9/11 Poll

For an object which can support several times the load above it to be demolished by that load, the load needs to be dropped on it and decelerate at a rate several times that of gravity. That is how the load is amplified dynamically in an impact.

The easier way to look at this is like the pressure above ambient where 14.7 psi is ambient pressure and that above is considered overpressure or above gage.

In reality anything at rest is being decelerated by 1g. If an object is accelerating at 0.7g then it is only being decelerated at 0.3g by the structure below it. If the object decelerated at 1g it would only be applying an equivalent of the static load and why would the structure fail if it could handle a 3g deceleration or three or more times that load? The amount of amplification is equivalent to the mass times the multiple of the deceleration of the rate of gravity. In other words the deceleration would need to be at least three times that of gravity if the structure below could take three times the load above it.

An simple example of this is to take a 100 lb. weight and support it with 30 columns which could each support 10 lbs. or 300 lbs. total. For the 100 lb weight to break the 30 columns it would need to be dropped and decelerate at 96.6 ft./second/second or 3g's to generate 300 lbs. of force and just enough necessary to start failing the columns. This deceleration would cause a velocity loss.

There is no velocity loss observed in the fall of the upper block of WTC 1. It is constantly gaining velocity, which is impossible in a natural collapse, since the load needs to decelerate at a rate greater than 1g to apply more force than it's static load.

Now in the above example, remove 27 of the columns and the weight will accelerate downward at 0.7g. The 3 remaining columns will cause some resistance and keep the acceleration from being the full rate of gravity but it was the removal of the 27 columns which caused the fall without deceleration being necessary.

Your handbrake analogy is not analogous at all. The force which can be applied by the engine is generally many times the resistive force of the hand brake. That isn't how buildings are constructed. In those cases, the columns are the brake against vertical collapse and they are sized to take several times the downward vertical force or load above them.

 

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it's quite possible butt joints were used in the core columns as well.
this situation could indeed support the weight but once the columns became misaligned the support simply vanishes.

 

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I know exactly how much the 12 story upper block of WTC 1 weighed. It was just over 69 million pounds. The structure below was designed to support at least three times that amount or 207 million pounds.

It sounds like you don't fully appreciate what I was saying and might benefit by reading the paper I wrote with a Canadian professor late last year on this issue. It is called "The Missing Jolt" and can be found at

http://www.journalof911studies.com/volume/2008/TheMissingJolt7.pdf

For an idea of the factors of safety designed into the columns of the towers, the Reference section of another paper I was involved in looks into that area and can be found at http://www.journalof911studies.com/...itionHypothesisForDestructionofTwinTowers.pdf

 

This is handwaving. Please explain how things could continuously be misaligned by a vertical load, in a braced system with a huge amount of lateral inertia.

 

i have no idea what you mean by "handwaving".
i'm simply throwing out plausible scenarios that fit what i know.

i believe i've already told you that i'm not a structural engineer.

you are going on the assumption of explosives, i'm going on the assumption of weak/ defective design/ construction.

 

I hear you. I don't mean to be harsh and understand that you are just throwing out possibilities. However, I do not believe what you are saying is plausible. There is simply no way to get around a need for deceleration of the upper section of the building to continue the collapse naturally. If it doesn't decelerate it can't be applying the amplified load it needs to cause failure of the lower section.

The reality is that there is no reason for the collapses to have even initiated. The aircraft impacts hardly affected the structural stability of the buildings due to redundancy. Then don't forget that WTC 1 had a very serious six story fire starting on the 11th floor which lasted for three hours back in 1975 and there was no structural degradation afterward.

 

The NIST has no physical evidence for high steel temperatures on the columns that would lower their strength, so there was no basis for reducing the energy required to cause them to fail. The current NIST theory is that the aircraft impact caused fireproofing to be removed from the floor trusses causing them to overheat and sag sufficiently to pull the perimeter columns on the 98th floor of WTC 1 inward initiating the collapse of that floor. Then Dr. Bazant's theory of an impulsive load occurring, when the upper section impacts the lower section, is used to justify a continued progressive collapse, which the NIST then doesn't analyze itself.

There are no velocity losses at any point in the fall. At 1.75 seconds the velocity remains constant for 1/6th of a second and as I explained that does not provide for a load amplification. Only velocity loss due to real deceleration, which would show itself as a negative slope on the velocity curve, can cause load amplification. Additionally, the first impulse should have occurred about one second into the fall as the measurements show the roof has dropped about one story in height at that point.

One could certainly say the proof that WTC 7 was demolished was it's freefall acceleration for 100 feet or eight stories, and this lack of deceleration of WTC 1's upper section for the nine stories it could be measured is proof that something other than it was causing the columns below to fail.

 

You are being trivial here. Of course there was some residual resistance left which caused the acceleration of the upper block to vary a slight amount. This is not deceleration and would not cause load amplification. I hoped you would have understood that by reading the paper. There would need to be a huge deceleration and velocity loss of the upper block to cause failure of the columns below with a factor of safety of at least 3.00 to 1. The paper shows how much this deceleration would have caused the velocity curve to deviate from what was actually observed, and it is quite obvious that it is far greater than any possible measurement error, and yet all you want to know is why we didn't apply an error bars to the velocity curve. I haven't seen anyone, including the NIST, do that, concerning the velocity curves of the falls of these buildings. If it makes you feel better, as we explain in the paper, one pixel = .88 feet, so you could use +/- .88 ft. to be the largest possible error in measurement. That would not make one bit of difference as the deviation far exceeds any possible error and that is completely obvious.

