WTC: Rate of Fall (rate of crush)

[George B]

And is my question not essential to the issue? It would be nice if you did dig out the formulae, you can't go off intuition and what you think is the right answer. Mick has put together a strong case here, you don't need to be an engineer or physicist to get a grasp of this stuff. If you're going to make the case you might as well do the math.

I don't feel I am qualified to go beyond where I have already ventured . . . the issue is not the correctness of the calculations . . . I agree they are most likely correct as far as my abilities can determine . . . I am and continue to state . . .show me the difference between a controlled demolition data, formulas, weights, assumptions and those of the WTC collapse(s) . . . is there a significant difference? Can these differences be explained or are they so close to each other one cannot determine which one is TWC and which one is a controlled demolition . . .

I am not competent enough to make that comparison . . . but I would love for someone to do it . . .

[George B]

Well, so why are you not scrutinizing the explanations? Why just rely on your intuition, which is known to be fallible, and has been thrown by the scale of the buildings.

I have scrutinized the alternate explanations and I find them all flawed at one level or another . . . but I feel the official explanation is also flawed . . . it fails to explain several things . . . IMO . . . like speed of failure and fall, hotspots, ability of inexperienced pilots to hit the targets to begin with . . . and so forth . . .

[Mick]

Content from external source:

http://www.911myths.com/WTCREPORT.pdf

Unfortunately there appears to be no simple way to calculate E
1 from first principles since the collapse of just one floor of a WTC tower is an extremely complex
process involving the bending and fracturing of numerous support structures


J. Unfortunately Bažant et al. do not give a detailed exposition on how this
value for E1 was derived, stating only that it is based on “approximate design

calculations” for one WTC tower /3/

Mick, math formulas are only as accurate as the assumptions, the weights and values used in them . . . I am not faulting the physics formulas or math theory, or computations used in them . . . I am saying the assumption that the floor resistance E1 has to be near zero is based upon what?. . . it needs to be (x) to fit what we observed so we will make (were biased by what they thought reality was) the value fit the situation . . . not the other way around . . .

You should continue reading that report, they independently derive figures for E1 that match (or are lower than) Bažant

Content from external source:

In spite of these uncertainties, some estimates of the magnitude of E1, (the energyneeded to bring about the collapse of one floor), have been made. For example, Z. Bažant
et al. at Northwestern University, Illinois, have estimated that the maximum plastic
energy dissipated by the collapse of one floor, i.e. our quantity E1, is approximately equal
to 5.0 x 10^8 J. Unfortunately Bažant et al. do not give a detailed exposition on how this
value for E1 was derived, stating only that it is based on “approximate design
calculations” for one WTC tower /3/.

Another calculation that may be used to estimate E1 was published by G.C. Lee et
al. in a MCEER Special Report /4/. Lee et al. assume that 36 exterior columns on WTC 1
were destroyed by the Boeing aircraft impact and conclude (without giving
computational details) that the energy absorbing capacity of these damaged columns
“does not exceed 7230 kips-ft” or about 107 J. Based on this estimate, and remembering
that one complete floor has 236 exterior columns, it follows that the exterior columns
comprising one floor of a WTC tower have an impact energy absorbing capacity of about
7 x 10^7 J. From the relative cross-sectional area of a core column (0.1236 m2) compared
to an exterior column (0.0184 m2), we estimate that the effective strength of the core
columns is about 6.7 times higher than the effective strength of the exterior columns. A
consideration of the collapse of the 47 core columns therefore adds about 9 x 10^7 J of
energy absorbing capacity. Thus, based on Lee’s calculations, the total energy absorbing
capacity of the structural supports of one floor of the WTC is estimated to be about 1.6 x
10^8 J, which we equate to our quantity E1 while noting that this estimate is significantly
lower than Bažant’s value of 5.0 x 10^8 J. However, it appears that Lee’s results are based
on very rough estimates of the energies involved so that the level of agreement with
Bažant’s estimates is as good as might be expected in view of the approximations
involved.

A much better estimate for E1, and one that is based on a very detailed analysis of
the aircraft impact events, may be derived from a paper published by T. Wierzbicki et al.
at MIT /5/. These authors have calculated the energy dissipated by the wing of a Boeing
767 cutting through the exterior columns of a WTC tower and report a value equal
to 1.139 x 10^6 J per column. On this basis, 2.69 x 10^8 J would be require to cut through all
236 exterior columns supporting one WTC floor. If we now assume, as previously
discussed, that the yield strength of the core columns is about 6.7 times higher than the
yield strength of the exterior columns, we estimate that an additional 3.60 x 10^8 J are
required to collapse the 47 core columns supporting each floor. Thus, based on T.
Wierzbicki et al. calculation, we estimate a total of 6.29 x 10^8 J of impact energy was
required to collapse one WTC floor, a value that is remarkably close to Bažant’s estimate
of 5.0 x 10^8 J for the plastic energy dissipated by the collapse of one floor.


The fact that the values of E1 derived from Wierzbicki’s and Bažant’s studies are
quite similar is very significant because these author’s calculations were actually
undertaken for two different impact events: (i) The collision of a Boeing aircraft with one
floor of a WTC tower, and (ii) The collapse of a block of WTC floors onto the floor
below. Thus Wierzbicki considers floor support failure under lateral impact loading
while Bažant’s considers the failure of the floor supports under axial impact loading. The
fact that the energy calculated in each of these cases is about the same suggests that the
energy dissipated in a floor collapse is relatively insensitive to the mode of failure of the
support structures. This is a common observation in studies of collisions of large objects
involving complex structures such as aircraft, automobiles, trains, and ships.

Feel free to check their math, it's quite straightforward.

[Note that notation like 2.69x10^8 means the decimal point is shifted right 8 places, so 2.69x10^8 = 269,000,000]

[Mick]

I have scrutinized the alternate explanations and I find them all flawed at one level or another . . . but I feel the official explanation is also flawed . . . it fails to explain several things . . . IMO . . . like speed of failure and fall, hotspots, ability of inexperienced pilots to hit the targets to begin with . . . and so forth . . .

