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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-1294
DTSTART:20090918T210000Z
DURATION:PT1H0M0S
DTSTAMP:20260501T204105Z
LAST-MODIFIED:20090825T142040Z
LOCATION:2241 Chamberlin Hall (coffee at 3:30 pm)
SUMMARY:On the Verge of Umdeutung in Minnesota: John H. Van Vleck and 
 the Transition from the Old Quantum Theory to Matrix Mechanics\, Physi
 cs Department Colloquium\, Michel Janssen\, University of Minnesota
DESCRIPTION:In October 1924\, The Physical Review\, a relatively minor
  journal at the time\, published a remarkable two-part paper by John H
 . Van Vleck\, working in virtual isolation at the University of Minnes
 ota. Using Bohr's correspondence principle and Einstein's quantum theo
 ry of radiation along with advanced techniques from classical mechanic
 s\, Van Vleck showed that quantum formulae for emission\, absorption\,
  and dispersion of radiation merge with their classical counterparts i
 n the limit of high quantum numbers. The paper is similar in many ways
  to the paper on dispersion theory by Kramers and Heisenberg a few mon
 ths later that led directly to the famous Umdeutung (reinterpretation)
  paper of July 1925 with which Heisenberg laid the foundations for mat
 rix mechanics. This makes Van Vleck's paper extremely valuable for the
  reconstruction of the genesis of matrix mechanics. It also makes it t
 empting to ask why Van Vleck did not take the next step and develop ma
 trix mechanics himself.
URL:https://www.physics.wisc.edu/events/?id=1294
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