British Institute of Nanotechnology: Military Involved in 9/11

[skyson]

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

This is easy to refute. The following example essentially illustrates why:
1) A truck carrying 5 tons of bricks for a construction project crashes into your stationary car at 40 MPH.
2) A truck carrying 5 tons of fine granulated sugar crashes through a brick wall at 60 MPH, slowing it to 40 MPH before impacting your stationary car.
Which truck does more damage?

Well, you are using the wrong example. You probably should rephrase your example as "A container truck". Without that condition, most of you bricks and sugar would probably fly into the air because different components of your truck will impact each other at the time the truck hit the stationary car, if the various components have no strong bonds connecting each other.

Also, I repeatedly point out that the size of the lower floor section is much larger than the upper floor section. So may be you should ask yourself:

"Your stationary car hit a container truck carrying 5 tons of bricks at speed of 90mph, will your car render the truck completely destroyed and your car remain intact?"

Even if the floors "destroy" each other, their mass does not vanish or disappear. The principle of the conservation of mass still applies. Certainly some becomes airborne as dust, and that is visible in the video. How many of the more than 50,000 or 100,000 tons of mass became airborne as a result of the initial collision between the upper section and the lower section? I imagine it was just a shade over statistical insignificance, but I do not have the tools to do that analysis. The rest which didn't become airborne, including dust, steel, and everything else, still fell and still imparted its kinetic energy.

I would say most of the 50,000 or 100,000 tons of mass became airbone as the result of collision(or shall I say explosion?). Have you seen the pictures and videos of WTC collapsing? See these two for some idea:

Sorry, as Ghent12 noted, mass = mass. Your ignorance of physics continues.

Avalanches are primarily composed of small to tiny chunks of snow and ice - yet they can scour out road beds and topple buildings. And avalanches aren't falling straight down - they roll along a slope losing energy to friction all the while.

Seriously, how much is the size of an avalanche compares with some road beds or building? A thousand of times? How long the distance the avalanche has advanced, at what speed(I heard avalanche could reach speed of sound?)? How much energy that could be?

You are ignoring the information in my various posts. I will say it again here, the lower sections of WTC1 is almost 8 times the size of upper section, and for WTC2 the ratio is 4:1.

We are talking about smaller objects destroying larger objects here. Not the other way around.

By the way, as cow point out, we are debating in good faith here. No need for pointing fingers at one's nose. Calm reasoning is the key.

You might try to argue that powderized WTC floors have a higher coefficient of friction in air, but even this becomes irrelevant if the powder is clumped together. Only the outside layers experience this friction while the vast majority of the mass falls at maximum gravitational acceleration.

This can be seen experimentally as well: dropping a spray of water vs. a giant droplet. A small amount - say 1 cup - will not see much difference. A large amount - say 1000 gallons - will see a significant difference.

So try again.

I don't have to try again. I ask you to see the picture above, and other videos I post before. The fact is, majority of the upper section mass fell outside of the building during its collapse. You simply forming your assumption regardless of reality.

More pictures for your reality check:
http://www.911research.com/wtc/evide...collapses.html

[skyson]

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

In one of the above post, I mentioned about the NIST Report, here is the correct link: http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201.pdf

This report is a must read for anyone interested in the matter of WTC collapses, for official theory apologist, or conspiracy theorists, or anything in between.

It is the US government's final and definite report of the WTC attack investigation. It suppose to carry the official conclusion about all aspect of the the destruction of the buildings. When it came out we all have been told that its conclusion is "the fire brought the building down", and many people believe that was the case. NIST, with hundreds of scientists and engineers, certainly had the ability and resource to do a thorough investigation, and dispelled any doubts about the cause of the collapses. However, if you read the actual report carefully, its conclusions are actually vague and leave room for interpretations.

First, look at its Abstract and Executive Summary, two points jump out immediately:

1. In Abstract, page xiii, line 15:

"This report describes how the aircraft impacts and subsequent fires led to the collapses of the towers after terrorists flew jet fuel laden commercial airliners into the buildings;"

2. Footnote of Executive Summary, page xxxvii, line 39:

"The focus of the Investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. For brevity in this report, this sequence is referred to as the "probable collapse sequence," although it includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable. "

At the very outset, the Report has limited its scope to only cover the events leading up to the "initiation of collapse". Whatever happened afterwards, NIST simply does not care.

Secondly, after the above opening, true to its promise, the bulk of the almost 300 pages report deals with various aspects of the events leading up to the collapse. Niceties include, not limited to: plane modeling, plane engine construction, building office furnishing, blahblahblah... non important things, and of course they do include important things like fire, heat, damage caused by plane impacts, etc. For the conspiracy theorists who are not concerned about the possibility of a fire induced initial collapse cough*like me*cough, then you pretty much can skip it.

Thirdly, we will go right to the meat of the report, where NIST discuss about the "COLLAPSE ANALYSIS OF THE TOWERS"(Section 6.4). Out of the 300 pages report, this section only utilize 3 pages of content. Here are the quotes:

p 145, line 5

6.14.2 Results of Global Analysis of WTC 1
...

The inward bowing of the south wall caused failure of exterior column splices and spandrels, and these columns became unstable. The instability spread horizontally across the entire south face. The south wall, now unable to bear its gravity loads, redistributed these loads to the thermally weakened core through the hat truss and to the east and west walls through the spandrels. The building section above the impact zone began tilting to the south as the columns on the east and west walls rapidly became unable to carry the increased loads. This further increased the gravity loads on the core columns. Once the upper building section began to move downwards, the weakened structure in the impact and fire zone was not able to absorb the tremendous energy of the falling building section and global collapse ensued.

page 145, line 35

6.14.3 Results of Global Analysis of WTC 2
...

The south exterior wall displaced downward following the aircraft impact, but did not displace further until the east wall became unstable 43 min later. The inward bowing of the east wall, due to the inward pull of the sagging floors, caused failure of exterior column splices and spandrels and resulted in the east wall columns becoming unstable. The instability progressed horizontally across the entire east face. The east wall, now unable to bear its gravity loads, redistributed them to the thermally weakened core through the hat truss and to the east and west walls through the spandrels.

