light (energy)

  1. Home
  2. top of the aat hierarchies
  3. Associated Concepts Facet
  4. Associated Concepts (hierarchy name)
  5. scientific concepts
  6. physical sciences concepts
  7. physics concepts
  8. [energy and related concepts]
  9. energy
  10. radiation (energy)
  11. electromagnetic radiation
  12. light
Scope note
That portion of the electromagnetic spectrum visible to the human eye, having a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye. It ranges from the red end to the violet end of the spectrum, with wavelengths from 700 to 400 nanometres and frequencies from 4.3 x 1014 to 7.5 x 1014 Hz. Like all electromagnetic radiation, light travels through empty space at a speed of about 186,000 miles per second (300,000 km/sec). In the mid-19th century, light was described by James Clerk Maxwell in terms of electromagnetic waves, but 20th-century physicists have shown that it exhibits properties of particles as well; its carrier particle is the photon. Light is the basis for the sense of sight and for the perception of color.
light
Accepted term: 22-Apr-2024