This ain't a playground, folks
It was brought to my attention via PM that this thread is actually a "Call Out" thread. I suppose I ought to respond.
I had
DC (formerly
Dictator Cheney) on Ignore for his strange behavior some time ago -- my Ignore list is a one-way ticket, following years and years of experience with Truthers. Having said that, I understand that
DC is no longer a Truther, and for that I offer my sincere congratulations. I may want to make an exception and take him off my list.
On the other hand, a thread such as this strikes me as in poor taste. Look, I make mistakes too. If you read through my whole posting history, I've made quite a few. The difference between myself and a Truther is that, if I am mistaken,
I want to know about it so I can fix it. You won't hurt my feelings. Just... tell me. No theatrics, like this thread for instance, are necessary.
On to the issue at hand:
Most FEA's use indeed Displacement scales, so you are able to see the deformations / displacements.
this is mostly needed as the FEA's are used to simulate the part when they are in use under normal loads. so the deformation is very tiny and cannot be seen with your eyes. so the Software does scale those deformations so you can clearly see them.
Minor quibble: FEA doesn't assume normal loads. One can input abnormal loads if desired. But structures that aren't actually collapsing tend to exhibit small strains and small displacements, so it is often useful to magnify them on a computer screen, yes.
But there are some FEA's that come without such displacement scalings, because it makes no sence.
for example a total collapse of a building or a crashtest of a car.
in those cases the deformation is so huge you can clearly see them with 1:1 scaling. and other scalings would only confuse.
Anyone can make a bad graph with any data. Sometimes magnifying displacement is counter-productive, yes.
a total collpase FEA of a building with other scales than 1:1 would mean that while the simulatiopn is only at 50% the animation would already show a total collapsed building. or the other way, while the simulation is already done the animation still shows half a building instead of a totaly collapsed building. that would make no sence at all.
This makes no sense at all, if I understand it properly.
The question is whether
certain pictures were magnified to better illustrate displacements. But if they were, all that is magnified is the picture. The magnification does not mean the displacements themselves, as part of a working model, are increased.
Think of a three-dimensional topographic relief map of the world. If the vertical scale wasn't exaggerated, it would be a very boring map, because the Earth is extremely flat compared to its radius, even at its most mountainous and the deepest abysses. But all we're doing is changing the look of the map. Same thing applies to NIST's result.
My original comment, an offhand one that seems to have started all this, is as follows:
We saw a similar bit of silliness with the WTC 7 collapse graphics in NCSTAR1-9. Those too are greatly exaggerated in scale, so naturally they look quite a bit strange, giving the collapse more of a crushing beer can look than what we saw in reality. Took quite some time for the Truthers to grasp this little detail.
Now, just to be clear, the specific pictures I was referring to include Figure 4-43 through 4-47 in NCSTAR1-9A. These pictures describe the predicted displacements of the outer perimeter of WTC 7, as modeled by NIST, as collapse of the perimeter set in.
Many folks criticized these pictures on the basis of their "looking funny," viz. the typical Truther appeal to ignorance. However, in the case of 4-43 to 4-46, there is a scale included with the picture that shows the maximum displacement contour is only +/- 1 meter. There does indeed appear to be some magnification here, perhaps best seen in the right side of Figure 4-44, showing the modeled southwest face starting to lean inward, dragged by the core collapse. The light blue contour corresponds to a displacement of only 20 to 60 cm, and is nearly into the plane of the picture, but is clearly visible. Thus, it seems quite likely that some sort of magnification was used
in the picture only, not the raw data. And that's why it "looks funny." One has to read the numbers, not just critique the image.
Figure 4-47 does not include an explicit scale, as it is intended to provide a geometrical view of the structure without color coding for any measured quantity. Since this picture is similar to 4-46, which is scaled as above, I assumed it was scaled in the same way.
This assumption could be wrong. I do not know what magnification factor was used. It could even be that I'm totally wrong, it's 1:1 and geometrically perfect. However, this kind of enhancement is extremely common. It often doesn't take much displacement to turn a sound structure into an impending collapse.
Does it matter? Not really. I'm not the one claiming NIST's FEA is bogus solely on its appearance. It's the numbers underneath that count.
I have yet to see a single critique of NIST's FEA that wasn't based on ignorance -- either complaining idly that they didn't hand the Truthers all of their tools, all of their data, and so on; or complaining prematurely that it simply "looks wrong." This kind of criticism is worthless. If you want to challenge NIST's FEA, by all means do so, but do it right. Run your own. Many teams have done this for WTC 1 and 2, and in many cases did so without any detailed knowledge of the blueprints themselves. Some of these critiques were even in two dimensions. And some of them were even valid, in my opinion more accurate than NIST's own. I don't expect to find anything differently for WTC 7. What is of greater relevance, however, is the thing the Truthers don't seem to grasp: None of these varying results supports any conspiracy hypothesis.
Hope that clears it up. If anyone knows for certain how the images I mentioned above were constructed, please feel free to correct me. I don't like being wrong, so if I am, just show me. Thanks.
