letter to NIST

Originally posted by exponent
NISTs simulation provides a pretty decent match of the collapse until a couple of seconds after the main collapse phase starts.

So the rest of the simulation is wrong.

After that it's not terrible, but it is not perfect, the perimeter panels bulge out without failure where it appears in the videos they do fail.

So, the simulation is wrong.

It's hard to know exactly what happened on the day to point out where NIST got it wrong, but they are aware that their collapse model becomes less accurate as it progresses.

So, the simulation is wrong. You admit that NIST got it wrong. NIST estimated a collapse sequence, that was ultimately, wrong.

This is the state of the art in modelling structural failure at the moment.

Yet, the simulated model is wrong. It doesn't say much for the state of the art, does it?

Pop quiz, how long did their typical global collapse model take to run?

Who cares? Their report was released almost seven years after the event took place. They've had plenty of time to get it 'right'.

If they think that the model took too long to run, then they should have invested more money into more powerful computers. That's right, they were probably short of money, as they were denied the chance to perform a real investigation, every step of the way.

exponent, your continual defence of the NIST report is ludicrious, when you admit, in your post, that NIST got it wrong. It probably makes you look more than foolish to support something that you admit is wrong. Each to their own, I suppose.

[edit on 30-8-2008 by tezzajw]

Originally posted by tezzajw
So the rest of the simulation is wrong.
So, the simulation is wrong.
So, the simulation is wrong.

No, the simulation is quite accurate up until about 2 seconds after the main collapse phase starts. There is no binary right and wrong here, we are not children.

The nature of the simulation NIST carried out guarantees that there will be errors, and that those errors will get bigger over time. This is inherent in the very nature of modelling. We don't know for sure every detail of every connection. Welds could be stronger than expected, they could be weaker. The steel is specified to a minimum grade, but only the manufacturer's efficiency guarantees the maximum. These variables, and many others are the reason that the model will inevitably be inaccurate.

NISTs model contains over 3 million elements, these will all have an effect on each other. If one value is even slightly wrong, this error can be significantly compounded even if efforts are taken to avoid this. The NIST report on the twin towers actually does quite a good job of explaining this, but they do somewhat assume professional experience, which I suspect is what throws a lot of people.

Yet, the simulated model is wrong. It doesn't say much for the state of the art, does it?

They managed to successfully simulate the collapse mechanism for a skyscraper. It's the first time that's been done.

Pop quiz, how long did their typical global collapse model take to run?

Who cares? Their report was released almost seven years after the event took place. They've had plenty of time to get it 'right'.

If they think that the model took too long to run, then they should have invested more money into more powerful computers. That's right, they were probably short of money, as they were denied the chance to perform a real investigation, every step of the way.

This is one of those repetitive arguments, you can always say they should have thrown more money at the problem, but who's to say they are going to get more accurate? If they started tweaking parameters at random that would illicit huge amounts of criticism from the truther community. They used their judgement in deciding on the amount of simulation to conduct and they are the ones qualified, educated and experienced to do so. I certainly am not, and I am guessing neither are you (no slight intended). You can't expect your personal opinion to carry much weight?

You admit that NIST got it wrong. NIST estimated a collapse sequence, that was ultimately, wrong.

exponent, your continual defence of the NIST report is ludicrious, when you admit, in your post, that NIST got it wrong. It probably makes you look more than foolish to support something that you admit is wrong. Each to their own, I suppose.

You can't simultaneously claim I am admitting NIST is wrong, and then chastise me for claiming this. I didn't, you did. Please don't put words into my mouth, I don't believe I have done it to you.

I am not admitting the NIST report's simulation is wrong or anything that ludicrous. As I said before, we are not children, this is not a world of binary rights and wrongs. Is Pi 3.14, or 3.14159, or 3.141592654? All of these are right, but not 100% accurate.

I hope this explains the issue reasonably, I am not the best at putting concepts forward, but this is not a simple right or wrong issue.

Originally posted by exponent
No, the simulation is quite accurate up until about 2 seconds after the main collapse phase starts. There is no binary right and wrong here, we are not children.