Then point out and explain the flaws to do with the speed of failure. (And "it does not feel right" is not a flaw).

[George B]

You should continue reading that report, they independently derive figures for E1 that match (or are lower than) Bažant

Content from external source:

In spite of these uncertainties, some estimates of the magnitude of E1, (the energyneeded to bring about the collapse of one floor), have been made. For example, Z. Bažant
et al. at Northwestern University, Illinois, have estimated that the maximum plastic
energy dissipated by the collapse of one floor, i.e. our quantity E1, is approximately equal
to 5.0 x 10^8 J. Unfortunately Bažant et al. do not give a detailed exposition on how this
value for E1 was derived, stating only that it is based on “approximate design
calculations” for one WTC tower /3/.

Another calculation that may be used to estimate E1 was published by G.C. Lee et
al. in a MCEER Special Report /4/. Lee et al. assume that 36 exterior columns on WTC 1
were destroyed by the Boeing aircraft impact and conclude (without giving
computational details) that the energy absorbing capacity of these damaged columns
“does not exceed 7230 kips-ft” or about 107 J. Based on this estimate, and remembering
that one complete floor has 236 exterior columns, it follows that the exterior columns
comprising one floor of a WTC tower have an impact energy absorbing capacity of about
7 x 10^7 J. From the relative cross-sectional area of a core column (0.1236 m2) compared
to an exterior column (0.0184 m2), we estimate that the effective strength of the core
columns is about 6.7 times higher than the effective strength of the exterior columns. A
consideration of the collapse of the 47 core columns therefore adds about 9 x 10^7 J of
energy absorbing capacity. Thus, based on Lee’s calculations, the total energy absorbing
capacity of the structural supports of one floor of the WTC is estimated to be about 1.6 x
10^8 J, which we equate to our quantity E1 while noting that this estimate is significantly
lower than Bažant’s value of 5.0 x 10^8 J. However, it appears that Lee’s results are based
on very rough estimates of the energies involved so that the level of agreement with
Bažant’s estimates is as good as might be expected in view of the approximations
involved.

A much better estimate for E1, and one that is based on a very detailed analysis of
the aircraft impact events, may be derived from a paper published by T. Wierzbicki et al.
at MIT /5/. These authors have calculated the energy dissipated by the wing of a Boeing
767 cutting through the exterior columns of a WTC tower and report a value equal
to 1.139 x 10^6 J per column. On this basis, 2.69 x 10^8 J would be require to cut through all
236 exterior columns supporting one WTC floor. If we now assume, as previously
discussed, that the yield strength of the core columns is about 6.7 times higher than the
yield strength of the exterior columns, we estimate that an additional 3.60 x 10^8 J are
required to collapse the 47 core columns supporting each floor. Thus, based on T.
Wierzbicki et al. calculation, we estimate a total of 6.29 x 10^8 J of impact energy was
required to collapse one WTC floor, a value that is remarkably close to Bažant’s estimate
of 5.0 x 10^8 J for the plastic energy dissipated by the collapse of one floor.


The fact that the values of E1 derived from Wierzbicki’s and Bažant’s studies are
quite similar is very significant because these author’s calculations were actually
undertaken for two different impact events: (i) The collision of a Boeing aircraft with one
floor of a WTC tower, and (ii) The collapse of a block of WTC floors onto the floor
below. Thus Wierzbicki considers floor support failure under lateral impact loading
while Bažant’s considers the failure of the floor supports under axial impact loading. The
fact that the energy calculated in each of these cases is about the same suggests that the
energy dissipated in a floor collapse is relatively insensitive to the mode of failure of the
support structures. This is a common observation in studies of collisions of large objects
involving complex structures such as aircraft, automobiles, trains, and ships.

Feel free to check their math, it's quite straightforward.

[Note that notation like 2.69x10^8 means the decimal point is shifted right 8 places, so 2.69x10^8 = 269,000,000]

So they are extrapolating that the 90 degree shearing (by an aircraft) of several columns can then be used to calculate the elastic resistance of the columns below the damage and two people came up with similar estimates of aircraft damage . . . Hmmmm . . . and I am supposed to accept that they are correct in their ESTIMATES and SUPPOSITIONS of shearing force estimates at the WTC towers. . . since it is impossible to get resistance measurements of the WTC towers since they obviously fell and are gone . . . I am sorry that is still what I was pointing out before . . . use the existing (outcome) supposed reality to prove the reality you think you saw is correct . . .

[George B]

Then point out and explain the flaws to do with the speed of failure. (And "it does not feel right" is not a flaw).

I keep saying the same thing again and again . . . show me the same equations, data, speeds, etc of a high-rise, steel reinforced building that has undergone a controlled demolition and let me compare it with the TWC towers . . . I don't think it would be intuition if the numbers are the same or statistically equivalent . . . how would you explain it if they were basically the same . . .

[Dan Wilson]

I don't feel I am qualified to go beyond where I have already ventured . . . the issue is not the correctness of the calculations . . . I agree they are most likely correct as far as my abilities can determine . . . I am and continue to state . . .show me the difference between a controlled demolition data, formulas, weights, assumptions and those of the WTC collapse(s) . . . is there a significant difference? Can these differences be explained or are they so close to each other one cannot determine which one is TWC and which one is a controlled demolition . . .

I am not competent enough to make that comparison . . . but I would love for someone to do it . . .

Then make yourself competent. Do the math, it doesn't take a degree and years of study. I don't understand why you see flaws yet deem yourself too incompetent to make your own assessment on a matter where all the resources you would need are available to you.

From what I understand, progressive collapse and controlled demolition do have similar consequences because in both cases the building is essentially brought down and dismantled by its own weight. With the WTC, the collapse started at the impact point, no clear indications of demolition were found during the collapse, and no evidence of explosives were found during cleanup. In this case IF explosives were involved then they would have to have been placed at the impact point either before the impact and survived the fire or afterwards. Both explanations seem incredibly unreasonable in light of all the research and calculations that have been done by people who are curious and willing enough to do the calculations. Calculations that are backed up by the video evidence, for what we see, calculate, and can model is that a monumental amount of force was released when the structure failed. A force that could not be stopped by the floor below it. When it could not be stopped it progressed down to the next floor and then the next and the next, hence progressive collapse. So, where exactly is the flaw? You can't say it just looks wrong. You can't just say that you don't trust calculations, you need a reason.

