What time period would you choose?...let's see...go back for more than 50 years, and you are just starting to struggle with the language 200 years, and you are almost totally lost and everyone else is tiny...all these fun new diseases that no-one can cure...at some point no-one speaks any language you understand...and go back to the dinosaurs, and you would be unable to breathe the atmosphere...going back in time?... I wouldn't go back much further than when I was born...what do you think?