Jokes:
A photon is going through airport security. The TSA agent asks if he has any luggage. The photon says, "No, I'm traveling light."
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Heisenberg was speeding down the highway. A cop pulls him over and says, "Do you have any idea how fast you were going back there?" Heisenberg says, "No, but I knew where I was."
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First Law of Thermodynamics: You can't win.
Second Law of Thermodynamics: You can't break even.
Third Law of Thermodynamics: You can't stop playing.
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A linguistics professor says during a lecture that, "In English, a double negative forms a positive. But in some languages, such as Russian, a double negative is still a negative. However, in no language in the world can a double positive form a negative."
But then a voice from the back of the room piped up, "Yeah, right."
:-P