"Hard Science and the Collapse of the World Trade Center"

[spooked911]

Good article here on why it was almost certainly controlled demolition that brought down the WTC 1, 2 and 7:

http://www.garlicandgrass.org/issue6/Dave_Heller.cfm

The author: "Dave Heller, who has degrees in physics and architecture, is a builder and engaged citizen in Berkeley, California."

excerpt:

The odd, swift collapse of WTC7 made me reconsider the Twin Towers and how they fell. As I had with WTC7, I first studied video footage available on the web. Then I acquired and watched a DVD of the collapses, frame by frame.

What struck me first was the way the second plane hit WTC2, the South Tower. I noticed that this plane, United Airlines Flight 175, which weighed over 160,000 pounds and was traveling at 350 mph, did not even visibly move the building when it slammed into it. How, I wondered, could a building that did not visibly move from a heavy high speed projectile collapse at near freefall speed less than an hour later?

Next, I turned my attention to steel beams that fell in freefall next to the building as it collapsed. The beams were falling at the same rate that the towers themselves were descending. Familiar with elementary physics, including principles of conservation of energy and momentum, this seemed quite impossible if the towers were indeed "pancaking," which is the official theory.

The height of the South Tower is 1362 feet. I calculated that from that height, freefall in a vacuum (read, absolutely no resistance on earth) is 9.2 seconds. According to testimony provided to the 9-11 Commission, the tower fell in 10 seconds. Other data shows it took closer to 14 seconds. So the towers fell within 0.8-4.8 seconds of freefall in a vacuum. Just like WTC7, this speed seemed impossible if each of the 110 floors had to fail individually.

As I was considering this, another problem arose. There is a principle in physics called the Law of Conservation of Energy. There is also the Law of Conservation of Momentum. I'll briefly explain how these principles work. Let's assume there are two identical Honda Civics on the freeway. One is sitting in neutral at a standstill (0 mph). The other is coasting at 60 mph. The second Honda slams into the back of the first one. The first Honda will then instantaneously be going much faster than it was, and the second will instantaneously be going much slower than it was.

This is how the principle works in the horizontal direction, and it works the same in the vertical direction - with the added constant force of gravity added to it. Jim Hoffman, a professional scientist published in several peer-reviewed scientific journals, took a long look at all of this. He calculated that even if the structure itself offered no resistance - that is to say, even if the 110 floors of each tower were hovering in mid-air - the "pancake" theory would still have taken a minimum of 15.5 seconds to reach the ground. So, even if the building essentially didn't exist - if it provided no resistance at all to the collapse - just the floors hitting each other and causing each other to decelerate would've taken 15.5 seconds to reach the ground.

But of course the buildings did exist. They had stood for over 30 years. The floors weren't hovering in mid-air. So how did the building provide no resistance?

Yet another observation one makes in watching the collapsing towers is the huge dust clouds and debris, including steel beams, that were thrown hundreds of feet out horizontally from the towers as they fell. If we are to believe the pancake theory, this amount of scattering debris, fine pulverized concrete dust, and sheetrock powder would clearly indicate massive resistance to the vertical collapse. So there is an impossible conflict. You either have a miraculous, historical, instantaneous, catastrophic failure that occurs within a fraction of a second of freefall and that kicks out little dust, or you have a solid, hefty building that remains virtually unaffected after a massive, speeding projectile hits it. You either have a house of cards or a house of bricks. The building either resists its collapse or it doesn't.

And we know the WTC Towers were made of reinforced steel and concrete that would act much more like bricks than cards.

Thus, put simply, the floors could not have been pancaking. The buildings fell too quickly. The floors must all have been falling simultaneously to reach the ground in such a short amount of time. But how?

I've never seen this publication "Garlic and Grass" before, but it has a bunch of stuff on 9/11. The mag claims to be a "grassroots journal of America's political soul".

[MrSammo1]

1. The article

explains the physical problem perfectly.

If only the myth minds could understand?

http://www.gallerize.com/150%20WINDY%20TOWERS%20OF%209-11%20One.htm

[pox americana]

2. "THE WINDY TOWERS OF 9-11"

Great photos on that site!

