gravity at centre of earth.....? first of all as we move towards the earth centre does the gravity and the acceleration due to it increase? secondly what is the affect on weight as we move towards the centre? is 'g' zero at centre? if we dig a tunnel across the earth passing through the centre from one pole toward the other and let a body freefall through it what will happen?will the body accelerate or not? will it stop at center or continue on towards other pole?