I'd go back and hang out with Isaac Newton. I'm torn between...

I'd go back and hang out with Isaac Newton. I'm torn between do I hang out with him or do I bring him into the present to hang out with me. See, that might be terrifying because his head will just explode once he sees everything that was derived from his discoveries, but I'd spend more time with someone who I think is one of the most brilliant minds our species has ever known.