Answer:
Very important fact, that comes up in hundreds of situations . . . . . We never feel motion.
We only feel changes in motion.
Example: You can read or sleep very well in a car going 70 miles an hour, as long as the
car doesn't speed up, slow down, turn, or hit a rough spot. And have you ever been on
an airliner, cruising along at 400 miles an hour and reading a book or taking a nap ?
It makes no difference whether you're moving fast or slow, horizontally or vertically.
You feel nothing until either the speed or the direction changes.
On the spinning earth, you're moving almost 1,040 miles an hour at the equator, or
730 miles an hour at the latitude of Chicago. You don't feel the speed in the direction
east along the ground, because it never changes. You do feel the force it takes to
keep you moving in a circle at that speed ... the force you call your "weight".