[janedoe]

7. Cool Site!

Check out this image from the above site. You can see the radio tower begin to sink before the building drops. So, this shows that the core was blown out, first.

[mirandapriestly]

166. what a wonderful site you linked to NT

[pox americana]

3. I think he nailed the problem with the pancake theory.

It happened to fast and too symmetrically, and how is gravity going to blow pulverized steel and concrete halfway across Manhattan?



This is NOT what a "progressive collapse" would look like.

[Christophera]

4. This is NOT what a "progressive collapse" would look like.

 pox americana wrote:

This is NOT what a "progressive collapse" would look like.

Words and images that should be echoing across America.

[spooked911]

6. Agreed. I think this article really helped put me over the top believing

it was controlled demo.

Also, I know a certain professor of engineering* who was recently making the same case to me-- that the speed of the collapse was much too rapid to be explained by pancake-type progressive collapsing.

*I hope that person will chime in on this thread, as they post here on DU.

[janedoe]

8. I think the minimum time would be longer.

The Case for Controlled Demolition.

For the following, I used the height of The World Trade Center Towers as 1350 feet and considered each floor as (1350/110) feet. Gravity = 32.2 ft/sec^2.

The official collapse time I first read was 8.4 seconds. Later, I read it was 10 seconds. I think the official story gives the time it took for the damaged zone to reach the ground in free-fall, not even the rooftop, as the total collapse time. But, this difference is small. Here, I will use the full height of the building. (This difference benefits the official story.)

Case 1.
Imagine this exercise with billiard balls. From the rooftop of WTC1, drop one (dark-blue) billiard ball over the edge. As it falls, it accelerates. If it were in a vacuum, it would hit the pavement (1350 feet below) in 9.490 seconds, shown by the first blue curve in the figure (Figure_1.jpg), below. It will take longer if air resistance is considered. For simplicity, we'll use the "no-air resistance" case. (This difference benefits the official story.)

Note, as the ball begins to fall, it accelerates. If the entire building is to collapse in 9.5 seconds, the other floors must start falling before the ball reaches that floor. This makes the "pancake theory" or "progressive collapse" theory impossible.


Figure_1.jpg

Case 2.
Now, let’s simulate a beam collapse every 10th floor. (This difference benefits the official story.) Refer to the figure (Figure_1.jpg),above. The clock starts when the blue ball is dropped from the roof (110th floor).

Just as the blue ball passes the 100th floor, the red ball drops from the 100th floor.
When the red ball passes the 90th floor, the orange ball drops from the 90th floor, ... etc.
This approximates the "pancaking" theory, assuming that each floor between the “pancaking”
(collapsing) floor provides no resistance at all. (This difference benefits the official story.)

With this theory, no floor below the "pancake" can begin to move until the progressive collapse has reached that level. For example, there is no reason for the 20th floor to suddenly collapse before it is damaged. As you can see, a minimum of 32 seconds is required. Of course it would take longer if accounting for the differences I've noted.

Now, let’s consider another scenario, considering momentum.

Case 3.
Assume that the top 10 floors stay intact as a solid block weight (Block-A). Start the collapse timer when the 100th floor fails. At that instant, assume floors 90-100 miraculously turn to powder and disappear. So, Block-A can drop at free-fall speed until it reaches the 90th floor. After Block-A travels 10 floors, it now has momentum. If all of the momentum is transferred from Block-A to the next floor (or floors), Block-A will stop moving, even if there is no resistance for the next floor to start moving. Recall the physics demonstration shown below. (I believe everyone who has finished high school has seen one of these demonstrations at some point in their life.)

http://scientificsonline.com/product.asp_Q_pn_E_3081502


So, if some part must stop and then restart its decent every 10 floors, the total collapse time must be more than 10 seconds. Also, consider the energy required to pulverize the 10 floors between each “pancake.”
Questions:

Now, consider reality. How likely is it that all supporting structures on a given floor would fail at exactly the same time?
What if all supporting structures on a given floor did not fail at the same time?
Would the building tip over or fall straight down into its own footprint?

