The Nature of Light

Important Terms

Radiation: Information from Space

• Light as a Wave and a Particle
  
  
  • Light waves are made up of both electric and magnetic components – taken together we refer to them as electromagnetic radiation. The wavelength is the distance between any two similar parts of successive waves (for example, peak to peak or trough to trough).

• Light can also behave like a particle – when it does, we refer to it as a photon. A photon can be thought of as a "bundle" or "packet" of waves.

• The Electromagnetic Spectrum.
  
  
  

• Note that visible light is only a very small fraction of the electromagnetic spectrum.

• Earth's atmosphere blocks most radiation – visible and radio radiation is transmitted through atmospheric windows.