than before—and that's like gravitation is anyway: inertia and acceleration. But we are talking about translation. The position of everything in the universe must be referred to some sort of coordinates. Suppose we change the angle or direction of the coordinates: then you have 'gone somewhere' and yet you haven't moved, nor has anything else moved."
I looked at him, holding my head in my hands.
"I couldn't swear that I understand that," I said slowly. "And I repeat, that it looks like lifting yourself by your own bootstraps."
The homely simile did not dismay him. He pointed a finger at me as he spoke:
"You've seen a chip of wood bobbing on the ripples of a pond. Now you think the chip is moving; now the water. Yet neither is moving; the only motion is of an abstract thing called a wave.
"You've seen those 'illusion' diagrams, for instance this one of a group of cubes. Make up your mind that you are looking down upon their upper surfaces, and indeed they seem below you. Now change your mind, and imagine that you are down below, looking up. Behold, you see their lower surfaces; you are indeed below them. You have 'gone somewhere,' yet there has been no translation of anything. You have merely changed coordinates."
"Which do you think will drive me insane more quickly—if you show me what you mean, or if you keep on talking without showing me?"
"I'll try to show you. There are some types of mind, you know, that cannot grasp the idea of relativity. It isn't the mathematics involved that matters; it's just the inability of some types of mental organization to grasp the fact that the mind of the observer endows his environment with certain properties which have no absolute existence. Thus, when you walk through the garden at night the moon floats from one tree top to another. Is your mind good enough to invert this: make the moon stand still and let the trees move backwards. Can you do that? If so, you can 'go somewhere' into another dimension."
Woleshensky rose and walked to the window. His office was an appropriate setting for such a modern discussion as was ours; situated in a new, ultra-modern building on the University campus, the varnish glossy, the walls clean, the books neatly arranged behind clean glass, the desk in most orderly array; the office was just as precise and modern and wonderful as the mind of its occupant.
"When do you want to go?" he asked.
"Then, I have two more things to explain to you. The fourth dimension is just as much here as anywhere else. Right here around you and me things exist and go forward in the fourth dimension: but we do not see them and are not conscious of them, because we are confined to our own three. Secondly: if we name the four coordinates as Einstein does, x, y, z, and t, then we exist in x, y, and z, and move freely about in them; but are powerless to move in t. Why? Because t is the time dimension; and the time dimension