Case 4.
Similar to Case 1, above, let's consider a floor-by-floor progressive collapse.
Refer to my figure below:

Figure_3.jpg

If the progression begins at the top, it takes about 100 seconds to collapse the building to the gound. If you want to use the 85th floor as a starting point, cut the lower 25 floors off the chart and it takes about 75 seconds. However, the top 25 floors must also have time to drop.

Now, consider the "stuff" flying out horizontally from the building. If the building were falling from gravity alone, it would take even longer to fall because a lot of the gravitational energy would be spent in the horizontal direction. (Actually, the horizontal and/or vertical motion and pulverization would consume many more times the available energy from just gravity alone.)

[pox americana]

16. So much for the terrorist theory.

But don't expect anyone to let go of it.

[janedoe]

18. Thanks.

When I hear Bush talk about the "terrorists," and how they hate this country and how they hate our freedom... I know he's right -- and I know why he knows so much about the "terrorists." He meets at least one of them every morning, right there over the bathroom sink (that is, assuming he does his own morning shave).

[Rich Hunt]

264. "the terrorist theory?"

So....3,000 people dying in a building that was destroyed on purpose is not terrorism?

[spooked911]

20. Beautifully and logically put! Thank you!

:toast: :toast: :toast: :toast: :toast: :toast: :toast: :toast:

[janedoe]

24. Many thanks! (n/t)

[LARED]

22. Those really are lovely graphs

Unfortunately they are not an accurate model of the pancake theory. In fact it does not model the pancake theory at all. The pancake theory is based on the assumption that the floors are impacted from above with enough energy to cause that floor to pancake onto the next floor.

They producer of the lovely graph makes an assumption that each floor is only under the influence of gravity. That is, at each discrete floor (whether it is defined as one floor or ten floors) it starts as a free fall transfer of energy, not taking into account the energy transferred via the impact.

The conservation of momentum principle tells us that the momentum of object one (defined as a discrete floor) when striking another object (next discrete floor) will transfer energy to the second object. The total energy of both objects is now equal to the momentum of the first object.

http://www.glenbrook.k12.il.us/gbssci/phys/Class/momentum/u4l2b.html

So according to the graph the first discrete floor starts free fall and impacts the second discrete floor. The graph states the the second discrete floor is only under the influence of gravity or potential energy. This cannot be true because the momentum transfer from the first to the second must transfer kinetic energy creating a much higher initial velocity and far shorter fall time.

They really are nice graphs.

[pox americana]

23. I think you missed the point

that at each floor or set of floors, energy has to be spent to break the rigidity of the structure below in order to continue the fall. This would slow or stop the velocity and thus the acceleration at each floor.

In other words, it wasn't made out of jello.

[LARED]

26. No I didn't miss that point

The graph indicate the the second floor (and subsequent floors) each fell as if the floor was only under the influence of gravity until it hit the subsequent discrete floor. That is not physically possible

Think of two billiard balls in a vertical tube. One is ten feet high and the other is five feet high. When dropping the first onto the second, the first does not momentarily stop after hitting the second ball. And the second ball does not fall exclusively under the influence of gravity. Quite a bit of energy will be transferred to the second ball to give it a far greater velocity than if it was just dropped from an initial velocity of zero and allowed to free fall.

The model I just presented is exactly what the graphs show except it models each floor falling under only the force of gravity. Each discrete floor falls as if it was disconnected from the tower and fell as if there was no impact from above. As I said the graphs look nice, but they do not represent the pancake theory.

[pox americana]

27. You just missed it again!

If the second billiard ball is stuck in the tube, requiring the first to expend force dislodging it, then yes, the first ball will be slowed if not stopped while freeing the second one. Then both will have to reaccelerate.

And anyway what other force besides gravity are you imagining?! Have you finally given up your illusions or what?

[hack89]

28. Kinetic energy perhaps? n/t

[pox americana]

29. What about it? n/t

[hack89]

30. From Lared's post

"The graph states the the second discrete floor is only under the influence of gravity or potential energy. This cannot be true because the momentum transfer from the first to the second must transfer kinetic energy creating a much higher initial velocity and far shorter fall time."

The point is simply that due to the great mass of the building above the impact zone there was tremendous KE that easily overcame any resistance the second floor might have. The floors were overwhelmed by the dynamic forces placed on them and collapsed with almost no resistance.

