Light Reference

Light or Electromagnetic radiation is a ubiquitous phenomenon that takes the form of self-propagating waves in a vacuum or in matter. It consists of electric and magnetic field components which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation.


Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what we call the visible spectrum, or light. The physics of electromagnetic radiation is electrodynamics, a subfield of electromagnetism.

App Store

Supported languages: English, Russian, German, Portuguese, French, Spanish, Turkish and Italian.
Supported devices: iPhone, iPad and iPod (Retina screen isn’t fully supported).

Click on the icon to install: