[Source Unknown]

You enter the laboratory and see an experiment. How will you know which class is it?

If it's green and wiggles, it's biology.
If it stinks, it's chemistry.
If it doesn't work, it's physics.

Seen on the door to a light-wave lab:
"CAUTION! Do not look into laser with remaining good eye"

Absolute zero is cool.

The renowned cosmogonist Professor Bignumska, lecturing on the future of the universe, had just stated that in about a billion years, according to her calculations, the earth would fall into the sun in a fiery death. In the back of the auditorium a tremulous voice piped up: "Excuse me, Professor, but h-h-how long did you say it would be?"
Professor Bignumska calmly replied, "About a billion years."
A sigh of relief was heard. "Whew! for a minute there, I thought you'd said million years."

A famous joke, as told by Douglas R. Hofstadter

An engineer, a physicist, a mathematician, and a mystic were asked to name the greatest invention of all times.
The engineer chose fire, which gave humanity power over matter.
The physicist chose the wheel, which gave humanity the power over space.
The mathematician chose the alphabet, which gave humanity power over symbols.

The mystic chose the thermos bottle.
"Why a thermos bottle?" the others asked.
"Because the thermos keeps hot liquids hot in winter and cold liquids cold in summer."
"Yes -- so what?"
"Think about it." said the mystic reverently. That little bottle -- how does it know?"

A hydrogen atom lost its electron and went to the police station to file a missing electron report. He was questioned by the police: "Haven't you just misplaced it somewhere? Are you sure that your electron is really lost?"
"I'm positive." replied the atom.

Electrons: 1$
Protons: 1$
Neutrons: free of charge

A physics student was hit by a brick falling from a house. He fainted, but came to after a while and started smiling. The onlookers were worried, so they asked him why the smile. "I just realized how lucky I am because the kinetic energy is only half m v squared."

Physics professor has been doing an experiment, and has worked out an emphirical equation that seems to explain his data. He asks the math professor to look at it.

A week later, the math professor says the equation is invalid. By then, the physics professor has used his equation to predict the results of further experiments, and he is getting excellent results, so he asks the math professor to look again.

Another week goes by, and they meet once more. The math professor tells the physics professor the equation does work, "But only in the trivial case where the numbers are real and positive."

A seminar on Time Travel will be held two weeks ago.

A mathematician and a physicist agree to a psychological experiment. The mathematician is put in a chair in a large empty room and a beautiful naked woman is placed on a bed at the other end of the room. The psychologist explains, "You are to remain on your chair. Every five minutes, I will move your chair to a position halfway between its current location and the woman on the bed." The mathematician looks at the psychologist in disgust. "What? I´m not going to go through this. You know I´ll never reach the bed!" And he gets up and storms out. The psychologist makes a note on his clipboard and ushers the physicist in. He explains the situation, and the physicist´s eyes light up and he starts drooling. The psychologist is a bit confused. "Don´t you realize that you´ll never reach her?" The physicist smiles and replies, "Of course! But I´ll get close enough for all practical purposes!"

Two physics students bump into each other walking across campus. One of them is toting his shiny new bicycle along with him. His friend says, "Wow! I really like your new bike!" "Thanks. It was the strangest thing! I was walking across campus the other day and a beautiful young girl rode her bike up to me, got off, ripped off all her clothes, threw herself on the ground, and said 'Take whatever you want!'"
"Smart move," he replied. "There's no way her clothes would have fit you."

An engineer, a physicist and a mathematician are sleeping in a hotel, which is unfortunetaly burning every night.
In the first night the engineer wakes up and notices the fire. He takes the fire extinguisher and stops the fire.
In the second night it starts to burn again. The physicist wakes up after a while (no one there to wake him up) and sees the fire. He is enthusiastic about the phenomen and dies in the fire while looking for a thermometer.
In the third night the mathematician wakes up because of the fire. He looks at the fire and sees the fire extinguisher. He states that the problem has a solution and fells asleep again.

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!"

The experimentalist comes running excitedly into the theorist's office, waving a graph taken off his latest experiment. "Hmmm," says the theorist, "That's exactly where you'd expect to see that peak. Here's the reason." A long logical explanation follows. In the middle of it, the experimentalist says "Wait a minute", studies the chart for a second, and says, "Oops, this is upside down." He fixes it. "Hmmm," says the theorist, "you'd expect to see a dip in exactly that position. Here's the reason...".

A mathematician, an engineer and a physicist sat around a table discussing how to measure the volume of a cow.

The mathematician suggested the use of geometry and symmetry relationships of the cow, but his idea was rejected on the grounds of being too time consuming.

The engineer suggested placing the cow in a pool of water and measuring the change in the height of the water, but his idea was rejected on the grounds of impracticality.

"It's easy," said the physicist. "We'll make an asumption that the cow is a small sphere, calculate the volume and then blow it up to the actual size."

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."

Gravitation can not be held resposible for people falling in love.

Albert Einstein

Chemistry is physics without thought.
Mathematics is physics without purpose.

Describe the universe in 200 words and give 3 examples

A rocket explorer named Wright
Once traveled much faster than light.
     He sat out one day
     In a relative way,
And returned on the previous night.

The Pan Book of Limericks

A Simpleton's Guide to Science

Relativity: Family get-togethers at Christmas.
Gravity: Strength of a glass of beer.
Time travel: Throwing the alarm clock at the wall.
Black holes: What you get in black socks.
Critical mass: A gaggle of film reviewers.
Hyperspace: Where you park at the superstore.

