there might be an infinite number of universes. It also talks about extra dimensions and string theory, and that "big bangs" could be taking place all the time. There's 5 parts to it.

"Scientists now believe there may really be a parallel universe - in fact, there may be an infinite number of parallel universes, and we just happen to live in one of them. These other universes contain space, time and strange forms of exotic matter. Some of them may even contain you, in a slightly different form. Astonishingly, scientists believe that these parallel universes exist less than one millimetre away from us. In fact, our gravity is just a weak signal leaking out of another universe into ours."

[Waves]

good stuff.

i do think an infinity number of universes exist, and our mind sort of aligns us with the one thats most pertinent to us in the moment. as that happens consciousness is able to divide and separate and increase in complexity while remaining wholeness and unity. and the idea that we are in all of those universes, experiencing them all just like we are this one intrigues me.

[Vik*star*]

Pre-big bang current ideas based on limited evidence:

Did pre-big bang universe leave its mark on the sky? - space - 10 April 2008 - New Scientist Space

Did pre-big bang universe leave its mark on the sky?
10 April 2008
From New Scientist Print Edition. Subscribe and get 4 free issues.
Stephen Battersby

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Contact us
Web LinksAlejandro Corichi, National Autonomous University of Mexico, Morelia
Parampreet Singh, Pennsylvania State University
Perimeter Institute for Theoretical Physics
Martin Bojowald, Pennsylvania State University
WHAT happened before our universe began? According to two theoretical physicists, if there was a universe before ours then it should have been remarkably similar to this one, with the same basic ingredients and properties. It may even be possible to see a faint picture of our parent universe imprinted on the sky.
Questions about a time before the big bang were once thought to be meaningless, because according to Einstein's general theory of relativity, the universe began at a singularity - a mathematical point with infinite density at which all calculations break down.
However, physicists now believe that the theory of relativity is limited and the effects of quantum mechanics would have blurred out the singularity just a little, so at a crucial moment the density of matter and radiation was not infinite. If this was the case, it becomes possible to try to work out what led up to that moment.
In cosmological models based on a theory called loop quantum gravity, our universe has a parent. Loop quantum gravity attempts to meld relativity with quantum mechanics by describing space-time as a constantly rearranging fabric of interconnections. On the smallest scales, around 10-35 metres, that fabric is a tangled mess, but on much larger scales the space and time of our universe look smooth.
The theory predicts that when this fabric is scrunched up, it becomes bouncy. So if the universe before ours was contracting, it would have reached a point of maximum density and then bounced out again in our big bang.
So what would this predecessor have been like? To find out, Parampreet Singh of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada, and Alejandro Corichi of the National Autonomous University of Mexico, Morelia, applied the equations of loop quantum gravity to a highly simplified model of the universe. They found that the properties of space, such as the quantity of matter and energy it contains, hardly change when the universe goes through the big bounce. "For the simple model considered, the universe is almost exactly the same on other side," says Singh.
It raises the possibility that we could see an imprint of the universe before ours. Singh suggests that the seeds of large-scale structures in our universe, such as superclusters of galaxies, would have been present on the pre-big-bang side. The pattern of those seeds might be preserved in the cosmic microwave background radiation - the relic radiation left behind by the big bang. "If this conclusion holds true, then it is possible that we are going to see signatures of the pre-big-bang universe," says Singh.
“Seeds of structures in our universe, such as superclusters of galaxies, would have been there on the pre-big-bang side”A pioneer of loop quantum gravity, Carlo Rovelli at the Centre for Theoretical Physics in Marseille, France, likes the work. "It is quite remarkable that we can begin to address these questions and find the first tentative answers," he says.
But the calculation doesn't convince Martin Bojowald, another loop quantum gravity theorist, based at Pennsylvania State University in University Park. He disagrees with their interpretation of the mathematics and also points out that loop models so far are still very simple.
Bojowald thinks that the universe before the big bang could have been a very different place, perhaps without even the familiar smooth, classical space-time of our world.


Also cyclic universe:

SPACE.com -- In New Theory of Universe, Time Never Ends

Paul Steinhardt's universe is a lot like the workaday world of many people, a cycle of early vigor, spent energy, exhausted return, and new beginnings. However, in Steinhardt's universe, there is absolutely no end to the cycle.

