Interview with Dr. Niels Harrit on Discovery of Nano-Thermite in WTC Dust

[Stanchetalarooni]

http://www.foreignpolicyjournal.com/2011/03/07/interview-with-dr-niels-harrit-on-discovery-of-nano-thermite-in-wtc-dust/

Dr. Niels Harrit is a retired associate professor of chemistry at the University of Copenhagen and one among an international team of scientists who published a paper in The Open Chemical Physics Journal on the discovery of nano-thermite in the dust from the World Trade Center collapses on September 11, 2001. He has recently finished a lecture tour of Canadian universities, where he spoke on the subject.

In this interview on the cable program Face to Face with Jack Etkin, Dr. Harrit discusses this finding and its implications. Dr. Harrit notes that World Trade Center building 7 (WTC 7), a 47-story steel-framed skyscraper that was not hit by one of the planes on 9/11, collapsed symmetrically into its own footprint, and that the official explanation for this is that it was due to fire. However, the finding of nano-thermite in the dust, along with other available evidence, leads inescapably to another conclusion. “There is no doubt that this building was taken down in a controlled demolition,” says Dr. Harrit. “I consider this to be mainstream scientific conclusion. There’s no way around this conclusion. There are so many observations that are only compatible with a controlled demolition.”

While conventional thermite is an incendiary, made from a mixture of powdered aluminum and iron oxide, Dr. Harrit explains that nano-thermite is manufactured from the atomic scale up. The ingredients are much more intimately mixed, he says, so they react with each other much faster. Unlike thermite, “Nano-thermite can be used as an explosive,” notes Dr. Harrit. “You can use thermite for cutting the steel beams, and it’s soundless,” he adds.

http://www.foreignpolicyjournal.com/2011/03/07/interview-with-dr-niels-harrit-on-discovery-of-nano-thermite-in-wtc-dust/

[zappaman]

1. Excellent post!

Thank you for this brand new information that cannot be debunked!
Good research!

[whatchamacallit]

2. Another deep and thought provoking response from

Dr. Zappman Ph.Bs

[zappaman]

3. Yes!

Can't wait to hear more about this new and exciting evidence!
No way this can be debunked!
Who would even try?!?!
Nope, rock solid!

[OnTheOtherHand]

4. the best-known mainstream scientific conclusion that most mainstream scientists have never heard of

Q.E.D. What a great time to be alive!

[KDLarsen]

5. I see Harrit has backed away from the conventional explosives

He does seem to be weaving quite a bit on those. Of course, it's not easy to explain away both the lack of a giant, blinding light on the southern tip of Manhattan, which would be a telltale sign of (nanuu-nanuu)therm*te, as well as the lack of signature explosions, which would have been a telltale sign of conventional explosives.

Oh, and no mr. Harrit, Nano-thermite most definantly cannot be used as an explosive. Not unless you start applying the name to something else, because (nanuu-nanuu)therm*te simply does not work that way.

[eomer]

8. Nano-thermite definitely can be used as an explosive.

One current promising nanocomposite being pursued by the
researchers at LLNL involves the use of Fe2O3 which is gener -
ated using the sol-gel method. The reason that Fe2O3 is chosen
is because its thermite reaction with UFG aluminum is very
exothermic (with only CuO and MoO3 yielding greater energy
of reaction). An example of the high degree of mixing and uni-
formity between two nanophases is found in Figure 7, which
indicates the excellent dispersion of Al and Fe on the nanoscale
domain. The Fe2O3 was prepared by the use of an organic
epoxide which was added to an Fe(III) salt solution resulting in
the formation of nanoscale crystalline and amorphous Fe2O3.
The reaction to produce Fe2O3 was done in solution which
already contained the UFG aluminum. In this case, the
nanoparticle aluminum was sonnicated (suspended in iso-
propanol and placed in an ultrasonic bath to break up any alu-
minum aggregates) before mixing with the Fe(III) salt solution.
For this work, the UFG aluminum was supplied by the NSWC
researchers at Indian Head using the dynamic gas-phase con-
densation method (discussed above), which yielded an average
aluminum particle size of approximately 35 nanometers.

As sol-gel materials and methodology advances, there are a
number of possible application areas that are envisioned. These
include: (1) high temperature stable, non-detonable gas gen-
erators, (2) adaptable flares, (3) primers, and (4) high-power,
high-energy composite explosives. In addition, the sol-gel
chemistry may have advantages of being more environmentally
acceptable compared to some other methods of producing
energetics.

http://www.p2pays.org/ref/34/33115.pdf

Nanotechnology is grabbing headlines for its potential in advancing the life sciences and computing research, but the Department of Defense (DoD) found another use: a new class of weaponry that uses energy-packed nanometals to create powerful, compact bombs.

With funding from the U.S. government, Sandia National Laboratories, the Los Alamos National Laboratory, and the Lawrence Livermore National Laboratory are researching how to manipulate the flow of energy within and between molecules, a field known as nanoenergentics, which enables building more lethal weapons such as "cave-buster bombs" that have several times the detonation force of conventional bombs such as the "daisy cutter" or MOAB (mother of all bombs).

Researchers can greatly increase the power of weapons by adding materials known as superthermites that combine nanometals such as nanoaluminum with metal oxides such as iron oxide, according to Steven Son, a project leader in the Explosives Science and Technology group at Los Alamos.

"The advantage (of using nanometals) is in how fast you can get their energy out," Son says.

Son says that the chemical reactions of superthermites are faster and therefore release greater amounts of energy more rapidly.

