The JDU, a panel truck and the death of a physicist

Physicist Philip Morisson died last Friday at 89. Many will remember him as a nuclear disarmament activist and Scientific American's book reviewer, but I will always remember him for his ambigiously-named PBS series, The Ring of Truth. Among his many novel illustrative aids, Morrison introduced the JDU or Jelly Donut Unit to the lexicon. He used the JDU (250 kilocalories in the days before Krispy Kreme) in the episode on "Change" to help viewers understand conservation of energy and the enormous intake (32 JDU) of world-class cyclists. Another episode on "Mapping" featured the measuring of the earth's circumference with electricians tape, a stretch of route 183 and a panel truck. Morrisson took two star sightings of Anteres, one at each end of the trip, and used simple geometry to make the estimate.

Peace