Over 400 years ago, the story goes, Galileo stood atop the Leaning Tower of Pisa and dropped two balls of different masses over the edge. As we all know, both balls smacked the ground at the same time, proving that gravity affects objects’ acceleration regardless of mass. (Though whether that was a real experiment or merely a thought experiment is still debated.)
Regardless, it’s a great, memorable visual. But be prepared to replace it with an even better one.