The building section above the impact zone began tilting to the east and south as column instability progressed rapidly from the east wall along the adjacent north and south walls, and increased the gravity load on the weakened east core columns. As with WTC 1, once the upper building section began to move downwards, the weakened structure in the impact and fire zone was not able to absorb the tremendous energy of the falling building section and global collapse ensued.

There you have it, two sentences and you have the explanation of how the buildings collapsed in a completed, total, and symmetric manner.

"the weakened structure in the impact and fire zone was not able to absorb the tremendous energy of the falling building section".

What about the structure below the impact and fire zone? Would that be able to absord the "tremendous energy" of the falling section? What there is no quantified analysis. My little postings at least attempted utilized the Third Newton Law, yet NIST feels no need to show any numbers, formulas, and calculations.

"global collapse ensued". WOW, simply bold, authoritative, no need to show any reasoning at all. Seeing this statement from the NIST, can you people not just trust the legions of PhDs would have some definite analysis in the back of their minds backing up their conclusion?
Lets continue:

page 146, line 4

6.14.4 Events Following Collapse Initiation

Failure of the south wall in WTC 1 and east wall in WTC2 caused the portion of the building above to tilt in the direction of the failed wall. The tilting was accompanied by a downward movement. The story immediately below the stories in which the columns failed was not able to arrest this initial movement as evidenced by videos from several vantage points.

Why "the story immediately below the stories...was not able to arrest the initial movement"? NIST does not feel the need to explain again, because...wait:"as evidenced by videos". OMG, it is proven by video. You people have seen them already. That was the result! As to why was that, well, err...I don't know.

The structure below the level of the collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structures below to absorb that through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.

Did you all see the bold quotes: "the structure below...offered minimal resistance". Since NIST did not tell me why that should be the case, dare I mention:"because it was significantly weaken by cough*explosives*cough"?

Notice the circular reasoning:"structure below..offered minimal resistance", so "potential energy released...far exceeded the capacity...of intact structure below"; "since stories below provided little resistance to the tremendous energy released", so "building...in free fall".

Also notice, the NIST Report did not actually say what cause all the structures offering minimal resistance. The little conspiracy theorist in my head tells me NIST is leaving itself a huge wiggle room here for future interpretation, and in essence avoiding any legal liability in the future should things turn sour.

So guys, you have a situation that the US government has not acutally provided any explanation as to why the buildings completely collapsed, while many people are fooled into believing otherwise. I urge everyone to have a good read at this report, for it is essential to understand the task at hand, no matter you support or disprove the official theory.

In addition we have the following facts:

1. the 19+1 suspects were annouced on day one by the administration which claimed to have absolutely no prior knowledge.
2. after 9 years investigation, no suspects was dropped from the above list, no new suspect added either. very unusual for a lengthy and complex investigation.
3. Bin Laden is not wanted by FBI for the WTC attack.
4. FBI admitted they have "no hard evidence connecting Bin Laden to the WTC attack.

We have allegations and allegations flying around, about the event, the people involved. But no proof. However, most poeple don't know the difference between allegations and actual truth.

Oh, the little voice in my head is saying something again:"evil vs. good...war for oil...with US or against US...weapon of mast destruction...fight against terror...spreading freedom...American way of life...change we can believe in..."

My head is spinning fast. It must be time for me to take my pill and go to bed. SHIT, which pill should I take, the red one or blue one? OK, I will toss my gold maple leaf to decide. Holycow, how come my coin both sides has the old lady from England? Please, someone help me...

[c1ue]

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

I would disagree with that. Some of the affects we're dealing with involve inelastic changes. Many materials, including steel, will bend but not break for a certain range of forces, but buckle or fail catastrophically with larger forces. A unified hard "pile driver" is able to focus forces, perhaps sufficiently to break some critical members or joints that a distributed force of similar total momentum couldn't break. I'd sooner get hit in the torso with a shotgun blast than a rifle shot, fired at close range with similar gun powder loads, if wearing a modest bullet "proof" vest (Mind you I have no direct experience on either end of either choice; someone out there may well know better.)

Each sentence you state is correct, but the problem is the scale. As has been alluded to by Ghent12 and others, a bullet gets its energy primarily from its velocity. Even assuming that the total energy from a bullet is equal to that from a shotgun shell, the individual energy of the bullet is far higher than that of each shotgun pellet.

However in reality the energy from a shotgun shell is higher than that of a pistol bullet, in turn lower than an assault rifle. Frankly getting shot by either a shotgun or an assault rifle while wearing a vest is still going to get you seriously injured or killed.

But again the analogy is incorrect. The energy of the WTC mass above impact point is not a result of velocity; the velocity of this mass was the result of the gravitational potential energy being converted to actual. As such the pile driver is much more likely as the loss of support means the simultaneous acceleration of all parts of the formerly supported structure falling due to gravity. The simultaneity in turn is very much likely given the huge mass and high density.

From my view, this explanation seems perfectly reasonable to me:

http://www.tms.org/pubs/journals/JOM...agar-0112.html

In any event here, c1ue, we're barking up the wrong tree.