"Superthermites can increase the (chemical) reaction time by a thousand times," Son says, resulting in a very rapid reactive wave.

http://www.technologyreview.com/computing/14105/

Work in reactive materials has two parts. The first includes development of more energetic explosives and the use of reactive materials as fragments to be applied explosively to the target in addition to the energy released within the target by the warhead bursting charge. The briefing indicates that projected advances are being regularly validated through experimental work, which appears to be well organized and productive. The reactive materials are of several compositions. The current baseline composition is aluminum (Al) powder suspended in a perfluoro polymer (PTFE or a similar derivative). When a conventional explosive propels a reactive fragment of Al/PTFE into a target, the fluorine in the PTFE reacts violently with the Al. As the Al/PTFE passes through the wall of a target, it reacts with oxygen in the air to produce an explosion within the target, causing much more damage.

Other energetic material compositions include thermitic material such as Al+MoO3 with a PTFE binder. This material is also known as a metastable intermolecular composite. The fluorine serves to initiate the reactivity of the Al. There are other fuel plus oxidizer thermitic materials that can advance this technology.

The second part of the work is the development of honeycomb warhead structures into which the explosive material can be infused. While somewhat less advanced, the work appears to be sound. There are several approaches to enhancing the energy of the warhead. These include new energetic molecules, the use of finely divided (nanosize) metal powder (e.g., aluminum or hydrides such as aluminum hydride), new metastable states, and sol-gel techniques for encapsulating these materials. Nano laminate materials also offer the possibility of hard energetic cases that will withstand penetration at high velocity and contribute energy when detonated via intermetallic reactions. The work is well coupled with the national effort in energetic material —the National Energetic Material Program and the Joint DOD/DOE Office of Munitions memorandum of understanding.

http://books.nap.edu/openbook.php?record_id=10594&page=22

Metastable Intermolecular Composite (MIC) Materials - Nanoscale energetic materials (superthermites) with tunable energy release were discovered and developed in C-ADI and have generated considerable interest in the DoD community. The applications include “green” primer replacement in munitions, electric matches, and modifying the properties of high explosives.

http://pearl1.lanl.gov/external/chemistry/capabilities.shtml

[TheWraith]

6. Well, so much for any credibility he had.

Completely aside from the fact that WTC 7 did NOT collapse symmetrically, nor into it's own footprint...

The idea of a "soundless explosion" is a contradiction in terms. It's like describing an invisible spotlight. An explosion is the rapid conversion of chemical energy to thermal energy, producing an expansion of hot gases. Those hot gases ripple outwards, causing sound waves. There's no way around that--any kind of explosion makes noise, just like throwing water on someone makes them wet.

[OnTheOtherHand]

7. we could play "What He Really Means Is..."

In this context, it seems possible that what he really means is that nanothermite played the role that explosives would play in most controlled demolitions.

One problem with that is that 9/11 Truth folks have been trumpeting supposed evidence of conventional explosives for years, so one would at least like to hear a coherent hypothesis. (I think someone did offer an account that brilliantly combined conventional explosives and therm*te charges; as I recall, it didn't especially make sense, but it was spunky, at least.)

Another is that the direct evidence for nanothermite seems incapable of convincing anyone who wasn't already rooting for a conspiracy, no matter how esoteric.

Another is the false premise that the observed collapses could only occur if a bunch of columns were cut simultaneously. I'm not sure how a retired chemistry prof thinks he knows that, but again, the argument seems incapable of convincing neutral observers.

[eomer]

9. Or we could play "what he actually said".

I would also note that we're hearing him through the filter of a reporter, but here's what he is quoted as saying:

Unlike thermite, “Nano-thermite can be used as an explosive,” notes Dr. Harrit. “You can use thermite for cutting the steel beams, and it’s soundless,” he adds.

"Nano-thermite can be used as an explosive."

"thermite ... [is] soundless"

So he did not say that nano-thermite, the explosive one, is soundless but rather that thermite, the non-explosive one, is soundless.

And how would coming up with a theory that essentially requires inventing details we don't know help, except that debunkers could then pretend to debunk it by pointing out that the details were invented.

[OnTheOtherHand]

10. I don't think that helps very much

Are you suggesting, then, that Harrit added a completely irrelevant comment about thermite? Or that he posits the use of both nano-thermite and thermite? Or what? I'll grant that it's possible -- even likely -- that Harrit made more sense than this piece does, but that still leaves me trying to parse What He Really Means.

And how would coming up with a theory that essentially requires inventing details we don't know help, except that debunkers could then pretend to debunk it by pointing out that the details were invented.

Wow, this is really interesting.

To me, this just might be the quintessence of the "debate" between 9/11 Truth and the rest of us. It often seems that in the world of 9/11 Truth, there is no need to try to explain anything; it's all about deriding other people's explanations. I have no idea how many brain-damaged "critiques" of the NIST report I've read that come down to complaining that some "details were invented." (Again, it's hard for me to overlook the parallels to "critiques" of evolution.)

Your question bewilders me. Trying to reconstruct causal sequences based on partial observables doesn't entail making everything else up, but it does entail some willingness to speculate about what might explain the observables. Positing that some Further Investigation might provide complete information is just an evasion of intellectual and moral responsibility. As far as I can tell, Griffin and Harrit both are acting like little shits. They're signaling to a whole lot of us that they really don't give a flying goddamn, and it ticks us off. In case you hadn't noticed.

[eomer]

11. I'm suggesting that extrapolating from two small fragments and a juxtaposition that may be

the reporter's rather than Harrit's doesn't appear like it will actually tell us anything.

And regarding a theory of the crime, what if hypothetically thermite were positively IDed and tracked back to a particular person but there remained, as now, few clues about where it was used in WTC7,having proved that it was placed in WTC7,just not on which floor or which structures? Would we require one theory even though it would be just a guess? I don't understand the thought process. Why not say what we can infer from the evidence and no more than that? Or put forth a theory yourself if you wish but respect others who prefer to only infer what they can?

