While the responses to questions 2, 4, 5 and 11 are consistent with the explanation that no explosives were used, they aren't strong enough to imply that there were no explosives.

That's because NIST was charged with simply determining the cause of the collapse. They determined a few things. Airliners filled with jet fuel were crashed into the towers hours before they collapsed. The collapse of the towers appears to start with the collapse of the floors that were crashed into by the airliners. Expert study of the damage caused to the building, including simulations and past direct experiment determined that the airliner crash and resulting fires were sufficient to cause the collapse. NIST then concluded that the cause of the collapse was the airliners that crashed into the towers that day.

They didn't specifically study the possibility of pre-planted explosives causing the collapse. There were thorough analysis of the dust from the collapse though, and they looked for trace elements of almost anything and everything. The came up with traces of asbestos and even pesticides, but no high explosives.

They didn't specifically test for pre-planted terrorist agents with arc welders cutting the buildings support beams either, but why should they?

They didn't specifically study the possibility of trained monkeys with hacksaws being pre-positioned at the pillars causing the collapse either, but why should they?

Thanks. I just read Cole's notes, and they actually agree with the quotes from this video.

My most serious concern is summarized by these paragraphs:

NIST did not test for the residue of these compounds [explosives or thermite residues] in the steel.

The responses to questions number 2, 4, 5 and 11 demonstrate why NIST concluded that there were no explosives or controlled demolition involved in the collapses of the WTC towers.

While the responses to questions 2, 4, 5 and 11 are consistent with the explanation that no explosives were used, they aren't strong enough to imply that there were no explosives.

I'm surprised that they chose not to test the steel for explosive residue, when the tests involved are well known and this was a terrorist attack.

It looks like NIST chose not to test the theory that explosives were used, and tried to find a model which explained the collapse using remaining factors. But this video strongly suggests that their model doesn't properly fit the evidence.

>> ^bcglorf:

But if this video is accurate and NIST didn't explain convincingly how the steel melted, then their report is disturbingly incomplete.
If you want a quick place to start, here's some Cole's notes that NIST put together specifically for truthers too lazy to follow the original report before outright rejecting it.

But if this video is accurate and NIST didn't explain convincingly how the steel melted, then their report is disturbingly incomplete.

If you want a quick place to start, here's some Cole's notes that NIST put together specifically for truthers too lazy to follow the original report before outright rejecting it.

Most people debating on the Internet know nothing about steel, explosives or the official report. Yet they somehow have very well defined opinions.

Yes, I'm looking at you, sifters.

I have BS degrees in electrical engineering and pure math. I'm finishing my Ph.D. in electrical engineering. However, I know very little about steel, explosives and I haven't read the NIST report. Next to an expert, my opinion is as good as a high school dropout's.

But if this video is accurate and NIST didn't explain convincingly how the steel melted, then their report is disturbingly incomplete. And by convincingly, I mean experimentally -- NOT with handwaiving and computer models based on guesswork.

During my career as a practicing engineer and a researcher, I've seen way too many computer simulations designed to "prove" something which is in fact false. Many of the papers I reject have some kind of bullshit assumption or simulation. By using the wrong model, it's possible to show pretty much anything, and in the end, nothing can replace real-world experiments, especially if you're trying to overcome skepticism and confusion.

I suppose I should read the NIST report and stop taking other people's word for it. Because if the quotes from this video are correct, then he's right and NIST's work is unconvincing at best.

For reference...

NIST report and press conference:
Sunder said that his team investigated these hypothetical causes [thermite] and ruled them out. "We asked ourselves what is the minimum amount of charge we could use to bring the building down," he said. "And we found that even the smallest charge would release an extremely loud sound heard half a mile away." There were no reports of such a sound; numerous observers and video recordings found the collapse to be relatively quiet.

FEMA:
The eutectic temperature for this mixture strongly suggests that the temperatures in this region of the steel beam approached 1,000 degrees C (1,800 degrees F), which is substantially lower than would be expected for melting this steel...

FEMA:
Temperatures in this region of the steel were likely to be in the range of 700 to 800 degrees C (1290 - 1470 degrees F).

