Other people are in the unit all sweaty and nervous and afraid to touch anything because they are so freaked out about the implications of changing history. Oh God, they say, what if I go back and a butterfly flaps its wings differently and this and that and world war and I never existed and so on and yeah. This is what I say: I’ve got good news and bad news. The good news is, you don’t have to worry, you can’t change the past. The bad news is, you don’t have to worry, no matter how hard you try, you can’t change the past.
