The Science Jokes

I told the beam it had to follow Snell's law.

Steel and air have the worst impedance mismatch in the shop.

My high-frequency probe and I have a lot in common.

The inverse square law says doubling your distance cuts the intensity to a quarter.

Half-life is how long it takes for half of a source to go away.

Magnetic domains are just tiny crowds.

I tried to explain damping to my kids.

What does the Doppler effect have in common with a client deadline?

A flaw is like a good secret.

A standing wave has a great job.

What did the steel say to the air?

Why did the beam bend as it entered the slower material?

Why does low-frequency sound go the distance?

How long does an Iridium-192 source take to drop to a quarter of its strength?

Why did the magnet win every argument?

Why do the front-row students get the most attention from the lecturer?

What did the shear wave say to the longitudinal wave?

Why does sound travel faster in steel than in air?

Why did the beam quit in the coarse-grained casting?

The speed of sound in steel is about 0.23 inches per microsecond, which is roughly how fast bad news travels through a plant.

Anything much smaller than a wavelength is invisible to the beam, which is also how I explain my filing system.

The inverse square law says doubling your distance quarters the intensity, which is why you stand where the rope says.

Half-life is the only measure of time where nobody asks if you can have it done sooner.

Eddy currents are just electrons trying to go around the problem.

Magnetic field lines never cross. Finally, a crowd that follows the rules.

Acoustic impedance is density times velocity, and nearly every disagreement is a mismatch.

Physics doesn't care that the schedule says Friday.

You might be an NDT tech if...

You might be an NDT tech if...

You might be an NDT tech if...

At a family dinner someone asked what I do. I said I use sound waves to find cracks in steel. 'So, like a bat?' 'Exactly like a bat,' I said, 'but with more paperwork and fewer insects.'

The instructor asked what happens to sound at a steel-to-air boundary. A student said, 'Almost all of it reflects.' 'Why?' 'Because the air isn't interested.' The instructor wrote that on the board and underlined it.

A retired radiographer explained half-life to his grandson with a bag of candy. 'Every minute I eat half of what's left.' After six minutes the boy asked how much remained. 'About one and a half percent.' 'That's still a lot of candy.' 'That's what the source people say, too.'

My nephew asked why a straw looks bent in a glass of water. I explained refraction. 'So the straw is fine?' 'The straw is fine.' 'Then how do you know the weld is fine?' I said, 'Same way: we look from more than one angle.'

Acoustic Impedance (n.): A material's resistance to being pushed around by sound, and the reason air gaps get all the reflection and none of the credit.

Half-Life (n.): The time it takes for half of anything to disappear: atoms, patience, or the last donut at a safety meeting.

Inverse Square Law (n.): The reason standing twice as far away makes you four times as comfortable.

Knock, knock.
Who's there?
Joule.
Joule who?

Knock, knock.
Who's there?
Gauss.
Gauss who?

Into slower steel
The beam bends toward the normal.
Sines hold the ratio.

Seventy-four days.
Half of the source is gone now.
The schedule remains.

A radiographer, careful and wise,
Doubled distance, to everyone's surprise:
The intensity fell
To a quarter, as well,
As the inverse square law justifies.

Are you Snell's law? Because every time I meet your boundary, I change direction.

Is your name Iridium-192? Because I know our time together is short, but I'd still like to see you again in seventy-four days.

Nobody warns you that learning wave physics ruins a quiet room: you start thinking about all the reflections.

Ever notice that 'it depends' is always true in physics and never fits on a sticky note?

Ever notice that the formulas in the training manual use nice round numbers, and nothing in the field ever does?

Nobody warns you that the inverse square law also applies to classroom attention, with distance measured in rows.

Ever notice that the velocity of sound in steel is the one number every technician remembers and the one number nobody writes on the report?

Ever notice that the source always needs changing on the one weekend you made plans?

Why are the office and the field like Snell's law?

Corrosion Allowance (n.): The extra wall thickness a vessel is born with, which the plant spends like an allowance on a Saturday.

Why are heat exchanger tubes bad at keeping secrets?

The distillation column inspector says the job is all about fractions, especially thirty-seconds of an inch.

Wind has more energy than any inspector at the top of a tower climb, and uses it more efficiently.

Ever notice that sound slows down in hot steel, and so does everyone standing next to it?

A track time window is a promise from the railroad that expires the moment a train shows up.

I asked my probe how it stays so calm under pressure.

The angle beam probe never answers a question directly.

Higher frequency sees finer detail and travels less far, which is also how I describe my patience.

Near field is where the beam can't make up its mind: strong, weak, strong, weak.

You might be an Ultrasonic Testing technician if...

You might be an Ultrasonic Testing technician if...

I admire Eddy Current Testing's honesty.

Copper and aluminum argued about who is more conductive.

Ferromagnetic materials are the drama queens of Eddy Current Testing.

