Joke relating to Jaques Lacan:

stranded on an island with Angelina Jolie, she says 'well we might as well get down to it', the evening passes. Later she asks you 'is there anything else I can do for you?' You say 'yes please, can you shave your head and pretend to be my best mate Steve?'. 'ooookay' she says, and she goes off to get into role. You meet later and you say 'steve, steve! guess what?! I f**ked angelina jolie!'

awful, i know.

What would circles look like if pi was exactly 3?

hexagons, although it does depend on your definition of radius.

A day without fusion is like a day without sunshine.

Barium: What you do with dead chemists.

"Today, everybody remembers Galileo. How many can name the bishops and professors who refused to look through his telescope?" – James Hogan, Mind Matters

Also from Wikipedia:

An astronomer, a physicist and a mathematician are on a train in Scotland. The astronomer looks out of the window, sees a black sheep standing in a field, and remarks, "How odd. Scottish sheep are black." "No, no, no!" says the physicist. "Only some Scottish sheep are black." The mathematician rolls his eyes at his companions' muddled thinking and says, "In Scotland, there is at least one sheep, at least one side of which looks black."

jahwomble and david_r had me genuinely laughing out loud

3 Microsoft and 3 Apple employees are getting a train up to London for a computer conference. The Microsoft guys buy 1 ticket, the Apple guys buy 3. On the train, the Apple guys ask,

"Aren't you going to get fined?"
"No. Watch."

So the Apple guys watch as they all jam themselves into a single toilet. The train guard comes along, knocks on the door, and asks for a ticket. The door opens a tiny bit and out comes a ticket. The train guard goes on his way.

Coming back from the conference, they all end up on the same train again, and the Apple guys reckon they can pull it off too, so they buy only 1 ticket. The Microsoft guys don't buy anything. So the Apple guys jam themselves into a toilet, then a few minutes later, one of the Microsoft guys goes over to the Apple toilet, knocks on the door,

"Ticket please."

Also

How many psychologists does it take to change a lightbulb?

One I heard here, I think:

How many Freudians does it take to change a lightbulb?

Two; one to change the bulb and the other to hold his cock err, ladder