 What don't they know about the time machine?
Yes, it'll be pretty obvious it must be a time machine. You'll be puzzling over what I'll tell you, and you'll be getting used to the idea that you are the man who makes atomic power practical. I figured out once that such a universe would need some seven or eight time and space dimensions. Maybe there is no machine, and it's just easier for us to imagine it. That means you either carry a small time field with you, or you are catching a small increment of time from the main field. Maybe the machine has a gravity field built in, or maybe the time that makes your watch run is responsible for gravity. There's no feeling of acceleration—some kind of false gravity they use in the future.
 who invented it
 who invented it  what the third set of buttons do  where it gets stored when not in use  how to make it go back and forth in time