JOKES IN PHYSICAL SCIENCES AND ENGINEERING
Theory is when one knows everything but nothing works. Practice is when everything works but nobody knows why. In our lab, theory and practice go hand in hand: nothing works and nobody knows why.
A body at rest remains at rest until a parental body comes and tells it to mow the lawn.
Everything that goes up must come down, man.
Atom #1: I have lost an electron!
Atom #2: Are you sure?
Atom #1: I am positive.
A neutron walks into a bar and asks the bartender, “How much for a beer?” The bartender says, “For you, no charge.”
One of the examiners addresses the PhD candidate:
My dear colleague, there are many new and accurate statements in your thesis. Unfortunately, those which are accurate are not new, and those which are new are not accurate.
A young physicist, upon learning that he was denied tenure after six productive years at a University in San Francisco, requested a meeting with the Provost for an explanation, and a possible appeal. At the meeting, the Provost told the young physicist, "I'm sorry to tell you that the needs of the University have shifted somewhat, during the past six-years leading up to your tenure decision. In point of fact, what we now require is a female, condensed-matter experimentalist. Unfortunately, you are a male, high-energy theorist!" Dejected but not defeated, the young physicist thought for a moment about the implications of the Provost's words. "Sir," he said, "I would be willing to convert in two of the three categories you mention, but ... I'll never agree to become an experimentalist!"
Heisenberg was driving down the Autobahn whereupon he was pulled over by a policeman. The policeman asked, “Do you know how fast you were going back there?” Heisenberg replied, “No, but I know where I am.”
Doppler effect is the tendency of stupid ideas to seem smarter when you come at them rapidly.
Question: What do you get when you cross an elephant with a grape?
Answer: Elephant grape sine theta.
A mathematician, a physicist, and an engineer were asked to review this mathematical problem. In a high school gym, all the girls in the class were lined up against one wall, and all the boys against the opposite wall. Then, every ten seconds, they walked toward each other until they were half the previous distance apart. The mathematician, physicist, and engineer were asked, “When will the girls and boys meet?”
The mathematician said, “Never.”
The physicist said, “In an infinite amount of time.”
The engineer said, “Well... in about two minutes, they'll be close enough for all practical purposes.”
An engineer, a physicist, a mathematician, and a statistician are all staying at a hotel. In the middle of the night the engineer wakes up to find that his trashcan is on fire. He runs to the sink, fills his ice bucket with water and douses the flames. Then, just to be sure, he runs back to the sink, refills the bucket and dumps more water into the trashcan. With the fire out, he goes back to sleep.
A little while later, the trashcan in the physicist's room spontaneously breaks into flame, waking the physicist. He whips out his slide rule, does some calculations, then runs to the sink, fills his bucket with exactly .75 liters of water, and douses the flames. Having put out the fire, he goes back to sleep.
A few minutes later, the mathematician wakes up to see that his trashcan is on fire. He whips out a piece of paper, scrawls out some equations, then goes back to sleep, comfortable that a solution exists.
Meanwhile, the statistician is running from room to room lighting trashcans on fire -- he needed more samples.
There are only 10 different kinds of persons – those who understand binary, and those who do not.
After every flight, Qantas pilots fill out a form, called a “gripe sheet,” which tells mechanics about problems with the aircraft. The mechanics correct the problems, document their repairs on the form, and then pilots review the gripe sheets before the next flight. Never let it be said that ground crews lack a sense of humor.
Here are some actual maintenance complaints submitted by Qantas’ pilots (marked with a P) and the solutions recorded (marked with an S) by maintenance engineers. By the way, Qantas is the only major airline that has never had an accident.
P: Left inside main tire almost needs replacement.
S: Almost replaced left inside main tire.
P: Test flight OK, except auto-land very rough.
S: Auto-land not installed on this aircraft.
P: Something loose in cockpit.
S: Something tightened in cockpit.
P: Dead bugs on windshield.
S: Live bugs on back-order.
P: Autopilot in altitude-hold mode produces a 200 feet per minute descent.
S: Cannot reproduce problem on ground.
P: Evidence of leak on right main landing gear.
S: Evidence removed.
P: DME volume unbelievably loud.
S: DME volume set to more believable level.
P: Friction locks cause throttle levers to stick.
S: That's what they're for.
P: IFF inoperative.
S: IFF always inoperative in OFF mode.
P: Suspected crack in windshield.
S: Suspect you're right.
P: Number 3 engine missing.
S: Engine found on right wing after brief search.
P: Aircraft handles funny.
S: Aircraft warned to straighten up, fly right, and be serious.
P: Target radar hums.
S: Reprogrammed target radar with lyrics.
P: Mouse in cockpit.
S: Cat installed.
P: Noise coming from under instrument panel. Sounds like a midget pounding on something with a hammer.
S: Took hammer away from midget.
#16 A Quote from Oksendal “Stochastic Differential Equations” (sent by Tim Field)
We have not succeeded in answering all our problems. The answers we have found only serve to raise a whole set of new questions. In some
ways we feel we are as confused as ever, but we believe we are confused on a higher level and about more important things.
Alfred Whitehead writes in his book The Concept of Nature: “I regret that it has been necessary for me in this lecture to administer a large dose of four-dimensional geometry. I do not apologise, because I am really not responsible for the fact that nature in its most fundamental aspect is four-dimensional. Things are what they are. . . ”
From George Gamow:
There was a young fellow from Trinity
Who took the square root of infinity
But the number of digits
Gave him the fidgets;
He dropped Math and took up Divinity.
