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# The Impossible Fast Collapse of The Towers

## 850 posts in this topic

1. Freefall from the height of a WTC Tower is 9.2 seconds.

2. The towers fell in about 15 seconds. Everyone has seen the videos.

3. For the moment, let's assume that the structural strength of the Towers is ZERO - all the tiny particles of steel, glass, concrete, etc. are just magically hanging in place ...but let's also assume that they do possess normal MASS, and that no material begins to fall until it is impacted from above, just as in the actual Tower collapses.

4. It takes energy to push stationary mass out of the way or to set mass into motion. If a moving mass collides with a stationary mass, the moving object is slowed down while the stationary object is sped up and total momentum is conserved. This is simple physics and is known as The Law of Conservation of Momentum. It works in all directions, even in the direction of Earth's gravitational pull.

5. Using mathematics or computer programs, it is fairly simple to calculate how many extra seconds, over and above freefall time, can be attributed to overcoming the static inertia of a WTC Tower's mass. That extra fall time is about 5 seconds (see notes below).

6. So absolute freefall is 9.2 seconds; adding 5 seconds to this number gives us a collapse time of about 14 seconds due to mass alone and Newton's Laws, while ignoring any effects of structural strength whatsoever.

7. Ok, now let's add back in structural strength. How many MORE seconds of collapse time will be required to overcome the immense strength of the towers' undamaged infrastructure below the impact zone? Remember, you have to not only overcome supporting strength but you also have to shred it to bits as well and pulverize all the concrete and other materials to fine powder. All of this work takes energy that is only available from gravitational potential energy if the official story is correct.

8. However, we are already certain that the total collapse time can be no less than around 14 seconds due to Newton's Laws alone. Yet, overcoming the steel infrastructure's strength can only INCREASE the total collapse time still further - by many more seconds, if collapse even takes place at all. Yet the towers fell through themselves as if they had hardly any structural strength.

9. Do you believe that the steel infrastructure's strength was no stronger than the surrounding air. No? Well, there you go: a gravitationally-driven collapse is absurd.

10. Even if you assume a collapse time of 20 seconds, this is like saying that the Towers' strength fell apart easily, like wet toilet paper; hardly any resistance at all. The Towers' structural strength was designed to support its mass by a safety factor of several multiples.

Imagine trying to crush and shred the monstrous strength of a WTC Tower's steel infrastructure in 1 second! -- all those immensely strong core columns and peripheral columns tied together in an integral steel framework. How much energy does it take to do that? Humongous amounts of energy! But, as you have seen, you have only a second or two delay time at the very most that you can attribute to the effects of structural strength because the Towers actually DID fall in about 15 seconds.

It seems that structural strength really WAS virtually zero on 911. Where is the flaw in this logic?

NOTES:

(1) A mathematics formula by Dr. Kenneth Kuttler, Pg. 6 (last one on the page)

http://www.journalof911studies.com/letters/ProfKuttlerWTC1CollapseTimeCalculations.pdf

(2) Dr. Kuttler's straight-forward calculation was written about WTC7 but the formula can be applied to the Towers simply by changing the variables (such as number of floors).

(3) It turns out that the greater building masses found at the bottom versus the lighter masses at the top of the buildings have little effect on the overall delay time due to Newton's Laws and overcoming static inertia.

(4) This puzzle also assumes that ALL of the building's mass was concentrated in the downward vertical direction, ie. none of it was blown outwards as occurred in reality. Obviously, if less mass were concentrated downwards because it was blown outwards, it could NOT have participated in the forces acting on the undamaged infrastructure below. Thus the total collapse time due to overcoming static inertia would have to be even greater. So this assumption favors the official story.

(5) There have been computer programs written to calculate the effects of overcoming mass static inertia also, but I could not locate them quickly.

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Welcome to the UM forums. I noticed you haven't actually done any of the math there. Get back to us when you have some numbers added in there. Otherwise, well, it's pretty much the same discussion that has been presented time after time after time.

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When I watch the videos, I have a difficult time making out when the actual building stops collapsing. I can see the debris (beams and such) falling, and the column of dust left behind, but I am unable to discern the actual collapse "front", or the upper parts of the building in the later portions of the collapse.