[George B]

Then make yourself competent. Do the math, it doesn't take a degree and years of study. I don't understand why you see flaws yet deem yourself too incompetent to make your own assessment on a matter where all the resources you would need are available to you.

From what I understand, progressive collapse and controlled demolition do have similar consequences because in both cases the building is essentially brought down and dismantled by its own weight. With the WTC, the collapse started at the impact point, no clear indications of demolition were found during the collapse, and no evidence of explosives were found during cleanup. In this case IF explosives were involved then they would have to have been placed at the impact point either before the impact and survived the fire or afterwards. Both explanations seem incredibly unreasonable in light of all the research and calculations that have been done by people who are curious and willing enough to do the calculations. Calculations that are backed up by the video evidence, for what we see, calculate, and can model is that a monumental amount of force was released when the structure failed. A force that could not be stopped by the floor below it. When it could not be stopped it progressed down to the next floor and then the next and the next, hence progressive collapse. So, where exactly is the flaw? You can't say it just looks wrong. You can't just say that you don't trust calculations, you need a reason.

If the WTC and controlled demolitions are basically the same . . . why would the professionals use explosives to remove or weaken the foundation and lower portions of the buildings nearly simultaneously with the upper detonations . . . are they concerned maybe that the resistance represented by the lower floor could stop the collapse of the rest of the building ???

[Dan Wilson]

If the WTC and controlled demolitions are basically the same . . . why would the professionals use explosives to remove or weaken the foundation and lower portions of the buildings nearly simultaneously with the upper detonations . . . are they concerned maybe that the resistance represented by the lower floor could stop the collapse of the rest of the building ???

Probably because going for those buildings' foundations would be the easiest way to demolish it. Not every building is prone to progressive collapse. As we can see in the examples of verinage, you don't need explosives for a demolition. There are many ways to skin a cat and many ways to bring down a building. It depends on the construction.

George, I don't think it is unreasonable to ask for math that might support your assertion that the building should not have fallen the way it did.

[George B]

Probably because going for those buildings' foundations would be the easiest way to demolish it. Not every building is prone to progressive collapse. As we can see in the examples of verinage, you don't need explosives for a demolition. There are many ways to skin a cat and many ways to bring down a building. It depends on the construction.

George, I don't think it is unreasonable to ask for math that might support your assertion that the building should not have fallen the way it did.

We are not talking about verinage we are talking about the demolition of a high-rise, steel reinforced building . . . can or should it not fall faster than the WTC towers? . . . seems like a simple question . . .

What equations are you talking about . . . the resistance elasticity of the beams ? What?

[George B]

Sorry, I need a break, this has been intense . . . I will return after I spend some time with my family . . .

[Oxymoron]

You mean like how people concoct explanation involving nano-thermite, mini-nukes, or space based energy beams?

Do the math.

Yes I do mean that. It is a way that people can make sense of otherwise inexplicable or fantastically unlikely events. But I also mean, politicians and scientists with conflicts of interest and a proven track record of extreme secrecy, lying and making stuff up to suit.

Politically based science is something people are very aware of, including politically based statistics, rationales and laws designed to steal the wealth, impoverish, oppress and criminalise people, thereby crushing dissent. The disparity in wealth distribution in the west is obscene and getting worse by the hour.

It is so blatant that 'they' constantly invent new terms to decriminalise it, such as 'mis sold' instead of fraudulently sold or ignoring the laws altogether in the cases of 'too big to fail... too big to jail'.

To my mind, even if you proved mathematically that it was 'possible' for the towers to collapse as per the OS, that would not prove that it actually happened.

As you rightly say, the math is too complicated and the variables too abstract for most to understand. Combine that with the extreme unlikeliness of it happening at all and that is why it is classified as a Black Swan event.

To me and to many others, whatever mathematical equations or made up variables you or anyone else manage to come up with to 'make it possible', it seems far more likely that it was an inside job, simply on the basis of qui bono and Bush et al certainly benefited big time.

When you factor in all the other anomalies and consequences, I think it points convincingly to at least a conspiracy to 'allow it to happen' and very likely a conspiracy to 'make it happen'.

[Mick]

We are not talking about verinage we are talking about the demolition of a high-rise, steel reinforced building . . . can or should it not fall faster than the WTC towers? . . . seems like a simple question . . .

Just for clarity George, can you point to one video example of the demolition of a high-rise, steel reinforced building. I just want to make sure that I understand what you are looking for.

And why exactly would you expect it to fall "faster" than the WTC? And what point and time are you measuring from?

[Dan Wilson]

We are not talking about verinage we are talking about the demolition of a high-rise, steel reinforced building . . . can or should it not fall faster than the WTC towers? . . . seems like a simple question . . .

What equations are you talking about . . . the resistance elasticity of the beams ? What?

A better question is could it. Which you can answer for yourself by doing the math. I'm not asking for a specific equation, it's however you choose to answer the question of how much force it would take to stop 15 floors falling, say, 10 ft. I'm not trying to make this intense for you, I apologize if I have. I'm just suggesting that you might want to dig deeper, because deeming yourself incompetent enough to make an assessment and then doubting those who try to do so based on nothing of substance does not make for a reasonable argument.

[Mick]

Yes I do mean that. It is a way that people can make sense of otherwise inexplicable or fantastically unlikely events. But I also mean, politicians and scientists with conflicts of interest and a proven track record of lying and making stuff up to suit.

Politically based science is something people are very aware of, including politically based statistics, rationales and laws designed to steal the wealth, impoverish, oppress and criminalise people, thereby crushing dissent. The disparity in wealth distribution in the west is obscene and getting worse by the hour.

It is so blatant that 'they' constantly invent new terms to decriminalise it, such as 'mis sold' instead of fraudulently sold or ignoring the laws altogether in the cases of 'too big to fail... too big to jail'.