NIST:
In no instance did NIST report that steel in the WTC towers melted due to the fires. The melting point of steel is about 1,500 degrees Celsius (2,800 degrees Fahrenheit). Normal building fires and hydrocarbon (e.g., jet fuel) fires generate temperatures up to about 1,100 degrees Celsius (2,000 degrees Fahrenheit). NIST reported maximum upper layer air temperatures of about 1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers (for example, see NCSTAR 1, Figure 6-36).
However, when bare steel reaches temperatures of 1,000 degrees Celsius, it softens and its strength reduces to roughly 10 percent [***NOTE: no reference] of its room temperature value. Steel that is unprotected (e.g., if the fireproofing is dislodged) can reach the air temperature within the time period that the fires burned within the towers. Thus, yielding and buckling of the steel members (floor trusses, beams, and both core and exterior columns) with missing fireproofing were expected under the fire intensity and duration determined by NIST for the WTC towers.

Modulus of Elasticity for Steel:
http://www.engineeringtoolbox.com/young-modulus-d_773.html

What is concerning is that thermite was rule out because of the noise, and that 1000 lbs would be needed.

Also, no one has explained the UL testing on the steel for 6 hrs at 1000C?

Finally, what is troubling is that softening girders causeing collapse, fine, steel is weakened at 1400degF, but the core wouldn't fall. Certainly wouldn't break apart.

>> ^Jinx:

I mean no offence to the OP, but if you don't know anything about the way the Towers were built and the reason for their eventual collapse then why do you think your opinion holds any weight? The official line, which is backed up by god knows how many engineers and demo experts seems plausible to me. Even if it did seem counterintuitive to me, I'd still just assume its because I am basically ignorant of how massive structures fall. Those towers aren't built out of Jenga blocks...
As for the whole conspiracy theory thing...Occam's Razer bro. I don't doubt the US govt has hid much from the public regarding 9/11, but I don't believe anybody could orchestrate the destruction of the twin towers to conveniently pin it on the Saudis, especially since the US did their damndest to swing the blame on Iraq. I can't see a motive, and I sure as hell can't see a means and I don't see any evidence. All I see is such a deep destrust of government. Simplest explanation wins.


From reading the thread, it apeared that he was unfamiliar with the details of the NIST report. It is counter intuitive that a building struck on the side would fall in its own footprint ( as any Jinga players would know), if one wasn't familiar with the finders in the report. I, too, didn't take the story on face value until I learned of the unique conditions of the towers. Wisdom comes from asking questions.

You know what buddy? FUCK YOU! I'm tired of you fucking pricks launching personal insult attacks on me because I don't blindly believe everything I'm told. I could give a fuckin' rats ass what NIST and all the other "experts" say. There are just as many experts that say the contrary so again, FUCK YOU!

In reply to this comment by StukaFox:
>> ^Duckman33:
>> ^IronDwarf:
Perfect video to show morons who think any of the WTC buildings were demolished by explosive charges. Even from a noisy helicopter you could hear the ridiculously loud explosives being set off in sequence before the building collapses. Where is that sound in any of the hundreds of collapsing WTC videos?

Morons? Why are we morons? Because we don't believe everything we are told?


No, you're a moron because you've been shown time and time and time and time and time again how the WTC collapsed -- everyone from NIST to Popular Science -- and despite all these reports, you and the rest of the dipshits in the Mystery Machine think you're going to pull the mask off Bin Laden and find Old Man Bush.

THAT'S what makes you a moron.

>> ^Duckman33:
>> ^IronDwarf:
Perfect video to show morons who think any of the WTC buildings were demolished by explosive charges. Even from a noisy helicopter you could hear the ridiculously loud explosives being set off in sequence before the building collapses. Where is that sound in any of the hundreds of collapsing WTC videos?

Morons? Why are we morons? Because we don't believe everything we are told?


No, you're a moron because you've been shown time and time and time and time and time again how the WTC collapsed -- everyone from NIST to Popular Science -- and despite all these reports, you and the rest of the dipshits in the Mystery Machine think you're going to pull the mask off Bin Laden and find Old Man Bush.

THAT'S what makes you a moron.

Did you bother to read the article or just decide to post something snarky? Popular Mechanics was reporting on the latest NIST report regarding Building 7, which determined that the building collapsed due to fire.

Also, check out NIST or their website. There is alot of fascinating research going on there. It's a full research lab.

Science is dying in America. NSF might have it's budget completely eliminated. NIST, NIH, NOAA, NRL, ANL, have all seen there budget sharply cut when compared to inflation. And you ask, who would I vote for?

