bushfriend, I do believe that the Tenth Dimension is the one which exceeds the other Nine
However i see you haven't used the search engine so here you are.
A 10 Dimensional Universe
The curious feature of superstrings, however, is that they can only vibrate in 10 dimensions. This is, in fact, one of the reasons why it can unify
the known forces of the universe: in 10 dimensions there is “more room” to accommodate both Einstein's theory of gravity as well as sub-atomic
physics.
In some sense, previous attempts at unifying the forces of nature failed because a standard four dimensional theory is “too small” to jam all the
forces into one mathematical framework. To visualize higher dimensions, consider a Japanese tea garden, where carp spend their entire lives swimming
on the bottom of a shallow pond. The carp are only vaguely aware of a world beyond the surface. To a carp “scientist,” the universe only consists of
two dimensions, length and width.
There is no such thing as “height.” In fact, they are incapable of imagining a third dimension beyond the pond. The word “up” has no meaning for them.
(Imagine their distress if we were to suddenly lift them out of their two dimensional universe into “hyperspace,” i.e. our world!) However, if it
rains, then the surface of their pond becomes rippled. Although the third dimension is beyond their comprehension, they can clearly see the waves
traveling on the pond's surface. Likewise, although we earthlings cannot “see” these higher dimensions, we can see their ripples when they vibrate.
According to this theory, “light” is nothing but vibrations rippling along the 5th dimension. By adding higher dimensions, we can easily accommodate
more and more forces, including the nuclear forces. In a nutshell: the more dimensions we have, the more forces we can accommodate. One persistent
criticism of this theory, however, is that we do not see these higher dimensions in the laboratory.
At present, every event in the universe, from the tiniest sub-atomic decay to exploding galaxies, can be described by 4 numbers (length, width, depth,
and time), not 10 numbers. To answer this criticism, many physicists believe (but cannot yet prove) that the universe at the instant of the Big Bang
was in fact fully 10 dimensional. Only after the instant of creation did 6 of the 10 dimensions “curled up” into a ball too tiny to observe.
In a real sense, this theory is really a theory of creation, when the full power of 10 dimensional space-time was manifest.
[Edited on 6-5-2004 by Sapphire]