They wanted to go back to when no one was alive. Now, I don't know if they meant no HUMANS were alive.. or absolutely NOTHING was alive (like Dinosaurs, etc.) The world would be incredibly boring if nothing existed.

Me? I'd like to go back to the 30's, so that I could be around when most of my favorite actors/actresses were big.. like Humphrey Bogart, James Cagney, Edward G. Robinson, Lauren Bacall, James Stewart.. it would have been neat to meet them, or at least go see some of their movies in the theater. I think so anyway.

I'd also like to go back to various points in time to see historical events take place.. like the Civil War.. the Revolutionary War.. Caesar's time.. Pyramids being built.. that sort of thing.