robert@fm, I know you have an interest in mathematics and logic so I thought you might enjoy these lightbulb jokes:

Q: How many existentialists does it take to screw in a light bulb?
A: Two: One to screw it in and one to observe how the light bulb itself symbolizes a single incandescent beacon of subjective reality in a netherworld of endless absurdity reaching out toward a maudlin cosmos of nothingness.

Q: How many mathematicians does it take to screw in a light bulb?
A: If x mathematicians can change a light bulb and if one more simply watches them do it, then x+1 mathematicians will have changed the light bulb. Therefore, based on this hypothesis, we may infer that for all n in the positive integers, n mathematicians can change a light bulb.