So, from there, the simulation is wrong.

The nature of the simulation NIST carried out guarantees that there will be errors, and that those errors will get bigger over time. This is inherent in the very nature of modelling.

So the NIST model is wrong. It has errors and they only get worse.

They managed to successfully simulate the collapse mechanism for a skyscraper. It's the first time that's been done.

Yeah, but the collapse sequence is wrong.

Is Pi 3.14, or 3.14159, or 3.141592654? All of these are right, but not 100% accurate.

You're wrong, again. Without stating a level of accuracy, they are all wrong. Pi is pi, it is a transcendental number. To begin writing it as a decimal means that you will never be able to write pi exactly. Any decimal approximation of pi will not be accurate, unless the required degree of accuracy is also stated. You did not state the required degree of accuracy for any of those approximations.

Correct to an accuracy of two decimal places pi = 3.14
Correct to an accuracy of five decimal places pi = 3.14159
Correct to an accuracy of nine decimal places pi = 3.141592654

Be careful about what you think is right or wrong, especially with numbers. I can recommend a couple of books about number theory, if you want to brush up on why your statement about pi was wrong.

LET IT GO!!! Come on people!!!! We will never no the truth and you know it. Why should we fight amongst ourselves. Either it was those guys who flew the planes, or a disfunctional government. You can surely say the airlines should take a big chunk of responsibility. Lets not let this pull good Americians apart. PLEASE stop the maddness!

reply to post by tezzajw


You are wasting your time on this one!
This one hangs on every word NIST prints & says.
These people don’t make mistakes they are perfect.
NIST is G-D to some of these people
We all know that NIST lacks real science to prove what brought the WTC down.
NIST report on the WTC7 is a fairy tail and that is a fact.
You cannot change a person mind that is still closed. Only open mined people are able to find facts and see though the lies that big corporation buys.

By the way it’s a game with this one I hope you know that.
I have been reading your post and I feel you are on the right track though.
You do know what you are talking about and it shows, Heck! I even learn some things from your post, keep up the good work.

Debunking NIST's conclusions about WTC 7 is as easy as shooting fish in a barrel.
Symmetrical Collapse

NIST lamely tried to explain the symmetrically collapse as follows:


WTC 7’s collapse, viewed from the exterior (most videos were taken from the north), did appear to fall almost uniformly as a single unit. This occurred because the interior failures that took place did not cause the exterior framing to fail until the final stages of the building collapse. The interior floor framing and columns collapsed downward and pulled away from the exterior frame. There were clues that internal damage was taking place, prior to the downward movement of the exterior frame, such as when the east penthouse fell downward into the building and windows broke out on the north face at the ends of the building core. The symmetric appearance of the downward fall of the WTC 7 was primarily due to the greater stiffness and strength of its exterior frame relative to the interior framing.
NIST can't have it both ways.
georgewashington2.blogspot.com...

Any one who dose a little research can find that NIST is LYING!

Originally posted by tezzajw
So, from there, the simulation is wrong.
So the NIST model is wrong. It has errors and they only get worse.
Yeah, but the collapse sequence is wrong.

In no situation by these criteria could it ever be "right". It becomes less accurate as it progresses, and matches the visual evidence until approximately 2 seconds after the main collapse phase starts.

You can keep insisting that it be called "wrong" if you like, but it doesn't change the fact that it matches observations throughout the important structural failures.

You're wrong, again. Without stating a level of accuracy, they are all wrong. Pi is pi, it is a transcendental number. To begin writing it as a decimal means that you will never be able to write pi exactly. Any decimal approximation of pi will not be accurate, unless the required degree of accuracy is also stated.

This is an interesting position you're taking. While I am aware that Pi is transcendental (hint: look at my username ) to say that they are "wrong" is somewhat disingenuous.

You're right in that the accuracy was not stated, but that is the point! NIST also has accuracy issues because of the nature of their simulation, but for some reason you wish to ignore this and go simply with the "wrong" label.

