  The realization of Karl Popper's EPR-like experiment by Shih and Kim
(published 1999) produced the result that Popper hoped for: no ``action at a
distance'' on one photon of an entangled pair when a measurement is made on the
other photon. This experimental result is interpretable in local realistic
terms: each photon has a definite position and transverse momentum most of the
time; the position measurement on one photon (localization within a slit)
disturbs the transverse momentum of that photon in a non-predictable way in
accordance with the uncertainty principle; however, there is no effect on the
other photon (the photon that is not in a slit) no action at a distance. The
position measurement (localization within a slit) of the one photon destroys
the entanglement between the photons; i.e. decoherence occurs.
