“The gravitational force inside a hollow sphere shell of uniform areal mass density is everywhere equal to zero, and may be proved by the following argument:
….[blahblahblahblahblah]…
The gravitational force within the sphere is everywhere equal to zero.”
The gravitational force inside a sphere would not be zero. The force between two bodies is propertional to their mass, and that applies in any direction.
rf- the people dancing in the streets on 9/11 were celebrating the murders of almost 3000 people. Today people were cheering the death of the man who murdered them. There is a hell of a big difference. Sad? Hell no.
The gravitational field inside of a hollow sphere is zero (with respect to the gravitational effect of the sphere itself, obviously not with respect to outside forces).
Take a sphere several million miles across and, say, a few feet thick.
At all point within the sphere the gravitational field would be zero.
But on the surface you would feel gravity as if you were standing on the surface of a planet.
Let’s say there was a manhole in the surface. From the surface you could descent into the manhole and immediately be weightless.
From the inside you could float around and somehow pick up speed going towards the manhole. Just as you popped up through the surface, however, gravity would push you back down…..into weightlessness.
San Francisco has really declined over the past 20 years. Alot more dirty, and homeless encampments all over the place. It’s a shame, as it is a beautiful city.
When I go to visit our San Jose office, we rarely venture up there any more.
A cut and paste from http://www.nasa.gov:
Gravitation Inside A Uniform Hollow Sphere
“The gravitational force inside a hollow sphere shell of uniform areal mass density is everywhere equal to zero, and may be proved by the following argument:
….[blahblahblahblahblah]…
The gravitational force within the sphere is everywhere equal to zero.”
Benson – remember, I’m usually right about this stuff.
physics won’t matter once the zombie apocalypse is upon us
Lech;
The gravitational force inside a sphere would not be zero. The force between two bodies is propertional to their mass, and that applies in any direction.
rf- the people dancing in the streets on 9/11 were celebrating the murders of almost 3000 people. Today people were cheering the death of the man who murdered them. There is a hell of a big difference. Sad? Hell no.
Consider the following:
The gravitational field inside of a hollow sphere is zero (with respect to the gravitational effect of the sphere itself, obviously not with respect to outside forces).
Take a sphere several million miles across and, say, a few feet thick.
At all point within the sphere the gravitational field would be zero.
But on the surface you would feel gravity as if you were standing on the surface of a planet.
Let’s say there was a manhole in the surface. From the surface you could descent into the manhole and immediately be weightless.
From the inside you could float around and somehow pick up speed going towards the manhole. Just as you popped up through the surface, however, gravity would push you back down…..into weightlessness.
Canada looks like it’s electing a Conservative majority govt tonight. Yay!
San Francisco has really declined over the past 20 years. Alot more dirty, and homeless encampments all over the place. It’s a shame, as it is a beautiful city.
When I go to visit our San Jose office, we rarely venture up there any more.
No dancing today Pete. But hope you are enjoying SF!