Stevenson replies: I thank John Knox and several others for pointing out my incorrect attribution of the W in WKB. The approximation predates their quantum mechanical application and was indeed to be found in the work of Harold Jeffreys. An interesting website, www.du.edu/~jcalvert/phys/wkb.htm, gives more historical details. The essential features of the so-called WKB or WKBJ approximation were known even earlier 1 but Lord Rayleigh already has too many things named after him.
REFERENCE
1.
Lord
Rayleigh
, Proc. R. Soc. London
, series A, 86
(586
), 207
(1912
), eq. 67 .© 2005 American Institute of Physics.
2005
American Institute of Physics
