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The most expensive number in engineering

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Re: The most expensive number in engineering

#81

Are we sure this is the most expensive? I would guess the number which represents the bit pattern of a Windows 10 iso cost Microsoft more than $1.5 billion to find. I am sure you can find other examples of numbers that were expensive to find.

Is your username a play on charcuterie?

No, it isn't

Re: The most expensive number in engineering

#82

Earlier quoted context omitted.

Aren't all the major bridges in New York built with ridiculous safety factors? It's why these century old bridges built for carriages and small trucks in a city of a million, can deal with 2021? It's fascinating to me, and I feel like over-spec'ing certain chokepoints in infrastructure makes sense like this.

The funny thing is a safety factor is a factor after all. Just one needs to be small enough, and the whole construction (pun intended) may collapse in the worst imaginable manner. This happened recently in Italy: https://www.bbc.com/news/world-europe-57219737 . "Engineers" didn't consider the safety brake essential (i mean, why do you even need it?), and Murphy took his chance.

That was the original article which didn’t have the cause, and I hadn’t seen that they’d decided it was disabling the brakes [1]. A couple days ago it was “not sure which was first: support cable snap or emergency brake”.

It seems like they’ve decided that the support cable was functioning after the main cable broke.

[1] https://www.nbcnews.com/news/world/blame-italy-cable-car-dea...

Re: The most expensive number in engineering

#83

Grossly increasing the factor of safety is a subtle way that science fiction stories connote a feeling of very advanced technology. For example in the JJ Abrams movie Star Trek Into Darkness we see the Enterprise operating at depth in an ocean, then dramatically zooming away into space. Then later another ship falls from orbital height and plows through San Francisco without losing its hull shape. In Star Wars the Mi…

Back in the old Star Wars RPG from Westend Games, hull integrity was amplified by ballistic shields that were always on. Reason being, that hull had to withstand debris hits at the rediculous speeds in space. Given the speed and energy, I would assume kinetic impact would matter much. Pressure is different so, as even the hardest space ship only has to hold 2 bar, give or take, of pressure in.

Re: The most expensive number in engineering

#84

The real number engineers should be considering is not the factor of safety, but the probability of failure. The probably of failure should be calculated considering material defects, forces larger than predicted, simulation errors, and all other causes the factor of safety is designed to protect against. Then the engineering process can allocate those probabilities in the most efficient way. For example, in a rocket…

Unfortunately, NASA was really bad at estimating the probability of failure. Feynman famously dissed their lack of mathematical rigour in this regard.

I'm guessing most engineers' grasp of proper statistics math is worse than their understanding of factors of safety.

Re: The most expensive number in engineering

#85
post #58
post #49

Earlier quoted context omitted.

Seems disingenuous to lump a science fiction movie where the focus is future technologies to an action movie with exaggerated physics and lack of real damage. In action movies, bad guys die with one bullet while the hero finds his way to safety (and survives!) despite having 10 or more lethal bullet wounds. For the record, Star Wars is not science fiction nor has it ever been portrayed as such. It's very much an acti…

> For the record, Star Wars is not science fiction nor has it ever been portrayed as such. FWIW this is literally the first time I’ve encountered someone claiming that it isn’t science fiction. ( Soft SciFi, to be sure, but still: https://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScien... )

And Vulcan are space elves, Klingon are space orcs and Borg are space undead.

All of this stuff has inspiration from classical fantasy. That doesn't change whether or not something is SciFi or not.

There is an intersection of SciFi and Fantasy for sure, and the line gets blurred. Artificial human stories can be cyborgs, androids, clones, golems, or chimera, or even explicit fantasy races like minotaurs.

If it's an android, then it's SciFi. But if it was a clay golem made with magic (but otherwise the same story) it's fantasy.

See golem stories for instance. They explore a lot of sci Fi themes but are basically a fantasy theme. https://en.m.wikipedia.org/wiki/Golem

Re: The most expensive number in engineering

#86
It’s kind of mentioned in the article, but to be more explicit: reducing safety factors has asymmetric risk vs reward. Reducing the factors “just” lowers cost or improves performance. But if your field is padding by 50%, then you need to tradeoff an “up to 50%” cost reduction (or similar) versus “had a catastrophic failure”.

So, reducing the padding from 5x to 1.5x was already most of the benefit. If you were at 1.2, there are probably better ways to shave costs than reducing your unexpected force multipliers. It’s definitely attractive to lower cost / increase speed / whatever if you truly think it’s “free”, but the benefits are diminishing.

Re: The most expensive number in engineering

#87
post #44

Earlier quoted context omitted.

About the Abrams movie: Too bad the same factor of safety wasn't applied to the buildings, where that should have been even cheaper. Your point is good though. Just like we're now starting to put wi-fi chips into absolutely anything just in case, why wouldn't an advanced civilization simply use their super strength nanoparticles for everything? Why go out of your way to use worse materials?

We use super-strength thousand year plastic for one time uses. It's a big problem.

It is only a problem for single planet species. Advanced multi planet or multi system civilizations may worry less about that than we do.

Also if the bio diversity dropped, and people are used to living in closed ecosystems to limit damages from such harmful chemicals, over long enough period everyone will forget what was there before , further making bad things will not impact their quality of life anyway.

Re: The most expensive number in engineering

#88
post #58

Earlier quoted context omitted.

> For the record, Star Wars is not science fiction nor has it ever been portrayed as such. FWIW this is literally the first time I’ve encountered someone claiming that it isn’t science fiction. ( Soft SciFi, to be sure, but still: https://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScien... )

And Vulcan are space elves, Klingon are space orcs and Borg are space undead. All of this stuff has inspiration from classical fantasy. That doesn't change whether or not something is SciFi or not. There is an intersection of SciFi and Fantasy for sure, and the line gets blurred. Artificial human stories can be cyborgs, androids, clones, golems, or chimera, or even explicit fantasy races like minotaurs. If it's an an…

Certainly many tropes are shared, but that is true beyond the scifi-fantasy intersection. (Although: I would say Klingons are the avatar of Russian-ness in the eyes of America at the time any given episode gets written. Beardy humans in TOS, impoverished but hard as nails in TNG, anarchic and self-destructive in ENT, sneaky and dangerous warmongers in DIS).

I regard the superhero genre as a modern version of the old divine pantheons — heroes and villains, supposedly far beyond human, yet oddly well-balanced against each other (Hawkeye should not be in the same battleground as Thor in the same way and for the same reason that Choi Mi-sun should not be in a battle featuring an attack helicopter).

Sufficiently advanced technology being indistinguishable from magic and all that.

Re: The most expensive number in engineering

#90

Grossly increasing the factor of safety is a subtle way that science fiction stories connote a feeling of very advanced technology. For example in the JJ Abrams movie Star Trek Into Darkness we see the Enterprise operating at depth in an ocean, then dramatically zooming away into space. Then later another ship falls from orbital height and plows through San Francisco without losing its hull shape. In Star Wars the Mi…

> Even as far back as the movie 2001, the monolith is made out of a material that humans can’t dent or cut. Why so strong? It’s basically just an automated radio.

It's an automated radio that is supposed to operate unattended for millions of years. You want a strong case for that.

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