British Institute of Nanotechnology: Military Involved in 9/11

[flintlock]

Re: British Institute of Nanotechnology: Military Involved in 9/11

No, not wasted.

On September 11, 2001, 7 WTC was damaged by debris when the nearby North Tower of the WTC collapsed. The debris also ignited fires, which continued to burn throughout the afternoon on lower floors of the building. The building's internal fire suppression system lacked water pressure to fight the fires, and the building collapsed completely at 5:21:10 p.m.^[1]. The collapse began when a critical column on the 13th floor buckled and triggered structural failure throughout, causing at first the crumble of the east mechanical penthouse at 5:20:33 p.m.

Try to picture this:
http://en.wikipedia.org/wiki/File:6-wtc-photo.jpg

This is a picture of building 6, after some cleanup. The building that you seem to think "shielded" building 7. I see a lot of debris on all sides of #6. At least 100 feet. Once again, people have a hard time getting a handle on the size of those towers and the forces in play. Was it unusual the way #7 collapsed? Perhaps. But so is two planes flying into 110 story skyscrapers. See those large chunks? They look small on the screen but they probably weigh many tons. Picture them falling, flaking off the collapsing towers. The dust concealed much of this from our view during the actual collapse. Now picture a mere 30 ton chunk blasting through building 7 walls and hitting a support column. Throw in a little fire, and you have a collapse. While I can't prove this happen, it is at least plausible.

I don't claim to be some expert on the event. I don't delve into it like you people because no one has been able to give me a plausible REASON to blow up buildings in NY in the first place. Not only buildings, but specific buildings. Any reason they did not "demolish" the remaining three building of the WTC complex? Or did those attempts fail?

To me it is a lot more reasonable to accept a version somewhat close to the official version than to accept some grand conspiracy involving the most powerful people in the world. Like I said earlier, my mind is open to hearing any rational arguments that a conspiracy was involved. I'd like to hear more on WHY and less on technical details that have shown to be at the very least, debatable.

Looking at a video of the collapse of WTC 7 I will agree it looks like a demolition. Fluke? I am no expert . Nor are 99% of the people who claim they see "proof" of a demolition. Why demolish it again? Twin towers not enough? The problem is, there is so much BS out there you have a hard time wading through it all. In the course of the last few minutes I've seen numerous theories like "All the film footage is faked because it is owned by Fox news". "The Jews did it" another popular one. Just nutty stuff. Almost as bad as the Bermuda triangle theory.

[skyson]

Re: British Institute of Nanotechnology: Military Involved in 9/11

Well you probably have more energy than I do in trying to defend your position. I might reply with more later if I feel like wading through this swamp of misunderstood physics, especially from skyson.

Thanks. You have my ears and eyes. I am a keen student awaiting for your teaching.;)

Well, I simply reverse-engineer Dr. Greening and Dr. Bazant's thinking in terms of the mechanism of collapse. So if you want to correct my "misunderstood physics", it would be necessary for you to study their thinking carefully, as well as the following papers with opposing view, before your next reply:

1. The Sustainability of the Controlled Demolition Hypothesis for the Destruction of the Twin Towers
2. The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis

Some snippets from the No. 2 article(Missing Jolt):

"Three essential elements of NIST’s hypothesis of total collapse are made explicit in the Final Report and the companion volumes of the study:

1. Because of damage to stories 93 to 98, and especially because of column buckling due to fire, the top 12 stories of the North Tower (99-110) plus the roof were, in effect, separated from the rest of the Tower and began to behave as a unit. [2]
2. This “rigid block” of 12 stories plus the roof began to move. First it tilted, and then it abruptly fell onto the stories beneath it. [3]
3. The fall of the rigid block caused such damage to the lower structure that “global collapse began.”[4]

The rigidity of the upper block of stories is crucial to this explanation. If the upper block were to break, disintegrate or flow on impact it would certainly not threaten the 92 intact floors beneath it.
In addition, the rigid block had to fall onto the rest of the building. Although this seems obvious, the NIST authors are often shy about saying it. We hear about the rigid block’s “descent.”[5] We hear of tilting and “downward movement.”[6] We have to look carefully to find the NIST authors using the language of falling. Whatever the reasons for their reticence, it is clear that it will not do for the upper block to ease itself onto the building beneath it, with a gradual creaking of buckled columns and sagging floors. If this were to happen, why would the structure beneath collapse?