[pox americana]

32. Let's see.

Why would a falling mass "easily" overcome the resistance of the building structures and fall at near free-fall speeds? Because they were built out of pudding?

Well, they were built out of highly engineered steel and concrete and had easily withstood gravity, wind loads and floor loads, not to mention a multi-floor fire in 1985, basement explosions in 1993, and of course two plane crashes, for thirty years. So I guess they weren't made out pudding.

Got any other ideas?

[LARED]

31. Again, the graphical model

shows that the floor being impacted did not receive ANY energy from the upper floor(s) being transferred to velocity. It shows it only falling based on available potential energy.

For this to be true the upper floor(s) would have to completely stop, and the moment it stopped, the lower floor breaks free from the structure.

That's not possible.

[pox americana]

33. "That's not possible. "

No, it isn't, not in 10 seconds. You can eat your dessert now.

[LARED]

43. So, you agree the graphs are meaningless?

Desserts? What are you talking about?

[janedoe]

44. It looks like LARED had nightmares all night. ;-)

[LARED]

47. Slept like a baby

I'm sure your post has some purpose, some implication, or is supposed to convey some type of message.

Could you fill me in on what it is?

Thanks in advance.

[janedoe]

49. It looked like you were disoriented and not fully awake.

You wrote, "Desserts? What are you talking about?"

[LARED]

56. That was in reponse to this comment

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=48327&mesg_id=48472

[Rich Hunt]

267. excuse me?

Aren't there supposed to be strict rules on this board regarding civility?

The insinuations directed at the OP are a bit....unsettling. Yes, even such insinuations don't fall under civility.

[LARED]

Are you one of those that have been taken in by the myth that

WTC 1 & 2 fell in about 10 seconds?

[StrafingMoose]

51. Hmm..

Isn't it about the time they took from standing to crumbled?

[LARED]

52. 10 seconds is far too short

An objective review of the videos indicate both towers fell somewhere around 14 to 15 seconds.

http://www2.bargerhuff.com:2020/Family/Interest/9-11/News/September%2011th%202001/Video%20Coverage/Attack/World%20Trade%20Center%20-%201st%20tower%20collapses.mpg

[pox americana]

53. I was trying to respect your personal beliefs.

Or are have you finally lost faith in the 9/11 Commission report?

[LARED]

57. I'm certain there's a coherent thought process somewhere

in your posting, but for the life of me I can't find it.

[pox americana]

59. read it over a few times

it'll come to you. :hi:

[LARED]

64. I've read it over a few more times

and you will need to spell it out for me.

[Make7]

140. Sometimes it can be difficult to answer a simple question.

I believe she is referring to this:

"From 9:59 until 10:28 A.M.

At 9:58:59, the South Tower collapsed in ten seconds, killing all civilians and emergency personnel inside, as well a number of individuals-both first responders and civilians-in the concourse, in the Marriott, and on neighboring streets. The building collapsed into itself, causing a ferocious windstorm and creating a massive debris cloud."

http://www.9-11commission.gov/report/911Report_Ch9.htm

:) Make7

[pox americana]

144. Yes, thanks for finding that.

I'm glad we all agree it's baloney.

[stickdog]

156. Well now, THAT makes all the difference, then. (nt)

[spooked911]

180. Yep, clearly that extra 5 seconds PROVES no explosives were used.....not.

:P

[janedoe]

181. But if in only takes 1/3 of the building's potential energy to destroy it,

you don't even need explosives!

:nuke:

[vincent_vega_lives]

188. do the math

1/3 of the building's potental energy times the velocity squared of that mass falling 12'.

[vincent_vega_lives]

209. Again

1/3 of the building's potental energy times the velocity squared of that mass falling 12'. Try it.

[Make7]

218. Who said it only took 1/3 of the buildings PE to destroy it? ( n/t )

[Christophera]

164. No Myth. Some Parts Of The Top Made It To the Ground In 10 Seconds

When things are blown up in place, it takes a while for the junk to settle, 5 to 10 seconds after the 10 second point is okay.

Close enough if you love the Constitution, your rights and freedoms and believe democracy is a need.

