Describe the short history of light.

(N/A) The wave theory was initially not accepted due to Newton's authority and the belief that light,unlike sound,could travel through a vacuum,whereas waves were thought to require a medium to propagate.
In $1801$,Thomas Young performed the interference experiment,which firmly established that light is a wave phenomenon.
Since the wavelength of visible light is much smaller than the dimensions of typical mirrors and lenses,light can be assumed to travel approximately in straight lines.
The branch of optics in which the finiteness of the wavelength is completely neglected is called geometrical optics.
$A$ ray is defined as the path of energy propagation in the limit where the wavelength tends to zero.
Numerous experiments involving the interference and diffraction of light waves were carried out and satisfactorily explained. Thus,by the middle of the $19^{th}$ century,the wave theory of light was well established.