There was nothing special about the weight of the upper block, rigid or otherwise. The lower part of the Tower had held up this weight without difficulty since 1970. The lower block had 283 cold steel columns, with less than 30% of their total load capacity being utilized for gravity loads, because of the factors of safety designed into the structure and the need to withstand high winds—and gravity loads were essentially the only loads the columns would have been subject to on a day such as 9/11 with little wind. The lower block was not weak, nor (excluding stories 93-98) was it damaged by plane impact or fire. The weight of the upper block posed no threat to it. If there were to be a threat, it had to come from the momentum of the upper block. But momentum is a product of mass and velocity, and since the upper block could not increase its mass it had to increase, if it were to become a threat, its velocity. Since NIST’s theory assumes the only energy at play at this stage of events was gravitational, the upper block had to fall, and the greater its velocity the greater its momentum. The longer and the less impeded its fall, the greater would be its impact on the lower structure. So it is no surprise that the NIST authors, however shy they are about affirming it, eventually come out in favour of the falling of the upper block. [7]

Zdenek Bazant and Yong Zhou, with whose September 13, 2001 back-of-the-envelope theory (with subsequent revisions and additions) NIST largely agrees, have never hesitated to say that the upper block fell. [8] Bazant has likewise been frank about the need for severe impact as the upper and lower structures met: he believes the impact may have been powerful enough to have been recorded by seismometers. [9] In his view, collapse initiation of the lower structure required “one powerful jolt.”[10] Of course, if there was a powerful jolt to the lower structure there must also have been a powerful jolt to the upper falling structure, in accord with Newton’s Third Law.

...............

We have tracked the fall of the roof of the North Tower through 114.4 feet, (approximately 9 stories) and we have found that it did not suffer severe and sudden impact or abrupt deceleration. There was no jolt. Thus there could not have been any amplified load. In the absence of an amplified load there is no mechanism to explain the collapse of the lower portion of the building, which was undamaged by fire. The collapse hypothesis of Bazant and the authors of the NIST report has not withstood scrutiny."

For your hypothesis of the upper floors destroying the lower floors(as well as Dr. Greening and Dr. Bazant's), these two observations must exist:

1. the upper floor must remain intact though out the whole process of collapse.
2. the upper floor must decelerate(slow down) at the moment it reaches the upper most floor of lower sections(again basic physics).

Do you see these in the this video?

For now though I'll simply address a quick point about the fires and about horizontal ejection. I don't recall any other skyscraper receiving nearly instantaneous substantial fires throughout multiple stories (and most or all of the affected floors) after being subjected to the impact of the giant plane. The force involved with the impact of the plane was absolutely enormous. That's something you need to wrap your head around.

Well said.

1) Many ignore the force of a 150(?) ton aircraft flying 550 miles hour. They focus on fire alone. The real wonder is that the buildings did not collapse immediately.
.....
I'm afraid the only way we'd ever convince the Truthers that it was merely the planes that brought down the towers would be to fly another plane into another building.

Are you suggesting that the original designers of the WTC did not take into account of damage caused by flying airplanes? Were they so incompetent? I thought they were the "finest of the finest" of US architects. ;)

Unfortunately, you two are seriously misinformed. Because the NIST said so! Surprise and surprise:

“While the buildings were able to withstand the initial impact of the aircraft, the resulting fires that spread through the towers weakened support columns and floors that had fireproofing dislodged by the impacts. This eventually led to collapse as the perimeter columns were pulled inward by the sagging floors and buckled.”
http://www.nist.gov/public_affairs/r..._april0505.htm

Yes, indeed the air planes did not caused the collapses! NIST then claims the fire caused the collapse. For refutation about this claim please see first half of this post and my previous post for info.

2) Air pressure explains why puffs of smoke are seen blowing out while the building collapses. That occurred to me immediately after seeing the claim it was "explosions".

As for debris, dust and the like; the towers were filled with air. That air had to go somewhere when the floor above it met the floor below it. It went out--horizontally.

The following two essays deal with your questions in very detail way. Please take a look:

1.Direct Evidence for Explosions: Flying Projectiles and Widespread Impact Damage
2.High Velocity Bursts of Debris From Point-Like Sources in the WTC Towers

I urge you two do a more thorough study before replying. I am a good student, but could be easily annoyed by instructors coming into the classroom obviously unprepared and uninformed.;)

[flintlock]

Re: British Institute of Nanotechnology: Military Involved in 9/11

There weren't rampant fires in building 7. The firefighters stated that there were small sparatic fires and announced the fires were contained shortly after going into the building. Don't start blabbering about "the palin truth" if you don't have the simple facts straight.

How do you people reconcile Larry Silverstein admitting on tape that they "pulled it"?

I just spent watching about 10 minutes of street level video of building seven burning like a Mo Fo. It looked like a blast furnace shooting out the side.

Here is video showing real damage

[MEDIA][/MEDIA]

Or was that all faked?


Maybe you are getting all your info from one side? Any pro-truth book or website is going to give people slanted info. They have a vested financial interest in all of this. Conspiracy sells.

You'll never find me blabbering about the "Palin Truth", I don't even like the lady.

