Light Bulb - Social Scientist

Q: How many social scientists does it take to screw in a light bulb?
A: They do not change light bulbs; they search for the root cause as to why the last one went out

Light Bulb - Dartmouth Students

Q: How many Dartmouth students does it take to change a light bulb?
A: None--Hanover doesn't have electricity! Note: Dartmouth is way out in the middle of nowhere in New Hampshire.

Science Fiction Writers to Change Lightbulb 2

Q: How many science fiction writers does it take to change a light bulb?
A: Two, but it's actually the same person doing it. He went back in time and met himself in the doorway and then the first one sat on the other one's shoulder so that they were able to reach it. Then a major time paradox occurred and the entire room, light bulb, changer and all was blown out of existence. They co-existed in a parallel universe, though.