We're not so much having problems understanding physics and mechanics as we are having problems getting full and reliable evidence and determining which detailed model of events (following the laws of physics, of course) accurately applies.

That is, as I can imagine saying when I was a student of mathematics, we're having trouble validating our model.

Dissing people's understanding of theory is an unfortunate distraction from the real difficulties this discussion faces.

Dissing people's understanding of theory is perfectly reasonable if the understanding is wrong. I've pointed out a number of very specific shortcomings with the posted critiques of NIST - principally that every single one makes at least one major assumption with zero evidence.

Well, you are using the wrong example. You probably should rephrase your example as "A container truck". Without that condition, most of you bricks and sugar would probably fly into the air because different components of your truck will impact each other at the time the truck hit the stationary car, if the various components have no strong bonds connecting each other.

Wrong. A container truck with 100 tons of feathers will still crush you. The feathers may fly out in all directions AFTER the impact, but it won't much matter to you. Inertia exists.

Seriously, how much is the size of an avalanche compares with some road beds or building? A thousand of times? How long the distance the avalanche has advanced, at what speed? How much energy that could be?

You are ignoring the information in my various posts. I will say it again here, the lower sections of WTC1 is almost 8 times the size of upper section, and for WTC2 the ratio is 4:1.

We are talking about smaller objects destroying larger objects here. Not the other way around.

Wrong again. WTC above the impact point vs. the 1st floor or even 1st 3 floors underneath is not a smaller object striking a larger one. The assumption made with this statement is that the objects are both solid.

Even though the WTC above the impact point is not solid, the energy associated with it striking the next floor down is equivalent to a near simultaneous impact. Why? Because all parts of the WTC over the impact point were accelerating simultaneously. Only if different portions are accelerating at different speeds would there be a division of the net gravitational potential energy of the overall structure. There is no way this could have happened given both the cause (a structural failure at the impact point) or the distance involved (only 12 feet).

As has been already repeatedly stated - there are also qualitative differences between a sharp blow vs. a continuous strain.

The reality is that for a tightly balanced structure such as a skyscraper, the loss of major parts of the load bearing portion can easily lead to catastrophic collapse. Fortunately it is very difficult to achieve such a loss - normal fires simply are not hot and widespread enough and impacts of moving objects are largely irrelevant due to the relative mass differences.

As for the energy of an avalanche, it can be seen here:

http://www.slf.ch/lawineninfo/zusatz...skala/index_EN

You'll note that the largest avalanches are still significantly less mass than the top 15 floors of the WTC - and more importantly are spread out over a much larger and longer area.

I would say most of the 50,000 or 100,000 tons of mass became airbone as the result of collision(or shall I say explosion?). Have you seen the pictures and videos of WTC collapsing? See these two for some idea:

You post yet another (series of) wrong statements.

The mass of dust in the sub-2.5um size range is estimated to be about 11000 tons - as compared to the 1M tons of mass used to construct the 2 WTC main buildings. Hardly a big fraction.

www.pnas.org/content/101/32/11685.full.pdf

The report also mentions 1M tons of total dust and smoke released into the air, unfortunately this mass doesn't distinguish what was already in the air (as air) vs. what actually came out of the WTC structures via disintegration or combustion. Clearly 100% of the mass of both buildings could not possibly have all flown up in the air or else there would have been hundreds of thousands killed by 100,000 or 1,000,000 tons of debris raining down in a multiple block radius. This 1M tons thus certainly includes the 95% of the WTC that was air as well as the ejecta after the WTC bits hit ground level.

Of course the conspiracy theorist likes to say that the speed of the collapse can only be due to enemy action. But as Archimedes clearly demonstrated thousands of years ago, a dense object falls very fast. The theoretical maximum speed of the WTC collapse should have been 300 mph; in reality it was 200 mph+ according to the link posted above.

Well within the realm of reason.

So BZZT! again.

I don't have to try again. I ask you to see the picture above, and other videos I post before. The fact is, majority of the upper section mass fell outside of the building during its collapse. You simply forming your assumption regardless of reality.

Your statement here again is based on nothing but your own belief.

Nowhere is it documented that the majority of the mass of the WTC - upper section or otherwise - fell outside of the building.

http://upload.wikimedia.org/wikipedi..._Locations.jpg

This picture in fact clearly shows the vast majority of the debris fell within the confines of the WTC parcel.

Austin Tobin plaza was 21500 square meters - roughly 150 meters per side. Given that the WTC was over 400 meters tall and 600m on a side, it is quite clear that there was very little WTC 1 & 2 mass that fell any significant distance from the original WTC 1 & 2 boundaries.

BZZT! BZZT! BZZT!

[c1ue]

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

Did you all see the bold quotes: "the structure below...offered minimal resistance". Since NIST did not tell me why that should be the case, dare I mention:"because it was significantly weaken by cough*explosives*cough"?

Or perhaps that the hundreds of thousands of tons falling would be barely inconvenienced by each layer of structure.

1. the 19+1 suspects were annouced on day one by the administration which claimed to have absolutely no prior knowledge.
2. after 9 years investigation, no suspects was dropped from the above list, no new suspect added either. very unusual for a lengthy and complex investigation.
3. Bin Laden is not wanted by FBI for the WTC attack.
4. FBI admitted they have "no hard evidence connecting Bin Laden to the WTC attack.

Given that the people who did it are dead, how exactly do you expect to add more?

And again you fail to consider a far more likely alternative: that there were credible reports of this plot - including names - which were dismissed and then hushed up after the disaster unfolded.

And that Bin Laden was not directly involved, but like any sharpish leader was quick to take credit where it could be stolen.