Be careful about what you think is right or wrong, especially with numbers. I can recommend a couple of books about number theory, if you want to brush up on why your statement about pi was wrong.

That's fine as you're clearly using the label "wrong" to denote anything that is not perfectly accurate. This is not an appropriate definition and it makes your arguments irrelevant. No scientific result can ever be right by these criteria.

Originally posted by cashlink
You are wasting your time on this one!
This one hangs on every word NIST prints & says.
These people don’t make mistakes they are perfect.
NIST is G-D to some of these people
We all know that NIST lacks real science to prove what brought the WTC down.
NIST report on the WTC7 is a fairy tail and that is a fact.
You cannot change a person mind that is still closed. Only open mined people are able to find facts and see though the lies that big corporation buys.

This is more handwaving, you can't present any convincing evidence so you claim that somehow I am biased and the NIST report must be God to me.

No, sorry, I have plenty of small criticisms of the NIST report but it goes far and beyond any alternate theory proposed so far. If you think I am somehow committed to the report above all other evidence, then don't bother replying to me! It's quite offensive for you to claim to know so many things about me when you have never even met me.

reply to post by exponent


AAwww, did I hurt your feelings
My dog and I feel for you.

Originally posted by cashlink
AAwww, did I hurt your feelings
My dog and I feel for you.

I may only be a newbie here, but I know what counts as polite and intelligent discourse and what doesn't. I don't go around claiming that you're irrevocably committed to an as-yet unspecified controlled demolition theory, why do you feel the need to claim I'm somehow religiously obsessed with NIST?

I appreciate that because of the nature of these boards people like me will often be in the minority, but that doesn't excuse impolite behaviour on either persons part.

Oh and just to note, you can be offensive without me caring. This is after all, only the Internet.

reply to post by exponent


False Dichotomy. No truth movement source has produced a comprehensive report, when they do would you like us to measure from 9/11 or from the time they actually started the report?

Trying to ridicule NIST by making false claims is probably not the best strategy.

edit: and for a laugh, we actually can show you another report, from 2004: wtc.nist.gov...

Still your point was entirely invalid and hopefully you will concede that.

[edit on 25-8-2008 by exponent

Just reading one of your own post I think you are the pot calling the kettle black!

Originally posted by cashlink
Just reading one of your own post I think you are the pot calling the kettle black!

I don't want to post a one liner, but I don't understand your point, where was I insulting anyone?

reply to post by exponent


Don't let the calls for perfection get to you.

There's no way NIST could know via hindsight what the condition of every component in the building was, the UTS and torque at ambient temperature on every bolt, the state of every weld, precise load on every m^2 of floorspace etc etc.
So the model can never perfectly match the entire observed collapse and, if it in fact did, there'd likely be even more cries of foul for them tweaking the parameters to death.

What's significant is that they did manage to induce a collapse sequence similar to the observed reality and that's about as good as it gets. They could still be wrong about the exact initiating failure but, to me, it doesn't appear to be too far from fact.

Originally posted by exponent

This is not a rigorous document.

If this is true then it should be possible for the truth movement to produce a superior document?

How can this be true when the "truth movement" has less evidence in hand and hardly no access to important documents than NIST does? Saying the truth movement doesn't have a superior document is a straw man and does not automatically cause the NIST's theory to be correct. Just my opinion of course.

BTW. Just as a reminder to everyone. At least the way I see it, the "truth movement" isn't/wasn't designed to "debunk" the government theories. The truth movement just wants an impartial, transparent investigation. Through and through. No skipping steps in the scientific and forensic way of doing things.

Just a reminder for 9/11 Denial Movement members that real engineers are laughing at you:

911-engineers.blogspot.com...

Originally posted by jthomas
Just a reminder for 9/11 Denial Movement members that real engineers are laughing at you:

911-engineers.blogspot.com...

