What Am I Looking At – Part VII

“Galileo”

     by Aaron Clevenson

 

This is the seventh in a series of interviews with famous astronomers of the ages.  Our ultimate goal is to trace our understandings of the physical universe.  This month we are going to talk to Galileo.

 

NORTHSTAR:  Galileo, you have been able to make great advances in astronomy.  Can you tell us about yourself?

GALILEO:  I was born in Pisa o February 15, 1564.  I tried not to take life too seriously.  In fact in college I was a little of a menace to my professors.  I studied medicine, but it was not satisfying to me.  At twenty-five, I was hired to teach astronomy, poetry, and mathematics in Pisa.  Unfortunately they didn’t take to well at my jests, and when my contract came up for renewal I was sent home.

NORTHSTAR:  What was your first great moment in astronomy?

GALILEO:  It would have to be when I made my first telescope.  I learned, while on a trip to Venice, that they were being made in Holland.  I went home to build one.  I realized that it would have great value in wars and navigation.  It was only later that I turned it to the sky.  My first public demonstration to the Venetian senators was on August 25, 1609.  They loved it!  Although one of my English contemporaries, Thomas Harriot, used a telescope to look at the moon, I was one of the first people to use it look at the heavens overall.  I saw phases of Venus which conclusively proved that it circled the sun inside the Earth’s orbit.  When I saw the detail on the moon it proved that it was a solid body just like the Earth.  I discovered the four moons of Jupiter.  The greatest reward was the stars.  It was obvious from the start that these were not points of light attached to a sphere, but were at differing distances in space.  There were hundreds of more stars visible in the telescope, which were not visible to the eyes alone.  I was able to discern individual stars in the Milky Way.

NORTHSTAR:  What about gravity?

GALILEO:  Contrary to popular opinion, I did NOT drop a cannonball from the leaning tower of Pisa.  I did perform some thought experiments though.  My most famous was:  Take a cannonball.  Time how long it takes to fall from a specific height.  According to Aristotle, if I cut the ball in half, each half will fall slower.  But, what happens if I then connect these two halves together by a thread.  Will they fall at the original rate, or the slower rate?  Aristotle had to be wrong.  Aristotle understood that a body at rest tries to stay at rest.  This is the first law of inertia, but he missed the second part.  I concluded that a body in motion will try to stay in motion.

NORTHSTAR:  How was this received by the Church?

GALILEO:    Initially fairly well, but I don’t understand why they would not accept all of theories.  These anti-Copernicans are so thick headed.  Well I pushed and pushed, and it finally all backfired.  Copernicus was basically banned, and I had fallen into disfavor.  In fact it got so bad that people were forging documents to frame me.  It was very bad.  I finally was put under house arrest, but they let me keep my telescope.

NORTHSTAR:  Thank you very much for your time and your insights with the telescope.