AstroChuck’s right. Try the following: take any globe and a standard size marble. Place the marble on New York, and release. You’ll find that it goes zooming down toward Florida (at least it did when I tried it). Now put it at Florida and you’ll find that you’ve actually got to push it all the way to New York. As I recall, Galileo actually proved this some time back, only he used canon balls and the tower of Pisa.