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

You can't use the MEDIA tag for youtube videos. MEDIA tags are for things like pdf files. You can embed youtube videos by copying and pasting the embed html code from the youtube video page, resulting in:

The above is a controlled demolition. A fire on portions of one or two floors doesn't uniformly so weaken a 40 story steel frame building such that it drops in its own footprint in 7 seconds.

The above is a raging inferno. It burned for over half a day in Madrid on Sunday 13 February 2005. No collapse.

The World Trade Towers were built to withstand a direct hit by a fully loaded passenger airplane. They withstood that fine.

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

I urge you two do a more thorough study before replying.

Good suggestion, but your plea seems to be falling on deaf ears. Those who still believe the official story are so convinced that no one would commit such a horrendous false flag demolition and mass terrorist attack on their "own" nation that they are apparently unable to look at the evidence with an open mind.

As flintlock wrote:

I don't claim to be some expert on the event. I don't delve into it like you people because no one has been able to give me a plausible REASON to blow up buildings in NY in the first place. Not only buildings, but specific buildings. Any reason they did not "demolish" the remaining three building of the WTC complex? Or did those attempts fail?

To me it is a lot more reasonable to accept a version somewhat close to the official version than to accept some grand conspiracy involving the most powerful people in the world.

Yes, the official story is "more reasonable." Unfortunately it doesn't fit the evidence. Sure, one can always come up with responses, like a high school debate team. But one cannot convert a steel frame skyscraper to dust, dropping the (in this case strangely small amount of) remaining rubble in the building's footprint at free fall speeds with just a plane crash and fire. Such work is the mark of a controlled demolition.

When one does look at what really happened, it changes ones understanding of things, a lot.

This event is a major litmus test. Those who remain blind to the facts are seriously impaired in their usefulness to our efforts to restore a free and just government.

That's why I persist in this matter.

[skyson]

Re: British Institute of Nanotechnology: Military Involved in 9/11

Good suggestion, but your plea seems to be falling on deaf ears. Those who still believe the official story are so convinced that no one would commit such a horrendous false flag demolition and mass terrorist attack on their "own" nation that they are apparently unable to look at the evidence with an open mind.

Well, faith based belief system does not require evidence or thinking. All one needs is the "good feeling" to satisfied his "inquiring mind". ;)

In this particular matter, I tried to look at it from both opposing sides. I have studied Dr. Greening and Dr. Bazant's work on this subject, as well as the NIST report, then I have also studied the work of Gordon Ross, Steve Jones, and other researchers works. I came to the conclusion that there is no way fire alone would cause total collapse of any steel frame building. Dr. Greening and Dr. Bazant's models have serious flaws, and on the other hand NIST report does not address the "total collapse" problem, instead it works to the point of "initiation of collapse" then assumes the collapse would be global. What a strange way of an official investigation report is developed. I guess NIST wants to leave some room for the "conspiracy theorists" to thrive in.;)

I am not fixed on one camp's thesis, but I have not found any convincing work that would uphold the office theory. If someone point me to resources suggesting otherwise, I am willing to study and rework my thinking. However, please do not provide me to junkie debunking sites. Trust me, I have studied at least 2 dozen debunking sources, and come across quite a few mouth dropping materials. For example, as flinklock suggested the WTC had stored energy of a number of atomic bombs, so the reasoning goes that "if one atomic bomb could level an entire city, then it is easy to understand the WTC towers could destroy itself because their stored energy is so and so number of atomic bombs". I know where he read this material, but simple question would have to asked: how many atomic bombs energy does the earth stored in itself? I guess must be billions. Does that mean any size of meteorites would cause the total destruction of the earth? Since when did all skyscrapers in the world became ticking time bombs, which any size of fire or a blow to their structure would cause them to completely destroy themselves and reduce to a pile of powders? How much energy an object could store is one thing, how easy that energy could be completely released is another. So much for critical thinking.:rolleyes::rolleyes:

At present, I am certain that the planes did not cause the collapses. I am also certain that the fire might cause partial structure failure, but impossible to cause total destruction of the towers. One highly possible alternative explanation is controlled demolition. But I cannot claim to be certain about the why and how.

I am open to other alternatives, but please provide materials better researched than the ones from Dr. Greening, Dr. Bazant, and NIST.

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

This paper is flawed via its first sentence: the argument made is that the energy transfer should be spread out through many floors under the impacted floor. This is directly in contradiction to the credible publications and has zero proof or examples provided to support this assumption.

Huh?

The "first sentence" of this paper reads "The author of this work, Gordon Ross, was born in Dundee, Scotland."

So I guess you don't mean quite that, but rather the first sentence of the (1) Summary, (2) Introduction, or (3) Analysis. Which is not quite clear to me, so my response will have to be a bit non-specific.