Recommendation 2. NIST recommends that nationally accepted performance standards be developed for: (1) conducting wind tunnel testing of prototype structures based on sound technical methods that result in repeatable and reproducible results among testing laboratories; and (2) estimating wind loads and their effects on tall buildings for use in design, based on wind tunnel testing data and directional wind speed data.
Affected National Standard: ASCE-7. Model Building Codes: The standard should be adopted in model building codes by mandatory reference to, or incorporation of, the latest edition of the standard.

Too bad NIST would fail their own standards if applied to them eh? Although this is wind load tests, what happened to fire load tests since it is now obvious that buildings implode from fire induced buckling?

Originally posted by Griff
[

Too bad NIST would fail their own standards if applied to them eh?

Denying the point again, are you, Griff? Let's be clear: your dreams of 9/11 being an "inside job" have been dashed again.

All that is left for you to do is admit it. If it is possible for a Denier to admit being a Denier, that is.

Originally posted by Griff
How can this be true when the "truth movement" has less evidence in hand and hardly no access to important documents than NIST does?

If this were true perhaps it would be valid, but I don't believe it is. NISTs paper does not describe WTC7s construction exactly but there are not a huge amount of missing details. If you were to file a FOIA request for perhaps their LS-DYNA model, you would be able to get all the information needed to do everything NIST did I believe. I mentioned earlier I would like to hear specifics of what is missing, and when you requested the connection information it didn't take me long to confirm a typical beam failure with a typical connection.

Saying the truth movement doesn't have a superior document is a straw man and does not automatically cause the NIST's theory to be correct.

It's not a straw man, as this would be a false representation of someone's position which I don't think I'm making. You are however correct in that the lack of an alternate explanation does not inherently make NISTs theory correct. What makes NISTs theory probable is simply the degree to which they have been able to replicate the failures through simulation.

BTW. Just as a reminder to everyone. At least the way I see it, the "truth movement" isn't/wasn't designed to "debunk" the government theories. The truth movement just wants an impartial, transparent investigation. Through and through. No skipping steps in the scientific and forensic way of doing things.

This is not an entirely unjust goal, I would entirely support any new investigation (and would be happy with taxpayer money in some cases, such as investigation into intelligence failures and executive decisions) into aspects of 911, but that investigation would be more like the 911 commission, rather than the NIST report. The NIST report has yet to receive any substantial correction thanks to controlled demolition theorists, and in fact so far the more rigorous the calculations, the more people agree (from both sides) that gravity collapse is plausible.

Lets not talk politics though, I don't like the US Government and I certainly didn't support the Iraq war. I am no rabid Bush follower, but I do get frustrated with people who are willing to claim ridiculous conspiracy theories based on poor evidence, see ULTIMA and "we have evidence it fell straight down" comments.

Have you had a chance to read any of NCSTAR 1-9 yet? Thoughts?

edit:

Too bad NIST would fail their own standards if applied to them eh? Although this is wind load tests, what happened to fire load tests since it is now obvious that buildings implode from fire induced buckling?

What do you mean "what happened to fire load tests"?

[edit on 1-9-2008 by exponent]

Originally posted by jthomas
All that is left for you to do is admit it. If it is possible for a Denier to admit being a Denier, that is.

Denier, truther, debunker, eggman, koo koo katchoo. Call me all you will. I have gone beyond caring anymore and refuse to play the childish games. Good day to you.

And I got your point. Please post the survey results of all those members and associations. I know I sure didn't get a questionaire as an ASCE member.

Originally posted by Griff
And I got your point. Please post the survey results of all those members and associations. I know I sure didn't get a questionaire as an ASCE member.

If you read the code of ethics of the ASCE, you'll find that investigation into flawed or incorrect reports falls under the mandate. You are expected and somewhat required to make known any engineering criticisms you have of the NIST report. At least as far as I, as a non ASCE member understands it.

edit: Page 14, Canon 1.d

d. Engineers who have knowledge or reason to believe that another person or firm may be in violation of any of the provisions of Canon 1 shall present such information to the proper authority in writing and shall cooperate with the proper authority in furnishing such further information or assistance as may be required.

I believe this is accurate.


[edit on 1-9-2008 by exponent]