reply to post by tdrowe2010
OK, all dimensions are really like directions that you can measure things in.
On a 3D graph, we have three axes, normally called X, Y & Z axes. This allows us to indicate the position of any point in 3D space, by measuring
offsets along each axis, from any known point.
Time is generally described as the fourth dimension, because we can only resolve/see four dimensions.
Measurements along the time axis are unusual in that we can only see the specific point we are at. We can't look ahead, or behind. We can, however
define these other points mathematically and we can retrieve past locations from our memory, which verify the mathematical assumptions.
Because of the limitation of the speed of light, we also know that one second is equal to 299,792,458 meters along the axis of time. This allows us to
perform mathematical functions on this 4 dimensional space-time (Minkowski Space), because we can use the same measure in all dimensions. Things like
velocity and acceleration can then be redefined as an offset, or change in offset along the axis of space-time, extending our mathematical description
of the world.
It is theorized that the reason we can't see any higher dimensions is that they are "rolled-up" at a radius too small for our instruments to
resolve. Please note that this is theoretical
and there may be other reasons we cannot see higher dimensions, probably related to the reason we
can only see an instant along the axis of time.
These higher dimensions, even though they cannot be seen, still exist mathematically. Also, when we explore some of the "holes" that we know of in
our understanding of physics, it appears that there may be actions that are occurring via these unseen dimensions. This is why string theorists are
fairly convinced that there are more than 10 dimensions required to make what we know of in physics, fit the mathematical models we have.