My expectation would be that if one whacked one end of a steel frame construction really hard, then the steel closest to the impact would start bending while the forces were transferred through the steel, away from the point (or surface) of impact, at roughly the speed of sound in steel.

When we view slow motion movies of crash test dummies in collisions, we do not see the dummies proceeding at constant velocity, unimpeded, until they directly hit the barrier. Rather there is a crush zone extending back from the collision, through much of the vehicle, deforming things.

Now it is difficult (honestly) for me to know just what you're saying here c1ue, as "directly in contradiction to the credible publications" is terribly non-specific and presented with (dare I say) "zero proof or examples" (not to mention zero references.)

By the way, it seems to me that G. Ross does present a reference for his claims here of this behaviour (which I guess is the behaviour you are ridiculing):

Bazant/Zhou [1] show in their analysis that elastic and plastic behaviour of a steel column under a dynamic buckling load can be shown to consist of three distinct phases.

But, to repeat myself, perhaps your scorn was addressed elsewhere; the focus of your scorn is unclear to me.

The second flaw: much verbiage is spent showing how total speed of 16 upper levels is reduced upon striking the 17th and successive level.

Yet zero coverage is addressed to recalculating what the speed of the resulting 17 level agglomeration is prior to impact on the 18th level.

Why is that a flaw? All analysis proceeds by analyzing specific details, to the necessary exclusion of other details. That is a flaw if the excluded details are essential to a correct understanding. You have to make that case with logic and evidence, not with the technically vacuous scorn of phrases such as "much verbiage" if you are to convince me that's a critical flaw.

The heavier and denser an object, the quicker it achieves terminal velocity.

Well, not exactly. If I drop a fluttering leaf in the air at sea level atmosphere and gravity (32 feet per second squared), then I expect it to reach it's terminal velocity (of say 32 feet per second) within about a second. If I drop a much heavier and denser brick in the air, I expect it to reach it's terminal velocity (of say 320 feet per second) in about 10 seconds (320/32). Ten seconds is not "quicker", it's ten times slower.

I would suggesting amending this statement to read:

The heavier and denser an object, the greater is its terminal velocity.

However I will confess I've already quite lost the thrust of your argument here, so I have no idea how my suggested amendment alters your points.

Well, to be more precise, I've lost the technical thrust. The emotional thrust of ridicule and scorn seems quite clear to me .

A man can stand on a brick, but the same man kicking the brick can break it in half.

Brick does not behave the same as steel on impact. Watch me the next time I'm caught in a major earthquake and notice how quickly I run away from any brick facades and toward the nearest steel frame doorway, seeking to stand in that doorway until the worst of the shaking subsides.

WTC was built for gradual horizontal load shifts due to winds, not near instantaneous massive vertical shocks.

The WTC was also built to support about five times it's own weight vertically (if my memory serves me well) and to sustain major airplane collisions.

More to the point here (if I am guessing your points correctly, that's uncertain) is that steel crumples on severe impact. It doesn't disintegrate into fine powdery dust. Crush a beer can in your hands next time you have a six pack. No dust. Cut hands maybe (that's why you drink the beer first, to anesthetize your hands ), but no dust.

A skyscraper does not do such a thing - it balances all its weight on a small portion of its structure.

The unstated implication of this sentence is that a skyscraper is at risk of toppling or of crushing it's lower levels, like a stack of six empty beer cans with myself (who weighs no small fraction of a typical cow) standing on them.

A skyscraper (or stack of beer cans) is at such risk only if the weight impressed upon it exceeds what it can withstand without severely deforming or of toppling. One has to make the calculations to determine roughly what those limits are.

BZZZT! Crap paper

Well, I can't really tell from your critique, c1ue, if the paper is crap or not.

But if I had not already been favorably inclined to your analytical skills from your work here on "global warming", I might be tempted to rudely rebut your critique of this paper with:

BZZZT! Crap critique

If you really want a plausible conspiracy theory - how about some portion of the WTC steel structure being defective? That is far more plausible. A partially defective structure would more easily lead to the initial collapse.

Well, yes and no. Sometimes bridges, buildings and such do fail due to defective material. I'd expect a crumpled, mangled mess of bent steel and concrete chunks, likely collapsing off to one side or another, in such a case.

Those World Trade Center towers were really tall c1ue. Have you seen them? Coming in from New Jersey they utterly dominated the lower west side Manhattan skyline. A material defect could perhaps I suppose lead to one of the towers toppling, causing fierce damage for several blocks in one direction.

It is beyond the limits of my fertile imagination to suppose any material defect of the steel in those buildings that would cause both towers to completely dustify in 10 seconds each.

Once the collapse began, the final result was inevitable.