Oh, the little voice in my head is saying something again:"evil vs. good...war for oil...with US or against US...weapon of mast destruction...fight against terror...spreading freedom...American way of life...change we can believe in..."

As someone who was about to fly into the US on September 12 from Japan, and thus who watched the events unfold from the moment of alarm until a week later, it was 100% clear that Bush and company had no clue what hit them.

It is also equally clear that pre-existing agendas were then polished off and fit to the opportunity much as any good politician or corporate infighter would do.

My head is spinning fast. It must be time for me to take my pill and go to bed.

I recommend the Valium pill.

[ThePythonicCow]

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

From my view, this explanation seems perfectly reasonable to me:

http://www.tms.org/pubs/journals/JOM...agar-0112.html

That paper, by Eagar and Musso, December 2001, is I believe one of the primary documents presenting what has come to be called the "pancake" theory of collapse, to which I referred above (with erroneous credits subsequently corrected by skyson.)

The pancake theory has since been rejected by various parties, both NIST (primary source for the official explanation) and various "truthers"

For example from the NIST site http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm:

NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram below). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.

Or for those (such as myself) who are inclined to the "truther" side of things, see The WTC, Dr. Eagar, and the Great Zipper and Pancake Revival.

As I've noted above, the pancake theory does not explain the collapse of the center columns. It also does not explain the collapse of Bldg 7. It also has the problem that it seems to require to the floor's connections to both the core and perimeter to fail simultaneously (as noted at http://www.bibliotecapleyades.net/so...ol_911_24d.htm.) It also does not explain the explosive horizontal ejection of large amounts of material, including sizable lengths of steel girders at sufficient velocity to embed them in the exterior walls of neighboring buildings.

A reasonably balanced (in my view) history of the more official efforts to understand the collapse of these buildings, such as the pancake theory, preliminary FEMA reports and subsequent NIST reports, can be found at http://www.search.com/reference/Coll...d_Trade_Center.

[ThePythonicCow]

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

Dissing people's understanding of theory is perfectly reasonable if the understanding is wrong. I've pointed out a number of very specific shortcomings with the posted critiques of NIST - principally that every single one makes at least one major assumption with zero evidence.

I was using the word "theory" in a more technical sense than you might have expected, so my statement was not clear.

By "theory" I meant an abstract, logically consistent, set of related ideas, such as set theory, string theory, or Newton's laws of physics. When you chastised skyson for not knowing that mass = mass, that was dissing his understanding of theory.

The actual application of a particular theory to a specific circumstance is a separate matter. For example, Newton's laws of physics don't help us much at very high speeds (near the speed of light), very small sizes (where quantum mechanics might be more useful) or very early in the origins of the universe (just after the Big Bang.) Newton's laws of physics are a quite fine and useful theory, but they aren't "valid" (don't fit reality) at these extremes.

When you protest that you've pointed out that "principally that every single one [of posted NIST critiques] makes at least one major assumption with zero evidence", you are commenting on whether the theory has been shown to be valid (you're saying it hasn't) not on whether the theory is a useful and logically consistent theory that might be worth studying in the abstract for some other purpose.

I quite agree with you, as I have stated in an earlier post above, that the questions of what actually happened (specific evidence) and whether the evidence fits the theory are major difficulties in these studies. For example, one can have a nice "pancake" theory that might fit some buildings and some building collapses that doesn't happen to be valid for the collapse of these buildings on that day.

So, as I said before, please don't diss others for lack of understanding of theory. Pretty much everyone in this discussion here has sufficient grasp of the theories of mechanics, fires and such to understand what needs to be understood, even if we have not taken Mechanical Engineering in college.

What we're disagreeing on are the facts of the case, the details of evidence, and which theory best fits that evidence.

[ThePythonicCow]

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

The energy of the WTC mass above impact point is not a result of velocity; the velocity of this mass was the result of the gravitational potential energy being converted to actual.

Huh?

"The energy of the mass is not the result of velocity; the velocity of the mass is the result of the [gravitational] energy"

You're saying that something I said is incorrect, but I don't get what you're saying, I don't know exactly what I said you're rebutting, and (not surprisingly therefore) I don't understand how what you said rebuts it.

As such the pile driver is much more likely as the loss of support means the simultaneous acceleration of all parts of the formerly supported structure falling due to gravity. The simultaneity in turn is very much likely given the huge mass and high density.

Why does the huge mass and density make simultaneous falling more likely? (And by the way, how do your "simultaneity" comments fit with the top of Building 2 (the South Tower, first to fall) going at a nice tilt as the collapse began?)

[ThePythonicCow]

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

In response to skyson, c1ue wrote:

Wrong. A container truck with 100 tons of feathers will still crush you.

I suspect you misread skyson, c1ue. He wasn't debating whether 100 tons (of feathers) weighs as much as 100 tons (of bricks), both of which are quite ample to crush any human being. He was recommending containing the loose material so that it wouldn't fly about and miss its target.

[c1ue]

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

As I've noted above, the pancake theory does not explain the collapse of the center columns. It also does not explain the collapse of Bldg 7. It also has the problem that it seems to require to the floor's connections to both the core and perimeter to fail simultaneously (as noted at http://www.bibliotecapleyades.net/so...ol_911_24d.htm.) It also does not explain the explosive horizontal ejection of large amounts of material, including sizable lengths of steel girders at sufficient velocity to embed them in the exterior walls of neighboring buildings.

The link you provided explicitly divides pancake theory as being that the breaking of one floor's links to the central support would overload the next lower floor, etc etc.

On the other hand, the weakening column theory is that the heat of the fire was enough to weaken the columns such that a structural break occurred at the impact floors and a collapse ensued.

