50 in 50

He sat with his back to the window, his thin, white hair catching the afternoon sunlight and making an aura about his head.

"Professor Einstein," Dan Coye said, "can you tell us what has happened? What has changed?"

"Nothing has changed, that is the important thing that you must realize. The world is the same and you are the same, but you have— for want of a better word I must say — you have moved. I am not being clear. It is easier to express in mathematics."

"Anyone who climbs into a rocket has to be a bit of a science fiction reader, and I've absorbed my quota.” Dan said. "Have we got into one of those parallel-worlds things they used to write about, branches of time and all that?"

"No, what you have done is not like that, though it may be a help to you to think of it that way. This is the same objective world that you left — but not the same subjective one. There is only one galaxy that we inhabit, only one universe. But our awareness of it changes many of its aspects of reality."

"You've lost me," Gino sighed.

"Let me see if I get it," Dan said. "It sounds like you are saying that things are just as we think we see them, and our thinking keeps them that way. Like that tree in the quad I remember from college."

"Again not correct, but an approximation you may hold if it helps you to clarify your thinking. It is a phenomenon that I have long suspected, certain observations in the speed of light that might be instrumentation errors, gravitic phenomena, chemical reactions. I have suspected something, but have not known where to look. I thank you gentlemen from the bottom of my heart for giving me this opportunity at the very end of my life, for giving me the clues that may lead to a solution to this problem."

"Solution. ." Gino's mouth opened. "Do you mean there is a chance we can go back to the world as we knew it?"

"Not only a chance but the strongest possibility. What happened to you was an accident. You were away from the planet of your birth, away from its atmospheric envelope and during part of your orbit, even out of sight of it. Your sense of reality was badly strained, and your physical reality and the reality of your mental relationship changed by the death of your comrade. All these combined to allow you to return to a world with a slightly different aspect of reality from the one you have left. The historians have pinpointed the point of change. It occurred on the seventeenth of August, 1933, the day that President Roosevelt died of pneumonia."

"Is that why all those medical questions about my childhood?" Dan asked. "I had pneumonia then, I was just a couple of months old, almost died, my mother told me about it often enough afterwards. It could have been at the same time. It isn't possible that I lived and the president died. .?"

Einstein shook his head. "No, you must remember that you both lived in the world as you knew it. The dynamics of the relationship are far from clear, though I do not doubt that there is some relationship involved. But that is not important. What is important is that I think I have developed a way to mechanically bring about the translation from one reality aspect to another. It will take years to develop it to translate matter from one reality to a different order, but it is perfected enough now — I am sure — to return matter that has already been removed from another order."

Gino's chair scraped back as he jumped to his feet. "Professor— am I right in saying, and I may have got you wrong, that you can take us and pop us back to where we came from?"

Einstein smiled. "Putting it as simply as you have, Major. . the answer is yes. Arrangements are being made now to return both of you and your capsule as soon as possible. In return for which we ask you a favor."

"Anything, of course," Dan said, leaning forward.

"You will have the reality-translator machine with you, and microcopies of all our notes, theories and practical conclusions. In the world that you come from all of the massive forces of technology and engineering can be summoned to solve the problem of mechanically accomplishing what you both did once by accident. You might be able to do this within months, and that is all the time that there is left."

"Exactly what do you mean?"

"We are losing the war. In spite of all the warning we were not prepared, we thought it would never come to us. The Nazis advance on all fronts. It is only a matter of time until they win. We can still win, but only with your atom bombs."

"You don't have atomic bombs now?" Gino asked.