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The Question

(Submitted July 26, 2006)

Since string theory implies up to 11 dimensions, could dark matter be gravitons leaking from other dimensions into ours?

The Answer

Actually, that's exactly one possibility that's being explored by brane-world theorists. Of course, the jury is still out on brane-world theories....

From the Cornell Chronicle:

"In brane-world theory, the ends of strings are anchored in our brane, so the particles we see can only move within the brane. But the particles that carry the gravitational force, known as gravitons, are closed strings -- little Cheerios -- and can "leak" out of the brane. This explains why gravity is much weaker than the electromagnetic force and the strong and weak nuclear forces. It also offers a possible explanation for the "dark matter" that astronomers need to explain why the mass of the universe doesn't agree with the observed objects. Dark matter could be in an adjacent brane, with its gravitons leaking into ours."

We hope this helps!

Barbara & Ilana
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