"The fourth dimension is a direction different from all the directions in normal space. Some say that time is the fourth dimension ... And this is, in a sense, true. Others say that the fourth dimension is a hyperspace direction quite different from time ... This is also true. There are, in fact, many higher dimensions. One of these higher dimensions is time, another higher dimension is the direction m which space is curved, and still another higher dimension may lead toward some utterly different universes existing parallel to our own. At the deepest level, our world can be regarded as a pattern in infinite-dimensional space, a space in which we and our minds move like fish in water."