tag:blogger.com,1999:blog-362590194397112658.post755091403829602970..comments2023-10-17T11:11:51.586-04:00Comments on Atheist Media Blog: Neil deGrasse Tyson: Journey Through the Center of the EarthDavidhttp://www.blogger.com/profile/02087144588713444364noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-362590194397112658.post-55109190170903552482010-01-03T09:14:35.000-05:002010-01-03T09:14:35.000-05:00Julian, the reason the pull of gravity lessens as ...Julian, the reason the pull of gravity lessens as you fall toward the center is because a portion of the earth is now above your head, and is pulling up on you to counter the mass pulling down on you. Once you hit the middle, it's pulling on all sides of you equally, cancelling itself out. As your momentum keeps you going past that point. Yes, the law of gravitiy is based on the square of the distance between two masses and thus gets stronger the closer you get to the earth, but once you are inside the earth you can no longer treat it like it was one single point in space concentrated at its center. That mathematical simplification of reducing the entire mass of the earth down to a single point stops being valid once you are inside the mass in question.Steven Madingnoreply@blogger.com