Useful Metric Conversions for the mathematically challenged

1 million microphones = 1 megaphone
1 millionth of a fish = 1 microfiche
1 trillion pins = 1 terrapin
10 rations = 1 decoration
10 millipedes = 1 centipede
3 1/3 tridents = 1 decadent
2 monograms = 1 diagram
8 nickels = 2 paradigms
2 wharves = 1 paradox

Teachers' remarks that changed the history of physics

Archimedes, you are late again. Don't tell me that you were locked again in the bathroom.
Copernicus, when will you understand that you are not the center of the world?
Galileo, if you will drop stones from the top of the tower one more time, you will be dismissed forever.
Kepler, till when will you stare at the sky?
Newton, will you please stop idling away under the apple tree?
Ohm, must you resist Ampere's opinions on current events?
Nikola Tesla, I see that everyone is attracted to your magnetic personality.
Einstein, a crocodile is greener or is it wider?
Schrödinger, stop abusing cats!
Heisenberg, when will you be sure of yourself?

Eight ways to use a barometer to find the height of a building:

  1. Measure the height of the barometer. Scale the side of the building, measuring its height in barometer-units.
  2. Drop the barometer from the top of the building. Measure the time until it hits the street. Correcting for the mass/surface ratio of the instrument, use basic acceleration equation to find the height.
  3. Tie string to top of barometer. Lower from roof to almost ground. Swing. Period of pendulum can be used to find distance from barometer's Center of Gravity to top of building.
  4. Tie a long cable to the barometer and lower it from the top of the building to the ground, and then measure the length of the cable.
  5. Take the barometer outside on a sunny day, measure its shadow and the buildings shadow.
  6. Drop the barometer from the top of the building. Measure how far was it shifted by Corriolis force. The rest is trivial.
  7. Sell the barometer. Purchase a tape measure long enough to measure the height of the building.
  8. Find someone who knows how tall the building is, and trade him the barometer for the information.

Why did the chicken cross the road?

Aristotle: It is the nature of chickens to cross roads.

Issac Newton: Chickens at rest tend to stay at rest, chickens in motion tend to cross roads.

Albert Einstein: Whether the chicken crossed the road or the road moved beneath the chicken depends on your frame of reference.

Werner Heisenberg: We are not sure which side of the road the chicken was on, but it was moving very fast.

Wolfgang Pauli: There already was a chicken on this side of the road.

A dictionary of useful research phrases: what physics researchers say and what they mean by it

It has long been known: I didn’t look up the original reference.
A definite trend is evident: These data are practically meaningless.
Of great theoretical and practical importance: Interesting to me.
While it has not been possible to provide definite answers to these questions: An unsuccessful experiment, but I still hope to get it published.
Three of the samples were chosen for detailed study: The results of the others didn’t make any sense.
Typical results are shown: The best results are shown.
These results will be shown in a subsequent report: I might get around to this sometime if I’m pushed.
The most reliable results are those obtained by Jones: He was my graduate assistant.
It is believed that: I think.
It is generally believed that: A couple of other people think so too.
It is clear that much additional work will be required before a complete understanding of the phenomenon occurs: I don’t understand it.
Correct within an order of magnitude: Wrong.
It is hoped that this study will stimulate further investigation in this: This is a lousy paper, but so are all the others on this miserable topic.
A careful analysis of obtainable data: Three pages of notes were obliterated when I knocked over a glass of beer.
Thanks are due to Joe Blotz for assistance with the experiment and to George Frink for valuable discussions: Joe did the work and George explained to me what it meant.

Physics Revisited

Gravity was discovered by Sir Isaac Newton. It is chiefly noticeable in the autumn, when the apples are falling off the trees.

You can listen to thunder after lightning and tell how close you came to getting hit. If you don't hear it, you got hit, so never mind.

When people run around and around in circles, we say they are crazy. When planets do it, we say they are orbitting.

The tides are a fight between the Earth and moon. All water tends towards the moon, because there is no water in the moon, and nature abhors a vacuum.

The moon is more useful than the sun, because the moon shines at night when you want the light, whereas the sun shines during the day when you don't need it.

To remove air from a flask, fill it with water, tip the water out, and put the cork in quick before the air can get back in.

Isn't it meaningless to speak of a 45 degrees angle unless you specify Fahrenheit or Celcius?

An object at rest will always be in the wrong place.
An object in motion will always be headed in the wrong direction.

For every action, there is an equal and opposite criticism.

Doppler effect is the tendency of stupid ideas to seem smarter when you come at them rapidly.

Lenz's Law: Everything you start works against you.

How physicists do it...

Physicists do it a quantum at a time.
Physicists do it at the speed of light.
Cosmologists do it in the first three minutes.
Mathematical physicists understand the theory of how to do it, but have difficulty obtaining practical results.
Quantum physicists can either know how fast they do it, or where they do it, but not both.
Particle physicists do it energetically.
Particle physicists do it with charm.
Aerodynamicists do it in drag.
Astrophysicists do it with a Big Bang.
Astronomers do it all night.
Astronomers do it in clusters.
Astronomers do it on mountain tops.
Astronomers do it with white dwarfs and red giants.

    You Might Be a Physicist if...

How many physicists does it take to change a light bulb?
Eleven. One to do it and ten to co-author the paper.

How many astronomers does it take to change a light bulb?
None, astronomers prefer the dark.

How many radio astronomers does it take to change a light bulb?
None. They are not interested in that short wave stuff.

How many general relativists does it take to change a light bulb?
Two. One holds the bulb, while the other rotates the universe.