(From my phone, excuse messiness)

[OnTheOtherHand]

12. I think we mostly agree about that part, at least

My point about "play(ing) 'What He Really Means Is...'" is that, in this case, I think it's impossible to know. Beyond that, we're somewhat at cross purposes still.

eomer, that's an interesting hypothetical, and if it helps me to underscore that I'm not actually encouraging 9/11 Truth folks (or anyone else) to make shit up, that's terrific. But I think there's a difference between caution in the presence of ambiguous data and finger-licking FUD.

I can't vouch for the accuracy of the following account (never mind the opinions), but it's on Griffin's site:

It was when Harrit left aside the official hypothesis, according to which fires were the cause, and started comparing the collapse of WTC 7 with controlled demolitions that we began to see the picture.

As part of the presentation, he showed a clip from a documentary in which the Dutch expert on the demolition of high-rise buildings, Danny Jowenko, ruled out everything except for a professional demolition of the building.

A slip of the tongue during an interview, in which the owner of the WTC complex, Larry Silverstein, confirmed that the building had been “pulled,” which he contradicted the following day, was also shown. Larry Silverstein, who had been the owner of the buildings for only a couple of months before September 11, had coincidentally purchased an insurance policy against terrorist attacks, which granted him enormous sums of money after the attacks.

Niels Harrit refrained, however, from speculating about who was behind the attacks of September 11, or who let them happen by not activating the defense mechanisms that would normally have been put in action.

Instead he focused on the technical realities of the collapse of WTC 7.

http://davidraygriffin.com/lectures/niels-harrit%E2%80%99s-lecture-on-the-world-trade-center/

Jowenko ruled out everything except a professional demolition? Silverstein's slip of the tongue confirmed that the building had been pulled? No matter what Harrit actually said about these clips, he obviously wasn't laser-focused on "the technical realities." That's not how a scientist does things, it's how a hack propagandist does them. (And, yes, I wonder whether Harrit said something along the lines of "as a scientist, I'm not going to speculate on who let this attack happen by not activating the defense mechanisms (etc.)," but it doesn't really matter.)

And here are comments that Harrit apparently wrote out for a German website:

The media hasn't reacted yet. It is the duty of the public to tell them that if they keep on lying for much longe(r), they will lose what little credibility they have left.

Silence gives consent! Ask questions!! Trust yourself. It is not so complicated. There were two airliners, but three skyscrapers. You don't need a scientist to count to three.

Everyone should push every button and demand truth in the press. This is very serious. Every action, no matter how small, counts.

My major point: Everyone is lying, everyone is scared. So we have to trust ourselves, and it is not so hard.

http://www.gulli.com/news/world-trade-center-destruction-2009-05-27

"You don't need a scientist to count to three"? "Everyone is lying"?! Please don't tell me this is a fellow who prefers to only infer what he can.

[eomer]

13. Harrit does have an opinion at a high level that WTC 7 was controlled demolition.

That's consistent with my hypothetical. He believes that evidence has been found that proves that it was controlled demolition (unreacted thermite, iron spherules, etc) but doesn't imply the specifics you want him to fill in, which he can't.

Jowenko actually does fill in your specifics:

http://www.youtube.com/watch?v=k3DRhwRN06I

He also is of the opinion that it was controlled demolition (which is his expertise) and tells how he would have done it (which obviously doesn't mean he's saying it's the one and only way it could be done).

I don't see how any of this is propaganda. If it is then you and I are equally guilty for posting our opinions here with the intent that they be read by an audience probably about the same order as Harrit's at that presentation.

[OnTheOtherHand]

14. remarkable

If Danny Jowenko has informed criticisms of the NIST report on WTC 7, it's amazing that all we know about his opinions comes from a few Truth interviews. Assuming for the sake of argument that Harrit is right, the incompetence boggles my mind.

(The beginning of that video is downright alarming. "Does the top go first? No, the bottom. They simply blew up columns and the rest caved in afterwards." That's a perfectly plausible inference from extremely limited information, which is all Jowenko appears to have -- I see no indication that he knew anything about WTC 7 before the interview, and he doesn't know much more at the end. That's fine, but it's hardly persuasive.)

But I suspect Harrit offers the key to understanding this kind of incompetence. Experts can't be trusted (unless they happen to agree with us), so there isn't really much point in exploring their opinions in detail. Even Jowenko is a dupe when it comes to WTC 1 and 2. So it makes perfect sense for the presumed intellectual leaders of the movement to spend most of their time trying to rally the public, not waste any more time with experts. After all, it doesn't take a scientist to count to three, and everyone is lying.

[eomer]

15. I don't know whether Jowenko has informed criticisms of the NIST report and don't think it matters.

Bazant's nonsensical claims killed any credibility NIST had (on this subject). I do agree that Jowenko's opinion is not based on all the information it should be -- he is shown a drawing of the column layout for a typical floor but isn't told that the lower levels had a different and unusual structure. His off-the-cuff opinion on how hard it would be to demo the building quickly may not be affected by that, but his opinion on whether the building would have fallen just due to an office fire would, seemingly.

But I don't agree with necessarily using the NIST reports as a starting point or with your implied requirement to rebut them in order to have an opinion. NIST's opinions are less reliable than Jowenko's, to me. At least Jowenko's are apparently sincere even if not completely informed. NIST's opinions (in this area) are clearly just a drive to justify a predetermined answer.

[OnTheOtherHand]

16. hmmmm

I'm not really griping at Jowenko for saying what he said on tape. I'm griping about the apparent inability of people like Harrit to enter into rational debate, even as they assert that the debate is over, and they won. I find it bizarre. And I can't even figure out how to get you to see the issue.

I wouldn't say that the NIST report has to be "a starting point," but in 2011, it certainly ought to be part of the discussion. Well, who am I to say? It's not as if Harrit seems to be all that interested in discussion anyway.