What I've been pointing out - and which was documented in the link in question - was that a combination of these 2 theories is quite reasonable in explaining what happened: the initial collapse was not a single floor or several floors getting disconnected from the support columns and causing a progressive collapse - it was the fire. But the speed of the overall building failure was still due to a pancake effect.

Huh?

"The energy of the mass is not the result of velocity; the velocity of the mass is the result of the [gravitational] energy"

You're saying that something I said is incorrect, but I don't get what you're saying, I don't know exactly what I said you're rebutting, and (not surprisingly therefore) I don't understand how what you said rebuts it.

The energy of a bullet is artificially induced: it is due to pressure from the (very) rapid burning of propellant in a confined space. Or in other words, the source of the energy of the bullet is a more or less specific event. After firing (and the ending of the event), entropy ensues and the total energy can only go down.

The energy of a falling object is fundamentally different. In this case the potential energy already exists - the only question is how quickly it is released/converted to actual energy. In this case there is still entropy, but the actual energy at any given point in the fall actually increases as time goes on.

Why does the huge mass and density make simultaneous falling more likely? (And by the way, how do your "simultaneity" comments fit with the top of Building 2 (the South Tower, first to fall) going at a nice tilt as the collapse began?)

Because huge mass and density means that the primary means of energy loss for a falling object - friction of air - becomes a miniscule factor. Archimedes again.

As for Building 2 - if indeed the initial cause of failure at the impact floors was due to fires weakening the support columns only on those floors, it is perfectly reasonable that some columns would fail later than others. This would induce a tilt in the floors, but depending on the difference in time of failure, might or might not induce significant lateral movement.

In simpler terms, if one side of the structural columns were cut at floor 80 but started failing only on one side, the remaining columns failing rapidly but not immediately would tilt the floors above. The columns failing less rapidly could theoretically tilt the entire WTC structure above floor 80 about the axis of the remaining columns but only if the columns could maintain structural integrity at a significant angle. As these columns were never even remotely intended to do so, it is quite conceivable that they failed almost immediately after integrity on one side was breached.

I suspect you misread skyson, c1ue. He wasn't debating whether 100 tons (of feathers) weighs as much as 100 tons (of bricks), both of which are quite ample to crush any human being. He was recommending containing the loose material so that it wouldn't fly about and miss its target.

Perhaps I am misreading, but a 2nd and 3rd reading yield the same understanding: skyson believes that the material billowing out in the form of dust somehow reduces the energy available to destroy the remaining structurally intact portions of the WTC.

This is wrong. It is irrelevant whether a pickup truck full of feathers or a container truck full of feathers hits you. The energy imparted is identical. Only if a lot of the feathers fly out BEFORE impact, or the feathers are inertially differentiated from each other/the truck (i.e. streaming in a trail behind the truck due to a tire squealing start) would it matter. Were the truck bed reasonably shielded from wind of the truck's passing, a slow acceleration to high speed would avoid the truck 'floating' the feathers due to the feathers' much lower energy transfer interface with the truck (as opposed to the very efficient energy transfer interface between the truck and its engine).

Even if the mass of the dust were greater than the 11000 tons estimated by NIST, the dust had to have gained its energy from somewhere or else it wouldn't be moving. This energy was gained via the mass of the moving parts of the WTC striking the not yet moving parts.

The real world dictates that energy is lost via entropy, but equally energy doesn't cancel out. It merely gets redirected.

[ThePythonicCow]

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

As I've noted above, the pancake theory does not explain the collapse of the center columns. It also does not explain the collapse of Bldg 7. It also has the problem that it seems to require to the floor's connections to both the core and perimeter to fail simultaneously (as noted at http://www.bibliotecapleyades.net/so...ol_911_24d.htm.) It also does not explain the explosive horizontal ejection of large amounts of material, including sizable lengths of steel girders at sufficient velocity to embed them in the exterior walls of neighboring buildings.

The link you provided explicitly divides pancake theory as being that the breaking of one floor's links to the central support would overload the next lower floor, etc etc.

On the other hand, the weakening column theory is that the heat of the fire was enough to weaken the columns such that a structural break occurred at the impact floors and a collapse ensued.

What I've been pointing out - and which was documented in the link in question - was that a combination of these 2 theories is quite reasonable in explaining what happened: the initial collapse was not a single floor or several floors getting disconnected from the support columns and causing a progressive collapse - it was the fire. But the speed of the overall building failure was still due to a pancake effect.

By "the link you provided" do you mean the link to bibliotecapleyades.net in what you quoted from me?

I don't see where that link even uses the word "pancake", so I don't see how you can say that it has some specific meaning for that word.

And if it did, so what?

The above bibliotecapleyades.net link does raise the following question about the FEMA 2002 explanation:

This approach finally fails to account for the observed collapse of the 47 interconnected core columns which are massive and designed to bear the weight of the buildings, and it has the striking weakness of evidently requiring the connections of the floor pans to the vertical columns to break, both at the core and at the perimeter columns, more or less simultaneously.

It was from this bibliotecapleyades.net quote that I noticed the simultaneous breaking of floor pan connections was a serious weakness, so was giving them credit by my link.

This FEMA 2002 explanation (combination of fire weakening floors near collision and subsequent pancaking of lower floors) sounds more like what you're thinking happened than the (Eagar and Musso, 2001) work you linked to when you wrote:

From my view, this explanation seems perfectly reasonable to me: http://www.tms.org/pubs/journals/JOM...agar-0112.html

In any case, I don't think you answered any of my questions above:

• Neither Eagar and Musso, 2001, nor FEMA 2002 explains the collapse of the center columns.
• Neither one explains the collapse of Building 7.
• Requiring the simultaneous failure of all of a floor's connections is a problem, as I shall elaborate on a little more below.