To my mind, even if you proved mathematically that it was 'possible' for the towers to collapse as per the OS, that would not prove that it actually happened.

As you rightly say, the math is too complicated and the variables too abstract for most to understand. Combine that with the extreme unlikeliness of it happening at all and that is why it is classified as a Black Swan event.

To me and to many others, whatever mathematical equations or made up variables you or anyone else manage to come up with to 'make it possible', it seems far more likely that it was an inside job, simply on the basis of qui bono and Bush et al certainly benefited big time.

When you factor in all the other anomalies and consequences, I think it points convincingly to at least a conspiracy to 'allow it to happen' and very likely a conspiracy to 'make it happen'.

But those are two entirely different things. One cannot use your suspicion of "allowed it to happen" to let you ignore science in the "made it happen category". That's kind of like say "there's no evidence for controlled demolition, and the figures fit progressive collapse, but since it sounds like something they might do, or at least let the torrorst do, then I'm going to assume they fudged the numbers"

I wrote an article mentioning this type of conflation yesterday:
http://metabunk.org/threads/1139-Fou...spiracy-Theory

Black swan events are not things that are very unlikely, they are events that are singular. One-off events. An asteroid hitting the Earth is a good example - it does not happen very often, and we are not prepared for it, but it's going to happen at some point. Or a large earthquake in Los Angeles. Or a Tsunami in Japan. These are all black swan events. But they are not improbable events to the extent that we do not believe in them when they happen.

Math is a problem. Because people don't understand it, they fall back on simple mistrust, and incredulity. It's not a problem with any easy solution, because it's easy to create illusions in math.

What I would recommend, is finding a neutral person to do the math for you. Or maybe a whole class of structural engineers could be persuaded to work on the calculations as an experiment. Maybe we just need better diagrams.

[Oxymoron]

But those are two entirely different things. One cannot use your suspicion of "allowed it to happen" to let you ignore science in the "made it happen category". That's kind of like say "there's no evidence for controlled demolition, and the figures fit progressive collapse, but since it sounds like something they might do, or at least let the torrorst do, then I'm going to assume they fudged the numbers"

I suppose it is like the fable of 'The Boy Who Cried Wolf'...

I wrote an article mentioning this type of conflation yesterday:

http://metabunk.org/threads/1139-Fou...spiracy-Theory

A very well thought out and logical article.

Black swan events are not things that are very unlikely, they are events that are singular. One-off events. An asteroid hitting the Earth is a good example - it does not happen very often, and we are not prepared for it, but it's going to happen at some point. Or a large earthquake in Los Angeles. Or a Tsunami in Japan. These are all black swan events. But they are not improbable events to the extent that we do not believe in them when they happen.

My understanding of a Black Swan event is 1) It is major and 2) It is unforeseen/unexpected

Content from external source:

Identifying a black swan event Based on the author's criteria:

1. The event is a surprise (to the observer).
2. The event has a major effect.
3. After the first recorded instance of the event, it is rationalized by hindsight, as if it could have been expected; that is, the relevant data were available but unaccounted for in risk mitigation programs. The same is true for the personal perception by individuals.

Therefore I am not actually sure an earthquake in L.A would qualify as it is expected to happen at some time. A major earthquake in London or Paris would be more of a Black Swan event.

Content from external source:

Math is a problem. Because people don't understand it, they fall back on simple mistrust, and incredulity. It's not a problem with any easy solution, because it's easy to create illusions in math.

Yes I think the possibility of making the math fit is where the problem/distrust arises, especially when there are disputed figures.

Content from external source:

What I would recommend, is finding a neutral person to do the math for you. Or maybe a whole class of structural engineers could be persuaded to work on the calculations as an experiment. Maybe we just need better diagrams.

That is easier said than done. It is certainly a very complex world and we all have different mixes and levels of ability with which to try and make sense of it.

[Mick]

My understanding of a Black Swan event is 1) It is major and 2) It is unforeseen/unexpected

Content from external source:

Identifying a black swan event Based on the author's criteria:

1. The event is a surprise (to the observer).
2. The event has a major effect.
3. After the first recorded instance of the event, it is rationalized by hindsight, as if it could have been expected; that is, the relevant data were available but unaccounted for in risk mitigation programs. The same is true for the personal perception by individuals.

Therefore I am not actually sure an earthquake in L.A would qualify as it is expected to happen at some time. A major earthquake in London or Paris would be more of a Black Swan event.

Drifting a bit OT, I read the book a few years ago, it was very interesting.

I think an Earthquake would qualify in two ways:

A) If it's very large. Nobody is expecting anything bigger than 7.5. An 8.5 or 9.0 would be a black swan for everyone.
B) It would be a black swan for most people, simply because most people here don't think about it, and they prepare for it only slightly. It's been 20 years since the last one, and that was only a 6.7

The 9/11 attacks certainly were a Black Swan event though. But that does not in any way mean there has to be a government conspiracy behind them. I'm quite willing to accept that there's a "glad it happened" conspiracy to exploite the events afterwards though.

[George B]

This is a point I have often raised in other debates... thanks for bringing it up here Lee, as I think it very important.

I also think it very important to note that acceleration due to gravity is only relevant when there is only the normal impedance due to air resistance and cannot be applied where further resistance is encountered.

People keep using this to demonstrate 'how it is mathematically possible for the towers to fall in such a time frame', when this really does not apply at all as the resistance of the supporting structure would significantly impede acceleration from taking place. By what factor seems impossible to conclude as there is no mathematical or evidential data on the resistance.

Long Span flooring sections are in common use and I think it important that people should be assured that the same design faults as allegedly caused wtc1, 2, & 7 to fall, are not inherent in all these other buildings.

I cannot seem to find if the new wtc 7 has long span flooring?

http://www.scribd.com/doc/19184820/E...te-Floor-Slabs

As for asbestos and other toxins... I think it typical of the cover up and disinformation that is put out and is appalling.

World Trade Center Rescue Workers Believed EPA, Ended Up Sick http://www.ucsusa.org/scientific_int...pollution.html

Content from external source:

The EPA's press releases and public statements after 9/11 were vetted by then-National Security Advisor Condoleezza Rice, suggesting that the White House placed politics over science

Politics over science... would they really do that?

