Light dispels darkness. Besides being a simple fact of physics, this statement is also a fundamental tenet of human belief.

Light, as knowledge or goodness, displaces the darkness of evil and ignorance. Humans need light.

As a staple, it ranks third in importance after food and shelter. Mankind's search for a clear, long lasting source of light began with crude firebrands and continues to this day. Just as humanity has dreamed of free energy to do its work--perpetual motion--so have many thinkers dreamed of perpetual light.

...up next: Perpetual Light in the Ancient World

Riddle of the Ever-Burning Lamp -- Ancient World -- Middle Ages -- Early Scientists
Robert Plot-- The Rosacrucians -- Sources