Not really. The final results depend on various factors, such as on the relative strength of the lower levels versus the higher levels. You seem to be making the same mistake as the 9/11 Commission report here, stopping the analysis with a wave of the hand just as the "real fun" begins.

Moreover, such a collapse, even if total, would be slowed all the way down by the enormous forces required to crush a massive quantity of steel, and the result would be a pile of crushed and mangled steel, intermingled I suppose with much concrete rubble of varying granularity, dust to chunks, and with crushed metal office furniture, bodies and ceramic plumbing fixtures.

One would not see the steel, concrete, furniture, bodies and plumbing fixtures almost entirely converted to very fine dust in 10 seconds flat (where free fall time for a brick dropped off the top floor in a vacuum was about 9 seconds.)

[tombat1913]

Re: British Institute of Nanotechnology: Military Involved in 9/11

If scientific arguements aren't convincing, debates about motive are going to be far more tedious. Giving examples of previous high rise fires which did not result in collapse, showing evidence of thermite and video footage of the owner of the 3 buildings admitting flat out that they demolished building 7 among many other things is something I can do.

Delving into the psychology of this conspiracy or other historically accepted conspiracies I can't do, even historians have to make assumptions about these things. The fact is that people do conspire to do these things, what the hell were the joint chiefs of staff thinking with Northwoods? You tell me what they hoped to gain. You tell my why this happened, it's not a theory anymore. You tell me why Watergate happened. It's a heck of a lot easier to debate motive when you have congressional investigations telling who was involved, you give me some answers. Stalin, Hitler, and Mao killed millions of their people to achieve their agendas, you don't think a few thousand would be justified in their minds. What, sociopaths only exist in other countries? Not in America? Not in our government?

Sometimes the doctor has to amputate to save the patient, it's not pretty but it has to be done. 3,000 people is a drop in the population bucket, like amputating the end of a small toe. One hell of an impact it had on our country though. A few thousand people who were all going to die someday got to die for their country for the continuity of the U.S. empire in the 21st century. Leaders send soldiers off to die all the time, but that just doesn't have the same impact on the psyche as civilians dying, airplanes crashing and buildings collapsing on loop, over and over and over. The dramatic changes to our domestic and foreign policies and a massive move on our front in the middle east never would have been allowed if 3,000 soldiers died, they're supposed to die, it's socially acceptable. But 3,000 civilians, and a few buildings that we're financially insolvent and required $200 million in asbestos abatement, now that's efficiency baby!

I just can't wrap my head around why a man with failing kidneys in a cave in Afghanistan orchestrating a plot to train amateurs to fly commercial airliners with expert precision and making NORAD fail for the first time in history is not a conspiracy to people. Somehow that scenario is plausible, but insiders with knowledge of training exercise schedules, power to stand NORAD down, power to keep peoples mouths shut under the guise of national security and threat of imprisonment or worse, and technological ability to achieve this is just waaaaaay far out there. Somehow suicide is logical, but orchestrating something like this is just too risky. Somehow hatred will corrupt a mans mind, but ungodly wealth and power won't. Somehow destruction for destuctions sake is logical, but destruction as a means to a political end is inconceivable.

[c1ue]

Re: British Institute of Nanotechnology: Military Involved in 9/11

1.Momentum Transfer Analysis of the Collapse of the Upper Storeys of WTC1

This paper is flawed via its first sentence: the argument made is that the energy transfer should be spread out through many floors under the impacted floor. This is directly in contradiction to the credible publications and has zero proof or examples provided to support this assumption.

The second flaw: much verbiage is spent showing how total speed of 16 upper levels is reduced upon striking the 17th and successive level.

Yet zero coverage is addressed to recalculating what the speed of the resulting 17 level agglomeration is prior to impact on the 18th level.

The heavier and denser an object, the quicker it achieves terminal velocity.

http://www.calctool.org/CALC/eng/aerospace/terminal

Enter in some large masses and see what the terminal velocity results in. Then figure energy = 1/2 M*V squared

Then the next error is equating structural support load handling vs. impact load handling. The two are not equal.

A man can stand on a brick, but the same man kicking the brick can break it in half.

WTC was built for gradual horizontal load shifts due to winds, not near instantaneous massive vertical shocks.

A pyramid or ziggurat, for example, isn't specifically designed for vertical shocks. But it can withstand them because it horizontally distributes the weight of the structure as it scales in height. A skyscraper does not do such a thing - it balances all its weight on a small portion of its structure.

BZZZT! Crap paper

Reply to Dr. Greening

This paper makes the same crap assumptions as its predecessor.

NIST and Dr. Bazant - Simultaneous Failure

This is an argumentative position paper basically saying that Bazant and NIST can't be relied on because they're only making calculations on paper. Yet the argumentative paper does the exact same thing.