[Make7]

165. I think the time in question is ...

... the amount of time it took for the intact structure of the building to collapse. Using the time it took for some detached part to reach the ground is not an accurate way to describe the collapse time for the building.

-Make7
Kick - for billard balls.

[Christophera]

171. Agreed, Estimates With Allowable +/- Will Suffice. They Fell Too Fast.

Perhaps the accumulation on the ground that rises to slow, still falling debris and the ET of the event, should reduce the over all time even though the pile is still settling.

The important thing is that they fell too fast and that speed is evidence of demolition.

[Make7]

172. It may have been too fast, it may not have.

I have yet to see a reasonable calculation for how fast the towers would have fallen if it was, in fact, a structural failure precipitated by planes being flown into them. Has anyone shown that the actual collapse times are less than a minimum time based on some reasonable theory?

Maybe I missed it, I am not always around.

-Make7

[Christophera]

175. Plane Impacts Could Have Only Caused The Tower Tops To Fall

I've not seen any cmoprehensive calcs either. The pancake thing is hoakie and simple logic can disprove it. That I've seen dozens of times.

Perhaps the scarcity of calculations of a normal collapse of the towers is due to that fact that steel does not collapse in the manner observed. It comes down, steel below parallelograms and bends, folding all the way down and it ends up fairly far from the footprint, on one side or the other. The lightweight concrete offcially present in the towers would not behave as seen in the videos.

Also the quantity and character of particulate indicates structural high strength concrete rather than light weight concrete which has distinctive, lighter colors and produces billowy clouds rather than arcing plumes of heavy particles traveling at higher speeds. Those type clouds are also present and collapse wouldn't cause that. Those inclined to complete the calculations probably could not reconcile these inconsitencies and declined to project normal collapse rates.

[Make7]

183. I don't believe it is "hoakie."

What I'm trying to grasp is how anyone can claim that the proof that the towers were blown up by conventional (or unconventional) means is that they fell too fast, but never give a reasonable estimation of the time it would take if the collapse was not caused by explosives or some other sinister means.

Too fast compared to what? That's what I want to know.

The too-fast theory is very prevalent, yet usually it is not shown what source was used for their claimed collapse times or how that is faster than it would have been without explosives.

Other aspects of the collapse can be discussed as to how they fit in with various theories, but I continually see the "too-fast" aspect of the collapses used as "proof" that there were explosives in the towers. What I haven't seen is someone actually prove it.

-Make7

[stickdog]

155. In your theory, what caused the the kinetic energy?

Where did the kinetic energy of the collapsing floors come from? What provided this energy?

[vincent_vega_lives]

184. Gravity

the KE equals the total mass of the building above the collapse point times the square of the velocity that component achives falling the 10' or so onto the floor below.

[pox americana]

192. More magical physics.

1) Translational kinetic energy = 1/2mvv, and 2) there were 287 steel columns including 47 very substantial core columns preventing "free fall" or any acceleration whatsoever, at least until they got blown away.

[janedoe]

193. But, what was pushing down?

I saw stuff flying up or out to the sides, not down.
Looking at the picture in your post#3, above the "collapsing floor," I only see mushroom clouds. There is no building above this "collapsing floor."

In this picture, the building appears to be about half-way down. So, this particular "collapsing floor" was designed to support the weight of about half of the building. Now, it doesn't even need to support that half of the building because it's not there!

[vincent_vega_lives]

195. The structure is disintegrating on the way down, true

but transmitting it's KE to lower floors with enough force to crush the concrete, knock it into lower floors, blast out the perimeter columns, and yes even buckle core columns.

Once it began, it there was sufficient energy to almost completely reach the ground...but not quite. Recall some firefighters survived in a stairwell on the 8th floor IIRC.

Forgot to include the 1/2 mass part of the equation.

[janedoe]

197. Magical Physics

To transfer momentum, you need mass.
Let's suppose that picture is of the 50th floor "collapsing." Are you saying that the weight of the 51st floor is suddenly heavier than the weight of 60 floors? If you consider the safety factor of the building as 5, that one floor (51st floor) would need to suddenly become 300 times heavier. Assuming gravity hasn't changed by 300 times, the mass would need to.