Just for clarity George, can you point to one video example of the demolition of a high-rise, steel reinforced building. I just want to make sure that I understand what you are looking for.

And why exactly would you expect it to fall "faster" than the WTC? And what point and time are you measuring from?

It is my assumption that successful controlled demolition(s) (using explosives by professionals) by definition would be the fastest possible collapse of a high-rise, steel reinforced building. You would disagree? After seeing several demolitions on video it would seem to be the case . . . the use of modern weapons of warfare may possibly be faster but I don't think we have sufficient video evidence of such. So I am saying it is the standard or measuring stick for the best possible speed record.

[lee h oswald]

What was that someone said about 'you can't topple a steel and concrete structure like wtcs 1, 2 and 7?

Cobblers! Looks like the south tower toppled over to 23 degrees. Cue more semantic argument on the meaning of the word 'topple'. At an angle of 23 degrees, well past its angle of repose by then, that block should have kept going in the direction it was headed - but it didn't; what force could cause that? And G isn't the answer, so don't bother.

[Mick]

What was that someone said about 'you can't topple a steel and concrete structure like wtcs 1, 2 and 7?

Cobblers! Looks like the south tower toppled over to 23 degrees. Cue more semantic argument on the meaning of the word 'topple'. At an angle of 23 degrees, well past its angle of repose by then, that block should have kept going in the direction it was headed - but it didn't; what force could cause that? And G isn't the answer, so don't bother.

I said:

No. I'm saying it's impossible for a building like WTC1,2 or 7 to topple over.

I did not say it's impossible for a portion of the building to lean 23 degrees when it's support is unevenly degraded. I was comparing the larger steel structures of the WTC to the smaller structures George had video of falling over.

Why did that portion of the building stop rotating then lee? What's your theory?

[lee h oswald]

Then make yourself competent. Do the math, it doesn't take a degree and years of study. I don't understand why you see flaws yet deem yourself too incompetent to make your own assessment on a matter where all the resources you would need are available to you.

From what I understand, progressive collapse and controlled demolition do have similar consequences because in both cases the building is essentially brought down and dismantled by its own weight. With the WTC, the collapse started at the impact point, no clear indications of demolition were found during the collapse, and no evidence of explosives were found during cleanup. In this case IF explosives were involved then they would have to have been placed at the impact point either before the impact and survived the fire or afterwards. Both explanations seem incredibly unreasonable in light of all the research and calculations that have been done by people who are curious and willing enough to do the calculations. Calculations that are backed up by the video evidence, for what we see, calculate, and can model is that a monumental amount of force was released when the structure failed. A force that could not be stopped by the floor below it. When it could not be stopped it progressed down to the next floor and then the next and the next, hence progressive collapse. So, where exactly is the flaw? You can't say it just looks wrong. You can't just say that you don't trust calculations, you need a reason.

So many words, yet so little substance. I haven't seen you do anything with any maths, you just talk about it. Meta indeed.

From what I understand, progressive collapse and controlled demolition do have similar consequences...

Right then. Other than wtcs 1, 2 and 7, show us a steel and concrete high-rise that's suffered a global 'progressive collapse' without the aid of explosives. One will do.

...in both cases the building is essentially brought down and dismantled by its own weight

And from those two lines alone, I know that you haven't a clue about any of it. A controlled demo with explosives destroying the structural integrity of the structure to ensure a vertical and complete collapse vs a phenomenon which has never happened - the global progressive collapse' of a similar building by accident. Now there's an open door for you - find that example of global 'progressive collapse' on a relevant structure and you can shut me right up. Otherwise, I'd suggest that you don't try to speak with faux authority on the subject of 'progressive collapse' when you don't understand what you're saying nor the mechanics involved.

Probably because going for those buildings' foundations would be the easiest way to demolish it. Not every building is prone to progressive collapse. As we can see in the examples of verinage, you don't need explosives for a demolition. There are many ways to skin a cat and many ways to bring down a building. It depends on the construction.

George, I don't think it is unreasonable to ask for math that might support your assertion that the building should not have fallen the way it did.

There you go again. Verinage is irrlevant to this discussion. How many times does it needto be said. It would be impossible to demolish those buildings uing that technique. The more you people keep using that example the more the paucity of your argument shows. The Emperor has no clothes. There's only ONE way to skin a rabbit.
And btw - Verinage is quite explosive - if not using explosives - it's hydraulics. But it's still irrelevant.

A better question is could it. Which you can answer for yourself by doing the math. I'm not asking for a specific equation, it's however you choose to answer the question of how much force it would take to stop 15 floors falling, say, 10 ft. I'm not trying to make this intense for you, I apologize if I have. I'm just suggesting that you might want to dig deeper, because deeming yourself incompetent enough to make an assessment and then doubting those who try to do so based on nothing of substance does not make for a reasonable argument.

This one is mangled and almost meaningless if you actually read it. There's nothing wrong with someone admitting their confidence in their own expertise of a given subject isn't up to the job at hand. It's an admirable quality. You might learn from it.



The bottom line of all this is it just goes to show that no matter what evidence might be placed in front of these wantonly blinkered-uber mindthink-science explains everything lot, they will just filibuster and deny and ignore the pertinent questions, sometimes in favour of quite breathtakingly banal statements that it makes the chin drop.
Bang on and on and on and on about the maths and then when someone presents some maths - well, it's not the right kind of maths, or there's errors in assumptions or or or - there's always some stupid unanswerable question that can be thrown out there to deflect from the real nub of the deal.

Who knew Descartes was inspired to his work by an angel - who would have thought it.

[lee h oswald]

I'm far too busy right now, but will come back to this.

[Mick]

There you go again. Verinage is irrlevant to this discussion. How many times does it needto be said. It would be impossible to demolish those buildings uing that technique. The more you people keep using that example the more the paucity of your argument shows. The Emperor has no clothes. There's only ONE way to skin a rabbit.
And btw - Verinage is quite explosive - if not using explosives - it's hydraulics. But it's still irrelevant.