You people. And you wonder why we have such a bad economy. The days of "Made in USA" are over people. We cannot compete with the foreign labor. Americans innovate. We make new things that no one has thought of, which are conceived in national labs and universities. Even Google was invented at a University.

"Google began in January 1996, as a research project by Larry Page, who was soon joined by Sergey Brin, two Ph.D. students at Stanford University in California."

And you ask me who I would vote for. Do you have any idea how bad it is and has been for science? This is ridiculous. Is there a choice?

Obama is the only one of those candidates who had a legitimate science policy. No one ever asked Ron Paul "What are you gonna do about Science?". Why? Because he would have said, "I would eliminate the NSF and all other research institutions and give tax incentives to corporations to do research."

And if you seriously think that is a viable economic philosophy, then you need to get off your computer, because that was also invented at a University.

>> ^manfromx:
So NIST is saying that there is no reason to even wonder about molten steel underneath the WTC because it's already been decided that it wasn't controlled demolition and the fires weren't hot enough to make molten steel.
Their theory for why it's there are fires burning within the pile after the collapse.
Interesting theory but that's not exactly convincing either. Seems unlikely office furniture could make molten steel after the admission that jet fuel cannot.
I sure as hell don't know exactly what happened. Some things do seem odd and I think the poster asked a decent question. If the corner was weakened why did the building fall nearly straight down and not to the side at least for a distance.
Don't see why everyone has to jump on the guy without trying to understand/learn from this.



Sulfurhexaflouride gas emitted from the burning of old office equipment containing sulfur based materials makes contact with hot steel, catalyzing the binding elements that keep the base alloys in tact (charcoal, iron, and other strengthening based additives), reducing hardened steel, into not so hardened steel, reducing its maximum heat threshold, and making jet fuel quite easy to melt the resultant material.

Down she comes.

Its a primary reason that decent office supplier manufacturers no longer use sulfur based materials...it doesnt react nicely to steel when its burned.

So NIST is saying that there is no reason to even wonder about molten steel underneath the WTC because it's already been decided that it wasn't controlled demolition and the fires weren't hot enough to make molten steel.

Their theory for why it's there are fires burning within the pile after the collapse.

Interesting theory but that's not exactly convincing either. Seems unlikely office furniture could make molten steel after the admission that jet fuel cannot.

I sure as hell don't know exactly what happened. Some things do seem odd and I think the poster asked a decent question. If the corner was weakened why did the building fall nearly straight down and not to the side at least for a distance.

Don't see why everyone has to jump on the guy without trying to understand/learn from this.

"The new NIST report does not mention the molten steel beneath the wreckage, "

Wrong(ish). The new one(which, as I believe, was about wtc 7, not 1 and 2) probably doesn't mention it... but NIST have mentioned the molten steel before:

http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm Scroll down to question 13.

Oh, btw. Found that in a matter of seconds, using Google.

NIST has a comprehensive report detailing how this particular structure collapsed, and how come others that have either been engulfed in flames for DAYS, OR also hit by a plane, did not collapse in the same manner.

It has to do with the way the floors were constructed around a central pillar.

Trusses linked to the outer frame, and the inner core with a few simple angle clips to hold and share the load, with no free-standing pillars like conventional towers. This gave the floors much much more open floor space than any other tower out there...with obvious advantages.

Take some of the clips out of one floor thats hooked into the outer shell, and you have to share the load of the floor on the rest of the clips.

Shock load the clips and you stress them to a point where they cant hold as much weight prior to a collapse as they used to.

Strip the fire-proofing material off the steel that was rated to handle fires much much hotter than jet fuel could possibly provide, expose said steel to a mix of noxious gasses (created by burning old office equipment) that destroyed basic bonds holding the alloys in the steel together and you turn said steel into iron...drastically lowering its strength potential.

Heat the iron up, she melts...more clips fail, floor pancakes onto one below it. The one below is shock loaded and snaps instantly.....domino effect ensues, tower collapses into its own footprint at close to free-fall.

And yes, concrete can vaporise if you provide enough force.

Other towers either hit by a plane, or had been exposed to much hotter fires for far longer, had drastically different internal designs. They had a series of cubes connecting to one another, essentially an intricate pattern of concrete covered steel beams criss-crossing their way through the entire structure.

Take one beam out (either by fire or collision)...big whoop, theres 300 others to do its job. Not so with twin towers, the clips holding the trusses were limited, and a significant portion of them on the central impact floor were taken out in the collision.