I learned that mass cannot be created or destroyed. So, what magic will increase the mass of that one floor by 300 times?

[vincent_vega_lives]

199. U2 with the magical crap?

Are you saying that the weight of the 51st floor is suddenly heavier than the weight of 60 floors?

No but that the impulse (force over time) of the building above the initiating point falling on the lower floor was much greater than the floor below could withstand. The building was both pancaking up and down at the same time, while retaining most of it's mass.

[pox americana]

204. "The building was both pancaking up and down at the same time"

So now gravity is explosive and bidirectional?

It doesn't get any more magical than that.

:rofl:

[vincent_vega_lives]

207. Tell ya what

Perhaps you need to go back to magic school. :think:

Gravity only operates in one direction. The part of the building above the point of collapse pancaked from the bottom up, like if you drop a chest of drawers from a second story building.

The part of building below the point of collapse pancaked from the top down.

But I have a feeling my typing is lost on you. I know you are trying to be clever and amusing, but it just comes of as rather trite.

[vincent_vega_lives]

210. "gravity is explosive"

Tell me now, what are the forces involved when a meteor the size of a building hits the earth? Magic?

:rofl:

[vincent_vega_lives]

222. Here's some calcualtions for you

The part of the building above the collapse point weighed around 100,000 Tons, falling 12' on to the floor below.
Instantanious velocity after falling 12' = 8.4m/s

KE = (.5)*(93,023,256kg)*(8.4m/s)sqd

KE = 3,281,860,472 joules (3281 MJ)

3,282 MJ = from 1,570 to 1,721 lbs of TNT depending on source



Rough estimates. Made slightly more accurate, but you still result in at least .5 to .75 tons of TNT

[pox americana]

223. Three wrongs don't make a right. (n/t)

[vincent_vega_lives]

237. Lay it out

What exactly do you disagree with?

[Make7]

239. But three lefts do make a right. ( n/t )

[vincent_vega_lives]

286. OK lets see your caculations

or can you just criticize and not actually come up with a counter argument

Come up with figures for:

1. The mass of the building above the point of failure.
2. The velocity of that mass.
3. The amount of KE generated.

[vincent_vega_lives]

194. You seem to be implying

that the aircraft impact and resulting fire had NO effect on the structure.

Nothing magical about it.

[petgoat]

203. Impact and Fire

Thomas Eagar said the mass of the tower was 2500 X that of the plane.
Eagar characterized the plane strike as "like bullet hitting tree."

http://www.google.com/url?sa=U&start=5&q=http://eagar.mit.edu/EagarPresentations/WTC_TMS_2002.pdf&e=9797

As to the fires, well NIST has no core steel samples showing heating
above 250 degrees C. Why not?

And Jane has the $64,000 question: what's behind that curtain of smoke
in the collapse picture ? A question that could have been answered by
carefully picking the steel up off the pile and identifying each piece.
But they didn't. Why didn't they get the steel that showed what
happened? Not MORE incompetence!

[pox americana]

205. "like bullet hitting tree."

For once the Beav is right!

[vincent_vega_lives]

211. A bullet hitting a tree

is absorbed by the homogeneous volume of wood. These buildings are composed of a lot of space, a thin skin, 110 concrete floors, and a dense core of steel columns. The MASS of the building was certainly sufficient to adsorb the impact of the aircraft, but not without damage to the components of the structure. Components that were part of the load bearing whole.

The fire without the impact may not have resulted in collapse, likewise the impact without the fire, the two together doomed the building.

The core columns didn't need to melt for the fire to compromise the structure, there were plenty of smaller components that were more easily effected by heat that were already under additional stress due to the impact damage, like the floor joists.

I see you pick and choose what you quote from Edger because he also says: 3. Fire was clearly principle cause of collapse

[janedoe]

213. A tree is not a homogeneous material!

A tree is a complex structure. Natural wood is a composite structure and must be modeled as such.

Actually, the structural design of each WTC tower is more like a tree than any other building I know of. My guess is that the structure of a tree may actually have inspired this unique design.

