At a given temperature, the intensity of light varies according to wavelength. The intensity of the radiation varies according to the wavelength and temperature of the object. The radiation which a black body emits is called black body radiation. After this, it starts emitting thermal radiation in a continuous spectrum according to its temperature. Objects having low temperature emit radio or microwaves (low-frequency waves) while objects having high temperature emit visible or ultraviolet light or even higher frequency radiations.Ī black body is an idealized object that can absorb all electromagnetic radiation that comes in contact with it. (Image will be Updated soon) Black Body RadiationĪccording to the temperature, all objects emit electromagnetic radiation. Radio waves, microwaves, infrared, visible light, UV-rays, X-rays, gamma rays are electromagnetic radiation. It is a form of energy that can propagate in a vacuum or material medium and shows both wave-like and particle-like properties. Let us start by understanding electromagnetic radiation in the coming section. In this article, we will discuss Max Planck’s quantum theory of radiation or quantum theory of radiation, black body radiation, electromagnetic radiation, evidence for a particle theory of energy, etc. During this time, the German physicist Max Planck put forward his theory of the quantized nature of the energy of electromagnetic waves. However, by the 20th-century scientists were able to discover that phenomena such as black body radiation, the photoelectric effect can’t be explained by classical theory or classical mechanics.

Scientists were able to define the properties of radiant energy by Maxwell’s equations given by James Clerk Maxwell, a Scottish physicist, in 1873.

By this time, matter and energy used to be considered distinct and unrelated. By the end of the 19th century, scientists were able to explain most of the natural phenomenon by Newton’s Laws of classical mechanics or classical theory.

Max planck atomic theory