Besides being a very popular R&B/soul/pop/psychedelia group in the late 60's, the fifth dimension is the one that, for me, starts the mindfuck. I can get my head around the orthogonality of time to the 3 dimensions we can perceive in our universe. So this cube moves through time, and as it does so, it travels in another dimension. Great. We don't know why time exists, or what it really is, but we all perceive it. In order for things to move, there must be time. OK. Once you tack on another dimension though, as physicists are want to do, I just don't understand where the dimension is supposed to go! What does it do? How do we move on it, and what does that mean? I know that thinking about these things really doesn't lead anywhere other than math problems I don't like to do, but I have to think these things.