comment by kleinbl00

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kleinbl00 · 4695 days ago · link · · parent · post: Why should you learn math? Because fuck you, that's why.

So you ask the prof, well how do I solve it then? And (s)he says "you approximate a solution by adding and subtracting!", and thus your mathematical life comes full circle (although, a computer is certainly going to do the heavy lifting for you).

Hah. I can beat the shit out of that.

I learned to build cars long before learning engineering. By the time I took my courses on steel I'd been welding for about six years (and taught the welding section of my class - because apparently, it's gauche for engineering professors to know how to weld). And I was getting my ass kicked by Mohr's Circle and psychometric charts and all these rootin' tootin' high falootin' engineering calcs and then we got to 495, capstone engineering, and you learn that

a) to do real engineering work, you take the answer that you think is correct and you stack six "bullshit factor" coefficients in front of it to get your real answer

b) more likely than not you skip those "bullshit factor" coefficients and just go with 1.6 for military hardware, 2 for racing, and between 5 and 10 for consumer gear and even then, the most successful designs are those that "look strong enough."

I've pulled engines with seat belts - they work really goddamn well. Meanwhile, we had an engineering homework question where we were supposed to use our "FS=2" bullshit factor, our "FS=1.6" bullshit factor and our "FS=5" bullshit factor to determine how thick the chain on a playground swingset needed to be to support a drunken, overweight frat rat of 250 lbs. You won't be surprised to find out that playground swingsets are actually sized such that they can support a drunken, overweight Buick LeSabre.

I decided I hated engineering when my Finite Element Analysis instructor docked us points if our answers weren't "heavy" enough (these were printouts from a server-based FORTRAN program and if your report didn't tip the scales at half a pound of paper, you didn't do enough work - something that would have been nice to have known before I imported it all into excel and truncated the last half of all my data tables because you know what? I like trees). Then I decided I loved engineering when I learned what dimensional analysis was.

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b_b · 4695 days ago · link ·

I too left engineering because I got so annoyed at the lack of a scientific approach. I hated engineering school in my third and fourth year, but thought maybe it would be better when making a paycheck. Fuck that. I worked from Chrysler in the final year or two it was owned by the Germans, and it was miserable. No one could possibly care any less about doing anything scientifically in that company, and you can see the result in the cars, unfortunately. That's why I quit and went into physics for grad work.

That said, safety factors can be important, mainly because material defects exist so often. Its easier to over-design by a factor of 2-10 than it is to perform quality inspections constantly (not to mention the whole lawsuit protection game).

+discuss+discuss

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kleinbl00 · 4695 days ago · link ·

I was more impressed that my redneck approach of "that looks about right" was the more dominant approach than "whip out some math and get efficient on that bitch." It was pretty fucking amazing, though - one of our final projects was to do the cost build, the analysis and build a working scale model of something capable of lifting a 150lb load 10' into the air and then move it side-to-side by 3'. I was so underwhelmed by the task that I designed mine out of bamboo and used a come-along as motive force. My build came in at $200.

The amazing thing to me wasn't that mine was far and away the cheapest approach, but that mine was the only successful approach. Here's all these 4th-year engineering students, and exactly two of them are capable of building a fucking hoist.