If you really want a plausible conspiracy theory - how about some portion of the WTC steel structure being defective? That is far more plausible. A partially defective structure would more easily lead to the initial collapse.

Once the collapse began, the final result was inevitable.

[sadsack]

Re: British Institute of Nanotechnology: Military Involved in 9/11

Thanks. You have my ears and eyes. I am a keen student awaiting for your teaching.;)

Lesson one: Static vs. dynamic loading

You quoted:

There was nothing special about the weight of the upper block, rigid or otherwise. The lower part of the Tower had held up this weight without difficulty since 1970. The lower block had 283 cold steel columns, with less than 30% of their total load capacity being utilized for gravity loads, because of the factors of safety designed into the structure and the need to withstand high winds—and gravity loads were essentially the only loads the columns would have been subject to on a day such as 9/11 with little wind.

This completely ignores (ignorance) or sidesteps (deceit by omission) the difference between static and dynamic loads.

This guy has already gone to the trouble of explaining it, so I'll quote him:

http://www.burtonsys.com/staticvdyn/

What the conspiracy theorists apparently don't understand is the difference between static and dynamic loading. ("Static" means "while at rest," "dynamic" means "while moving.")
If you don't think it can make a difference, consider the effect of a stationary bullet resting on your chest, compared to the effect of a moving bullet striking your chest. The stationary bullet exerts a static load on your chest. A moving bullet exerts a dynamic load.
As a more pertinent example, consider a 110 story building with a roof 1,368 feet high (like the WTC Twin Towers). Each floor is 1368/110 = 12.44 feet high, or aproximately 3.8 meters.
Now, suppose that the structural steel on the 80th floor collapses. (Note: I'm using as an example 2 WTC, which was the building that collapsed first.)
The collapse of the 80th floor drops all the floors above (which, together, are equivalent to a 30 story building!) onto the 79th floor, from a height of aproximately 12 feet.
Of course, the structure of the lower 79 floors has been holding up the weight of the top 31 floors for many years. (That's the static load.) So should you expect it to be able to hold that same weight, dropped on it from a height of 12 feet (the dynamic load)?
The answer is, absolutely not!
Here's why.
First, let's calculate aproximately how fast the upper 30 floors slammed into the 79th floor. (If you slept through high school physics, you may want to skip ahead to the result.)
d=distance, g=acceleration of gravity, t=time, v=velocity
d = 0.5 g x t²
Solving for t:
2d = g x t²
t² = 2d / g
t = sqrt(2d/g)
t = sqrt(2d) / sqrt(g)
v = g x t
Substituting for t:
v = g x sqrt(2d) / sqrt(g)
v = g x sqrt(2d) / sqrt(g)
v = (g / sqrt(g)) x sqrt(2) x sqrt(d)
v = sqrt(2g) x sqrt(d)
g = 9.8 m/sec²
d = 3.8 meters

Thus:
v = sqrt(19.6 x 3.8) m/sec
v = sqrt( 74.5 ) m/sec
v = 8.6 m/sec

1 meter = 39.37 inches, so
v = 8.6 m/sec x (39.37/12) ft/m = 28 ft/sec.
which is 19 mph.

In other words, if you drop something from a height of 12 feet, it will be moving at about 19 miles per hour by the time it reaches the ground. It doesn't matter whether it is a single brick or a 30 story building. After falling 12 feet it will be moving at about 19 mph.
That's about the speed of a collegiate sprinter. (The world record for running the mile is 3:43.13, which is an average speed of 16.134 mph.) If you could sprint that fast and ran into a brick wall the impact might well kill you.
So if the lower 79 floors are strong enough to support a stationary 31 story building, do you think they will be strong enough to support a 31 story bulding falling at 19 mph?
The answer is emphatically no! But if you are not convinced, then ask yourself this roughly equivalent question. Suppose that you can hold up a 50 lb weight with little difficulty. Do you suppose that you could survive a 50 lb weight falling on you from a height of 12 feet - i.e., at 19 mph? (Warning: Do not try this!)
To answer that question without killing someone, I devised the following experiment. First, I found an easily dividable weight: I used my penny jar. Then I made a support for it: I used a piece of notebook paper stretched over a loaf pan, and taped in place. As you can see, the paper was strong enough to support the jar:




(click on the photo for a close-up)
(I was going to determine the limit to the amount of weight it would support, by adding pennies to the jar until the paper tore, but that's all the pennies I had in my penny jar.)
Then I removed the jar from the paper, and set it aside. I took five pennies from the jar, and taped them together. I stood on a stepstool, reached as high into the air as I could (about 9 or 10 feet from the floor), and dropped the 5 pennies onto the paper from that height. As you can see, even though I didn't drop it from a full 12 feet, the paper still could not withstand the falling pennies:




(I took the pennies out of the loaf pan for this photo; that's them next to the lower-right corner of the pan.)

