Existence of extra dimensions – finally the truth is coming out
Finally scientists are experimenting to prove the existence of extra dimensions. They 'see'' the extra dimensions through particles interacting with the gravitons that do still live in all 9 dimensions, but the effects of the gravitons living in these extra dimensions are so small that actually there are extremely large extra dimensions without terrestrial technologies 'seeing'' them through gravitational forces.
Actually, these extra dimensions are as large as a tenth of a millimeter without us being able to seem them at this moment. Experiments are now being done that would allow us to see extra dimensions that are as big as a tenth of a millimeter, but since they involve the very weak gravitational force, the experiments are technically very involved.
The world would be thrilled when we finally see deviations in the gravitational force due to the existence of extra dimensions.
The whole thrust of this discovery comes from the Open-String Theory of modern Physics and the concept of Branes.
We find that the open strings are now restricted to live on objects called Branes. The open strings cannot freely move everywhere in space, but their endpoints are confined to move on these Branes.
The branes that we find can have dimension 0 (points), 1 (stringlike branes), 2 (membranes), 3 (volumes, like the space we live in), and even higher dimensions, up to nine, since otherwise they wouldn''t fit into our nine-dimensional space anymore. These are new objects in string theory, and they allow for amazing new possibilities.
Assume that we have a Brane that is three-dimensional, just like our space. Then we would have gauge fields living on the Brane, in three spatial dimensions. That Brane could look exactly like our world.
In other words, our world is a three-dimensional Brane. And since, say, the photon only lives on the Brane, all the other six dimensions is literally dark. Indeed, no photons, or light, would come from these other dimensions, and no light would leak into these dimensions, since the photons (gauge fields) can only live on the Brane.