By the way, according to this same bibliotecapleyades.net link, the NIST report rejected the Eagar/Musso/FEMA hypotheses involving -failing- floor pan connections and instead presumed that these connections held so that the floor pans could "pull" with enormous force on the perimeter columns, sufficient to cause the final collapse. I haven't got the stomach to read the NIST report (despite skyson's urgings), so can't verify this description of the NIST report. Perhaps you know -- is this a correct statement about the NIST report, and if so, are you knowingly choosing to reject the NIST conclusions and stay with the earlier Eagar/Musso/FEMA fire weakening then pancake hypotheses? If so, could you explain why?

===

On to the next confusion.

Skyson made a point, a ways back, as to the difference between a single connected mass and a disconnected bits of matter having the same total mass.

The dynamics of what forces get applied where with what focused concentration or dispersed uniformity are different between a connected and disconnected collider.

I brought up the analogy of a shotgun versus rifle in an effort to convey this difference. You responded that my "analogy is incorrect." No, for the purposes of my analogy, it was correct. Of course, it's not a perfect analogy for all aspects of the World Trade Center collapse. The force of gravity persisted until the building collapse was complete, whereas the force of the exploding gun powder persists only until the bullet leaves the barrel, as you have explained. But that wasn't relevant to the purpose of my analogy.

Now that I realize that my gun analogy was a distraction for you, let's put that aside and return to the point that gave rise to this unfortunate distraction.

You had written, a ways back, that:

Pile Driver or not is also totally irrelevant.

I had replied (this time I will leave out my unfortunate gun analogy distraction):

I would disagree with that. Some of the affects we're dealing with involve inelastic changes. Many materials, including steel, will bend but not break for a certain range of forces, but buckle or fail catastrophically with larger forces. A unified hard "pile driver" is able to focus forces, perhaps sufficiently to break some critical members or joints that a distributed force of similar total momentum couldn't break.

You replied in turn:

Each sentence you state is correct, but the problem is the scale. ... As such the pile driver is much more likely as the loss of support means the simultaneous acceleration of all parts of the formerly supported structure falling due to gravity. The simultaneity in turn is very much likely given the huge mass and high density.

This reply of yours gets us back to a matter I've asked about since, when I wrote:

Why does the huge mass and density make simultaneous falling more likely?

To which you replied:

Because huge mass and density means that the primary means of energy loss for a falling object - friction of air - becomes a miniscule factor.

I do not find your reply here convincing.

Yes, I will agree that when objects fall in a fluid at significant fractions of their terminal velocity, then aerodynamics can significantly affect their velocity (the directional vector.)

However we're talking here about the point at which immobile floors start to become (downwardly) mobile due to fastener failure. At that point, aerodynamics due to the objects current motion in air are not in play, as the object (the floor) isn't moving much until after the fastener has already failed.

So ... tell me again why you'd expect that the fasteners for a given floor would be more likely to fail simultaneously, just because the floor is one heavy dude.

Perhaps I am misreading, but a 2nd and 3rd reading yield the same understanding:

The 2nd and 3rd reading of -what-, the feathers and bricks analogy, or what skyson wrote regarding the WTC towers?

I suspect (once again, apparently) our discussion has gotten bogged down in misreadings, confusions, and ambiguous references to prior content.

Rather than patiently try to unravel the confusions this time, I'll just cut back to the main point that (hopefully) we're discussing here.

I agree with skyson that some falling floors will exert more downward pressure on the floors below if the falling floors remain intact than if they disintegrate and partially blow out the side as dust. The more weight that is still falling straight down, the more force there is on the next floor level below.

As best as I can tell you're disagreeing with that position. Is that so? Do you disagree? If you disagree, please explain yourself, preferrably in nice simple clear language. Thanks.

[c1ue]

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

Rather than patiently try to unravel the confusions this time, I'll just cut back to the main point that (hopefully) we're discussing here.

A fair point - there is so much flying around that confusion is inevitable.

Let me then summarize what seems reasonable to me as to what happened:

1) The original cause of failure was the weakening of the steel support structure - possibly abetted by partial mechanical damage from impact - in the levels of the WTC where the planes struck and the burning jet fuel was active.

2) Once a failure occurred at the impact point, the floors above the impact zone effectively were simultaneously accelerated by gravity. This large mass then caused the rest of the building to collapse. Is the collapse specifically due to a pancake effect of each upper floor's fasteners failing in turn, a buckling of the remaining steel frame due to the shock of the impact, or some combination - not clear but all 3 options are equally plausible.

3) Viewed externally, the speed of collapse was not at pure free fall. Pure free fall would have yielded a speed of 300mph vs. the 200+ mph observed. But this is useless because the argument can then be made that the explosives were simply staggered.

Similarly the lack of debris scatter is inconclusive. As noted previously, the steel frame of the WTC was not intended to withstand any significant vertical shocks - rather it was intended to withstand relatively (compared to the vertical impact) horizontal ones. A catastrophic failure is thus quite conceivable.

And in the vein of catastrophic failure - the dust raised, the mechanical shear and compression induced by the falling debris, etc etc are all forces but are forces 1 or 2 orders of magnitude smaller than the primary one of gravity. Why? Because the buildings were 95% air. The equivalent structure is a 10 foot high buildng made of matchsticks. This building can be made and likely the matchsticks can support the building, but a breaking of the support structure will quickly lead to catastrophic collapse.

Other issues with nano-thermite and what not:

1) The trace substances associated with thermite are not present. This was presented in the earlier threads
2) No evidence of detonation mechanisms was ever found. Certainly this could be suppressed, but the det cords, radio contacts, fuses, etc etc associated with mining a 1000 foot tall structure is non trivial.