[vincent_vega_lives]

219. Compared to an office building it most certainly is

Actually, the structural design of each WTC tower is more like a tree than any other building I know of. My guess is that the structure of a tree may actually have inspired this unique design.

Like a tree that had been almost completely eaten by termites maybe.

Edger used the tree analogy not as a comparison of composition, or design. It was an example as to why the plane did not knock it over.

[pox americana]

206. Negligible. Find a floor plan and look at it. You'll see why.

There's one in here somewhere:

http://www.house.gov/science/hot/wtc/wtc-report/WTC_ch2.pdf

[Rich Hunt]

266. Wait a minute

Who said the balls were "stuck" in a tube?

[pox americana]

275. Just a hunch, but did your physics teacher also teach PE?

If the second ball wasn't stuck in the tube it would already be falling.

[StrafingMoose]

48. Hmm..

"dropping the first onto the second, the first does not momentarily stop after hitting the second ball."

Wouldn't that depend on how tight is the tube?

[janedoe]

35. Thanks. Good answer.

I typed my response off-line, and didn't see your response until after I posted mine.

[janedoe]

34. Thanks for the compliments!

My objective is not to model the WTC buildings, but to demonstrate the Case for Controlled Demolition.

Recall the last paragraph, of my post #8, above:

"Now, consider the "stuff" flying out horizontally from the building. If the building were falling from gravity alone, it would take even longer to fall because a lot of the gravitational energy would be spent in the horizontal direction. (Actually, the horizontal and/or vertical motion and pulverization would consume many more times the available energy from just gravity alone.)"

You asked a good question. What happens to the kinetic energy from the floors above? Look in the pictures above, and you will see "stuff" flying out the sides of the building (or even flying upward). How much energy is needed to pulverize the concrete, file cabinets, desks, etc., like that? Let's see if we can get an idea.

Drop a cement block off the roof of a 10-story building onto the concrete road, below. What do you think will happen?

(a) it lands, looking in the same condition as when you dropped it?
(b) it lands, and crumbles into several pieces, as well as fine dust.
(c) it lands, and instantaneously turns to dust?

To make sure we give the benifit of any difference to the official story, let's use (c). Somehow, I think I'd need to drop it from a 100=story building or an airplane to have enough energy to completely turn it to dust. But, for this argument, let's say a 10-story drop would turn this material to dust, similar to the dust in the picture, below. (This difference benefits the official story.)



So, it seems that if one floor "pancaked" every 10 stories, any energy from momentum would be spent pulverizing the "dropped" material. We know it was pulverized, as we can see it in the picture above. Actually, the majority of the "dust" evaluated from the WTC site (on several different streets) was less than 100 microns in diameter. That's pretty pulverized -- as if the building had been dropped the height of a high-flying airplane.

Thanks again for your compliments, as well as your good questions.

[pox americana]

38. Those are the most incriminating photos I've seen.

The Bush reign of terror is upon us, and it's brutal.

[janedoe]

40. Thanks.

We really owe a lot of thanks to the photo journalists who took these pictures.
You've just convinced me that these pictures have captured more truth than the 911 omission commission can hide.
Golly. How do we package this?

[philb]

129. The beams were designed to hold the entire weight of the building

and much overbuilt. There were interior cores and exterior beams tied together by a structural system.

there wasn't any additional weight added along the way;

what caused the momentum of the tilting south tower to shift so that the momentum was broken? What other than explosions?

Why did the volume/dimensions of the upper section above the crash level reduce greatly at the beginning of the the "collapse"?

what caused the explosive expulsion of materials far below where the supposed pancake effect was occurring, other than explosions/squibs?

What caused the huge explosive expulsions of materials upward and outward at the top of the building at the start of the "collapse"- what could explain it other than explosions.

We've seen the pictures many times. I've seen no suggestion of an explanation that deals with the pictures. Or of the many witnesses who saw and experienced the explosions, before and during the collapse process.

[vincent_vega_lives]

185. Big difference between mass at at rest and at acceleration

there wasn't any additional weight added along the way

Actualy there was. The force of the mass of the structure above the point of collapse times the velocity squared is MUCH greater than the potential energy of the mass of the building at rest.

what caused the momentum of the tilting south tower to shift so that the momentum was broken? What other than explosions?

