In 1678, the Dutch physicist Christiaan Huygens put forward the
wave theory of light – it is this wave model of light that we will discuss in
this chapter As we will see, the wave model could satisfactorily explain
the phenomena of reflection and refraction; however, it predicted that on
refraction if the wave bends towards the normal then the speed of light
would be less in the second medium This is in contradiction to the
prediction made by using the corpuscular model of light It was much
later confirmed by experiments where it was shown that the speed of
light in water is less than the speed in air confirming the prediction of the
wave model; Foucault carried out this experiment in 1850