Great one-liners from PF members

[Ibix]

If you can blow up the sun, powering a dipping bird may not be high on your list of tasks remaining to be accomplished.

I guess it depends how big a dipping bird...

 

[sysprog]

What did work-energy ever do to you to deserve this abuse? $-$ @russ_watters

 

[sysprog]

Breaking an incalculable problem into two incalculable steps may not get you very far. $-$ @Vanadium 50

 

[berkeman]

From a thread in Academic Guidance where we were trying to help a struggling Engineering student who kept alluding to using cheating to get by...

Its probably worth pointing out that when engineers cheat, people die.

 

[fresh_42]

From a thread in Academic Guidance where we were trying to help a struggling Engineering student who kept alluding to using cheating to get by...

Its probably worth pointing out that when engineers cheat, people die.

When Ferdinand Sauerbruch [a famous surgeon] had Max Liebermann [a famous painter] portray him, he soon found sitting too long. But the artist reassured him: "There's no other way. If you make a mistake, the green lawn will cover it up the next day. But you can see my mistake hanging on the wall for a hundred years."

 

[valenumr]

From a thread in Academic Guidance where we were trying to help a struggling Engineering student who kept alluding to using cheating to get by...

It's a very good point. I remember very distinctly the Kansas city walkway collapse, and it really came down to a poor engineering decision. The original design should have been fine.

 

[berkeman]

LOL, this was asked of me in a thread today...

Odd. Why is Google your friend if you're looking it up in Wikipedia?

 

[sysprog]

The universe is not Euclidean. That doesn't mean there isn't (still) Euclidean geometry. $-$ @PeroK

 

[PeroK]

The universe is not Euclidean. That doesn't mean there isn't (still) Euclidean geometry. $-$ @PeroK

I'm glad someone understood what I meant!

 

[Ibix]

I would describe your theory in tauro-scatological terms.

 

[gmax137]

I would describe your theory in tauro-scatological terms.

That one took me a few minutes.

 

[PeroK]

That one took me a few minutes.

I stole it from Tom Wolfe, in The Bonfire of the Vanities.

 

[berkeman]

That one took me a few minutes.

It probably helps if you click the up-arrow in the quote to see the context of his reply.

 

[gmax137]

It probably helps if you click the up-arrow in the quote to see the context of his reply.

I tried that, and still sat and stared at it until the light bulb lit.

 

[DaveE]

Vanadium 50 said:
Its probably worth pointing out that when engineers cheat, people die.

Sometimes, that's the rub. Usually though, the people they work for make a bit more money, at least for a while until the market decides your product sucks or the regulators and lawyers find out.

Hence the quality/safety problem that isn't uncommon in engineering: Do I quit, or do what my idiot boss wants? This is often an extremely complex and subtle issue. No ethics class will give you the answer to your particular dilemma. Other times it's not a dilemma, you might be clueless working beyond your expertise, à la Dunning-Kruger.

Are the engineers that designed the Ford Pinto worse than the engineers that designed the Toyota Corolla? I think probably not, they just worked for different people.

 

[Astronuc]

I tried that, and still sat and stared at it until the light bulb lit.

You have one of those energy efficient bulbs that take a while to brighten?

 

[sysprog]

Do I quit, or do what my idiot boss wants?

Chicago Police: Who called the Police?
Beautiful girl (PhD candidate) working at coffee shop counter: My idiot boss.
Police: Why did he call the Police?
Beautiful: Because he's an idiot.
CPD: Tell your idiot boss don't call the Police unless he has a good reason.
BG: Well, I'll tell him, but I don't think he'll listen.
CPD [Leaves without comment]: (maybe a bit of a harrumph).

