— I’m talking about the classic paradox of time. Imagine, for example, I go back in time and meet my own grandfather. Long before he got married, before he had children. And we have an argument, and I kill him. Now if that happens, how am I ever going to be born? And if I can never be born, how can I go back in history and meet my very own grandfather?
— For Christ’s sake! What is this, some half-assed Princeton debating society? We are in a war situation! This is a United States warship! Or, at least, it used to be. Or will be. Or what the hell ever! Oh, Goddammit, you can drive yourself crazy just trying to think about this stuff!

This is the kind of movie that some kids would probably enjoy — it’s filled with technology, special effects and action. But it just doesn’t make any sense. And it lacks the wit to have fun with its time travel paradoxes […]. It just plows ahead. Or behind. Or somewhere. — Roger Ebert, 1980.