I’m writing a short story where this bright young person is starting college and wants to build a time machine. Granted this is fiction but please take the question seriously.
Quite simply, what area of science should they go into? I’m thinking theoretical physics like Stephen Hawkings. Or maybe astrophysics? Or Quantum mechanics?
First decide how time travel works in your story, then enroll your character in the right course of study.
If your travel works using the closed time-like loops around a sufficiently massive rotating object, then astrophysics is the way to go. If it is related to coupling in some way, then quantum mechanics. Etc.
Urbanredneck writes:
> I’m thinking theoretical physics like Stephen Hawkings. Or maybe astrophysics? Or
> Quantum mechanics?
O.K., the first thing you need to get straight is the name of the department. At the vast majority of universities there is just one department, and it’s called the department of physics. There may be some places that have separate departments of theoretical and experimental physics, but that would certainly be rare. Professors in some departments might call themselves specifically theoretical or experimental physicists, but they would still be working alongside each other. Quantum mechanics isn’t a separate department anywhere, I assume, and in any case there are both theoretical and experimental physicists who specialize in quantum mechanics. Astrophysics is a separate department at some large universities, but that’s because it covers both things taught in the astronomy and the physics departments in other universities.
This bright young person will almost certainly major in physics as an undergraduate. As a grad student, they would probably be specializing in either quantum mechanics or relativity in a department of physics. It’s hard to say what field of physics would be most useful, because . . . um, time travel is impossible in the current formulation of physical law. A physics professor who has a freshman come up to say that they are studying there because they want to invent a time machine would, at the very least, say, “Uh, huh, whatever.” At the most, they would edge away from the student and later call the psychological counseling office of the university to report a crazy student.
The second thing is that the famous physicist’s name is Stephen Hawking. 
He could also do a minor in English Lit, with the possibility of discovering some unpublished works by previous time travel writers like H G Wells or Isaac Asimov
Very creative idea! Since you’re writing this story, and it’s SF anyway, you could inject something even more creative than just the “physics student builds time machine” thing. Maybe have them do a minor in Ancient Near Eastern Languages and link in a discovery of an ancient Babylonian tablet on time travel. Or maybe the character is a scholar of Ancient Babylon who comes across a tablet in Iraq describing a time machine and is inspired by that to go on and do a doctorate in Physics to get the skills to actually try to build the thing written about in the tablet.
because this is GQ: yes, physics, like they said.
for the alternate reality where this isn’t GQ: I always wondered if DaVinci was a time traveller.
However many alternate realities the OP wishes to construct, there could be a distinct Stephen Hawking in each of them. Hence, lots of Stephen Hawkings.
And Jack Finney.
Samuel Madden, Edward Page Mitchell, Lewis Carroll - there are quite a few, but Wells and Asimov came straight to mind.
How could one study time travel?
I’ll drop by yesterday and tell you everything about it.
On a more serious note, I would add engineering into the curriculum, not much use knowing the theory if the character doesn’t know how to put together the contraption for traveling in time.
I’m not sure why Asimov would come to mind at all-- He never wrote any decent time-travel fiction. Although I suppose one might posit that he had a few actual samples of resublimated thiotimoline lying around, and that a dedicated literary snoop might figure out what he did with them…
Lewis Carroll?
My favourite time-travel story (‘The Anubis Gates’ by Tim Powers) features a second-rate Coleridge scholar, though to be fair he doesn’t come up with the method.
Heck, in Somewhere in Time it’s a philosophy professor who comes up with the answer. Study Of Everything for the win!
The End of Eternity has lots of good time travel ideas, including ways to communicate through time and an early suggestion of the Chronological Protection theorem.
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.
You’d think Asimov would have done a timetravel story using thiotimoline, doesn’t seem to have done so.
You could include an ethical dilemma, in that if they can’t use the time machine to cheat in their finals they fail the course.