Then I weighed both the five taped-together pennies (12 grams), and the penny jar full of pennies (1372 grams):





As you can see, 5 taped-together pennies weigh just 1/114th as much as the penny jar, yet they tore the paper on the first try. (I didn't try an even smaller stack of pennies.)
You can imagine what would happen if I'd dropped the full penny jar on the paper from 10 feet up. If a 12 gram penny stack broke right though the paper, obviously the paper would hardly have slowed the 1372 gram jar full of pennies at all... just as the lower floors of the WTC towers hardly slowed the fall of the upper floors.
That is experimental proof that a stiff (inelastic) structure which can support a given static load may break when less than 1% of that mass is dropped on it from a height of 10 feet. From that fact, it follows that if the full mass which the structure is capable of supporting is dropped on it from a height of 12 feet, the strength of the structure can be expected to slow the fall by less than 1%.
In the case of the WTC towers, there was a second factor which also slowed the collapse, but not by much. When the top 30 floors of a 110 story building fall 12 feet onto the 79th floor, due to the collapse of the 80th floor, the mass of the 79th floor is suddenly added to the mass of the falling structure. The momentum of a 30 story building falling at 19 mph suddenly becomes the momentum of a 31 story building falling at a slightly smaller velocity. The question is, how much smaller?
p = momentum = m x v
m1 = mass of the top 30 stories
m2 = mass of the top 31 stories = aprox. (31/30) x m1
v1 = velocity before the additional mass is added = 19 mph
v2 = velocity after the mass is added
Momentum is conserved, so:
p = m1 x v1 = m2 x v2 = (31/30) x m1 x v2
Solving for v2:
v2 = v1 x (30/31) = 0.968 x 19 mph = 18.4 mph

So you can see that the two factors which slowed the fall of the WTC towers were both very small. The strength of the structure below the point of collapse could be expected to slow the rate of collapse by less than 1%, and the accumulation of additional mass by the falling part of the structure due to the the "pancaking" of the lower floors could be expected to slow the rate of collapse by about 3%.
Of course, the above analysis is just about what happened when the top 31 stories fell onto the 79th floor. To predict the progression of the entire collapse, you have to repeat the calculations for each floor. For the next floor, calculate a 32-story building starting with an initial velocity of about 18.4 mph, and accelerating for another 12.4 feet to about 27 mph, and then slamming into the 78th floor. Since kinetic energy is proportional to velocity squared, the falling mass hits the 78th floor with about twice the kinetic energy that the top 31 stories had when they hit the 79th floor. Obviously, the 78th floor could be expected to slow the collapse by even less than the 79th floor did, which is why the building collapsed at nearly free-fall speed.
Dave Burton
Cary, NC USA
Feb. 21, 2007









References:

1. wtc.nist.gov: National Institute of Standards and Technology reports & information
2. FEMA: World Trade Center Building Performance Study (or here)
3. www.9-11commission.gov: 9-11 Commission Report
4. Scientific American: Preliminary Opinions of M.I.T. Stuctural Engineers (Oct. 2001)
5. Article: Engineers blame collapses on fires
6. Article: Faulty Fireproofing Is Reviewed as Factor in Trade Center Collapse
7. BBC: Q&A: What really happened
8. WGBH/Nova: Building on Ground Zero
9. Popular Mechanics: Debunking The 9/11 Myths (March 2005), and Editor's Notes
10. Book: Debunking 9/11 Myths: Why Conspiracy Theories Can't Stand Up to the Facts, by The Editors of Popular Mechanics
11. WGBH/Nova: Demolition Woman, Interview with Stacey Loizeaux (1996)
12. jod911.com - Journal of Debunking 911 Conspiracy Theories
13. 911myths.com - 9-11 Myths... Reading between the lies
14. debunking911.com - Debunking 911 conspiracy theories
15. 429truth.com - a campaign to expose the truth of 4-29
16. Did the U.S. government plan and execute the 9/11 attacks?
17. xkcd.com

College level courses in Mechanics I and II can do wonders to inoculate against trutheritis . . .

[Ghent12]

Re: British Institute of Nanotechnology: Military Involved in 9/11

Good suggestion, but your plea seems to be falling on deaf ears. Those who still believe the official story are so convinced that no one would commit such a horrendous false flag demolition and mass terrorist attack on their "own" nation that they are apparently unable to look at the evidence with an open mind.

...

When one does look at what really happened, it changes ones understanding of things, a lot.

This event is a major litmus test. Those who remain blind to the facts are seriously impaired in their usefulness to our efforts to restore a free and just government.

That's why I persist in this matter.

