Galileo's Chandelier
timing devices - pendulum isochronism - clocks
What it shows:
Rumor has it that one day at the cathedral, Galileo watched the swinging of a chandelier after it had
been displaced and lit. By using his own pulse as a timer, he noticed that the period of the swing
remained constant despite the fact that its amplitude decreased. And thus was born an important
discovery that was later used by Huygens in the invention of the astronomical and navigational clock.
How it works:
This demonstration is a bit of a joke on the theme. The "chandelier" is a bowling ball pendulum
1
hung from the ceiling skyhook. Candles are stuck into the thumb and finger holes of the bowling ball. The candles
are lit and the bowling ball is set into motion. How the rest goes is left to the imagination of the lecturer.
Setting it up:
A little bit of advanced notice is required on this one as it involves bringing the "hyjacker" in and out of the lecture
hall to put up the pendulum cable. This ought to be done first before any other demonstrations are set up. Rating *
1 A 5 meter long, 3/16" dia. stranded cable hangs from the ceiling skyhook. A large (3/8"-16) eye-bolt, threaded into a ten-pin bowling ball serves as the suspension point.