Plus, the view is blocked by surrounding buildings in the later stages of the collapse, so this adds to the difficulty in seeing the collapse front as it progresses downward.

Might you be able to point us towards a clear video of each tower collapse that would help here?

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And when does the collapse actually stop? How do they tell when to start the stopwatch and when to end it?

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7. Ok, now let's add back in structural strength. How many MORE seconds of collapse time will be required to overcome the immense strength of the towers' undamaged infrastructure below the impact zone? Remember, you have to not only overcome supporting strength but you also have to shred it to bits as well and pulverize all the concrete and other materials to fine powder. All of this work takes energy that is only available from gravitational potential energy if the official story is correct.

Looks like you're saying the towers collapsed from the point of impact with the rest untouched, the videos don't support this. Edited by Rlyeh

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It seems that structural strength really WAS virtually zero on 911. Where is the flaw in this logic?

The flaw lies in believing your own expectations rather than doing the maths to see how large the expected effect of structural strength actually is.

Welcome to the UM forums. I noticed you haven't actually done any of the math there. Get back to us when you have some numbers added in there. Otherwise, well, it's pretty much the same discussion that has been presented time after time after time.

It's just as well that four engineers have done the maths and published the results. Their paper is here:

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/476%20WTC%20collapse.pdf

They end their paper: These conclusions show the allegations of controlled demolition to be absurd and leave no doubt that the towers failed due to gravity-driven progressive collapse triggered by the eﬀects of ﬁre.

Edited by flyingswan

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Dude, I hope your up on your CT's because these guys will eat you alive Welcome to U.M. and have fun and good luck

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1. Freefall from the height of a WTC Tower is 9.2 seconds.

Yes, freefall in a vacuum, aerodynamic drag notwithstanding, and all that boring nonsense like terminal velocity. Velocity under the same circumstances would be ~ 201 SMPH, or ~ 295 FPS.

2. The towers fell in about 15 seconds. Everyone has seen the videos.

Really?

It's just a wee difficult to time the fall of either "tower", as they were progressively collapsing and being pulverized into a menagerie of various sized particles, and pieces of bulding invisible due to the spreading , descending dust clouds.

Part of the debris was lower than other parts during the descent, and the fact is, some of the building remained airborne for a good while. The bulk of the buildings were likely on the ground in 15-25 seconds. It's excedingly difficult to get a view that allows one to actually time the finish of a collapse.

If your point is to show that the towers did not collapse in "free fall" (and old and silly CT claim put forth), then you've succeeded.

3. For the moment, let's assume that the structural strength of the Towers is ZERO - all the tiny particles of steel, glass, concrete, etc. are just magically hanging in place ...but let's also assume that they do possess normal MASS, and that no material begins to fall until it is impacted from above, just as in the actual Tower collapses.

4. It takes energy to push stationary mass out of the way or to set mass into motion. If a moving mass collides with a stationary mass, the moving object is slowed down while the stationary object is sped up and total momentum is conserved. This is simple physics and is known as The Law of Conservation of Momentum. It works in all directions, even in the direction of Earth's gravitational pull.

5. Using mathematics or computer programs, it is fairly simple to calculate how many extra seconds, over and above freefall time, can be attributed to overcoming the static inertia of a WTC Tower's mass. That extra fall time is about 5 seconds (see notes below).

6. So absolute freefall is 9.2 seconds; adding 5 seconds to this number gives us a collapse time of about 14 seconds due to mass alone and Newton's Laws, while ignoring any effects of structural strength whatsoever.

7. Ok, now let's add back in structural strength. How many MORE seconds of collapse time will be required to overcome the immense strength of the towers' undamaged infrastructure below the impact zone? Remember, you have to not only overcome supporting strength but you also have to shred it to bits as well and pulverize all the concrete and other materials to fine powder. All of this work takes energy that is only available from gravitational potential energy if the official story is correct.

