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On bowling balls, hammers, and feathers

“To develop working ideas efficiently, I try to fail as fast as I can.” — Richard Feynman

Aristotle (384–322 BCE) argued that if the void existed, every object would fall through the void at the same unlimited speed, because there would be nothing to hinder its motion. Therefore, Aristotle concluded, the concept of the void is absurd. This was one of several arguments he gave for its nonexistence. Over eight centuries later, John Philoponus (Approx 490-570 CE) thought otherwise. He lived over a thousand years before Galileo, and his works of critical commentary on Aristotle’s physics were largely forgotten for many centuries.

So, what actually happens when you drop a feather and a bowling ball in vacuum? Here is a full-scale demonstration, carried out in the world’s largest vacuum chamber:

An earlier demonstration was carried out on the Moon using a hammer and a feather by Apollo 15 astronaut David Scott:

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Space Oddity on the ISS

This video has received over 30 millions views since the astronaut Chris Hadfield posted it in 2013. David Bowie considers it the ‘most poignant’ cover of his song.

A perfect example the Equivalence Principle in action, and a good intro to our discussion of local frames, the General Theory of Relativity, and so forth…