plash-shaped piece of clear, colorless
gelatin.

Suppose that for the sake of experimenting you have brought an
elephant along on this trip. You can move under him (or over
him--anyway between him and the floor), brace your feet on the floor,
and give him a push. (If he happens to step on your toes while you are
doing this, you do not mind in the least, because he does not weigh
anything, you know.) If you push hard enough to get the elephant
started, he rises slowly toward the ceiling. When he objects on the
way, and struggles and kicks and tries to get back to the floor, it
does not help him at all. His bulky, kicking body floats steadily on
till it crashes into the ceiling.

No chairs or beds are needed in this place. You can lie or sit in
mid-air, or cling to a fixture on a wall, resting as gently there as
a feather might. There is no need to set the table for meals--just lay
the dishes with the food on them in space and they stay there. If the
top of your cup of chocolate is toward the ceiling, and your plate of
food is turned the other way, no harm is done. Your feet may happen
to point toward the ceiling, while some one else's point toward the
floor, as you sit in mid-air, eating. There is some difficulty in
getting the food on the dishes, so probably you do not wish to bother
with dishes, after all. Do you want some mashed potatoes? All right,
here it is--and the cook jerks the spoon away from the potatoes,
leaving them floating before you, ready to eat.

It is literally a topsy-turvy place.

Do you want to know why all this would happen? Here is the reason:
There is a great force known as _gravitation_. It is the pull that
everything in the universe has on everything else. The more massive a
thing is, the more gravitational pull it has on other objects; but the
farther apart things are, the less pull they have on each other.

The earth is very massive, and we live right on its surface; so it
pulls us strongly toward it. Therefore we say that we weigh something.
And since every time we roll off a bed, for instance, or jump off a
chair, the earth pulls us swiftly toward it, we say that the earth is
down. "Down" simply means toward the thing that is pulling us. If we
were on the surface of the moon, the moon would pull us. "Down" would
then be under our feet or toward the center of the moon, and the earth
would be seen floating up in the sky. For "up" means _away from_ the
thing which is pulling us.

WHY W