8. However, we are already certain that the total collapse time can be no less than around 14 seconds due to Newton's Laws alone. Yet, overcoming the steel infrastructure's strength can only INCREASE the total collapse time still further - by many more seconds, if collapse even takes place at all. Yet the towers fell through themselves as if they had hardly any structural strength.

9. Do you believe that the steel infrastructure's strength was no stronger than the surrounding air. No? Well, there you go: a gravitationally-driven collapse is absurd.

10. Even if you assume a collapse time of 20 seconds, this is like saying that the Towers' strength fell apart easily, like wet toilet paper; hardly any resistance at all. The Towers' structural strength was designed to support its mass by a safety factor of several multiples.

Imagine trying to crush and shred the monstrous strength of a WTC Tower's steel infrastructure in 1 second! -- all those immensely strong core columns and peripheral columns tied together in an integral steel framework. How much energy does it take to do that? Humongous amounts of energy! But, as you have seen, you have only a second or two delay time at the very most that you can attribute to the effects of structural strength because the Towers actually DID fall in about 15 seconds.

It seems that structural strength really WAS virtually zero on 911. Where is the flaw in this logic?

I have a feeling that your logic may have missed something.

Who said that the structure of the entire tower's infrastructure was destroyed in one second?

Your item 10) is a flawed assumption. That type of failure wasn't necessary to cause these progressive collapses.

Each floor of a WTC tower was capable of supporting a load of ~ 2,600,000 lbs.

The collapse began when 25 floors or so of the tower began to fall into the weakened floor where damage from heat had weakened the floor's structure.

That's about 227 million pounds falling onto a floor designed to support 2.6 million lbs. It fell of course with acceleration,and crushed into the floor below, making it fail, and the next thing you know, 235 million pounds are descending again into another floor that can only support 2.6 million pounds...etc., etc.

I'm thinking maybe you're not quite understanding that the energy produced by that mass moving is what caused the collapses, not the strange idea that the toweres didn't have any structural strength...

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I'm thinking maybe you're not quite understanding that the energy produced by that mass moving is what caused the collapses, not the strange idea that the toweres didn't have any structural strength...

Once again, the numbers are available in a published paper, which shows that after a drop of just one floor, the kinetic energy of the moving mass is more than eight times that required to crush the next floor, columns and all:

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

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Methinks that old Carl is a troll and stroll.

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Once again, the numbers are available in a published paper, which shows that after a drop of just one floor, the kinetic energy of the moving mass is more than eight times that required to crush the next floor, columns and all:

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

It seems very hard for people to understand this kinetic energy thing, you know Swanny?

I'm wondering if your efforts here will have any effect at all...or if Mr. Nelson will come back and read the report???

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...or if Mr. Nelson will come back and read the report???

Perhaps Mr. Nelson has "collapsed" realizing the wrongfulness of his position.

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Perhaps Mr. Nelson has "collapsed" realizing the wrongfulness of his position.

Wouldn't be the first time...

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Regarding the topic... well, I could muse how fast a pig should fly... but I'll wait for someone to show they can really get off the ground first. The official story has yet to prove that the towers should or even could have collapsed due to the impact and fire conditions present on 9/11.

The NIST study demonstrated only that a damage scenario greater in severity than that present on 9/11 could initiate a collapse. The simulation most closely matching the actual damage characteristics did not lead to collapse in their model.

There is no way around this.

And then this, thank you flyingswan...

Once again, the numbers are available in a published paper, which shows that after a drop of just one floor, the kinetic energy of the moving mass is more than eight times that required to crush the next floor, columns and all:

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

... a blatant faulty paper.

A few of the most glaring errors: -

• Assumes unimpeded initial drop of upper block.
It did not happen - the tilt alone shows this.
• Treats upper block as solid hammer/piledriver throughout collapse.
It did not happen - Newton's third law dictates upper block must deteriorate.
• Assumes complete impact energy transfer to lower structural columns.
It did not happen - energy was lost in breaking connections and debris falling outside building footprint.
• States (correctly) that a "powerful jolt" at impact of upper block is a necessity.
It did not happen - engineering analysis has shown the roof acceleration to be relatively linear and this missing jolt is completely incompatible with the theory.

