Talk:Rattleback
Size
Not sure how relevant the size is. Of course the ratio gravity force/friction is important, so the range of sizes which exhibit spin reversion will depend on the material but especially of the surface roughness (which depends more on surface treatment than on material) of both the rattleback and the support on which it is spun. --Josce 14:35, 14 December 2006 (UTC)
References
Removed
- Elliott, W.A. The inside story of the whirlygig! W.A. Elliott Co., Toronto.
- Elliott, W.A. The Tate's compass. W.A. Elliott Co., Toronto. 1982.
- Freeman, Ira B. "What is Trevelyan's rocker?" The Physics Teacher, 12:382. American Association of Physics Teachers. College Park, Md. 1974.
Tate's Compass is a compass which has no marking or wrong marking to differentiate North and South ! Trevelyan's Rocker is a thermal oscillator ! Whirligig seems to be suspended and wind-driven
I guess they are referred-to in some papers about Rattlebacks, but weren't checked before adding ? Can anyone see others ? --195.137.93.171 (talk) 01:46, 11 February 2008 (UTC)
External links
Removed
- Keltischer Wackelstein "Celtic Wacklestein."
wundersamessammelsurium.de currently offline - back soon
Please re-instate if it does come back !
--195.137.93.171 (talk) 02:06, 11 February 2008 (UTC)
Multiple reversals of spin ?
There are a couple of reports of the direction of rotation (yaw) changing twice.
- I can spin it with the weight in one direction and it turns back twice - it doesn't like spinning in either direction.
- However if I spin it in the other direction, it wobbles about a different axis, comes back, wobbles faster, and comes back again
- If there is less friction, it may indeed happen that it once again changes rolling direction.
(Computer simulation - I suspect the animation is just looped)
- Keath, Ed. Turning a celt.
- In several of the celts that I have made the +yaw motion couples into a rolling motion and the rolling motion couples into -yaw motion.
- The problem is that while the coupling between -yaw and pitch and between pitch and +yaw are strong, the coupling between +yaw and roll and between roll and -yaw are very weak.
Even this article says:
- Glass rattlebacks, however, were reported to exhibit "unstable behavior" when spun in either direction, and incur up to four or five successive rotations during a single experiment.
Anyone know who found this, and how ? Have I done the links above OK, to tie the fact to the source ?