[FredZarguna]

A better variation on this joke, and a trade joke, which appeals to the prejudices of many...

A mathematician, a physicist, and an engineer are driving through Wisconsin. By the side of the road they see a Holstein with no (visible) black spots.

"Wow!" says the engineer, "I didn't know there were white cows in Wisconsin!"

The physicist, slightly more precisely notes, "Well, all you really know is that there's one white cow in Wisconsin."

The mathematician, slave to rigor, corrects them both, "Actually, all we really know is that there is at least one cow in Wisconsin which is white on at a least one side."

[Vicomte13]

"A mathematician, a physicist, and an engineer are driving through Wisconsin. By the side of the road they see a Holstein with no (visible) black spots.
'Wow!' says the engineer, 'I didn't know there were white cows in Wisconsin!'
The physicist, slightly more precisely notes, 'Well, all you really know is that there's one white cow in Wisconsin.'
The mathematician, slave to rigor, corrects them both, 'Actually, all we really know is that there is at least one cow in Wisconsin which is white on at a least one side.'"

And then I chirp in from the sidelines: "Wisconsin does not exist, except as an arbitrary opinion of men drawing imaginary lines on pieces of paper which they imagine represents the ground, and accepting that the imaginary lines on the pieces of paper actually create something that is more than an opinion."

[grey_whiskers]

The mathematician, slave to rigor, corrects them both, "Actually, all we really know is that there is at least one cow in Wisconsin which is white on at a least one side."

And then a FREEper who had listened in on the whole conversation added under his breath "...at least PART of the time!"

Cheers!