Brane Theory
"Gravity: Strength in Weakness" by Michelle Thaller:
We measured the strength of all the forces, and gravity came in last. End of discussion. But that's not enough of an answer for scientists, and the real reason gravity is so weak may break open the next major advance in our perception of the universe. There are some tantalizing suggestions that gravity is, in fact, not weak at all, it's just diluted by having to act over more than our familiar four dimensions (three of space and one of time).
By now you may have heard that scientists strongly suspect that there are more than four dimensions in our universe. The big question is why we can't experience those other dimensions directly; why do they seem to be hidden from us? An increasingly popular theory of fundamental physics, call Brane Theory, is being used to explain that, and a whole lot more about how our universe really works.
