Related:

• How many theoretical physicists -- does it take to change a light bulb?
  If you want to know how many, you can observe them as they come in the door....
• How many aerospace engineers -- does it take to change a light bulb?
  None. It doesn't take a rocket scientist, you know....
• How many Heisenbergs -- does it take to change a light bulb?
  If you know the number, you don't know where the light bulb is....
• How many Scorpios -- does it take to change a light bulb?
  Why do you want to know? Are you a cop?...
• How many theoretical physicists -- does it take to change a light bulb?
  The probability that the light bulb will actually be changed in any time interval is independent of how long you've been waiting....
• How many lawyers -- does it take to change a light bulb? How many can you afford?
• How many librarians -- does it take to screw in a light bulb?
  I don't know, but I can look it up for you....
• How many programmers -- does it take to change a light bulb?
  One, but you can never change it back again....
• How many electrical engineers -- does it take to change a light bulb?
  We don't know yet. They're still waiting on a part....