Middle School Physical Science: Visible Light - The Light We See — Flashcards

The visible light spectrum is the segment of the electromagnetic spectrum that the human eye can view. More simply, this range of wavelengths is called visible light. Typically, the human eye can detect wavelengths from 380 to 700 nanometers.
 

How Visible Light Is Produced    
The sun and other stars produce light because they are so hot. They glow with visible light due to their extremely high temperatures. This way of producing light is called incandescence. Some objects produce visible light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Objects that produce light by luminescence are said to be luminous. Luminescence, in turn, can occur in different ways:    
- One type of luminescence is called fluorescence. In this process, a substance absorbs ultraviolet light and then gives off the energy as visible light. Certain minerals produce light in this way.    
- Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current runs through it. Some gases produce light in this way.    
- A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. Examples of bioluminescent organisms include jellyfish and fireflies.