Friday, September 24, 2010

Aristotle's wheel paradox

Embarrassingly I'm still slowly reading Galileo at Work: His Scientific Biography by Stillman DrakeAristotle's wheel paradox came up several times in the book so I finally looked it up at Wikipedia.
When the inner and outer attached wheels make a complete revolution, they trace out lines of equal length, yet their circumferences are different.
How can that be?