Can you explain WHY it is irrelevant? And WHY is is impossible to demolish the building using that technique? Because otherwise you are making a circular argument.

(the following conversation is not real, it is parphrased for illustrative purposes, corrections and clarifications invited)
Mick: "progressive collapse is inevitable, because, like with Verinage, the top of the building will destroy the lower portion"
lee: "that would not work, because verinage would not work".

Why would it not work?

[George B]

Can you explain WHY it is irrelevant? And WHY is is impossible to demolish the building using that technique? Because otherwise you are making a circular argument.

(the following conversation is not real, it is parphrased for illustrative purposes, corrections and clarifications invited)
Mick: "progressive collapse is inevitable, because, like with Verinage, the top of the building will destroy the lower portion"
lee: "that would not work, because verinage would not work".

Why would it not work?

Mick,
Is it reasonable to assume you believe the WTC I & II were collapsed (basically) by Verinage like forces as in an overwhelming force via mass and acceleration crushes an otherwise intact structure . . . with of course no pre-weakening of the foundation or lower floors?

[Mick]

Mick,
Is it reasonable to assume you believe the WTC I & II were collapsed (basically) by Verinage like forces as in an overwhelming force via mass and acceleration crushes an otherwise intact structure . . . with of course no pre-weakening of the foundation or lower floors?

Essentially, because:

A) That's what it looked like
B) That's what all scientific studies show
C) There's no evidence it was otherwise

Actual Verinage does perform some pre-weakening of the structure, to ensure a neater collapse. The towers collapses were probably not up to code.

[George B]

Essentially, because:

A) That's what it looked like
B) That's what all scientific studies show
C) There's no evidence it was otherwise

Actual Verinage does perform some pre-weakening of the structure, to ensure a neater collapse. The towers collapses were probably not up to code.

Good . . . at least we now have a starting point for analysis . . .

1) I agree that Verinage like event is the only rational explanation if one accepts the official story
2) What is the effect in your opinion of the " not up to code " on the rate of collapse?
3) Do you agree a controlled demolition using near simultaneous detonations of the foundations and lower floors would result in a faster collapse than would occur with unassisted Verinage alone?

[Mick]

Good . . . at least we now have a starting point for analysis . . .

1) I agree that Verinage like event is the only rational explanation if one accepts the official story
2) What is the effect in your opinion of the " not up to code " on the rate of collapse?
3) Do you agree a controlled demolition using near simultaneous detonations of the foundations and lower floors would result in a faster collapse than would occur with unassisted Verinage alone?

2) My "not up to code" comment was a joke referring to the demolition code, not building code. The building WERE up to code with the building codes in place at the time of construction. However there have been recommendations and changes to the code made in light of the 9/11 events. If all those recommendations were in place, then the towers would not have collapsed.

3) It would be hard to get a significantly faster collapse. The rate of a collapse would depend on just how much of the lower structure was destroyed. It might seem like a symmetrical type of event, but the bottom of the building is much stronger than the top (with thicker columns), it also is braced against bedrock. The more of the bottom of the building you "destroyed", then the closer it would get to freefall, but as noted the difference would be minimal. If only, say, the bottom floor was destroyed, then I suspect the collapse would be slightly slower than the top down collapse. And of course it would look radically different.

Remember the intent of controlled demolition is NOT to bring the building down as quickly as possible, but as safely as possible.

Note that real controlled demolitions generally first fire charges though the entire structure of the building, and a second later sever the bottom columns to start the collapse. Just severing the columns at the bottom alone in many building might lead to demolition fail. It all depends on the building and the circumstances.

[George B]

2) My "not up to code" comment was a joke referring to the demolition code, not building code. The building WERE up to code with the building codes in place at the time of construction. However there have been recommendations and changes to the code made in light of the 9/11 events. If all those recommendations were in place, then the towers would not have collapsed.

3) It would be hard to get a significantly faster collapse. The rate of a collapse would depend on just how much of the lower structure was destroyed. It might seem like a symmetrical type of event, but the bottom of the building is much stronger than the top (with thicker columns), it also is braced against bedrock. The more of the bottom of the building you "destroyed", then the closer it would get to freefall, but as noted the difference would be minimal. If only, say, the bottom floor was destroyed, then I suspect the collapse would be slightly slower than the top down collapse. And of course it would look radically different.

Remember the intent of controlled demolition is NOT to bring the building down as quickly as possible, but as safely as possible.

Note that real controlled demolitions generally first fire charges though the entire structure of the building, and a second later sever the bottom columns to start the collapse. Just severing the columns at the bottom alone in many building might lead to demolition fail. It all depends on the building and the circumstances.

So you do NOT agree that hypothetically a properly performed controlled demolition using explosives would be faster than a Verinage demolition . . . or are you saying the difference would be so small as to be stastically unmeasurable?

[Mick]

So you do NOT agree that hypothetically a properly performed controlled demolition using explosives would be faster than a Verinage demolition . . . or are you saying the difference would be so small as to be stastically unmeasurable?

I'd say it depends. Just eyeballing the demolitions I've seen, the conventional implosion demolitions generally seem seem slower than verinage demolition, but it's going to vary based on what is demolished. In an implosion they usually stage the collapse from one side to another, and part of the building (usually the outside) is left with some rigidity so it leans in a certain direction. The goal is NOT to bring it down as fast as possible.

Look at Ocean Tower, Padre Island, Texas:



The explosions are set so the building falls inwards and down, the top is clearly not coming down in free-fall. That's not what they want.

The Landmark tower was more evenly straight down, and falls in about 5 seconds.



There's a nice collection from CDI showing a wide range of demolitions:

[George B]

I'd say it depends. Just eyeballing the demolitions I've seen, the conventional implosion demolitions generally seem seem slower than verinage demolition, but it's going to vary based on what is demolished. In an implosion they usually stage the collapse from one side to another, and part of the building (usually the outside) is left with some rigidity so it leans in a certain direction. The goal is NOT to bring it down as fast as possible.

Look at Ocean Tower, Padre Island, Texas:



The explosions are set so the building falls inwards and down, the top is clearly not coming down if free-fall. That's not what they want.