What you are saying above would be like criticizing a report concerning a fatality involving a dragster hitting concrete wall at 300 mph for not providing error bars which would show their velocity measurement could have been in error by as much as 10 mph.

The NIST/Bazant explanation for the collapse of WTC 1 is shown to be nonsense by an actual measurement of the fall of the upper block as it does not comport with observation. You can't rehabilitate their explanation by picking on insignificant matters of style and value. I have a feeling that you are disingenuous concerning these matters and that I am wasting my time talking to you about it. That may not be true of others on this forum, who still don't believe that the twin towers and WTC 7 were intentionally demolished and that the aircraft impacts and fires did not cause the collapses.

 

Tony, I think you know I've certainly put in my time debating in this forum as well as in another. I know full well how tiring the experience can be. In fairness, I believe that it's also tiring for Trippy. In essence, having one's beliefs challenged on a regular basis, especially when one believes one has provided all the relevant information for everyone to come to the same conclusion.. I don't know of many things more frustrating. Again in fairness to Trippy, he does put up what to me are persuasive arguments; you always seem to go right through them though.

I've just started reading a book edieted by David Ray Griffin and Peter Dale Scott; 9/11 and American Empire. Quite a good read. I'm not sure if you've read it, but I'll share an excerpt of it as I think it deals with what might be part of the reason that Trippy sees no need to prove that the official story is correct:

Swiss historian Daniele Ganser's contribution is relevant to one of the main a priori reasons Americans have had for rejecting the idea that 9/11 could have been orchestrated by our own government: the assumption that American political and military leaders simply would not do such a heinous thing. He presenets evidence, widely discussed in Europe during the 1990s but hardly at all in the United States, that during the Cold War, the CIA and NATO (and hence the Pentagon) supported various right-wing movements in a "strategy of tension" to prevent left-wing electoral victories. The methods included staging "false-flag" terrorist attacks that would be blamed on the left to discredit them and justify their suppression.​

 

Scott, what David Griffin is describing is an emotional barrier which when presented with hard facts has to wilt away in an adult. I didn't want to believe it either but facts are what adults need to build their reality around, not wishful thinking.

There have been massive revelations over the years, concerning serious moral transgressions by elements within the U.S. government, and anyone who doesn't believe these things are possible is extremely naive. It also does not require the entire government to be corrupt.

 

Where do I say the mast moved 100 feet before the rest of the building? The exact quote from the paper is

It is instructive that the first visible signs of failure on the North Tower are when the antenna mast moves downward by ten to twelve feet before the perimeter roof line moves. This is indicative of the central core suddenly and completely failing first. If you haven’t seen this watch it frame by frame at the link below.

This was also an approximation done in 2007 almost a year and a half before the measurement of the fall of the roofline of the upper block was done. If you are now going to somehow try and say my estimate at that time is off by one or two feet to somehow show how I could be wrong you are picking on nonsense.

You can't show that the huge velocity loss that would have been necessary could have been missed due to the relatively small error potential, so your reason for wanting error bars which are statistically insignificant is nonsense. The fact that you are trying to use them to somehow show that the paper could be in error is thus disingenuous.

 

I agree for the most part. I have a feeling, however, that many people don't know a lot of the facts. I was talking to a few young guys on the bus today concerning 9/11 (one wanted to see what I was reading and that started the conversation going on that), and, not for the first time, I was amazed at how little they knew; they weren't even sure what year it had happened.

So yes I definitely agree that there are emotional barriers. But sometimes I think it's also the case that there are technical barriers; as in, since you're a mechanical engineer, you know a fair amount concerning why a buiding should fall. Trippy is a scientist, but not a mechanical engineer and so I think that in some respects here, he doesn't quite make the mark; thus you are able to put in statements like that bit about the 10mph error margin thing. I actually remember doing the same thing myself in the past once; if I've read up on the material recently, I can atleast temporarily retain enough to make some good arguments. But unlike you, engineering isn't what I dedicate my life to and so I am frequently at a loss to counter Trippy's posts myself; and as I said before, if I find his arguments persuasive, I can easily imagine that Trippy does.

However, I have been noticing something, something that's been happening for a while now; essentially the official side supporters seem to be content to search for flaws concerning the alternative theories out there but they don't seem all that interested in questioning the official story. This is why I felt it would be a good idea to post that excerpt from David Ray Griffin's book; to in essence go into why they would rather nitpick at margins for error then look at the gaping holes within the official story.

 

What government is that? Australian?

Ok. Well you know that a while back I said that you don't have to prove that the official story is correct. And I meant it. You could certainly just ignore this 9/11 thread and do other things. So I appreciate the time you've spent here. However, the gaping holes in the official story makes it seem that you scrutinize every single detail of Tony's points while refusing to look at the pink elephant that you implicitly believe in.

 

If you aren't American, then you don't have nearly as much at stake in all this as those that are do. All most Americans are asking for is a new investigation of the events of Sept. 11, 2001 with subpoena power. With that in mind, if I were in your shoes I would butt out unless I had absolute proof that 911 was not an inside job. You don't have that in any way, shape, or form, and since you seem so adamant about it I for one now consider you at best an irresponsible meddler. You will not be getting any more replies from me Trippy.

 

That's incredibly wrong. It's 2 digits of precision at best. The 0 in from of the decimal point does not count.:bugeye: