Save yourself!
If you were transported 500 years into the past, with no objects-no clothes or anything, how would you prove you’re from the future? You don’t have much time to prove yourself, so inventions are pretty out of the question. I found this question very hard to answer. I have to admit that I’m not even sure I know what was happening in the world in the 1600’s. If you weren’t royal or wealthy, you probably lived a hard life. People around you might find your incessant chatter suspicious and assume you’re possessed. The only thing I can come up with, is music. I’d sing for them. What songs would you choose to save your life? Halleluiah by Leonard Cohn, Imagine by John Lennon, Sweet Child O Mine by GnR, and a few Bob Dylan songs definitely come to mind. I’d probably throw in the Macarena, for good measure.