[ThePythonicCow]

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

2) No evidence of detonation mechanisms was ever found.

You don't know that. All "crime scene" evidence was carefully controlled or destroyed by the FBI and other such federal agencies. The steel was shipped off for scrap to Korea or China. Anyone working in the cleanup soon learned to keep quiet about what they might have found.

No plane parts were "found" that we know of either, except for one rather suspicious wheel, with its rubber tire still in good shape (rather amazingly so, given that it had just survived such an "inferno".) But no aircraft engines or black boxes were found, so far as we know. Those should have survived, perhaps worse for the wear.

(The above is written from memory, by someone with a well known bias to the conspiratorial side of things. If someone has evidence or references supporting or refuting the above, go ahead and present it.)

[skyson]

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

Quote:

Originally Posted by skyson
Well, you are using the wrong example. You probably should rephrase your example as "A container truck". Without that condition, most of you bricks and sugar would probably fly into the air because different components of your truck will impact each other at the time the truck hit the stationary car, if the various components have no strong bonds connecting each other.

Originally Posted by c1ue
Wrong. A container truck with 100 tons of feathers will still crush you. The feathers may fly out in all directions AFTER the impact, but it won't much matter to you. Inertia exists.

....................................
Ha, no shit. A hammer traveling at 90mph, will punch a hole in your head and instantly kill you! LOL.

Are you telling me the arrangement methods of the objects being hauled on a truck does not affect the total kinetic energy level when the truck impacting on another object? Even in an ideal physics environment(vacuum), this is certainly untrue.

Lets make an extreme example:

Your 10 tons truck has a load of 100 tons of feather, with total weight of 110 tons. Each feather stacks up upon one another, so forming a very high say 100 miles?) straight vertical line on the truck. When your truck hit my car with a speed of 90 mph, at the exact moment of impact, your kinetic energy is E = m x (v)2 = 110 x (90)2. After impact, your truck's bumper reaches to the driver seat of my car, and your truck decelerates to 80mph. The speed difference between your truck and the stack of feathers overcomes the friction force holding the stack of feathers on your truck, and puff, the whole stack of feathers fall over and outside of your truck. Now, your kinetic energy is E = 10 x (80)2.

Understand my point now, Sir?

Will this significant change of the amount of available kinetic energy affect the way your truck crashing the rest of my car, after the initial impact? Sure will. Now add air, the impact position on my car, impact angle, structure composition of my car and your truck. Will these factors have significant impact on the final outcome of the crash?

Now step back, going back to our main focus. The lower margin of WTC1 impact zone was at 93 floor, and WTC2 was at 78 floor. So we have these pre-collapse conditions:
1. WTC1 impact zone was at the middle; WTC2 impact zone was at a corner.
2. WTC1 retained most of jet fuel from the plane after impact; WTC2, most jet fuel burnt off right at impact time.
3. WTC1 available upper floor section was 17 floors; WTC2 was 32 floors.

From the above different factors, would you expect the collapse of WTC1 would be quite different from WTC2, if they did collapse because of gravity? Yet their collapses were strikingly similar:
1. total. 2. symmetric. 3. pulverized. 4. straight down. 5.debris, including steel beams, ejected horizontally up to 100 meters.

Now take a careful look at this picture: http://911research.wtc7.net/wtc/evid...gzaerial3.html

And ponder for a while, see the huge piles of uniform debris of WTC1, WTC2, and WTC7(upper middle), evenly distributed in a large area(up to 100 meters away from WTC1 and WTC2). Do they look like some sort of bombing aftermath, or natural building collapse?

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

Originally Posted by skyson
Seriously, how much is the size of an avalanche compares with some road beds or building? A thousand of times? How long the distance the avalanche has advanced, at what speed? How much energy that could be?

You are ignoring the information in my various posts. I will say it again here, the lower sections of WTC1 is almost 8 times the size of upper section, and for WTC2 the ratio is 4:1.

We are talking about smaller objects destroying larger objects here. Not the other way around.

Originally Posted by c1ue
Wrong again. WTC above the impact point vs. the 1st floor or even 1st 3 floors underneath is not a smaller object striking a larger one. The assumption made with this statement is that the objects are both solid.

....................................
Wrong again? I am afraid not. Let me rephrase your sentence:

"WTC below the impact point vs. the 1st floor or even 1st 3 floors above is not a smaller object striking a larger one."

Your apparent inability to appreciate an opposing view is amazing. You see the upper section as one single mass, but see the lower section one floor at a time.

Your statement again:" Because all parts of the WTC over the impact point were accelerating simultaneously. Only if different portions are accelerating at different speeds would there be a division of the net gravitational potential energy of the overall structure."

Do I have to rephrase again:" Because all parts of the WTC below the impact point..."? Please be reminded that the Third Newton Law does applied here.

"The assumption made with this statement is that the objects are both solid". Now, we are on the same page. One large object(lower section) vs. one small object in a collision. Who wins again?

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

Originally Posted by c1ue
The reality is that for a tightly balanced structure such as a skyscraper, the loss of major parts of the load bearing portion can easily lead to catastrophic collapse. Fortunately it is very difficult to achieve such a loss - normal fires simply are not hot and widespread enough and impacts of moving objects are largely irrelevant due to the relative mass differences.

.....................................
Are you kidding me? I have to ask again: since when did skyscrapers around the world become ticking time bombs, which would reduce themselves into a pile of dust/uniform debris when part of their structure destroyed for whatever reason? I know they frequently have safety factor of 3-6, and if somehow something caused the loss of major parts of the load bearing portion, they would more likely topple over? Am I missing something?

