Three Laws of Thermodynamics

An easy and funny way to define the three laws of thermodynamics (by C.P. Snow, a British scientist and author):

1. you cannot win (you can’t get something for nothing because matter and energy are conserved. 
2. You cannot break even (you cannot return to the same energy state because entropy always increases
3. You cannot get out of the game (because absolute zero is not attainable).

From http://www.physicsplanet.com/articles/three-laws-of-thermodynamics