a: Atom in the ground state ~
b: boulder at the bottom of a hill
What: An analogy may be helpful in understanding this abstract discussion of energy states. An atom in the ground state is like a boulder at the bottom of a hill: it's very unlikely that it's going to do anything unless something interacts very strongly with it. Stimulated absorption is like pushing that boulder up to the top of the hill. It takes energy to get it there, but it makes it more likely that the boulder will do something-most likely, roll downhill. The top of the hill is a rather precarious position, so there is a fair likelihood that the rock will roll down even if we don't push it. This is analogous to spontaneous emission.
Writer: Elson Liu
Date: Aug 26 2013 7:19 PM
# 3633 Critique Analogy