Proof of an extra dimension may not be so hard to find. I think I may originally have found this link on this forum!

http://www.sciam.com/article.cfm?articleID=2D3D296B-E7F2-99DF-3D73118D0D9F5D10

This kind of experiment anticipates that there will be a measurable effect upon gravity, and therefore upon space-time. If such an experiment ever gives positive results, then it would be necessary to incorporate the extra dimension(s) into a new space-time theory, e.g., M-Theory.

"Time is what prevents everything from happening at once" - John Wheeler