"This is not the moment for any detailed explanation, Rob. I need only say this: As I told you a while ago, the fundamental substance of which our bodies are composed is--not substance, but a mere vortex. A whirlpool, a vibration let me term it. And the quality of this vibration--this vortex--the time-factor controlling it, governs the material character of our conscious universe. From birth to death--from the beginning to the end--we and all the substance of our universe move along this unalterable, measured flow of time. "Do I make my meaning clear? From--nothing but a vibrating whirlpool the magic of chemistry has built with this unalterable time-factor what we are pleased to call substance--material bodies. These material bodies have three varying dimensions--length, breadth and thickness. But each of them inherently is endowed also with the same basic time-factor. The rate of time-flow governing them, let me say, is identical." He spoke now more slowly, with measured words as though very carefully to reach my understanding. "You must conceive clearly, Rob, that every material body in our universe is passing through its existence at the same rate. Now if we take any specific point in time--which is to say any particular instant of time--and place in it two material bodies, those two material bodies must of necessity occupy two separate portions of space. That's obvious, isn't it? Two bodies cannot occupy the same space at the same time. "Now Rob, I have spoken of this unalterable measured flow of time along which all our substance is passing. But it is not unalterable. I have found a way of altering it." He raised his hand against my murmur, and went on, carefully as before. "What does this do? It gives a different basic vibration to matter. It gives a different rate of time-flow, upon which, building up from a fundamental vortex of changed character, we reach substance--a state of matter--quite different from that upon which our present universe reposes. A different state of matter, Rob--it still has length, breadth and thickness--but a different flow of time. "You follow me? Now, if we take a material body of this--call it secondary state--and place it in the same space with a body of our primary state, they can and do occupy that space without conflict at the same instant of time. "Why? Ah Rob, it would take a keener mind than mine or yours to answer that, or to answer the why of almost anything. The knowledge we poor mortals have is infinitesimal compared to the knowledge we have not. I can conceive vaguely, however, that two primary bodies, placed in identical points of space and time would be moving through time at identical rates and thus stay together and conflict. Whereas, with a primary and secondary body, their differing time-flows would separate them after what we might call a mere infinitesimal instant of coincidence." * * * * *