Describe the nature of light and characteristics of radiant energy.

Light is an important form of energy, According to Newton's corpuscular theory,the light was considered as a stream of particles called corpuscles of light. This theory could explain the phenomenon of reflection and refraction, but failed to explain the phenomenon of diffraction and interference. Therefore, the corpuscular theory was discarded and replaced by the wave theory of light. According to this theory, light is transmitted in the form of electromagnetic waves. These waves are associated with the oscillating electric field and magnetic fields.
The energy emitted from any source in the form of radiation is called radiant energy. The most common forms of radiant energy are cosmic rays, gamma rays, X-rays, ultraviolet rays, visible rays, infrared rays, radio waves and heat. Clark Maxwell (1856) proposed that radiant energy has wave character. These waves are associated with both electric and magnetic fields, thus, these radiations are called electromagnetic radiations. All types of electromagnetic radiations travel through space with the same velocity i.e. the velocity of light (3 x 10⁸ ms^-1).