NIST's opinions (in this area) are clearly just a drive to justify a predetermined answer.

I'm not sure which area you mean. NIST's approach seems pretty straightforward and familiar: gather evidence, adduce hypotheses, look for ways to disambiguate among the hypotheses, refine the hypotheses, repeat. I don't think they went in saying, "We're gonna pin this on effing Column 79." Did they?

[eomer]

17. What I mean

No, NIST didn't go in with a beef against column 79. They went in determined to put together some scientific-sounding formulas that result in the building collapsing. As they arbitrarily chose some formulas and tweaked them to make the building collapse, column 79 happened to be standing at the wrong place at the wrong time and got pulled down by the idiosyncracy of the arbitrarily chosen and tweaked formulas.

In reality the problem exceeded their understanding and their capabilities to create a deterministic model. No way do they know that column 79 failed and pulled the rest of the building down. But it suited their goals and was as good as any of the other answers that showed the building collapsing due just to office fire so they went with it. It is trumped-up nonsense and I think that pretending it doesn't exist is a perfectly valid approach.

I do get your point about acting like the debate is over. I hadn't noticed Harrit doing it but I'm sure you're right. I have noticed it in this forum about a brazilian times by people who support the official story. I'm sure I could find it in some threads currently showing in the queue, probably toward the top.

[OnTheOtherHand]

18. that's quite a set of unsupported allegations

We observe, inter alia, unfought fires and the penthouse collapsing several seconds before the rest of the building starts down. Jowenko presumably was not allowed to see that, or else he hardly would have said, "Did the top go first? No, the bottom."

So we have NIST trying to investigate possible connections among the observables -- some of which don't pan out, causally. (The dramatic exterior damage appears to be irrelevant.) And we have 9/11 Truth people trying to conceal some of the observables, and a chemist telling us that we don't need to be scientists to count to three. Not really much of a "debate." I imagine things would go better if you took over, except that first you would have to understand how appalling things look right now.

Yes, of course a building collapse exceeds our capabilities to create a (flawless) deterministic model. Similar problems apply to climate science and evolutionary biology. The people who use these problems to dismiss climate science and evolutionary biology are, let's just say, not my heroes, but the problems are real. It ought to be possible to have a serious discussion of those topics, and it ought to be possible to have a serious discussion of this one. But if you can look at NIST on the one hand, Niels "everyone is lying" Harrit on the other, and accuse NIST but not Harrit of "trumped-up nonsense," then I just don't know what to say.

[eomer]

19. My allegations were supported in previous discussions we've had.

From previous discussions (from my best recollection):

1. Bazant's statement (for WTC 1 and 2) that the pile driver assumption in his calculations represents a "limiting case" without providing any basis, not even a shaky one.
   
2. The nonsensical analysis that it would take tons of thermite to bring down the towers and therefore we can conclude that the towers came down with the help of zero thermite.
   
3. The tweaking of the WTC 1 and 2 models to assume temperatures that they admit were not obtained.
   
4. The approach in general of pretending their deterministic models can be trusted to draw conclusions and not disclosing the fact that they backed into them to get a predetermined result.

But hopefully we can not go through all that again right now. I do see your point about Harrit and Jones. They appear to have hunkered down on certain points rather than address arguments. Honestly this is the first time I've seen some of the arguments about spherules and I do see that the implications are at least debatable.

So it seems to me (for now, pending further developments on the spherules) to come down to what the red/gray chips really are. I don't buy the argument that they are paint chips. What are they?

[OnTheOtherHand]

21. I'm not sure what else to do

We don't have to spend equal and infinite time on every point, but if NIST did half as bad a job as you say, I don't see why it should be so hard for you to demonstrate the point.

(1) Bazant and Zhou enumerate a set of conservative assumptions in their analysis, then generalize that they have used "the most optimistic assumptions by far." You disagree.

That must be an unfair paraphrase, but I'm not sure why. Really, even if you think you've caught Bazant and Zhou ruling out some plausible (or logically possible) alternative, I don't see how you get from there to your dismissal of the NIST study.

(2) Basically, NIST's position on thermite is the same as Laplace's position on God: "Je n'avais pas besoin de cette hypothèse-là." I don't understand the basis of the confusion on this point. If NIST claimed to have proven that thermite wasn't present, that would be an odd overreach. As far as I can remember, it didn't happen.

(3) I'm not sure how to paraphrase this one. It might be construed to mean that NIST's own analysis rebuts its collapse scenario. If that is true, then I'm really rather astonished that such a poor job has been done of explaining how.

(4) I think you're flat-out wrong about this. I think NIST explains pretty carefully how the modeling works. The fact that a model can be "tweaked" doesn't assure that one can use it to "get a predetermined result," short of entering a bunch of bizarre counterfactuals. (In fact, I would have thought that was likely to be your point in (3).)

So it seems to me (for now, pending further developments on the spherules) to come down to what the red/gray chips really are. I don't buy the argument that they are paint chips. What are they?

This is where we seem to come back to diverging models of causal inquiry. I don't remember seeing an intelligible explanation of how the chips could have been used to bring down the building (or have been left behind in the aftermath), so I'm not sure why I should care what they are. I don't mean that I would rule out investigating them a priori. But I'm impressed by how unimpressive the results of the investigation have been so far. If something in the composition of the chips tended to persuade neutral observers that they indicated foul play -- even without a clear hypothesis about how -- I'd be more interested.

[OnTheOtherHand]

22. oops

I still haven't figured out how to make the last point. I don't know to what extent our "models of causal inquiry" diverge. But there seems to be some basic difference in our approaches, and I can't figure out how to name it in terms that make sense to both of us.

