How could one study time travel?

[Lemur866]

Here’s how you do it: enroll in physics with the express inexorable goal of building a time machine. One day in the future you will invent the time machine. When this happens, go back in time to your freshmen student self and hand him the papers and theoretical framework one must study in order to invent a time machine. It’s bound to work, since the papers you got from your future self made it a lot easier to build the time machine in the first place.

If you’re going to invent a time machine, you’ve already invented it in the future, so you may as well explain how to invent it to your past self and save yourself a lot of wasted effort.

So from a story point of view how it works is this:

“Hey, I’m going to invent a time machine! I don’t know how, and I don’t know when, but I just know I will!”

BZZZZZZZT! A time machine appears and a grizzled old dude steps out. He wordlessly hands the kid a book entitled “How I Invented the Time Machine” by Myself, steps back in the machine and disappears.

Or, just skip another step just like in “The Man Who Folded Himself” and hand your younger self the time machine so you can get started time traveling right away.

[Schnitte]

@Chronos

The End of Eternity was Asimov specifically setting out to prove that he could write a time travel story… and failing. There’s hardly any time travel in the book at all: It’s a space-travel story, with the planets renamed as “centuries” and space re-named as “time”. He mentions a few of the classic time-travel puzzlers, but he never actually addresses any of them.

I disagree respectfully. The End of Eternity is arguably not a very good time travel story, but I wouldn’t say it’s not a time travel story at all. The “centuries” his “technicians” travel to are not just distant planets; it is said in many instances that changes made to one century can change the way history unravels and affect later centuries. There’s also a nice plot twist at the end of the book which is based on time travel ideas, even though it is admittedly not essential for the plot. It is revealed that the present reality, in which the first nuclear detonation took place in 1945, was the outcome of a reality change effected by a Technician, and that without this change nuclear energy would have been developed much later The logic of the plot wouldn’t work if the “Technicians” were simply travelling to distant but contemporaneous planets, so I don’t think it’s accurate to say that Asimov wrote a space travel story and changed the labels.