Following the
failure of classical physics theories to explain the interference patterns
observed in double slit experiments and other light diffraction experiments and
because of the similarities between these patterns and the interference
patterns produced by waves at the surface of a liquid, physicists deduced that
light was behaving as a wave. However, only the particle model appeared to explain
phenomena such as the photoelectric effect. Consequently, physicists deduced that
light was corpuscular or wave-like depending on the experiment performed on it.
But what these experiments show is that neither accepted models of light could
explain both behaviours and emphasized the need for a new theory.
