🚀 go-pugleaf

In article <BxA2GC.6yE@wsrcc.com>, alison@wsrcc.com (Alison Chaiken) writes:
> 
> You're wrong.  As far as the theory of the electron goes, QED has had
> no impact on solid-state physics whatsoever. 

 One counterexample (not "solid state", but certainly condensed matter):
 at large distances the interaction potential between neutral molecules is
 proportional to r**(-7) (Casimir-Polder potential) rather than r**(-6)
 (the usual London dispersion potential). This is a radiative correction;
 it can be understood physically by invoking retardation but a quantitative
 calculation requires QED (nonrelativistic QED suffices). Casimir's work
 on this was inspired by anomalous results concerning the stability of
 certain colloids. I do not know whether the Casimir-Polder force
 does in fact explain those colloid experiments (according to a ~1960
 review by Hirschfelder they do.) 
 What about polaritons? Much of their behavior can be understood physically
 in terms of purely classical electrodynamics, but a complete quantum-mechanical
calculation would have to treat the radiation field quantum-mechanically (long
ago I read a paper by Hopfield that does just that. This is way outside my
 field, though.)

> 
> Having said all that, the theories of broken symmetry and elementary
> excitations (Goldstone bosons) in solid-state physics have been heavily
> influenced by particle theories.  Here solid-state is using the
> _concepts_ of field theory, not the results!  My understanding is that
> particle theories have been in turn influenced by solid-state theories
> (e.g., non-perturbative field theories are greatly influenced by the
> BCS theory of superconductivity).
> -- 
 Which is why some condensed-matter physics books talk about the "Anderson-
Higgs mechanism."

Robert