An inclined Levitron demonstration serves to illustrate macroscopically the basic non-quantum mechanical principle of nuclear magnetic resonance. By tuning a “rotary driver” to either the precession or the nutation frequency, the levitated top is made to precess or nutate visibly. By reflecting the beam from a laser-pointer off the Levitron, cycloidal pictures of the induced motion are obtained. Steady inclination at a steep angle is demonstrated in contrast to rotating inclination. Levitron traps are analogous to particle traps. Inclined or horizontal axis operation could lead to nearly frictionless bearings.
REFERENCES
1.
2.
E. W.
Hones
and W. G.
Hones
, “Magnetic levitation device and method
,” U.S. patent 5,404,062 (1995
).3.
M. V.
Berry
, “The Levitron: An adiabatic trap for spins
,” Proc. R. Soc. London, Ser. A
452
, 1207
–1220
(1996
).4.
M. D.
Simon
, L. O.
Heflinger
, and S. L.
Ridgway
, “Spin stabilized magnetic levitation
,” Am. J. Phys.
65
(4
), 286
–292
(1997
).5.
L. A.
Romero
, “Spin stabilized magnetic levitation of horizontal rotors
,” SIAM J. Appl. Math.
63
(6
), 2176
–2194
(2003
).6.
R.
Edge
, “Levitation using only permanent magnets
,” Phys. Teach.
33
, 252
–253
(1995
);R.
Edge
, “Corrections to the levitation paper
,” Phys. Teach.
34
, 329
(1996
).7.
J. L.
Synge
and B. A.
Griffith
, Principles of Mechanics
, 3rd ed. (McGraw-Hill
, New York
, 1949
).8.
M. M.
Michaelis
, “Making waves with magnetic couples
,” New Scientist
89
, 616
–618
(1981
).9.
M. M.
Michaelis
, “Permanent magnets help model masers and N.M.R.
,” Phys. Educ.
18
, 82
–84
(1983
).10.
A. D.
Snider
, “Visualization of nutation and precession phenomena
,” Am. J. Phys.
39
(11
), 1385
–1386
(1971
).11.
H. L.
Armstrong
, “On the precession and nutation of gyroscopes
,” Am. J. Phys.
35
(11
), 883
–885
(1967
).12.
E.
Butikov
, “Precession and nutation of a gyroscope
,” Eur. J. Phys.
27
, 1071
–1081
(2006
).13.
B.
Wie
, Space Vehicle Dynamics and Control
, 2nd ed. (AIAA
, Reston, VA
, 2008
).14.
S.
Earnshaw
, “On the nature of the molecular forces which regulate the constitution of the luminiferous ether
,” Trans. Cambridge Philos. Soc.
7
, 97
–112
(1842
).15.
J.
Pierrus
and M. M.
Michaelis
, “Demonstration of coupled oscillations using permanent magnets
,” Phys. Teach.
39
(1
), 39
–39
(1980
).16.
M. M.
Michaelis
and C. M.
Haines
, “Oscillating permanent magnets
,” Phys. Educ.
24
, 359
–364
(1989
).17.
G. B.
Andresen
et al, “Trapped antihydrogen
,” Nature
468
, 673
–676
(2010
).© 2012 American Association of Physics Teachers.
2012
American Association of Physics Teachers
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