What are the Other kind of forms of radiant energy?

Answer 1

Radiant energy is the energy of electromagnetic waves. The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time and, like all forms of energy, its SI unit is the joule. The term is used particularly when radiation is emitted by a source into the surrounding environment. Radiant energy may be visible or invisible to the human eye.

The term "radiant energy" is most commonly used in the fields of radiometry, solar energy, heating and lighting, but is also sometimes used in other fields (such as telecommunications). In modern applications involving transmission of power from one location to another, "radiant energy" is sometimes used to refer to the electromagnetic waves themselves, rather than their energy (a property of the waves). In the past, the term "electro-radiant energy" has also been used.

Historically, the propagation of electromagnetic radiation was presumed to rely on a medium filling all space, known as the aether. Electromagnetic waves were presumed to propagate through this medium by inducing transverse electric and magnetic stresses and strains, analogous to those induced by shear waves propagating through a physical medium. In modern times, the propagation of electromagnetic waves has been shown not to require any physical medium, although some interpretations of general relativity can be viewed as implying that space acts as a kind of non-physical "medium" for light.