WHAT A WEIRD PLACE THIS planet is. But especially southern Illinois, according to this map of gravity anomalies across three Midwestern states.
Gravity is what made the apple fall from a certain tree (in Woolsthorpe, Lincolnshire), causing Newton to wonder why it fell down straight. But the law of universal gravitation he formulated (and published in 1687) by way of explanation is a lot less uniform than you’d think.
For gravity does vary across the earth, meaning Newton’s apple has a slightly different weight in various other parts of the world and falls at slightly different speeds. That’s due to a combination of four factors.
Hellbound and Down 