[eomer]

23. What I was referring to, primarily, was Bazant's "limiting case" trickery.

Bazant's WTC 1 and 2 report is one gigantic begging of the question. He assumed the answer but did it in a place that was mathematically remoted from the final conclusion. He assumes that the upper block of WTC 1 and 2 was able to apply the entire force of its momentum onto the columns of the lower block instantaneously. This assumption is of course a highly idealized simplification and cannot be used safely unless there is some science that tells us it is capable of serving as a proxy for the incredibly more complex problem in the real world. Bazant provides no such justification of the simplification, he merely claims it is a limiting case. But it is a claim without any scientific basis or even any scientific argument; it is a mere assertion with no foundation.

Once Bazant made this assumption then he just let the computer work through the equations and spit out the answer he wanted. But he hasn't proved anything -- he just moved the burden of proof elsewhere. Now rather than being called on to prove the buildings would collapse Bazant must be called on to prove that the simplification is a limiting case, or else he's proved nothing.

Here is a thread from 2009 where I made this point:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=275922&mesg_id=276041

I also made the point somewhere in that thread that I consider the question "answered" by the NIST WTC 1 and 2 report to be irrelevant with regard to the use of thermite. If thermite is positivley IDed then it doesn't matter whether it did or could have brought down the towers. If it was used at all that day then there is someone guilty of a crime who has not been brought to justice. The detonation of a bomb in one of the WTC towers in 1993 did not bring that tower down and yet it was a crime.

_{edit: typo}

[eomer]

25. And let's be clear about how ridiculous Bazant's "limiting case" is.

Dr. Bazant needs to go back and repeat middle school science class, particularly the experiment where they drop an egg off a building. If you drop the egg directly onto a concrete sidewalk then you've simulated Bazant's limiting case. All the energy that's available is used within a very small time interval and of course the egg can't withstand it and is crushed. From the fact that the egg broke, Bazant thinks he can use his brilliant limiting case to prove that the egg will always crush, even if you cradle it in a mechanism that will distribute the application of the energy over a longer time interval. But of course most middle schoolers and middle schooler parents can attest that it is in fact possible to create a mechanism that lets the egg survive.

In fact Bazant has his limiting case exactly backwards. If you find a height from which dropping an egg onto concrete will not break it then you can be pretty sure that the egg will still not break if it is dropped from the same height cradled in a mechanism that spreads the same energy over more time.

Circus acrobats, many of whom don't have a PHD in engineering mechanics, also know that Bazant has it exactly backwards. They know that if they fall from 50 feet onto concrete the application of energy to their body will be almost instantaneous and their structure will be crushed, as it were. If they fall, on the other hand, onto a mechanism (a net) that spreads the application of that same energy over a longer time interval then their structure will not be crushed; they will be totally unharmed.

Really, can we be so ignorant as to believe Bazant's ridiculous "limiting case"? If so then we all need to go back and sit next to Bazant while he repeats middle school science class and go outside with him and watch the egg experiment over and over until we understand its meaning. If he'll show up I'll supply the eggs and some cardboard, rubber bands, and tape.

[OnTheOtherHand]

27. ruh roh

My other reply seems to fit here, and I'll venture that it is really hard to understand how you can believe this argument yet not attempt to publish it in the original journal.

What's especially odd is that B&Z's analysis is largely* focused on estimating the capacity of each tower to function as a "net," in your acrobat analogy.

You may construe that the top of each tower was somehow akin to an egg "cradled in a mechanism." You might even be able to make the argument. But your confidence that Bazant is obviously making a middle school science error is really, really alarming.

*Edit: I had written "primarily," which I think is defensible, but open to interpretation.

[LARED]

44. Just out of curiousty have you read the addendum titled

"Didn’t Plastic Deformations ‘‘Cushion’’ the Vertical Impact?"

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

[OnTheOtherHand]

26. y'know...

eomer, in the final analysis, I could take that criticism of Bazant and Zhou a lot more seriously if you took the time and trouble to write it up and get it peer-reviewed and published, the same way they did.

OK, you're out of field. But if Bazant's paper rests on "trickery," it shouldn't be hard for someone to get a rebuttal published. No CT required, even. Talk about a "missing jolt"!

Now, as I understand it, your rebuttal runs something like this: sure, maybe Bazant and Zhou used a high estimate of the plastic energy dissipation W_p, but their estimate of the released potential energy W_g that would have to be offset by plastic dissipation is also high, because the top isn't falling as a solid block.

My inexpert response to that last part is: well, damn nearly. The upper mass isn't drizzling down in small pieces; the basic structural elements are connected. It will pack one heck of a wallop over a very short time, and the elements that are subjected to this wallop will have no opportunity to rebound in mid-collision. IANAE, but it seems to me that the lower-part calculations are indeed quite conservative, and the upper-part calculations are reasonable. Bazant and Zhou don't have to discuss how much of that kinetic energy might be dissipated by other means, because the basic result is facially obvious: the towers lose.

That's how I read the article, and based on all evidence available to me, that's how competent authorities read the article as well. AFAICT, even if a competent engineer had a serious reservation about Bazant and Zhou's analysis, s/he wouldn't accuse them of "trickery" on the flimsy basis that you've presented. That isn't a matter of etiquette; it's a matter of understanding the genre. It goes without saying that a simple analysis oversimplifies a complex process; that's why it's called "simple." You may think you have a counterargument to their analysis, but the terrifying thing is that you don't seem to realize that you need a counterargument; you just think their argument is obviously wrong and therefore crooked. That's a fail.

