It all comes down to how things of different sizes behave.
Here's what they're working on at Fermi that may actually physically detect the other dimensions.
http://news.uns.purdue.edu/UNS/html4...h.Casimir.html
and different explaination etc here
http://people.cs.uchicago.edu/~mbw/a...ons.html#extra
They're both really long or i would post them. +you'd miss out on all the neat pictures and diagrams. I didnt get any pop-ups