I would strongly urge you to enroll yourself in some college level engineering classes. Statics, Dynamics, and Structures/Materials/DMP would be the three best ones. You think that so much is unusual about this because it doesn't fit your understanding of the world--well change that! Educate yourself in some of these principles. Let me ask just one more question, in hopes that you will see what the context is of your world view: What's the highest building ever subjected to an official controlled demolition?

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

That is experimental proof that a stiff (inelastic) structure which can support a given static load may break when less than 1% of that mass is dropped on it from a height of 10 feet.

Pray tell, by what means does the steel framing of a floor of the World Trade Center towers, that was able to support many stories of skyscraper in one second, transition to a material with the strength of air in a fraction of a second (fast enough to remove support instantly, in the manner of the hand letting the five pennies drop?)

Also pray tell, how is it that the elastic properties of paper resemble those of steel?

Finally, what would you expect to find if someone dropped the largest of the pyramids, upside down, directly on your automobile, from a height of twelve feet, at sea level gravity and atmosphere?

I'd expect to find a seriously flattened car underneath the rubble of the pyramid. I would not expect the car to vaporize or convert to fine dust.

College level courses in Mechanics I and II can do wonders to inoculate against trutheritis . . .

Insults are usually more persuasive to the insulter than to the insulted.

In other words, resorting to ad hominem ridicule suggests to me you are more interested in scoring debating points than in improving our understanding.

Obviously, I am not going to rush out and spend the next year getting the particular mechanical engineering courses you list. However some of the engineers contributing to the website Architects & Engineers for 911 Truth have such credentials and are confident that it took a substantial amount of carefully placed explosives or other such forms of additional focused energy, not just the airplane impacts and resulting fires, to bring down those towers in the manner that they came down.

Of course, if you will only be convinced of this if I personally take those courses and report back to you they don't support the official collapse theory, then you can remain clue deficient.

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

I would strongly urge you to enroll yourself in some college level engineering classes. Statics, Dynamics, and Structures/Materials/DMP would be the three best ones.

You misrepresent this matter with your arrogance. As I noted in my previous reply above, such analyses are fatally flawed.

See further Architects & Engineers for 911 Truth.

What's the highest building ever subjected to an official controlled demolition?

I would say about 110 stories -- the two World Trade Center towers .

[ThePythonicCow]

Re: British Institute of Nanotechnology: Military Involved in 9/11

If scientific arguements aren't convincing, debates about motive are going to be far more tedious.

Yes, more tedious, which is in part why I avoid such efforts.

You took an excellent stab at it though. Good post. Thanks.

[sadsack]

Re: British Institute of Nanotechnology: Military Involved in 9/11

PC, my comments were not directed at you; they pertained specifically to excerpts of an article quoted by skyson. If my post was not clear in this I apologize for the confusion.

That being said, I object to my post being characterized as an ad-hominem attack. Skyson asked for instruction, I provided it, as well as additional helpful resources that he would require (Mechanics I & II, at a minimum, as has also been stated by Ghent).

The article in question stated that the structural supports were supporting 30 percent of their designed load-bearing capacity. The article then went on to state that because the structure could support the static weight of the top floors, it should therefore be able to support the dynamic loading of the same mass traveling at (per the article I linked) almost 20 mph! :eek::confused:

The massive additional kinetic energy of the falling upper floors is what caused the underlying structure to collapse. Recall, that a force of more than three times the static load of the upper floors (per skyson's article) would be enough to cause the structure to fail.

I'm writing off the rest as a "heat of the moment thing" - no harm, no foul

Pray tell, by what means does the steel framing of a floor of the World Trade Center towers, that was able to support many stories of skyscraper in one second, transition to a material with the strength of air in a fraction of a second (fast enough to remove support instantly, in the manner of the hand letting the five pennies drop?)

Also pray tell, how is it that the elastic properties of paper resemble those of steel?

Finally, what would you expect to find if someone dropped the largest of the pyramids, upside down, directly on your automobile, from a height of twelve feet, at sea level gravity and atmosphere?

I'd expect to find a seriously flattened car underneath the rubble of the pyramid. I would not expect the car to vaporize or convert to fine dust.
Insults are usually more persuasive to the insulter than to the insulted.

In other words, resorting to ad hominem ridicule suggests to me you are more interested in scoring debating points than in improving our understanding.

Obviously, I am not going to rush out and spend the next year getting the particular mechanical engineering courses you list. However some of the engineers contributing to the website Architects & Engineers for 911 Truth have such credentials and are confident that it took a substantial amount of carefully placed explosives or other such forms of additional focused energy, not just the airplane impacts and resulting fires, to bring down those towers in the manner that they came down.

Of course, if you will only be convinced of this if I personally take those courses and report back to you they don't support the official collapse theory, then you can remain clue deficient.