Galileo

February 15 is Galileo Galilei's birthday.

Galileo Galilei (1564-1642)

Galileo is perhaps best known for the story of his demonstration dropping balls of different weight from the Leaning Tower of Pisa, showing that they did fall at the same rate - counter to intuition and the view of Aristotle. Most historians of science doubt seriously that the dmonstration ever happened.

From what we do know about his actual experiments regarding the physics of mass and motion, Galileo rolled balls or cylinders down inclined planes. When I first read about this back in high-school days it stuck me as particularly clever: Galileo needed to slow down the phenomena, since he had little with which to time his observations other than his own pulse.

Perhaps not coincidentally, he also advanced the development of the pendulum clock.

Galileo at Wikipedia.

In an homage to Galileo, astronaut David Scott from the Moon mission Apollo 16 (1971):

In my left hand I have a feather, and in my right hand, a hammer. I guess one of the reasons we got here to day was because of a gentleman named Gallileo a long time ago, who made a rather significant discovery about falling objects and gravity fields ... I'll drop the two of them here, and hopefully, they'll hit the ground at the same time.

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