Really, the confusion seems just about that basic. It's almost as if someone produced an analysis to show that even a small handgun could easily fire a bullet through a thin plywood wall, and a "skeptic" retorted that the analysis was "trickery" that "proved nothing" because it neglected air resistance. In some contexts, neglecting air resistance really would be prima facie evidence of incompetence or fraud. In others, raising it as a serious objection -- much less evidence of "trickery" -- would also be prima facie evidence of incompetence or fraud, but in the opposite direction. (And there is a middle ground where it may not be facially obvious whether air resistance "really matters" or not.)

As to your last point: certainly if someone tried to 'blow up' the towers with thermite, that is a crime regardless of what the thermite actually did. Whether the NIST analysis is "irrelevant with regard to the use of thermite" depends on the specific arguments. I don't think the overlap between people who believe there is direct evidence of thermite and people who believe there is indirect evidence of some sort of controlled demolition is coincidental. As a matter of logic, the direct evidence could be strong even if the indirect evidence is weak, or vice versa, or the two might tend to buttress each other. As a matter of fact, I don't think either line of evidence is strong or provides much support for the other.

[eomer]

28. You ignore the point that Bazant's limiting case is backwards.

It is like demonstrating that an egg will be broken if dropped on concrete and then claiming that proves it will be broken if dropped on an elastic net. There is a limiting case somewhere in there but it is backwards from the one that Bazant asserts. And that really is understandable by a middle schooler.

And the fact that he got it backwards in a paper that was peer reviewed shows that peer review can be ridiculously unreliable, especially if the topic is a political hot potato like this one.

[OnTheOtherHand]

29. actually, I can't make heads nor tails of that "point"

It seems to mean that B&Z assumed that the bottoms of the towers were like concrete, when actually they were like elastic nets. That would be a rather wild misreading of their analysis.

You may be at a loss to understand why anyone thinks B&Z is a decent paper, but to blame it on politics won't help you to figure it out. It just won't. And it doesn't show you at your best. A credible critique of this paper will not take the form: "any middle-schooler could tell you that X." You don't have to trust me on that. You don't have to infer it from almost a decade of collective experience. But I think you would be wise to give it serious consideration.

[eomer]

30. The reason you can't make heads nor tails is because you've got it upside down.

Bazant assumes that the upper block, not the lower, is rigid like concrete and therefore can deliver all of its energy onto the bottom block in a single instant. In reality the upper block will crush, it will not hit the bottom block all at once head on but will rather hit the bottom in a complex manner with different components missing, colliding, piercing, and otherwise interacting with the bottom section in a complex way that delivers the energy over a longer time interval than Bazant's assumption of all at once in a single instant (the equivalent of an egg hitting concrete, turned upside down).

Bazant claims in his paper that all his simplifications go in favor of the lower section surviving. He is wrong on this simplification that obviously goes in the opposite direction - it goes in favor of the lower section being crushed.

Anders Björkman puts it this way:

Björkman scoffs at Bažant’s mythical free-falling
top block bringing 287 columns hammering down in
perfect array on the 287 columns below. Steel bends
and mashes in Björkman’s salty world, and “it is not
certain that the hammer even hits the nail.” Real-life
columns miss, lodge in horizontal structures, and
punch holes in floors, creating energy-absorbing
frictions, deformed steel, local failures, and “a soft
collision (not impact!)” that tangles damaged floors in
a shuffled array – and stops well short of total
collapse.

Videos show that Bažant’s alleged pile driver
disintegrates “within 3.5 seconds after the roof starts
to fall.... before global collapse starts!” Björkman
challenges Dr. Bažant and his followers to produce a
“timetable, analysis, and explanation” consistent with
the video evidence. “And tell us ... what happened to
the upper block!”

http://www.scribd.com/doc/36173672/9-11-Engineering-View

[KDLarsen]

31. I wouldn't trust Anders Björkman with a teaspoon

The man is mentally unstable, as his many thought experiments over the past few years have shown (http://sites.google.com/site/wtc7lies/home/anders-bjorkman-s-world). It's downright scary that other peoples lives may depend on some of the work he has done.

[eomer]

32. Oh, I don't trust him (or distrust him).

I just borrowed his description because it conveyed the meaning I was after.

[OnTheOtherHand]

36. OK, I think this has been covered already

It's quite obvious that Bazant and Zhou focuses on estimating conservatively what impact forces the towers could withstand. In that regard, as far as I can tell, their assumptions are all pretty conservative. Tilt, per se, doesn't reduce the energy imparted by the upper portions.

One still might wonder: is it reasonable to treat the upper portions as approximately rigid for purposes of this analysis? I see good reasons to think so, including later elaborations in the professional literature. (One consideration is that the impact needn't be instantaneous in order to be inexorably devastating.) You might have counterarguments, but the suggestion that any middle schooler could see that the tops of the towers are like cradled eggs isn't compelling.

[eomer]

37. Their assumptions are not all pretty conservative, which is my point.

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf">Bazant, Zhou says: "This may be demonstrated by the following elementary calculations, in which simplifying assumptions most optimistic in regard to survival are made."

But not all their simplifying assumptions are optimistic toward survival.

Their simplification that focuses the application of energy by the top part onto the bottom into a single instant of time is pessimistic toward survival. If the same amount of energy is applied over a much longer interval of time (say a magnitude or two longer) then this simplification is grossly pessimistic.

And their simplification that the bottom part always loses and the top part remains intact (which allows all the energy to go into crushing the bottom instead of using some of the energy for crushing the top) is pessimistic toward survival.

And their simplification that all the energy remains directed vertically is pessimistic toward survival.

So the question then becomes: what is the net effect of all the simplifications put together. Some of the simplifications are optimistic toward survival and some are pessimistic toward survival. How do we know the net effect?

But the problem is that in order to know the net effect you seemingly would need to be able to do the more exacting calculation that you weren't able to do in the first place and that caused you to use simplifying assumptions in its stead.