The Princeton physicist and his colleague, Neil Turok of Cambridge University, have developed a whole new theory for how the universe came to be. Their proposal seeks to explain recently uncovered flaws in the scientifically accepted model for the origin and evolution of all known things. It describes a series of big bangs and equally significant crunches that form a never-ending cycle of rejuvenation and destruction.

In this universe -- our universe -- time never ends.

The current leading theory for the universe holds that it emerged from a single Big Bang sometime around 12 billion to 15 billion years ago, undergoing an early and rapid period of inflation. That much remains widely accepted.

"However, the standard model has some cracks," Steinhardt and Turok write in a paper published today in the online version of the journal Science.

Astronomers have in recent years learned that the universe is not just expanding, but is doing so at an ever-increasing pace. This can't be explained given the known matter and energy that exists. To account for the acceleration, theorists have conjured a product they call dark energy, which supposedly repels things rather than attracting, as gravity does.

No one has seen this dark energy, and scientists don't even know what it is. But they say it's all around us.

More important, it shouldn't be there.

"The recent discoveries of cosmic acceleration and gravitationally self-repulsive dark energy were not predicted and have no particular role in the standard model," Steinhardt and Turok argue. "Furthermore, the standard model does not explain the beginning of time,' the initial conditions of the universe, or what will happen in the long-term future."

So to patch some of the theoretical cracks, Steinhardt and Turok envision a universe based on perpetual expansion and contraction.

Here's how it works, and keep in mind we're jumping into the middle of the explanation: A big bang sends everything outward. Matter and radiation develop. Dark energy drives an expansion -- as is presently underway -- that lasts trillions of years. Finally, the matter, radiation, and even black holes are "diluted away," leaving the universe smooth, empty, and flat.

Then everything contracts in a so-called big crunch, and a fresh cycle begins.

"In this picture, space and time exist forever, Steinhardt says. "The big bang is not the beginning of time. Rather, it is a bridge to a pre-existing contracting era."

Curiously, the cyclic universe, as it is called, puts the origin of some present-day structures and events prior to the Big Bang.

While existing theory states that galaxies and large clusters of galaxies developed from lumps and filaments that formed in the otherwise smooth fabric of space and time shortly after the Big Bang, Steinhardt thinks the seeds of galaxy formation were created by instabilities that arose during the last contraction, before the crunch that led to "our" bang.

The new model "turns the conventional picture topsy-turvy," he says.

The cyclic universe has roots in even more complex thoughts like so-called superstring theory, which suggests there are as many as 10 spatial dimensions, not just the three we know of. The seemingly inexplicable physics of a big crunch and a big bang might be explained with the aid of these extra dimensions, which are otherwise invisible to us, several theorists believe.

In fact, Steinhardt, Turok and others proposed last year that our universe might have sprung from the collapse of an extra dimension, an idea they called the Ekpyrotic Universe. The cyclic universe builds on this former work but, Steinhardt says, does a better job explaining observations of our present universe.

Other theorists are not quick to give up their standard model, so the concept of a cyclic universe faces an uphill battle for prominence. Even Steinhardt acknowledges that the prospect of unseating a well established cosmological theory "would seem extremely dim."

Meanwhile, the new concept is not free of cracks, either: Even the cyclic universe does not address when the cycles began, so "the problem of explaining the beginning of time remains," the researchers say.

[Vik*star*]

Personnally, I do think there would be parallel universes, but I dont' think they would contain "identical" us. Also I think cyclic universe or universes makes more sense than Parallel world theory. JUST My opinion

[BearsysRevenge]

A really great documentary and book is Brian Greene's The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory.
It's a three hour program for NOVA, from back in '03.
Here it is, on YouTube... YouTube - Broadcast Yourself.

[FourtySecondRip]

so with the millimeter away thing i can do a sweet round house and take out like 5,333,294 people!

seriously tho really cool stuff

[Vik*star*]

So there might me parallel universes around here which will contain much cheaper gas??

Certainly not my one> Why god???

[FourtySecondRip]

theres probably not very many of those infinite universes that even have humans left. if you think about it most of them probably didnt survive the iceages or dinosaurs or meteors or nukes. id rather pay 10 bucks a gallon then be dodging sabertooth tigers again, that was a bitch and a half!

have u guys seen sliders? i just started watching the series on netflix but so far they went to a universe with an iceage and now they are in the peoples united states with statues of lenin everywhere lol