“If you had been born and raised on a moving train, no one could convince you that the landscape was not in rapid motion. Well, our conception of the universe is quite as relative as that. Sir Isaac Newton tried in his mathematics to express a universe as though beheld by an infinitely removed and perfectly fixed observer. Mathematicians since his time, realizing the futility of such an effort, have taken into consideration that what things ‘are’ depends upon the person who is looking at them. They have tried to express common knowledge, such as the law of gravitation, in terms that would hold good for all observers. Yet their leader and culminating genius, Einstein, has been unable to express knowledge in terms of pure relativity; he has had to accept the velocity of light as an arbitrarily fixed constant. Why should the velocity of light be any more fixed and constant than any other quantity in the universe?” “But, what’s that got to do with going into the fourth dimension?” I broke in impatiently. He continued as though I hadn’t spoken. “The thing that interests us now, and that mystifies modern mathematicians, is the question of movement, or more accurately: translation. Is there such a thing as _absolute translation_? Can there be movement--translation--except in _relation_ to something else than the thing that moves? All movement we know of is movement in relation to other objects, whether it be a walk down the street, or the movement of the earth in its orbit around the sun. A change of _relative_ position. But the mere translation of an isolated object existing alone in space is mathematically inconceivable; for there is no such thing as space in that sense.” “I thought you said something about going into another universe--” I interrupted again. You can’t argue with Woleshensky. His train of thought went on without a break. “By translation we understand getting from one place to another. ‘Going somewhere’ originally meant a movement of our bodies. Yet, as a matter of fact, when we drive in an automobile, we ‘go somewhere’ without moving our bodies at all. The scene is changed around us; we are somewhere else; and yet we haven’t _moved_ at all. “Or suppose you could cast off gravitational attraction for a moment and let the earth rotate under you; you would be going somewhere, and yet not moving----” “But that is theory; you can’t tinker with gravitation----” “Every day you tinker with gravitation. When you start upwards in an elevator, your pressure, not your weight, against the floor of it is increased; apparent gravitation between you and the floor of the elevator is greater 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.”