“Exactly. Our microscopes show nothing which is actually more solid than the sky itself. From here, on earth, to the Milky Way is to us a tremendous distance. But suppose that we were so gigantic—so vast in comparative size—that we needed a powerful microscope even to perceive that space. What would we see? A multiplicity of vibrating particles! And without the microscope the whole space would seem solid. We could call it . . . well, say a grain of gold.” For a moment we were silent. There was to all this an awesome aspect. Yet its actual simplicity was overwhelming. Dolores said timidly, “It seems strange that so simple a thing should have been unknown for so long.” “Not at all,” said Dr. Weatherby. “The knowledge came step by step. It is only the final conception which seems so startling. To me it is the logical, inevitable conclusion. How could the facts be otherwise? “Always, therefore, we have conceived ourselves and our earth to be some masterful dividing line between what is smaller and what is larger than ourselves. That is fatuous. “We call the one our microscopic world. The other our astronomical world. And we sit between them, puzzling over their difference! They are both one, and we are in them—a mere step of the ladder.” “It makes me feel very small,” said Alice. “Or large,” I said. “According to the viewpoint.” I added to Dr. Weatherby, “I realize now why no size, no motion, no time, nor density can be absolute. Everything must be relative to something else.” “Exactly,” he nodded. Jim was puzzling. “This voyage we’re going to make—beyond the stars. How are we going to make this trip? What in? By what method? By the nine airy demons, Dr. Weatherby, there’s an awful lot you haven’t told us yet!” “Not so much,” said Dr. Weatherby smilingly. “Because,” I interposed, “you don’t need to know very much, Jim.” “We’re going in a projectile,” said Dolores. “At least they say it looks like a projectile.” “Like Mallen’s moon rocket of 1989,” Tim exclaimed. Dr. Weatherby shook his head. “The various anti-gravity methods devised so far would help us very little, except Elton’s electronic neutralization of gravity. I use that principle merely in starting the flight. A trip to the moon, such as Mallen’s rocket made, had nothing in common with this journey of ours.” “They say Mallen is going himself next year—to Mars,” Alice remarked. “Let’s see our projectile,” Jim demanded. “In a moment,” Dr. Weatherby said. “There is, first, one conception I want to make sure you have grasped. Forget our earth now. Forget yourself. Conceive the material universe to be a vast void in which various densities are whirling. “From the infinitely small to the infinitely large, they are of every size and character. Yet all are inherently the same, merely apparently solid. I will ask you, Leonard, this space between the earth and Mars—of what would you say it is composed?” I hesitated. “Nothingness,” I ventured finally.