Time Travel in fiction

[Chronos]

@solost

Either they go through with the test 5 minutes later, and create a closed loop in which the scientists at the T-5 mark would actually have gotten infinite blue widgets,

No, just one, the one they sent back. Why would there be infinite?

@Mangetout

Except the problem with this one is that, by handling the blue widget during that 5 minutes, they cause a tiny amount of wear to it, so the widget they send back is 5 minutes older and more worn out than the one they received, which I think means it wears down to nothing instantly because it’s a loop

No, they get the blue widget out of the closet where they’d been storing it, and send that back. So for those five minutes, there are two instances of the blue widget in the lab, one slightly older and more worn than the other.

@Mahaloth

I have no idea. I don’t think the movie suggested this.

You do realize, I hope, that the trope of the Holy Grail dates back long before there was ever any such thing as any movie?