Is there a place on Earth that a person can experience
During swimming and during some amusement park rides a
person may experience weightlessness.
NASA also has a special plane used to train astronauts that performs
a parabolic free-fall that produces weightlessness for about 90
seconds. It is affectionately known as the barf wagon.
Sure. Every time you jump from some height, during the
fall you are experiencing the same "weightlessness" that the astronauts
aboard the Shuttle experience. The term "weightlessness" is rather
deceiving; to some people it implies that it is a condition in which
gravity is not acting (a "zero-G" environment). Not so. It is more
correct to say that the astronauts are in free fall; they, their craft,
and its contents are all continuously falling, under the action of
the Earth's gravity. Since they all fall at the same rate, the falling
cannot be perceived by the astronauts; the only motion they see
(if they do not look out at the Earth)
is their relative motion to one another, the interior of the ship, etc.
When the first astronauts were being trained, one thing that was done was
to take them up several thousand feet in a plane, then the plane would go
into a dive in which it was essentially free-falling. This was intended
to duplicate to some extent, for a few seconds, the free-fall environment
they would experience while in orbit.
It is proper to think of an orbit as a continuous fall; this is in fact
how Isaac Newton came to view the orbit of the Moon around the Earth,
and that realization helped him to perceive that the fall of objects
(like apples) near the Earth's surface and the orbiting of the Moon are
two instances of the same physical phenomenon -- gravitation.
But if you are asking if there is a place on earth where you can exper-
ience this free-fall condition without actually falling, I would say no.
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Update: June 2012