Although he might not have been the absolute first to propose it, Galileo is widely credited with proposing the concept in 1638 that all bodies fall with equal acceleration through a vacuum, and mythologically with actually testing it at the Leaning Tower of Pisa.  This concept was a necessary precursor to Newton's law of universal gravitation (ask me sometime why the inverse square rule is SO COOL) and Einstein's general theory of relativity.

Over 300 years later, David Scott, commander of Apollo 15, decided to test Galileo's theory.  On the Moon.

I think we tend to forget that not only were these astronauts incredibly brave explorers, but they were also intelligent and scientifically curious individuals.  They were truly the best of the best.

While I am on the topic of astronaut bad-assery, here is video of Buzz Aldrin decking Moon Hoax conspiracy theorist and all around tool, Bart Sibrel in his face.



Now, you might say Buzz cold cocked him.  I disagree.  If I am going to regularly harass a man and call him a coward and a liar from less than five feet away, it is completely reasonable to assume that I am prepared to defend my sacred honor from violence.  Maybe we should bring back dueling.