Again, there is no way around this.

The paper, produced within two days of the collapses, still forms the crux of the official collapse progression theory.

A U.S. attorney has noted with examples how the author is given favourtism in the peer-review process: -

"As will become apparent below, the rules at JEM that govern other authors do not apply to Dr. Bazant."

The view of a European structural engineer on the author: -

“I think he is a criminal. You can quote me because I’ve already said that on my web site,” he said. “This guy is a Lysenko-type scientist. He’s presenting a false theory for whatever purpose. I don’t know why he does it.”

And another 1,500+ architects and engineers who disagree with the author.

So what are we left with? An inconclusive study and assumptive/incorrect paper.

Well then, I guess pigs can fly... or back to reality, scrutiny shows that the official conclusions are farcial.

Dude, I hope your up on your CT's because these guys will eat you alive Welcome to U.M. and have fun and good luck

You take these guys seriously?

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to Q24. I wish I knew as much information regarding 9/11 as you do so I could debate and counter the debunkers more than I'm currently able to. I hope you continue doing what you've been doing here.

Edited by Crazy Horse

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to Q24. I wish I knew as much information regarding 9/11 as you do so I could debate and counter the debunkers more than I'm currently able to. I hope you continue doing what you've been doing here.

Whew...

That is pretty amazing.

As far as him continuing to espouse his profound engineering knowlwedge to engineers. You can be assured he will indeed continue.

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Regarding the topic... well, I could muse how fast a pig should fly... but I'll wait for someone to show they can really get off the ground first. The official story has yet to prove that the towers should or even could have collapsed due to the impact and fire conditions present on 9/11.

Which is a perfectly valid point...for a different topic, in a different thread. This one is about freefall. It is about how the towers fell, not why. There's dozens of threads where you can discuss the why. No need to hijack this one.

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Whew...

That is pretty amazing.

As far as him continuing to espouse his profound engineering knowlwedge to engineers. You can be assured he will indeed continue.

What's wrong with this link he offered?

From what I've gathered Q24 knows far more about the events surrounding 9/11 than just about anyone else on this site. He also seems to come from an unbiased position when presenting information, which is something that can't be said about most.

If the information available about 9/11 and the events leading up to that day gave no reason to believe it was an inside job than I doubt Q24 would have any difficulties stating such.

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What's wrong with this link he offered?

This is what's wrong with AE911T. One of their own members thought they were making unrealistic claims and published an open letter to them:

http://www.cool-places.0catch.com/911/OpenLetterToRichardGage.pdf

My conclusion is that there is no claim favoring the controlled demolition hypothesis over NIST’s

impact/fire/gravitational collapse hypothesis.

This was two years ago, and we're still waiting for a reply that answers the points.

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... a blatant faulty paper.

A few of the most glaring errors: -

• Assumes unimpeded initial drop of upper block.
It did not happen - the tilt alone shows this.
• Treats upper block as solid hammer/piledriver throughout collapse.
It did not happen - Newton's third law dictates upper block must deteriorate.
• Assumes complete impact energy transfer to lower structural columns.
It did not happen - energy was lost in breaking connections and debris falling outside building footprint.
• States (correctly) that a "powerful jolt" at impact of upper block is a necessity.
It did not happen - engineering analysis has shown the roof acceleration to be relatively linear and this missing jolt is completely incompatible with the theory.

Perhaps you should look at the other paper as well, covers the objections in detail.

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/476%20WTC%20collapse.pdf

This includes the ways the damage progresses in the upper block as well as the lower one, energy absorbed in other ways and an excellent agreement between the predicted and observed rates of fall of the upper block.

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What's wrong with this link he offered?

Refer to the engineer's comments above.

If the information available about 9/11 and the events leading up to that day gave no reason to believe it was an inside job than I doubt Q24 would have any difficulties stating such.

Your last sentence above is a primer for the CT to follow.

Q did so.

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to Q24. I wish I knew as much information regarding 9/11 as you do so I could debate and counter the debunkers more than I'm currently able to. I hope you continue doing what you've been doing here.

Thank you, I'm finding your JFK posts to be interesting too.

