How many communists does it take to change a light bulb?

None. The light bulb contains the seeds of its own revolution.

This was from Julia, at the new HSHM admits’ dinner. Unfortunately there aren’t any historian lightbulb jokes worth telling. But, as is the wont of historians, I’ll share some anyway.

How many historians does it take to change a light bulb?

1.) Only one, but to tell anyone else about it you need an entire department: the historian of science to describe the development of electricity; the economic historian to describe the rise of power companies and disposable lightbulbs; the environmental historian to talk about the relationship between replacement bulbs and landfill issues; the political historian to describe the decision-making process in lightbulb replacement; and the social historian to argue about whether more lightbulbs are replaced by women or by men. Graduate students are working on the incandescant-fluorescent issue, but no publications yet.

2.) (with trembling and fear) “Change???!!!”

Julia’s joke comes from (among other places) this site, which has a few other good ones, like:

How many feminists does it take to screw in a lightbulb?
That’s not funny!

How many Freudian analysts does it take to change a lightbulb?
Two; one to change the bulb and one to hold the penis. I mean ladder.

The Wikipedia article on lightbulb jokes also has some good stuff (along with the discussion page):

How many Yalies does it take to change a lightbulb?
None. New Haven looks better in the dark.

Q: One.
A: How many time-travellers does it take to change a lightbulb?

And the Prairie Home Companion website has an endless supply of bad ones, with a few good ones thrown in.