The French mathematician Augustin-Louis Cauchy made many contributions to the field of complex variables.
In fact, his dog even proved a theory: around any closed path, the dog would leave a residue at every pole.
Q: How many sound engineers does it take to change a lightbulb?
A: None, You get the assistant to do it…
(An assistant engineer is on “the rung below” on the ladder of Sound Engineer-hood. All crappy jobs that the engineer can’t/won’t do gets “delegated” to the assistant. …who then hands it on to the Tape Op!)
a UNIX programmer wore this shirt in one day:
rm -Rf /bin/Laden
Explanation:
rm -Rf means “remove all contents of this directory, and don’t ask any questions. Just do it. Including sub-directories. Yes, I’m sure. Do it now. Make the stuff go away forever.”
/bin is a top-level directory with large amounts of programs, executables, scripts and generally “stuff that makes the computer work right”.
Not very obscure but…
Whats the difference between the Army and the Boy Scouts?
The Boy Scouts have adult supervision.
Q: What do you call an ion with three hydrogen atoms and a Ailuropoda melanoleuca bpnded to a central nitrogen?
A: Pandamonium! (yeah, it’s pandemonium – sue me).
A high-energy astrophysicist is someone who thinks one photon is a detection and two photons is a spectrum.
(Not literally true but close. “High energy” usually means X-rays and gamma rays. Especially in gamma rays, we are working with very few numbers of very high-energy photons, so detecting a dozen photons can be a valid “detection,” and the more despearte scientists may draw a spectrum based on a few dozen photons.)
Hey! I resemble that remark! 
I knew someone, working with old ROSAT data (its an obsolete X-ray observatory satellite) that once had so few photons in his data, he named them all.
My friend just gave me this one:
Q: What’s purple and commutes?
A: An Abelian grape.
(In abstract algebra, an Abelian group is a group in which all members commute,
that is, such that a * b = b * a for all a,b in the group. This is not true for
the majority of groups.)
Q: What do you get when you cross an elephant with a giraffe?
A: |elephant||giraffe|sin(theta)
In a similar vein:
Q: What do you get when you cross a mountain climber with a mosquito?
A: Silly, you can’t cross a scalar with a vector.
From my uncle the chemist:
A physicist, biologist and a chemist were going to the ocean for the first time.
The physicist saw the ocean and was fascinated by the waves. He said he wanted to do some research on the fluid dynamics of the waves and walked into the ocean. He drowned and never came back.
The biologist said he wanted to do research on the flora and fauna inside the ocean and walked inside the ocean. He drowned, too.
The chemist waited for a long time and afterwards, wrote the observation, “The physicist and the biologist are soluble in ocean water”.
From my brother the physicist:
A farmer has problems with his chickens - all of the sudden, they are all getting very sick. So he calls up a biologist, a chemist and a physicist
The biologist runs several experiments, but can’t come up with the answer. The chemist also runs several experiments, but he can’t come up with the answer, either.
So the physist trys. He stands there and looks at the chickens for a long time without touching them or anything. Then all of the sudden he starts scribbling away in a notebook. Finally, after several gruesome calculations, he exclaims, “I’ve got it! But it only works for spherical chickens in a vaccum.”
If I had time, I’d post the classic Steve Martin plumber joke. Maybe when I get home from work, if no one beats me to it.
An engineer, a physicist and a mathematician are walkng past a burning building just as the fire truck arrives.
The fireman implores them, “Please help me!”
The engineer says “Give me the building blueprints.” Within two minutes, he draws up a plan to fight the fire, which the firefighters use to save the building.
A week later, the physicist comes by the fire station. He tells the fire chief, “I’ve written a booklet on general principles for fighting fires”. The chief thanks him, and says he will use the booklet in training his firefighters.
Six months later, the mathematician comes to the fire station and drops a huge box of papers on the fire chief’s desk: “I’ve done it!”
“Done what?”, asks the fire chief.
“I’ve proven fires exist!”
This is not so much a joke in the traditional sense, but I worked at a CPA firm with someone who always had trouble with his computer, so the IT guy that we called made reference to the problem being “an I-D-ten-T”. We didn’t get the joke until he said “Write it down”.
ID10T.
A tool-and-die shop hired a new guy, a full-blooded Cherokee. He wasn’t great on the older equipment, but the boss put him in charge of inspection of outgoing work. After that, nobody ever left early. They loved to gather 'round at the end of the day to hear him proclaim, “It is a good die today.”
Ghani was a chemist,
Now Ghani is no more,
What Ghani thought was H2O
Was H2SO4.
H2O is of course water and H2SO4 is Sulfuric acid, which is odorless, clear and tasteless, making it nearly indistinguishable from water, except that it would kill you if you drank it.
Show me an embezzling glacial geologist, and I’ll show you a man with his hand in the till.
(Glacial geology is the study of landforms and sediment deposits produced by glaciers and ice sheets; till is the loose gravel and sand deposited by glaciers.)
A guy applies for a faculty position as a hydrogeologist. Since his job touches on applied math and physics as well as geology, he has to interview with a variety of people.
His first interview is with a mathematician. The interview goes very well, and at the end the applicant asks the mathematician, “Can you please tell me, what is the answer to 2 + 2?” The mathematician replies, "Why, of course the answer is 2.0000000000… "
His second interview is with a geologist. This interview goes very well too, and at the end the applicant asks the geologist, “Can you please tell me, what is the answer to 2 + 2?” The geologist replies, “Hmm, somewhere between 3 and 5.”
Finally, his last interview is with a geophysicist. The interview again goes very well, and at the end the applicant asks the geophysicist, “Can you please tell me, what is the answer to 2 + 2?” The geophysicist leans forward across his desk and whispers, “What would you like it to be?”
(The idea here is that the mathematician has a precise view of the world seldom mirrored by observations; the geologist is always forced to guess because he can never quite be sure he has all the data he needs, although he can get close to the answer; and the geophysicist often has to make interpretations from remotely-sensed data that are, well, wide open to interpretation. )
How many hardware guys does it take to change a light bulb?
Well, it passed the diagnostics so it must be a software problem…
What’s the difference between a green rope and a blousing strap?
A blousing strap serves a purpose.
Ahh, the joy of musician jokes .
Q: How do you stop a guitarist from playing?
A: Put music in front of him.
Q: What do you call new age music played backwards?
A: New age music.
Q: What’s the difference between an oboe and an onion?
A: No one cries when you chop up an oboe.
Q: How do you keep two flute player in tune?
A: Shoot one of them. (I can totally understand where they’re coming from. The flute section in the band I play has the worst intonation of all the instruments.)
And remember, wind kicks brass!