Difficult Physics Question?

Question

My friends and I were having a conversation and the question arose (somehow), "If you were to take a 7 foot (in diameter) sphere out of the center of the Earth and put a human in there, what would the effect be?" One of my friends says gravity would tear him apart or compact him, but another says forces would cancel out. If anyone can answer this I would be greatful.

Answer 1

You're in luck. Someone has already done the thinking and the math for you. According to the Shell Theorem, the gravitational force inside a spherically symmetric shell (due to that shell) is zero. You would still experience the gravitational attraction of the sun and the moon, but conveniently, your resulting orbit would match earth's orbit exactly. So, you'd experience weightlessness and would float freely within that sphere.

As others mentioned, you'd need to take care of the other environmental problems of heat, pressure, and breathable atmosphere.

Answer 2

I can't speak from personal knowledge, but according to an old column by the mathematician Martin Gardner in Isaac Asimov's Science Fiction Magazine, the forces would indeed cancel out. Every point in space, after all, would have nearly exactly the same amount of force exerting each particle in all directions, ipso facto the total result would be nullified.

Answer 3

If it is at the center, the forces of gravity would cancel each other out.

Answer 4

Gravity would be nil, but the pressure would be astronomical from all the gravity working on the overhead mass. You would indeed be compressed to jelly (neglecting temp effects).

Answer 5

all grafitional forces go top the center so how would they cancel each other i think u will be compacted

Answer 6

hed burn to smitherines cause its hot as hellz down there.
then he would be compressed by so much pressure he would die (( thats why your ears get hurt when you go too far down under water ))