 Which item doesn't get mentioned while they're in the year 2150?
You will, you know, so why quibble about it? 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. "Maybe it's no dimension—or it might be the fifth; if you're going to skip over the so-called fourth without traveling along it, you'd need a fifth. I figured out once that such a universe would need some seven or eight time and space dimensions. That means you either carry a small time field with you, or you are catching a small increment of time from the main field.
 flying vehicles
 flying vehicles  diamond makers  an elevator that you can't feel move  a modified English language