 

[anorlunda]

This might be a chance to teach the most useful general rule in all of science:

(Some of it) + (The rest of it) = (All of it)

 

[sysprog]

Mass is constant in a closed system. But in an open system where stuff can come in or out, it manifestly isn't constant, as the example of a person eating shows. $-$ @Ibix

 

[sysprog]

If I know it I will be able to figure it out. $-$ @rudransh verma

 

[sysprog]

It's like watching a tennis match and focusing on how the players have tied their shoelaces. Yes, it's important that a player's shoes don't fall off while he/she is running around; but, it hardly adds to an understanding of the game. $-$ @PeroK

 

[jrmichler]

And no-one gets banned on PF. They get liberated from the tyranny of the forum rules.

Sadly, this is all too true.

 

[epenguin]

"I confess that I get tired of HW problems that are trying to trick the students instead of focusing on the key analytical issues."

DaveE in "Find the current through a complicated circuit"

(However I am not saying that that problem is an example of this artificiality.)

 

[epenguin]

That is a different principle introducing real-world type situations, suitable for the more advanced stages IMHO.

 

[ergospherical]

"I confess that I get tired of HW problems that are trying to trick the students instead of focusing on the key analytical issues."

This statement is pretty misguided. The problem in that thread is typical of Olympiad-style papers (viz: circuits with a few little twists or exotic geometries), designed to make the student think instead of chugging through the mindless book-work level analysis.

 

[BvU]

"I confess that I get tired of HW problems that are trying to trick the students instead of focusing on the key analytical issues."

DaveE in "Find the current through a complicated circuit"

(However I am not saying that that problem is an example of this artificiality.)

here's the link. A simple flattened-out redraw of the circuit is all that's required. Not a trick, but simple stereometric insight. Admittedly unrelated to key analytical issues.

$\$

 

[sysprog]

@berkeman, I would interpret "It was not a theory but imagination" to mean something like "it's not something that I think is surely or necessarily very likely true or hold as a theory, but something that I imagine might be true" $-$ I think that the 'appears in a reputable textbook or peer-reviewed journal' criterion that PF embraces is a useful 'guidepost' or 'bright line' idea here.

 

[DaveE]

This statement is pretty misguided. The problem in that thread is typical of Olympiad-style papers (viz: circuits with a few little twists or exotic geometries), designed to make the student think instead of chugging through the mindless book-work level analysis.

The "mindless book-work level analysis" you refer to is in the realm of physics HW assignments or circuit simulators. The real working analog EEs have their hands full with schematics of real world, complex circuits to deal with.

This is the world EEs work in:

Not contrived puzzles with 6 identical resistors in tetrahedrons. It's a math puzzle, maybe a lesson in recognizing symmetry, that is all it's good for. So, if you need to quiz a freshman physics student with a HW puzzle, go for it, but it has virtually no value in the real EE world. This is a great example of why EEs think physicists don't understand circuit analysis. Perhaps it's beneath y'all, IDK.

In my studies at prestigious universities in EE, and then in 30 years of working with circuits, I never, ever, had to deal with anything as contrived as this tetrahedron. Teaching students methods to deal with complexity will pay off, teaching them to find tricks for quick solutions to quizzes is fleeting at best. Either they'll never need it, or it won't work for real problems.

 

[ergospherical]

It's a math puzzle, maybe a lesson in recognizing symmetry, that is all it's good for.

I think many would argue this is quite valuable. Inspect, for example, the following problems. Although you'd probably say they're completely useless for a budding electronic engineer, both provide insight into some key physical principles and problem-solving techniques.

 

[hutchphd]

I think that both @ergospherical and @DaveE are correct. I have designed production electronics and I have occasionally had lovely inspired flashes of insight. They are synergistic.

 

[phinds]

 

[sysprog]

Thanks @phinds, back on track:

Having done countless computing interviews, school prestige is nowhere near the importance many students think. $-$ @bhobba

 

[sysprog]

Please don’t misquote your own source. $-$ @Dale

 

[sysprog]

If you reach down and pull up on your bootstraps (shoelaces), you don't reduce your weight, you just strain your back. $-$ @russ_watters

 

[sysprog]

Let me say it again: never never use physics textbooks for studying math. $-$ @wrobel