Jim Muth wrote:
Sometimes, while discussing fractals, I remark that the image on the screen is but a slice through an abstract four-dimensional object. When I say this, the question is often asked, 'where is the fourth dimension?' I then reply by stating that the fourth dimension is sideways to the inside of solid objects, and of course, the person I am talking with remarks that such a direc- tion does not and cannot exist because there is no space for it.
A mathematician would argue that a fourth dimension is conceptually no different from the other three. Of course, you'll have a hard time pointing in a direction at right angles to three other orthogonal directions, but that's not the fault of mathematics, but of the way the universe is built - quite a different matter. "Where is the fourth dimension"? is not question relevant in mathematics.
The real difficulty with the fourth, and all higher dimensions, is that we cannot visualize them. Early in life, we learn to decipher and organize our sensory input so that it forms in our minds the image a three-dimensional exterior world. The image works quite well because all people, (with the possible excep- tion of the insane), have formed the same image. Of course, stereo blindness is not that uncommon - people who's three-dimensional picture of the world is more abstract than that of other people - the difference is usually unnoticeable because their deficient model is just as comfortable to them as that of the stereo-sighted.
Then there are the people who can't see movement. And the people who can't see at all.
Maybe he could, maybe not. We'll never know because the experi- ment will never be done. Ethical reasons aside; why not?
Morgan L. Owens "We say space is three-dimensional because the walls of a prison are two-dimensional."