So if that calculation (without simplifications) is truly beyond our capabilities, then a proxy with all simplifications optimistic toward survival might be a possible solution. Then you could reasonably claim that you've established a limiting case. But the approach of Bazant, Zhou that allows in simplifications that are pessimistic toward survival drains the force of argument and just moves the problem elsewhere: now they need to demonstrate that the net effect of their simplifications is optimistic toward survival.

The other approach (besides making sure all your simplifications are optimistic toward survival) would be to run physical experiments to validate the model. That obviously hasn't been done.

[AZCat]

38. What physical experiments...

would you suggest be run to validate BZ's model?

[eomer]

39. Most likely there are none that are actually feasible. That doesn't change the reality, though.

The reality is that the Bazant, Zhou modeling is highly speculative and demonstrates nothing unless it can be validated with experiments. If it is impossible to validate with experiments then it is impossible to validate.

[OnTheOtherHand]

40. I can't even tell what that would mean

If every assumption in the analysis has to be most optimistic toward survival (which I don't think was B&Z's meaning), then do they have to assume that the upper portion vaporized?

AFAICT, it isn't as if they rummaged through a box of assumptions and arbitrarily chose some "optimistic" ones and some "pessimistic" ones. Basically your criticism of the simple analysis seems to boil down to the fact that they did the simple analysis. I've read many, many criticisms along those lines, and I don't find them inherently very persuasive.

We seem to be stuck talking past each other to the extent that I'm not sure what more I can say that wouldn't be misleading.

[eomer]

41. What it would mean

is that you demonstrate something only if you actually demonstrate it. Just because you wish you could demonstrate it doesn't make it so.

And, clearly, it wasn't going to take much to persuade you. It was your default position that you were persuaded of before Bazant said anything; he had you at hello. Bazant's job is to persuade someone who is skeptical of the conclusion.

A simple analysis for a complex event is inherently unconvincing. The burden is on the one making the argument to demonstrate that the simple analysis can by some specific argument serve as a proxy for the complex event. Bazant tries to make that argument by saying that their simplifying assumptions all go in a direction against their favor, thereby acknowledging the need to make such an argument. But their statement is not true, all their simplifying assumptions do not go in a direction against their favor.

To just gloss over it and essentially say, oh well close enough, is not good enough. For that we may as well just take our best guess at the original question and go with our gut instinct, which would be more honest. "In our gut we feel like the top block had enough momentum that it was going to crush the bottom block" is not particularly different than "in our gut we feel like the net result of the simplification is good enough" except that it is more honest. It doesn't pretend that anything has been proved by equations of physics when it really hasn't.

[OnTheOtherHand]

42. oh, brother

I should have cut this short a while back, before it came to this.

[SDuderstadt]

43. Now, you're...

thinking.

[OnTheOtherHand]

45. a hit, a most palpable hit

I wish I had the insouciance, or whatever it is, to be sure that I can run rings around experts in their own fields. I'm not talking about the capacity to suspect that experts might be wrong, which comes naturally; no, I crave the certain subjective knowledge that I can see right through them. It just seems like it would be a hoot and a half.

[eomer]

46. I don't think that at all.

This just happens to be a case where the blunders are so gross they are apparent to anyone.

And it seems to me that insouciance would be supporting a position over several years while remaining indifferent to the details; to not engage in the specific arguments and yet still express support for it. Or do I misunderstand the definition?

You seem to concede that not all the simplifying assumptions are optimistic toward survival and I don't see that you've said that Bazant, Zhou demonstrate somewhere how they net out, yet you still express support for the result, somehow, without a very specific explanation of why. I, on the other hand, insist on digging into the details. Please help me with your understanding of insouciance.

[LARED]

47. 'where the blunders are so gross they are apparent to anyone'.

Your insistence that there is something wrong in the Bazant and Zhou paper caused me to re-read it in it's entirety, and I can tell you as a mechanical engineer with over 20 years experience, I find little wrong with the paper.

[OnTheOtherHand]

48. let me ask you this

There seems to be a fundamental disagreement about how to read B&Z, but let me set that aside for now.

B&Z treat the top of each tower as a rigid body. In your opinion, why (or to what extent) is that a reasonable simplification in this context? (I know why it seems reasonable to me, but IANAE.)

[LARED]

51. To me it fits the type of analysis performed

First it is clearly stated the analysis is simplified. B&Z are essentially using energy formulas to evaluate how much energy was available from the falling upper section verse how much energy could be absorbed without inelastic deformation / fracture. They develop ratios between the two to show that from an energy balance there was little chance the lower sections could manage the forces it underwent. The only way I know of to do this simply, is to assume the upper sections were ridged bodies.

To assume otherwise automatically prevents one from using the formulas used because they are not valid unless one assumes you are dealing with a rigid body. Of course someone could call got'ca and say assuming a ridged body so you get to pick the right formulas is cheating. But frankly if someone does that they are seriously ignorant of newtonian mechanics.

Also the video of the event makes a strong case for a simplified rigid body dynamic approach. The upper section appears to move as a unit. It does not appear to move or act like particles. The upper section is clearly intact as a uniform body until the collapse is well under way.

I hope that answers your question.

[OnTheOtherHand]

52. sounds about right

(1) The simplification makes the problem tractable.
(2) The simplification isn't facially unreasonable.
(3) The simplification is consistent with observation.

I think from later papers we could add (4): More elaborate "crush-up" models yield substantively the same results.

None of which amounts to a Euclidean proof, to be sure.

[eomer]

56. The simplification is not consistent with observation.

Here are selected frames from video of the South Tower collapse:

http://911research.wtc7.net/wtc/evidence/videos/st_nbc1.html

The top block does not remain intact. From the beginning of collapse until our view is obscured by dust clouds at frame "14 07:00" it is mostly the top block that is being crushed, not the bottom. (I can draw a block diagram on top of frame "13 06:15" to make the point more clear, but won't have time until perhaps this evening. Such drawings can be found by Google but I haven't found one that doesn't also make points I don't agree with.)

