“An argument often given for why Earth couldn't host another form of life is that once the life we know became established, it would have eliminated any competition through natural selection. But if another form of life were confined to its own niche, there would be little direct competition with reg”

“I mean, the first 'Back to the Future' is kind of a perfect script, I think, in terms of handling time travel the best. It depends on your definition. To me, that means it effectively uses it in the story.”