Time travel novell: Ändra nutiden genom att flytta en sten i det förflutna

"Jag, jag själv och jag" , en kortfattad historia av William Tenn , pseudonym för Philip J. Klass; först publicerad (som av Kenneth Putnam) i Planethistorier , Vinter 1947 , tillgängligt på Internetarkiv .

Jag letar efter en novell där en ung man skickas tillbaka i tid till en ålder av 1 miljon år sedan. Professorn som bygger tidsmaskinen varnar honom för att inte röra någonting när han är "där" men han flyttar en sten i vatten ur nyfikenhet.

Det är 110 miljoner år, och professorn har faktiskt instruerat honom att flytta berget:

Ruddle watched while the check was carefully placed in the outer breast pocket of the ancient sweater. He picked up an expensive miniature camera and hung its carrying strap around his employee's neck. "Now, this is fully loaded. Are you certain you can operate the shutter? All you do—"

"I know all right. Fooled around with these doohickeys before. Been playing with this 'un for two days. You want me to step out of the machine, take a couple of snaps of the scenery, and move a rock."

"And nothing else! Remember, you're going back a hundred and ten million years and any action on your part might have an incalculable effect on the present. You might wipe out the whole human race by stepping on one furry little animal who was its ancestor. I think that moving a rock slightly will be a good first innocuous experiment, but be careful."

Och när han kommer tillbaka till sin egen tid finner han att allt är nästan detsamma, men en liten bit förändras. Liksom professorns namn är något annorlunda och nu har han en mustasch, etc.

After the rich sunlight of the Cretaceous, the laboratory seemed smaller than he remembered it. The Professor came up to him breathlessly as he stepped from the time machine.

"How did it go?" he demanded eagerly.

McCarthy stared down at the top of the old man's head. "Everthin' O.K.," he replied slowly. "Hey, Professor Ruddle, what for did you go and shave your head? There wasn't much of it, but that white hair looked sorta distinguished."

"Hair? Shave? I've been completely bald for years. Lost my hair long before it turned white. And my name is Guggles, not Ruddle—Guggles: try and remember that for a while. Now let me see the camera."

Det var det första av flera resor tillbaka till samma plats i Kreten. I den ursprungliga tidslinjen var professorn en ungkarl. För andra gången är han en gift man, så skickar han sin assistent tillbaka för att ångra skadan:

"Yes, of course. H'mmm. That may have been it. The centipede jumping out of the rock may have altered subsequent events sufficiently to make me a married man instead of a blissful single one, to have changed my name from Ruddle to Guggles. Or the rock itself. Such an intrinsically simple act as moving the rock must have had much larger consequences than I had imagined. Just think if that rock had not been moved, I might not be married! Gallagher—"

"McCarthy," the tall vagabond corrected resignedly.

"Whatever you call yourself—listen to me. You're going back in the time machine and shift that rock back to its original position. Once that's done—"