What did the stainless steel tube say about its pit?

Why did the technician lower the frequency?

Why did the impedance plane never get lonely?

Why do eddy currents make poor mountain climbers?

Eddy currents, like most good gossip, die out quickly the deeper you go.

Phase angle is the one thing in Eddy Current Testing everyone says they understand and nobody can explain on a whiteboard.

Eddy Current Testing is the method where 'it depends on the frequency' is always a complete and correct answer.

You might be an Eddy Current Testing technician if...

You might be an Eddy Current Testing technician if...

The client asked if Eddy Current Testing could find a flaw on the far side of a thick steel plate. I explained skin depth. He nodded. 'So you need to be on the other side.' 'Yes.' 'Then why are you on this side?' That was a fair question.

Skin Depth (n.): How far into a metal an eddy current will go before it loses interest.

Frequency (n.): The setting you change when the flaw is deeper than your confidence.

Knock, knock.
Who's there?
Phase.
Phase who?

Eddy currents fade.
Deeper in the steel they thin.
Surface flaws shout loud.

You must be copper, because you're my 100 percent on the conductivity scale.

Gamma rays are bad at stand-up. Every joke goes straight through the audience.

Inverse square law: the only place where doubling the distance divides your problems by four.

Backscatter is just radiation coming back to see if you remembered the lead letter B.

A radiographer never judges a part by its cover. She prefers to see what's inside.

Geometric unsharpness is a radiograph's polite way of saying your source was too big for the job.

Lead is the only worker who gets praised for letting nothing through.

How does a radiographer end an argument?

Why did the Iridium-192 source refuse to make long-term plans?

Why did the radiographer think the film was haunted?

Half-Life (n.): The point at which your source and your patience are both at fifty percent.

Knock knock.
Who's there?
Source.
Source who?

Knock knock.
Who's there?
Gamma.
Gamma who?

Double your distance from the source,
And the dose falls to a quarter, of course.
So step back a few feet,
Let the math take your seat,
And let the law do the rest, with full force.

Are you Iridium-192? Because I'd still be in love with you after 74 days, even at half strength.

A residual field is just magnetism that refuses to move on.

At a crack, the part's field leaks out. It's finally letting its guard down.

What do you call a part that can't let go of the past?

Why does Magnetic Particle Testing prefer a crack across the field?

What did the inspector say to the steel bar that kept picking up paper clips?

Nothing clings like a part that was never demagnetized.

Never argue with a magnetic field. It has two poles and no interest in compromise.

You might be a Magnetic Particle inspector if you've explained longitudinal versus circular magnetization to a spouse who just wanted to watch television.

Leakage Field (n.): The only leak the customer is glad you found.

Residual Field (n.): A magnetized part's way of saying, 'I'll never forget you.'

Knock knock.
Who's there?
Particle.
Particle who?

A steel bar with a field far too strong
Kept the washers and bolts all day long.
It collected a spoon,
Then a clipboard by noon,
And the boss said, 'Something is wrong.'

Part leaves the machine,
still holding on to its field.
Wrench sticks to it too.

Are you a crack at ninety degrees to my field? Because you've got all my particles gathering around you.

Are you a residual field? Because I'm never going to get over you.

A good penetrant has low surface tension and high curiosity.

Capillary action is just penetrant being nosy about every opening.

Guided wave testing is a long-distance relationship that works: you send out a wave and hear back from every weld along the way.

Shearography is the only inspection that works because of a little tension.

Why did the thermographer cancel the scan of the shiny pipe?

Thermography on shiny metal is mostly a thermal selfie.

You might be a thermographer if you've ever apologized to a pipe for its emissivity.

Emissivity (n.): How much a surface is willing to admit about its own temperature.

Flux Leakage (n.): The only kind of leak the inspector is happy to find.

Tap, tap, tap, clear tone,
then near the edge, a dull thud:
the glue has let go.

Experience hours have a half-life. Log them this week, or half of them will have decayed by Friday.

Why did the Level II study Snell's law the night before the exam?

Inspection: two hours. Report: two days. Turns out time-of-flight is only fast for the sound.

I've figured out why it's called the graveyard shift.

What did the wing skin say to the eddy current coil?

Why is a fatigue crack the most dedicated employee on the bridge?

Why did the high-strength bolt always win at tug-of-war?

Why does a delaminated bridge deck make a hollow sound?

Why do blade root bolts make good friends?

The tower flange bolts went on a team retreat. They said it was the first time they were all on the same torque.

Why does the gage block always win the argument?

Nobody warns you that the new edition changes exactly the table you just memorized.

Why did the penetrant fail on the hot plate?

Eddy currents flow in circles, which makes them the only thing at the outage that never needs directions.

Ever notice that Thanksgiving dinner has more dwell time than a penetrant: hours of waiting, one minute of eating?