Monday, June 27, 2011


EVERYBODY KNOWS that the period of a pendulum is proportional to the (square root of the) length of the line suspending the weight. The longer the pendulum, the slower it swings (i.e. the longer the period).

So . . . some kid at Harvard built a device with a series of 15 pendulums in a row, each one slightly longer than its neighbor, set them in motion, and filmed the result . . . fascinating to watch, think about, and try to explain:

"Pendulum" is derived from the Latin "pendulus", of course, meaning "hanging". Pendulums were used as the most accurate form of time-keeping from the time of Galileo, who discovered their basic properties, until the 1930s.

Today's Bird HERE



  1. That's pretty darn neat. Your eyes really fool you into seeing different things on that.

  2. I love to see the pendulums moving because it relaxes me I do not know why but it does, I actually have a collection of pendulums in my house!