By the way, my argument is not if the weaken structure will lead to a collapse. My argument is if this gravity acting alone collapse will be total, symmetric, and pulverized? Will the small object finish off the much larger object?
.....................................

Originally Posted by skyson
I would say most of the 50,000 or 100,000 tons of mass became airborne as the result of collision or shall I say explosion?). Have you seen the pictures and videos of WTC collapsing? See these two for some idea:

Originally Posted by c1ue

You post yet another (series of) wrong statements.

The mass of dust in the sub-2.5um size range is estimated to be about 11000 tons - as compared to the 1M tons of mass used to construct the 2 WTC main buildings. Hardly a big fraction.

www.pnas.org/content/101/32/11685.full.pdf

The report also mentions 1M tons of total dust and smoke released into the air, unfortunately this mass doesn't distinguish what was already in the air (as air) vs. what actually came out of the WTC structures via disintegration or combustion. Clearly 100% of the mass of both buildings could not possibly have all flown up in the air or else there would have been hundreds of thousands killed by 100,000 or 1,000,000 tons of debris raining down in a multiple block radius. This 1M tons thus certainly includes the 95% of the WTC that was air as well as the ejecta after the WTC bits hit ground level.

..........................................
I am not sure about your logic here. I said debris from the broken mass became airborne, I did not say they would disappear. Airborne means not attaching to any structure, or floating in air, temporally or permanently. Majority of the debris was ejected outside of the building perimeter, as far as 100 meters away, horizontally. And then, they fell to the ground. My point was they did not contribute to the energy needed to "smash" on the lower floor sections. After impact, majority of the debris went to the point where there was least resistance(outside the perimeter of the buildings), not available at the center to "crash" things. This is apparent from the videos and pictures.

I was merely making the point that they did not "clumped together"(oh, by the invisible hand?) as you suggested in previous post "to give a deadly blow" to the lower structure.
..........................................

Quote:
Originally Posted by skyson
I don't have to try again. I ask you to see the picture above, and other videos I post before. The fact is, majority of the upper section mass fell outside of the building during its collapse. You simply forming your assumption regardless of reality.

Originally Posted by c1ue

Your statement here again is based on nothing but your own belief.

Nowhere is it documented that the majority of the mass of the WTC - upper section or otherwise - fell outside of the building.

http://upload.wikimedia.org/wikipedia/......Building_Locations.jpg

This picture in fact clearly shows the vast majority of the debris fell within the confines of the WTC parcel.

Austin Tobin plaza was 21500 square meters - roughly 150 meters per side. Given that the WTC was over 400 meters tall and 600m on a side, it is quite clear that there was very little WTC 1 & 2 mass that fell any significant distance from the original WTC 1 & 2 boundaries.

BZZT! BZZT! BZZT!

..........................................
Your statement here again is based on nothing but your own belief!!! LOL!

Can you take a better look at the picture you referenced again? Do you have a pen? OK, first circle the total debris area. Then circle the WTC1 and WTC2 areas. Can you see at least 2/3 of debris was actually outside of the two towers' boundaries? Can I say majority of the upper section mass fell outside of the building during its collapse?

What do you exactly mean by "WTC parcel"? Oh, you mean the area that surrounding the two buildings? Is the area inside the buildings or outside the buildings? YOU REALLY GETTING ME CONFUSED!!!

Now it is apparent the whole point of your post is winning debating points, which I have no interest in. My intention is to enhance our understanding about this matter. If you wish to do the same, please carefully review my various posts, including all references, and try to understand other people's opposing view first. Then we could be debate in good faith.

Please note that while you making numerous mistaken critiques about my thinking, you have not challenged the fundamentals of my theory in any form and any way.

Final words to you, unless you abandon your condescending attitude, and relax your heightened emotional state, I will no longer engage in any conversation with you. Good night.
..........................................

[ThePythonicCow]

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

The equivalent structure is a 10 foot high buildng made of matchsticks.

How about a 10 foot structure made of wire? I'll wager one could cut quite a few of the wires with little affect on the overall structure.

Steel wire would seem offhand to be a better analog to steel beams than toothpicks.

[Ghent12]

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

Your statement again:" Because all parts of the WTC over the impact point were accelerating simultaneously. Only if different portions are accelerating at different speeds would there be a division of the net gravitational potential energy of the overall structure."

Do I have to rephrase again:" Because all parts of the WTC below the impact point..."? Please be reminded that the Third Newton Law does applied here.

"The assumption made with this statement is that the objects are both solid". Now, we are on the same page. One large object(lower section) vs. one small object in a collision. Who wins again?

Okay, apparently the example I previously presented with regard to trucks is causing more confusion than clarity.

Try this one for size:
Scenario 1) A 75 kg man balances a 15 kg barbell weight on his shoulder.
Scenario 2) A 75 kg man attempts to catch (with his shoulder) a 15 kg barbell weight dropped from a height of 10 feet.
Who "wins" this one? Yes, the man is more massive, but surely you can see the point now.

Now you might say that the barbell is harder and denser than the man. Fair point, so try this one:
Scenario 1) a 75 kg man balances a 15kg baby on his shoulder.
Scenario 2) a 75 kg man attempts to catch (again, with his shoulder, no arm catch decelerating the fall as it is being caught) a 15 kg baby dropped from the height of 10 feet.
You might survive the catch. Of course, this is an imperfect analogy, because all people generally attempt to catch heavy things by moving with the object they are catching. If you can picture yourself catching any 15 kg object with a rigid, standing-tall shoulder from a height of 10 feet, you might get the gist.