Which proves that whether the simplification is facially unreasonable or not, the model resulting from that simplification does not correctly predict the behavior of the building.

This proof that the model doesn't work makes my point that Bazant needed to demonstrate that the net effect of the simplifications is optimistic toward survival. But if they had tried to do so, and had done their math correctly, they would have proved the opposite since the opposite is what occurred. The top did not remain intact and crush the bottom. On the contrary, the top mostly crushed itself against the bottom.

[LARED]

57. After reading your post I can draw only one conclusion

You have no clue what B&Z was attempting to show in their paper.

[OnTheOtherHand]

58. "I haven't found one that doesn't also make points I don't agree with"

I admire that you work at winnowing arguments, instead of uncritically endorsing or indiscriminately linking to anything that Challenges the Official Story. Nevertheless, at some point you should consider that your environment may be giving you strong clues about the underlying weakness of your position.

I should have caught it the first time you said it, but: while B&Z's model does literally assume that the top part remains "intact," you haven't yet made a case that the result depends on that assumption. Until you see the gap between where you are and where you need to be in order to get people's attention, we are likely to continue to talk in circles.

...the opposite is what occurred. The top did not remain intact and crush the bottom. On the contrary, the top mostly crushed itself against the bottom.

I'm not sure what "mostly" means here, but if you think that you can prove that observationally, I guess I wonder what you're waiting for.

[eomer]

59. From the train, on my phone ...

What I'm waiting for, as I said, is a time when I can work on it, perhaps this evening.

[OnTheOtherHand]

49. meh

You think you're engaging in the details; I don't. I would try to elaborate, but none of my other elaborations have made any sense to you, so I don't know what to try next. Probably my best advice is to write the rebuttal yourself, since none of the professional readers of JEM seem to be up to the task.

[eomer]

50. Here are the details:

Their demonstration hinges on this assertion:

"This may be demonstrated by the following elementary calculations, in which simplifying assumptions most optimistic in regard to survival are made."

I've shown that some of their simplifying assumptions are not optimistic in regard to survival.

That is exactly the level of detail that is needed, no more, no less.

If you want to counter argue, don't you need to show either that their conclusion doesn't hinge on that assertion or else that the assertion is true?

[OnTheOtherHand]

53. sorry, but I don't find that argument any more convincing than the first five times

If you construe that, with selective literalism, to mean that every assumption has to be "most optimistic," then where could the enterprise possibly end? Hell, where could the enterprise even begin?

[William Seger]

60. Baloney

> Their demonstration hinges on this assertion: "This may be demonstrated by the following elementary calculations, in which simplifying assumptions most optimistic in regard to survival are made."

No, it does not. Like any other simplified analysis, you need to use some common-sense judgment about whether or not a more precise analysis would change your conclusion:

Once accurate computer calculations are carried out, various details of the failure mechanism will doubtless be found to differ from the present simplifying hypotheses. Errors by a factor of 2 would not be terribly surprising, but that would hardly matter since the present analysis reveals order-of-magnitude differences between the dynamic loads and the structural resistance. There have been many interesting, but intuitive, competing explanations of the collapse. To decide their viability, however, it is important to do at least some crude calculations. For example, it has been suggested that the connections of the floor-supporting trusses to the framed tube columns were not strong enough. Maybe they were not, but even if they were it would have made no difference, as shown by the present simple analysis.

http://www.911-strike.com/BazantZhou.htm

> I've shown that some of their simplifying assumptions are not optimistic in regard to survival.

You haven't "shown" squat. Some vague misconception about BZ requiring all the energy of the falling top to be applied "in a single instant" is not "showing" anything flattering.

[LARED]

54. Let me provide an example of a complex event

to counter your position that "A simple analysis for a complex event is inherently unconvincing."

I drop a softball from the roof of my house in order to calculate the local gravitational constant. A simple analysis will easily provide a very good approximation of the gravitational constant using rigid body dynamics.

This is in reality a pretty complex event.

I assume negligent air resistance, I assume the ball is a perfectly homogeneous object. I assume the mass centroid is exactly in the center. I assume the stitches on the ball have negligent effects, I assume there was no initial downward or upword force, I assume the timing device is synchronized correctly. I assume there was zero cross wind. I assume there was no rotational forces acting on the ball. I assume no insects intercepted the ball on the way down. I treat the ball as a rigid solid and not a particle.

In reality dropping a ball is a pretty complex event with lots of varibles. But even with all the complexity inherent in this event a simple anaylsis can tell you a lot.

[LARED]

55. Dupe

[LARED]

20. Do you honestly believe your statement?

They went in determined to put together some scientific-sounding formulas that result in the building collapsing. As they arbitrarily chose some formulas and tweaked them to make the building collapse, column 79 happened to be standing at the wrong place at the wrong time and got pulled down by the idiosyncracy of the arbitrarily chosen and tweaked formulas.

Really? Are just being hyperbolic, or do you really think the NIST model is based on arbitrary scientific sounding formulas.

[eomer]

24. Yes, because it is demonstrably true.

See #23.

[LARED]

33. It's not quite clear what you have demonstrated

but it seems you are satisfied with your answer, so enjoy.

[eomer]

34. I wonder, can you see the irony.

What I've demonstrated is that Bazant has demonstrated nothing and that the answer therefore remains to be found.

You're satisfied with an answer you think has been demonstrated, but hasn't.

[LARED]

35. The problem is you not demonstrated in the least

that Bazant demonstrated nothing, or at a minimum you have demonstrated you lack understanding of what he was trying to demonstrate.