Three Feynmans walk into a bar...

[Edward Green]

The first two vanish into the back room to play a game of darts,
leaving the third to chat up the barmaid. After emptying a stein, he
pulls a bit of ribbon from his pocket and entertains her with a trick
whereby he ties the ribbon to the handle, twists the stein around two
full turns, and then magically untwists the ribbon without moving the
stein. He tells her how particles he studies have a property called
"spin", and that particles whose spin is 1/2 actually behave like the
stein with the ribbon tied to it: coming back where they started only
after two, but not one, full turns. Feynman then leans closer, and
conspiratorially whispers to her why (in language a barmaid can
understand), just spin 1/2 particles act this way, and not other
particles.

What story does the Feynman tell the barmaid?

[H. Farmer]

Edward Green wrote:

Ah ha he tells her : The trick is one of the other Feynmans sneaks out of
the back room and untwist the ribbon when she isn't looking. The quantum
particles are not spinning so calling this property spin is also a trick."

This makes the barmaid think "All physics is crap. But hey those guys make
plenty of money. Right?"

--
You do realize.....

[Douglas Eagleson]

A spin as described where the Feynman theorest is the only allowed
answered is a quite simple story.

"A spin to the stein takes the steinist out of all."

A story where the particle never quite entertains the state in
question. A transverse.

Why spin 1/2 exists is the stein. A large effect making the surface the
particle as opposed to the geometric center. Causing all dilemma to
vanish. Gravity all.