A question for Kent or Sarah. When I jump into the air, at the point where I am at the top of the arc, neither rising nor yet falling, am I experiencing zero G? Am I floating?
To see jumpers as I am describing, view this website:
http://www.jumpbecause.com/
posted by Dr. G @ 11:19 AM
2 comments
2 Comments:
How technical do you want to get? :)
The term "zero G" is a bit of a misnomer. Gravity never goes away. It just feels like it does because you're in free-fall.
On planes like the Vomit Comet, the plane flies a parabolic profile and when you go "over the top" of the arc, you're essentially weightless because you're falling along with the plane.
Astronauts are weightless because they are in constant free-fall -- the space shuttle is falling toward the earth the whole time. It simply has enough forward velocity that it never hits the ground because the earth keeps curving away from it. (The classic drawing of this principle uses a cannonball as an example and is here: http://en.wikipedia.org/wiki/Image:Newton_Cannon.svg) If you have enough forward speed, you'll never hit the ground.
Anyway -- point being -- sure, I'd say that when you jump, you are weightless at the top of your trajectory, as well as on the way down. It just lasts for such a short period of time that it doesn't really feel the same.
Here's more: http://en.wikipedia.org/wiki/Weightlessness
Thanks Sarah! That's what I thought.
Dr. G
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