The Landmark tower was more evenly straight down, and falls in about 5 seconds.



There's a nice collection from CDI showing a wide range of demolitions:

OK, it depends on the objective . . . but is it hypothetically possible for a controlled demolition of a high-rise, steel reinforced building using near simultaneous detonations of explosives to bring down the building in question FASTER than a Verinage collapse where the foundation and lower portions of the building are intact and basically undamaged??

[Mick]

OK, it depends on the objective . . . but is it hypothetically possible for a controlled demolition of a high-rise, steel reinforced building using near simultaneous detonations of explosives to bring down the building in question FASTER than a Verinage collapse where the foundation and lower portions of the building are intact and basically undamaged??

Yes. Think about it this way, if you have a 100 story building, and and you destroy the bottom floor, then the upper 99 floors will probably collapse, but it will be slower than free fall. (if one floor is not sufficient to cause progressive collapse, add a few).

If you destroy 99 floors, then the remaining one floor will fall at near free-fall speed.



So the speed of collapse is related to the number of lower floors you "destroy". This is not the only factor, but it's an important one. Probably it would not take that many floors to be destroyed to get close to free-fall, but the amount of explosives would be quite considerable.

[George B]

Thank you, Mick . . . to recap . . . do you agree with the following?

1) The WTC towers I & II appear to have collapsed by the forces which are comparable to Verinage demolition technique where the top portion of a structure basically slams into the lower part of the structure like a sledgehammer . . . the difference being at the WTC the lower part of the buildings was not weakened in preparation for the collapse . . .
2) It is hypothetically possible that a controlled demolition using modern techniques could bring a building down faster than through Verinage, especially if the lower floors are not compromised prior to the demolition . . .

[lee h oswald]

Other than wtcs 1, 2 and 7, show us a steel and concrete high-rise that's suffered a global 'progressive collapse' without the aid of explosives. One will do.

A controlled demo with explosives destroying the structural integrity of the structure to ensure a vertical and complete collapse vs a phenomenon which has never happened - the global 'progressive collapse' of a similar building by accident. Now there's an open door for you - find that example of global 'progressive collapse' on a relevant structure and you can shut me right up. Otherwise, I'd suggest that you don't try to speak with faux authority on the subject of 'progressive collapse' when you don't understand what you're saying nor the mechanics involved.

There you go again. Verinage is irrlevant to this discussion. How many times does it need to be said. It would be impossible to demolish those buildings using that technique. The more you people keep using that example the more the paucity of your argument shows. The Emperor has no clothes. There's only ONE way to skin a rabbit.

That's open to anyone by the way. Let's see your example, Mick. I imagine it will be ignored because there is no such example.

As predicted

Why did that portion of the building stop rotating then lee? What's your theory?

The words are meaningless. Once a mass like that starts moving, what's going to stop it once it's past its angle of repose? You're fond of idiotic videos with people stacking boxes or dropping pencils on to desks to 'prove' that steel bounces - ofcourse - it bounces 600ft sideways at 70 mph - everyone knows that.

I invited you to do some maths - something you're always banging on about - but you just avoided it. Why don't you address it?

Can you explain WHY it is irrelevant? And WHY is is impossible to demolish the building using that technique? Because otherwise you are making a circular argument.

Yes, I can explain why. But what would be the point? Why don't you ask one of your engineer friends and report back? The question to ask would be: Would the Verinage method of controlled demolition be considered for wtcs 1, 2 or 7? I'll lay money on - you won't do it.

Originally Posted by George B

Mick,
Is it reasonable to assume you believe the WTC I & II were collapsed (basically) by Verinage like forces as in an overwhelming force via mass and acceleration crushes an otherwise intact structure . . . with of course no pre-weakening of the foundation or lower floors?

Essentially, because:

A) That's what it looked like
B) That's what all scientific studies show
C) There's no evidence it was otherwise

A) That's what it looked like

That's funny, because when I say that things often look like what they are - you say the opposite. 'Just because something looks like something, it doesn't mean it is that thing' - those were your words. Handy you can just change it around when you want it to help your belief.

B) That's what all scientific studies show

I've not seen Verinage cited by any of them. Those studies all gave up their investigation at the point of collapse initiation - with the banality/false meme you parrot a lot (and it's a dead parrot - but you'll tell me it's just resting) - 'once collapse was initiated, 'progressive collapse' was inevitable'. 'Science' has betrayed us all.

C) There's no evidence it was otherwise

That's a shocking piece of garbage. NO EVIDENCE? There's a mountain of evidence to the contrary, you are in denial - and it helps if your 'scientific' studies had actually bothered to LOOK FOR IT.

Hobby? Obsession. This really is Huis Clos. You'll never change your mind - not via this place - you don't really want to seriously entertain evidence - and who knows what other reasons, and frankly, who cares? You're an ardent denialist. Any possibility you could be wrong has been backed into a tight corner, it would just be far too embarrassing a climb-down now, wouldn't it? After having invested all this time and effort into denying, to the point of saying repeatedly, 'There's no evidence'. That alone describes your state of denial. It's not a discussion or a debate you want, you just want to indulge yourself 'correcting' all the 'errant' people who appear here.




This the best compilation of south tower collapse shots. Good quality images. all worth a look, but I'd point out 1) Around 1:50 mark for some of that impressively bouncy steel again, 2) From 5:15 to 6:25 - good shot of the tilting top section which should have kept going on its merry way, but didn't because a greater force than the force of the rotation acted upon it. If it were just G, then the weight of the top block had shifted significantly in rotation and was moving on a pivot - lots of momentum there - it's off centre, so the weight is not bearing down evenly on the structure below, and some of the mass is heading east with plenty of inertia in its favour. Watch after the tilt stops and it disappears into the already expanding, pyroclastic type clouds and sprays of steel and pulverized concrete and contents (and this is one second into 'collapse'). A split second after it disappears it reappears again; it is pulverized and thrown forward, towards camera. It's repeated a few times, it's clearly visible - and begs the question I've asked many times before here - What sufficient mass remained to crush the building from top to bottom in no time - where is this sledgehammer - The Crusher - if it was so hard that it could crush all that building, then some of it should have survived hitting the ground - it's just absurd. Not just once but twice and then another.
And 3) Just after that, someone called it just right on tape - 'Dude, the top of the building just fell off!' Which is what was happening and what he reported....and it puts us all to shame when it comes to getting to the point. Sometimes it's just that simple.

