 Why is there no feeling of acceleration in the elevator in the future?
Yes, it'll be pretty obvious it must be a time machine. "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. Maybe there is no machine, and it's just easier for us to imagine it. You suddenly realize that everything in the machine is wide open, yet you haven't seen any effects of air loss. You still feel gravity, but I can't explain that, either. There's no feeling of acceleration—some kind of false gravity they use in the future.
 The false gravity used in the interstellar civilization.
 The force is too fast to be felt.  The elevator doesn't actually move, only the scenery does.  It's moving slower in opposition to the gravity.  The false gravity used in the interstellar civilization.