|
|
Code Number: 1M40.90
Demo Title: Celts or Rattle Backs
Condition: Excellent
Principle: Centers of Mass, Vibratory Modes
Area of Study: Mechanics
Equipment:
Small and Large Plastic Celts, Large Wooden Celt.
Procedure:
Put the Celt on a smooth surface. Start it spinning in a clockwise direction. After a few turns it will stop and then go in its preferential counter-clockwise direction. It will also turn in a counter-clockwise direction if you just start it rocking by tapping one end.
The large Celt can be set to rotate in either direction or not at all using the attached cross arm.
References:
- Rod Cross, "Rocking and Rolling Rattlebacks", TPT, Vol. 51, #9, Dec. 2013, p. 544.
- Steve Dail, "Rattleback Bet", TPT, Vol. 49, #5, May 2011, p. 316.
- Ronald D. Edge and Richard Childers, "Curious Celts and Riotous Rattlebacks", TPT, Vol. 37, #2, Feb. 1999, p. 80.
- H. Richard Crane, "The Rattleback Revisited", TPT, Vol. 29, #5, May 1991, p. 278.
- Jearl Walker, "The Amateur Scientist: The Mysterious 'Rattleback': A Stone That Spins in One Direction and Then Reverses", Scientific American, Vol. 241, #4, Oct. 1979, p. 172.
- Jodi and Roy McCullough, "Center of Gravity with a Celt", The Role of Toys in Teaching Physics, p. 4.114.
- Jearl Walker, "1.109. Rattlebacks", The Flying Circus of Physics Ed. 2, p. 54.
- Jearl Walker, "2.72. The Rebellious Celts", The Flying Circus of Physics with Answers.
- Christopher P. Jargodzki and Franklin Potter, "226. The Mysterious", Mad About Physics, p. 90, 226.
- Robert Ehrlich, "F.5. Rattleback", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 71 - 72.
- Sir Hermann Bondi, "The Rigid Body Dynamics of Unidirectional Spin", Proceedings of the Royal Society of London, Vol. 405, #1829, June 1986, p. 265 - 274.