Astronomy college course/Wikipedia Sidereus Nuncius/Quiz01/2

During Galileo life, cannons were being invented and tested as well as used. To remember the answer just think about how cannons and Galileo came around the same era. Which is the reason he named his telescope the Optical Cannon. BAhrns15 (discuss • contribs) 18:48, 22 January 2016 (UTC)