#19 Spherical Chicken in a Vacuum (from Richard Martin’s compilation http://www.phy.ilstu.edu/~rfm/107F07/EPMjokes.html)
A farmer, an engineer, and a physicist were all asked to build a chicken coop. The farmer says, “Well, last time I had so many chickens and my coop was so and so big and this time I have this many chickens so I’ll make it this much bigger and that oughtta work just fine.” The engineer tackles the problem by surveying, costing materials, reading up on chickens and their needs, writing down a bunch of equations to minimize the cost per chicken, taking into account the lay of the land and writing a computer program to solve the problem. The physicist looks at the problem and says, “Let’s start by assuming a spherical chicken in a vacuum...”.
Although locked in fierce competition for what seems like forever, God and the Devil meet once every week for coffee just to catch up with each other. One week they are in heaven and the next they are in hell. When it was God’s turn to host last week, the Devil was whistling a happy tune as he walked through the gates and wore a huge smile as he plopped down in the golden chair. As he poured a cup, God said, “You look pretty pleased with yourself.” “Yeah,” said the Devil, “Things are really looking up since I got that engineer last week. He’s put in escalators and flush toilets, and he even found a way to control the heat in those old furnaces. I’ve been meaning to thank you for turning him away up here.” God looked stunned, and almost spilled coffee into the saucer. “You know that you're not supposed to get any engineers,” God said. “Peter was bringing in some new help at the gates last week, and they must have made a mistake. Just send him back up and we’ll straighten it out.” But the Devil just chuckled and said, “No. I think I’ll keep him. He was talking about looking into better ventilation this week. I can see why you keep them all for yourself.” “Send him back,” demanded God “No,” smirked the Devil. God thundered, “Send him back, or...” “Or what?” the Devil asked. “Or I’ll sue,” finished God. The Devil chuckled again. “Where are you going to get a lawyer?”
Once many professors were called and asked to sit in an airplane. After they sat they were informed that the plane was made by their students. All of them ran and got out of the plane except one.
When asked for his reason to stay, he said, "If it's made by my students it will not even start."
#23 General Knowledge of Calculus (sent by Steve C. Cripps)
Two mathematicians were in a restaurant arguing about the mathematical abilities of the general public. One was particularly convinced that people had no general knowledge of calculus. While he was visiting the toilet his colleague decided to play a little trick on him, and beckoned to their blond waitress and said to her "when you come to take our order I will ask a question, you must reply 'X cubed over three'. When the other returned to the table the waitress came over and the trickster said "what is the integral of X squared?". She dutifully replied "X cubed over three" then fixed him with a sarcastic stare and added "...plus the arbitrary constant of integration".
Frankenstein Research Laboratory, Castle Frankenstein
I know I should not have laughed at the highlighted statements below but I did.
In 1958 Leo Esaki, a Japanese scientist and a Nobel Prize winner, discovered the tunnel diode phenomenon (when he wasn't saying "rook, Godzirra!). If a semiconductor junction diode is heavily doped with impurities, its I-V curve will have a region of negative resistance (the slope is negative, or downward). Such diodes are called "tunnel diodes", and have broad applications in microwaves. This region has been exploited to create oscillators, but it also makes a very efficient detector. Why the word "tunnel"? We'd have to resort to quantum physics to explain that, but we won't, because no real microwave engineer cares!
1. Thou shalt test for grid independence.
2. For transient problems: thou shalt test for time step independence.
3. If simulating particles: thou shalt release enough particles for statistical significance.
4. If using wall functions: thou shalt check that the Y+ value at the wall is in the log-law region.
5. Thou shalt understand the equations being solved.
6. Thou shalt check sensitivity to uncertain inlet conditions such as turbulence intensity and length scale.
7. Thou shalt backup thine data.
8. Thou shalt read the literature.
9. Thou shalt validate CFD predictions against experiments.
10. Thou shalt verify CFD predictions against analytical results wherever possible.
11. Thou shalt document all of thine inputs and analysis
12. Thou shalt double check all inputs into CFD codes.
13. Thou shalt not plagiarise.
14. Thou shalt show up to meetings on time.
15. Thou shalt bring thine own pen.
16. Thou shalt respond to emails and shall use appropriate ‘subject’.
17. Thou shalt have a strong work ethic, be self-motivated, and treat graduate studies as a full time job.
#27 Coaxial Connectors (from Edward F. Kuester, University of Colorado Boulder, http://ecee.colorado.edu/~kuester/Coax/connchart.htm)
Those unaccustomed to the use of the terms "male" and "female" to describe connectors will have to get used to this time-honored engineering nomenclature. Those of us who work with them regularly use the terminology without a second thought. One day a number of years back, my daughter (who was about 8 years old at the time, if memory serves) was in the lab with me while I was working at the network analyzer with one of the grad students. She overheard our conversation, peppered as it was with the terms "male connector" and "female connector". After we were done, she asked me why the connectors were named that way. Well, this was a conversation I had expected to have in somewhat different circumstances, but I gave her a quick summary of the "how-babies-get-made" story, followed by the analogy that is implied by the connector terminology. She thought about it for a few moments when I was done, and then said, "Daddy, that's just weird." It's hard to argue with that.