Universe Favoured Three and Seven Dimensions

Three and Seven Dimensions are the only Surviving Dimensions in the Universe.

For String Physicists, Universe is a Crystalmaze with at least nine spatial dimension. Universe for us is 3 dimensions as remaining seven are curled up in some way so that they can untraceable to us. Physicists struggling to find answer that why we experience universe with three dimensions, why no six, four or eight. String Physicists Andreas Karch and Lisa Randall can explain the phenomenon with the help of what they called relaxation principle which suggests that universe started diluting after big bang, and this dilution favoured three and seven dimensions. The one we happened to experience is three dimension universe.

"That's what comes out when you do the math," said Andreas Karch, a University of Washington assistant professor of physics and lead author of a new paper that details the theory.

String Physicists Andreas Karch and his collaborator Lisa Randall, a physics professor at Harvard, set out a Hypotetical model of the universe right after the big bang. They studies the evollution of cosmos after the big bang, while doing this they assume that universe started with a simple configuration with numerous structures, called membranes or branes. These Membranes existed in various dimensions from one to nine, All of them very large and non-curled up in the begining.

String Physicists allowed cosmos to evolve naturally without any additional assumption or a big event, they found that membranes all the
dimensions except three and seven are started diluting. Membranes in three and seven are the only survivors, the universe we exprience resides in three dimensional membrane.

Other realities, either three- or seven-dimensional, could be hidden from our perception in the universe, Karch said.

"There are regions that feel 3D. There are regions that feel 5D. There are regions that feel 9D. These extra dimensions are infinitely large. We just happen to be in a place that feels 3D to us," said Andreas Karch.

In our world, forces such as electromagnetism only recognize three dimensions and behave according to our laws of physics, their strength diminishing with distance. Gravity, however, cuts across all dimensions, even those not recognized in our world, Karch and Randall say. But they theorize that the force of gravity is localized and, with seven branes, gravity would diminish far more quickly with distance than it does in our three-dimensional world.

"We know there are people in our three-brane existence. In this case we will assume there are people somewhere nearby in a seven-brane existence. The people in the three-brane would have a far more interesting world, with more complex structures," Karch said.

With gravity diminishing rapidly with distance, a seven-dimensional existence would not have planets with stable orbits around their sun,
Karch said.

"I am not precisely sure what a universe with such a short-range gravity would look like, mostly because it is always difficult to imagine how life would develop under completely different circumstances," he said. "But in any case, planetary systems as we know them wouldn't form. The possibility of stable orbits is what makes the three-dimensional world more interesting."

Karch and Randall detail their work in the October edition of Physical Review Letters, published by the American Physical Society. The
research was supported by grants from the U.S. Department of Energy and the National Science Foundation.

Karch said they hope the work will spark extensive scientific exploration of many other questions involving string theory, extra dimensions and the evolution of the cosmos.

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