No problem. Just don’t say that the bar for acceptable modern engineering is set at “highly flawed.”
Um, no. I absolutely will.
Physical mechanical load bearing systems are among the most studied problems in physics. The FEA used is based entirely in old simple beam calculations. And despite the fact that plenty of computational horsepower gets thrown at it, it’s wrong as often as not. At best the old physics highlights things to do more testing on.
The fact is, most American buildings and bridges don’t fall down (unless subjected to tremendous stress). For practical purposes, engineers use approximations that are ‘good enough,’ but that is hardly the same thing as saying their working standards are ‘highly flawed.’
That said, if you wish to continue insisting–to strangers thousands of miles away, via a computer linked to a sophisticated social-interaction website on the internet–that ‘most science is bunk’ and that ‘high regard for scientists is misplaced,’ I will leave you to it.
You are out of your depth. Science doesn’t make buildings not fall down. Native Indians built boats without understanding the scientific principals of water displacement. And yes, that’s true even though they built canoes that didn’t sink.
Your second paragraph has nothing to do with anything I’ve written, though it’s pretty evident you probably just don’t understand what Push posted.
I would love it if I could get an explanation as to the 20 character rule. I have been TOLD (TOLD I SAY!!) that it is to maintain quality of posts.
However, funneling traffic to FREAKING FACEBOOK (land of the totally insane posting) in order to comment on an article is A-OK.
Color me confused.
I guess you can spend 10’s of thousands here over 15+ years and get the boot for using an extra period to hit TEH PRECIOUSZ TWENTZ.
Can we vet the Mod who evaluates whether a post is worthy or not? That would be fun.
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It’s true, I haven’t read the book. But I did read the portion of the review you chose to include, and based my comment on that. If you will re-read your own post, you’ll see that my comment is a fair encapsulation of that review, and thus hardly a “beyond stupid” thing to have written.
The fact that you are forced to resort to name-calling and belittling simply reinforces the impression that you haven’t been able to rebut my arguments.
At any rate, if the alternative is to be anti-science and reactionary, I’ll take ‘dumb’ every time, thank you very much.
I responded to the info you presented about the book. If that info is not representative of the book, that’s on you.
I only mentioned my PhD because Duce mentioned his work. He was touting his credentials; in response, I was touting mine.
I don’t think I’ve been either defensive or nonsensical, but I’ll leave that to others to judge.
Well, there is also the matter of the book review you chose to post–some would say that provides a “logical explanation” for what I wrote.
There was an article published today here on T-mag by Matt Kroc. This is confusing.
I asked about this before, but looking into it, the “tips” are mostly just excerpts from previous articles, with that one being no exception. At the time the article was written, Kroc’s legal name was Matthew, but it is an interesting question in regards to how one would document it.
As an engineer who has done FEA, testing (burst, fatigue, crack propagation…etc) and regular support for multiple technical product lines I would never think the engineering is based on dis-proven physics models. What have they been dis-proven with?
R&D engineering has allowed us to continue pushing technology. I’m amazed you think its based of real-world experience and intuition, not science. If I had to support a product in front of a customer and explain a failure I would be laughed out of the room if the only reasoning was that it has previously worked. They need proof of design, which requires scientific analysis.
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Not necessarily non-analytic, but decidedly non-exact theoretically. FEA is a perfect example. Model simplification and constraint as well as force application is as much art and feel as scientific. Yes I consider good FEA an art. We subcontract a lot of our FEA even though the other company has the same scientific tools because they have a better feel for setup. But all that on top of the fact that stress/strain FEA is based on a simple beam Newtonian physics problem. And yes, Newtonian physics is scientifically disproven and there is no such things as a simple beam. It’s close enough and works so the pragmatic engineer doesn’t really care about the “scientific truth” of their calculations.
What was the safety factor on your last analysis and why?
Using assumptions to clarify complex problems is hardly non-scientific. I don’t understand your point. The goal is to get as close as possible, there is always a margin of error. There is no “scientific truth” to FEA. Materials always have flaws, defects, cracks, etc… depending on the analysis changes whether those need to be considered of if they can be covered with a safety factor.
I use a minimum SF of 1.1 for most body calculations, 1.25 when considering different materials, and 1.32 when dealing with gas. If the hand calcs (done in a massive spreadsheet but more or less normal burst calcs) go below the safety factor FEA is performed to analyze the assumptions in more detail. We use the assumptions so you can easily identify if the part is close to a weak point or not. Not going to waste the time on FEA if the part has a SF of 3.
My point is that understanding the flaws of nature is hardly un-scientific and modern engineering is extremely science driven. I cannot use real world experience and the common “that’s the way its always been done” excuse to account for flawed designs. That is how you lose business. You have to back it up with scientific analysis, which is what a good engineer does.
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Um, there are no flaws in nature. If there is discrepancy between science and nature, the science is wrong. Nor does real world experience amount to “that’s the way it’s always been done.” It could be “when we’ve tried designs like this we’ve gotten higher than simulated stress at this weld joint.” Or “when we use nordlock washers it helps to tweak the bolt constraints in the model like this”. That is real world experience and that is what a good FEA analyst does. And even with all of that and lots of money spent of FEA, it’s still wrong sometimes even with a safety factor. Again, an engineer cares about what works and what solves the problem, not what scientific truth is. Just remember the physics used in your high tech analysis was disproved in the 1920s and not many engineers have any sort of use for general relativity or quantum. Why? Because even if they are correct, they aren’t useful.
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The effect of gravity on time has come into play quite a lot lately, but aside from simply knowing that, I’m way out of my depth on this turn that the topic has taken.
Although, DD, you bring up an important point for consideration- when the science doesn’t match nature, it is the science that is wrong.
Can you see how that may apply to the original topic?
You and I must have different understandings of “nature”. I mean that material has flaws. There is no perfectly flat surface, no perfect straight line. You have to assume things, but if you go down to a granular enough level your assumption is not correct. A good surface finished piece of metal can be assumed to be flat, and you can use a safety factor to account for the flaws of its non-flat surface. Again, I don’t understand how this is a non-scientific way of viewing things, we are only able to do the type of analysis because science has studied things to such depth. If we were to account for every atomic flaw and every possible force, the analysis is impossible. You use assumptions to speed things up and get a better idea of what is going on.
I’m not trying to say science is always right. You make assumptions to analyze a problem, you might make too many. When they designed the Tacoma Narrows Bridge they didn’t account for the resonant frequency. We can understand what happened because of science.
I don’t understand your concept of the scientific truth. If the science was true, it would predict what would happen, thus it would work and solve the problem. If the analysis was wrong, then it was wrong and it wasn’t the “scientific truth” whatever that is.
What was it disproved with? Know-how or science? I don’t used general relativity… that doesn’t make it non-scientific or what I do non-scientific. Science has led us to a greater understanding of the way things work, I’m honestly shocked you don’t believe that.
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You disagree that Newtonian physics is disproved? General relativity and quantum (all of the known universe large and small) disobey Newtonian physics. In all of the fancy computer based analysis you do, you are still using formulas invented in the 1600s and trashed by physics in the early 1900s. You are using 1600s physics with lots of computing power, nothing more.