[Mick]

Thank you, Mick . . . to recap . . . do you agree with the following?

1) The WTC towers I & II appear to have collapsed by the forces which are comparable to Verinage demolition technique where the top portion of a structure basically slams into the lower part of the structure like a sledgehammer . . . the difference being at the WTC the lower part of the buildings was not weakened in preparation for the collapse . . .
2) It is hypothetically possible that a controlled demolition using modern techniques could bring a building down faster than through Verinage, especially if the lower floors are not compromised prior to the demolition . . .

Essentially, although I would say "similar" rather than "comparable", as comparable implies (to me) closeness in magnitudes. The scale is very different here to any verinage demolition. I'm also assuming when you say "if the lower floors are not compromised prior to the demolition" then you are referring to lower floor in verinage.

Also, here's an update to my illustration with what actually happened added for comparison:

[Mick]

One things at a time lee. You know we don't like Gish Gallops here. If you want me to address something in detail, then pick it.

But to your criticism of this:

The words are meaningless. Once a mass like that starts moving, what's going to stop it once it's past its angle of repose?

I find that quite amazing, because the diagram explain very clearly what stops it. What stops it rotating is the building beneath it. If the rotation was NOT stopped, then that means the building was offering no resistance, which I'm quite sure is not what you are suggesting.

Look at this, consider two possible hinge points A and B



Now clearly the rotation cannot START at point A, because that would mean the entire block would have to rise up in the air. So the rotation is about point B, which means that point A have to pass though several more floors than point B, and so would encounter a lot of addition resistance slowing it down. (This motion is relative, as A and B are both sinking, in addition to the block rotation).

So the only way that the rotation would continue would be if the center of gravity (C) we outside of the base (i.e to the left of A).

Now you say it is "past it's angle of repose", meaning it would slide off the building. That's very different from continuing rotation. The upper building is NOT sliding, it's rotating, and falling. The rotation is arrested by the crushing of the building more under point A. Then it's just falling.

[Jazzy]

It's quite apparent that you have all forgotten PRIOR DEFORMATION.

BEFORE the towers (and WTC7) assumed an angle, and even BEFORE they began their collapses, they ALL VISIBLY DISTORTED.

They distorted that way BECAUSE they were about to collapse THAT WAY.

Don't waste your breath on any other stupid argument. You all look stupid enough as it is.

They were all about to fail, then they all DID fail.

It really isn't my fault I'm so "blunt". You all appear to require it.

[George B]

One things at a time lee. You know we don't like Gish Gallops here. If you want me to address something in detail, then pick it.

But to your criticism of this:




I find that quite amazing, because the diagram explain very clearly what stops it. What stops it rotating is the building beneath it. If the rotation was NOT stopped, then that means the building was offering no resistance, which I'm quite sure is not what you are suggesting.

Look at this, consider two possible hinge points A and B



Now clearly the rotation cannot START at point A, because that would mean the entire block would have to rise up in the air. So the rotation is about point B, which means that point A have to pass though several more floors than point B, and so would encounter a lot of addition resistance slowing it down. (This motion is relative, as A and B are both sinking, in addition to the block rotation).

So the only way that the rotation would continue would be if the center of gravity (C) we outside of the base (i.e to the left of A).

Now you say it is "past it's angle of repose", meaning it would slide off the building. That's very different from continuing rotation. The upper building is NOT sliding, it's rotating, and falling. The rotation is arrested by the crushing of the building more under point A. Then it's just falling.

That is interesting . . . so the block rotation was arrested by the resistance of the intact building below, but the same resistance isn't sufficient to slow the collapse beyond 10% of a free fall rate in a vaccuum . . .

[lee h oswald]

It's quite apparent that you have all forgotten PRIOR DEFORMATION. BEFORE the towers (and WTC7) assumed an angle, and even BEFORE they began their collapses, they ALL VISIBLY DISTORTED. They distorted that way BECAUSE they were about to collapse THAT WAY. Don't waste your breath on any other stupid argument. You all look stupid enough as it is. They were all about to fail, then they all DID fail. It really isn't my fault I'm so "blunt". You all appear to require it.

heard the first time; gave up listening a while back.

[Jazzy]

heard the first time; gave up listening a while back.

Before you arrived here.

the same resistance isn't sufficient to slow the collapse beyond

28% or 36% of free fall.

The temporarily-intact core would tend to "thread" the falling floor conglomerate back to the vertical. The external fragments would continue their trajectory and maintain their angular velocity.

[lee h oswald]

One things at a time lee. You know we don't like Gish Gallops here. If you want me to address something in detail, then pick it.

But to your criticism of this:




I find that quite amazing, because the diagram explain very clearly what stops it. What stops it rotating is the building beneath it. If the rotation was NOT stopped, then that means the building was offering no resistance, which I'm quite sure is not what you are suggesting.

Look at this, consider two possible hinge points A and B



Now clearly the rotation cannot START at point A, because that would mean the entire block would have to rise up in the air. So the rotation is about point B, which means that point A have to pass though several more floors than point B, and so would encounter a lot of addition resistance slowing it down. (This motion is relative, as A and B are both sinking, in addition to the block rotation).

So the only way that the rotation would continue would be if the center of gravity (C) we outside of the base (i.e to the left of A).

Now you say it is "past it's angle of repose", meaning it would slide off the building. That's very different from continuing rotation. The upper building is NOT sliding, it's rotating, and falling. The rotation is arrested by the crushing of the building more under point A. Then it's just falling.

Yes. Slide off. No mistake. It's got momentum, it's a big mass moving in a direction. It's just physics! Please, think about it. It all says: Dude the whole top of the building just...etc. But 'something else' or 'other' happened.

More important - the towers weren't ultra long layers of horizontals with four fat bits in the middle. I'm sure you could render them more accurately.