9: Heavier Objects Fall Faster

OK, trick question: do heavier objects fall faster than lighter ones? Today, we all know that they don't, but it's understandable how Aristotle could've gotten this one wrong.

It wasn't until Galileo came along in the late 16th century that anyone really tested this out. Though he most likely did not, as legend holds, drop weights from the tower of Pisa, Galileo did perform experiments to back up his theory that gravity accelerated all objects at the same rate. In the 17th century, Isaac Newton took us a step further, describing gravity as the attraction between two objects: on Earth, the most important being the attraction between one very massive object (our planet) and everything on it.

A couple of hundred years later, Albert Einstein's work would take us in a whole new direction, viewing gravity as the curvature that objects cause in space-time. And it's not over. To this day, physicists are ironing out the kinks and trying to find a theory that works equally well for the macroscopic, microscopic and even subatomic. Good luck with that.

Find out more about Newton's Laws of Motion with our Newton game. No, seriously ... it's fun!
Ever wonder what it would be like if there were no gravity on Earth? The folks at How Stuff Works know.