Showing posts with label Harvard. Show all posts
Showing posts with label Harvard. Show all posts

Monday, June 27, 2011

PENDULUM WAVES

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


.

Monday, July 5, 2010

STUNNING CARTOON FROM 1934

This cartoon was in the Chicago Tribune in 1934. Click on the image to read the plan of action in the lower left corner.



Remember the adage:
"Those who their forget history are doomed to repeat it."


.