Home             Musings

Galileo's Kid Brother

Thanks to the excellent Dava Sobel, many of us know about Virginia Galilei (aka Suor Maria Celeste). So it was a charming surprise to come across Michelagnolo Galilei lutenist and composer.

Galileo Galilei (he had his surname for his firstname too) came from a musical family. His father Vincenzo is the most famous musically, having been a lute player, teacher, and writer on music. Contemporary accounts praise Galileo's music too. I don't know if any has survived, but certainly it is nice to hear some his brother's.

In an article on The Role of Music in Galileo's Experiments the great Galileo scholar Stillman Drake put forward a fascinating theory about Galileo's inclined-plane experiments. We know he worked out how falling bodies accelerate---but how did he measure time accurately? Drake suggests that Galileo rolled balls down inclined planes with little movable frets as obstacles. The frets were there to make an audible click each time a ball passed, without disturbing the ball too much. By listening to the clicks he could mark out equal intervals in time, and then measuring the distances between the frets told him everything he needed to know.

You can try and (re-)discover constant acceleration using your sense of rhythm and a nice simulation by Joakim Linde which comes complete with cute Renaissance lute music. Better still, you can try it with a real inclined plane. I remember being inspired enough to re-create the experiment after reading Drake's article when I was in high school. Indeed it works, you can measure time accurately without a clock.