The Tower of Pisa Experiment in QuickTime
Physics textbooks frequently mention Galileo and the Tower of Pisa Experiment. They might also mention that the story may be apocryphal but all too often leave the impression that the experiment would have worked if only it had been done. While the truth of the matter is that he likely did tower experiments while he was in Pisa (1589-1592) and his purpose would be to see if objects of different sizes but the same density would fall at the same rate and that objects of the same size but different densities fell at rates proportional to their densities. In 1638, almost 50 years later, he published, Two New Sciences in which he discusses "tower" experiments predicting among other things that a lead ball and an ebony ball of the same size would be separated by less than 4 inches after a fall of 100 m. This and other stories are often associated with his (much) earlier tenure at Pisa.
The above is a synopsis, more detail can be found in
"Galileo and the Tower of Pisa Experiment" Carl G Adler and Byron L Coulter
American J. of Physics, Vol. 46, No.3, March 1978, pp. 199-201
In 1977 three Professors
- Carl Adler
- George Bissinger
- Byron Coulter
at East Carolina University reenacted one version of the experiment. George Bissinger was the photographer . THe film was made into a filn loop and distributed by the AAPT in 1977.
Below are web based movies of that film loop in various formats and sizes (MB).
The QuickTime movies are supposedly optimized for the users connection speed
Note: The heavy ball (white) weighs about 12 pounds, and the light ball (blue) weighs about 0.5 pounds. The building height is about 100 feet and at the end of the fall the balls are separated by about 15 feet with the separation increasing rapidly. The Tower of Pisa is 180+ feet, the separation in that case would be very dramatic.
Note: The Quicktime movie below supposedly detect the connection speed of the user and adjust what they deliver accordingly. So the size given may be meaningless.
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