"Lightbulb joke collection 27" joke

Q: How many light bulbs does it take to change a light bulb?
A: One, if it knows its own Goedel number.

Note: I thought this was something to do with the maths/logic theories of Kurt Goedel, about it being impossible to prove things, and finally a more complete explanation arrived in my mailbox: - A Goedel Number is one of several ways to encode a Turing Machine, the classical abstraction of a computer, or for that matter of any algorithm. The idea (as best I see it) is that if the machine knows its own Goedel Number it can simulate itself... It does come from the mathematician Goedel - partly because he used TMs in his famous theorem, I believe.)

Q: How many spies does it take to change a lightbulb?
A: Why bother?

Q: How many KGB agents does it take to change a lightbulb?
A: Two: One to screw it in and the other to check it for microphones.

Q: How many Trimarians does it take to change a lightbulb?
A: Leave it out, it was only attracting mosquitos anyway.

Q: How many Caidans does it take to change a lightbulb?
A: Nobody knows. They can't figure out what to wear to change one.