I don't have much time for the 'debunkers' at the moment, and they have been no challenge for a long time anyhow.

This is what's wrong with AE911T. One of their own members thought they were making unrealistic claims and published an open letter to them:

http://www.cool-places.0catch.com/911/OpenLetterToRichardGage.pdf

My conclusion is that there is no claim favoring the controlled demolition hypothesis over NIST’s

impact/fire/gravitational collapse hypothesis.

This was two years ago, and we're still waiting for a reply that answers the points.

It is completely ridiculous to say that 1,500+ architects and engineers are "wrong" because one member criticised them equally to his criticism of NIST.

NIST's own former chief of the fire science division was scathing of the official investigation, yet you don't claim that invalidates the specific collapse theory they came up with, do you? No.

Biased.

Perhaps you should look at the other paper as well, covers the objections in detail.

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/476%20WTC%20collapse.pdf

This includes the ways the damage progresses in the upper block as well as the lower one, energy absorbed in other ways and an excellent agreement between the predicted and observed rates of fall of the upper block.

As we have just seen, the lead author has been described by a fellow professional as a "criminal" and "Lysenko-type scientist" who a U.S. attorney has also demonstrated receives special treatment from the peer-review process.

The paper does not suitably address any of the points.

Which is a perfectly valid point...for a different topic, in a different thread. This one is about freefall. It is about how the towers fell, not why. There's dozens of threads where you can discuss the why. No need to hijack this one.

The opening post is quite clearly designed to refute a gravity-driven collapse: -

Well, there you go: a gravitationally-driven collapse is absurd.

Note that a gravity-driven collapse is the official theory of "why" the towers fell.

See the subsequent paper kindly linked by flyingswan titled, "Why Did the World Trade Center Collapse?"

And the later dated paper titled, "What Did and Did Not Cause Collapse... "

Note the words, "Why" and "Cause"; discussion of the reasons for collapse, both entirely relevant to the opening post. The "how" and "why" are inseperable here as dictated by intention of the opening post.

I simply continued discussion of why the gravity-driven collapse theory is unfounded... impossible in fact, as the thread title terms it.

1) because the probability is that such a collapse should not begin once, never mind twice,

2) because if it does begin there is no evidence it should continue and

3) because features the theory relies on are absent from the witnessed collapse.

In other words, whether the towers took 10, 15 or 20 seconds to fall... it was not due to a gravity-driven collapse.

Align that conclusion with the quoted passage above - I am entirely on topic.

If you are telling us, from your position of "Senior Moderator", that this thread is now purely an observational exercise of "how" the towers fell, then it is regrettably you who have hijacked proceedings - from that the original post intended, from flyingswan's response and from my follow-up.

Anyway, I don't have time at the moment so I'll leave you 'debunkers' to slap yourselves on the back for now.

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Align that conclusion with the quoted passage above - I am entirely on topic.

If you are telling us, from your position of "Senior Moderator", that this thread is now purely an observational exercise of "how" the towers fell, then it is regrettably you who have hijacked proceedings - from that the original post intended, from flyingswan's response and from my follow-up.

Anyway, I don't have time at the moment so I'll leave you 'debunkers' to slap yourselves on the back for now.

This topic is about how the tower fell. Not about why it fell. Feel free to start yet another thread on why the tower fell. Do not derail this discussion anymore. Since you want me to act like a big bad moderator, consider this your only warning.

It is completely ridiculous to say that 1,500+ architects and engineers are "wrong" because one member criticised them equally to his criticism of NIST.

There are somewhere between 80,000 and 120,000 architects in the US (depending which census you read), and 500,000 to 750,000 engineers (depending on which type of construction engineers you are counting). Is it ridiculous to assume that 580,000 to 870,000 professionals noticed the same thing these 1500 did, but really can't be arsed to comment on it?

Or should we assume that an opinion held by .17% (or .25%, if you want to use the higher number) of all the professionals in a field is significant in some way?

1500 architects and engineers is only an impressive number when you ignore the hundreds of thousands of others who don't find the situation worth commenting on.

Edited by aquatus1

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