  We report on the simultaneous determination of complementary wave and
particle aspects of light in a double-slit type "welcher-weg" experiment beyond
the limitations set by Bohr's Principle of Complementarity. Applying classical
logic, we verify the presence of sharp interference in the single photon
regime, while reliably maintaining the information about the particular pinhole
through which each individual photon had passed. This experiment poses
interesting questions on the validity of Complementarity in cases where
measurements techniques that avoid Heisenberg's uncertainty principle and
quantum entanglement are employed. We further argue that the application of
classical concepts of waves and particles as embodied in Complementarity leads
to a logical inconsistency in the interpretation of this experiment.