Momentum WAS NOT broken. The tower that tipped did NOT fall in it's own footprint, but neither did it continue to tip as a whole peice. The tipping caused it to break apart, so that peices impacted buildings nearbye (like WTC7).

Why did the volume/dimensions of the upper section above the crash level reduce greatly at the beginning of the the "collapse"?

Because when they impacted the floors below they began to break up at the same time the floors below began to pancake. The building essentally ground it self down to the ground.

what caused the explosive expulsion of materials far below where the supposed pancake effect was occurring, other than explosions/squibs?

No "squibs" could cause the explosive expulsion of materials that we saw. Absent any significant Kinetic energy it would have taken significant explosive charges to achive the force needed. The thing is there was PLENTY of force available to do the trick. Ever see a non explosive KE projectile striking a concrete wall? Now greatly reduce the velocity and greatly increase the mass. Same deal.

What caused the huge explosive expulsions of materials upward and outward at the top of the building at the start of the "collapse"- what could explain it other than explosions.
same deal.

[Rich Hunt]

265. THANK YOU

L-O-G-I-C.

But you don't even need much of a background in physics - a lot of this stuff is intuitive just from watching things around you every day. Physics just explains what we see - a lot of which already "makes sense" to the mind's eye.

[LARED]

271. You're welcome (n/t)

[Make7]

45. 99.5 seconds

From the article in the original post:

Jim Hoffman, a professional scientist published in several peer-reviewed scientific journals, took a long look at all of this. He calculated that even if the structure itself offered no resistance — that is to say, even if the 110 floors of each tower were hovering in mid-air — the "pancake" theory would still have taken a minimum of 15.5 seconds to reach the ground. So, even if the building essentially didn't exist — if it provided no resistance at all to the collapse — just the floors hitting each other and causing each other to decelerate would've taken 15.5 seconds to reach the ground.

http://www.garlicandgrass.org/issue6/Dave_Heller.cfm

Why is his estimate so much shorter than yours? Perhaps you should recheck your math.

-Make7

[janedoe]

46. Read both again. He's not solving the same problem.

From what I understand, he's floating the floors in mid-air, then dropping them. He even states that he assume NO resistance between floors. I assume the kinetic energy is consumed by breaking up the material.

Remember, none of our models are meant to be the exact situation. These are simplified models meant to demonstrate that the official story is physically impossible.

[Make7]

139. floating floors, no resistance, and kinetic energy

janedoe wrote:
From what I understand, he's floating the floors in mid-air, then dropping them. He even states that he assume NO resistance between floors. I assume the kinetic energy is consumed by breaking up the material.

It seems to me in your "Case 4", the floors are floating and they offer no resistance.

Height of building              : 1368 ft
Number of stories               : 110
Height of one story             : 12.436 ft    (1368 ft / 110)
Time for one story to fall      : 0.8794 sec   (t2 = d * 2 / 32.16)
Time for "progressive" collapse : 96.734 sec   (0.8794 * 110)

Maybe you arrived at that number differently. You never showed your calculations factoring in your assumption of kinetic energy being used to break up the building.

I also did not see any calculations for momentum transfer in Case 3. You just state that it must have taken more than 10 seconds. Which I fully agree with - in fact the collapse did take more than 10 seconds - so I don't see how that scenario proves anything except that the actual collapse took longer than your theoretical minimum.

janedoe wrote:
...none of our models are meant to be the exact situation. These are simplified models meant to demonstrate that the official story is physically impossible.

Do you think you can prove anything with over-simplified models of an enormously complex situation? I don't think you have demonstrated what you intended at all.

-Make7

[janedoe]

141. simplification

I don't think you really need a response, do you?

But, I'll assume your question was one of honesty and sincerity.

Let's say you tell me that you ran (by foot) to a store 10 miles away, then to the bank (5 more miles), then to the dog track (7 more miles), then to your friend's house (21 more miles), then home ...all in 2 minutes.

To disprove your story, I would present to you a simple case. I would present to you that the world's record for running just one mile is 3 minutes and 43.13 seconds, so it does not seem possible that you could have run over 40 miles in 2 minutes.

Remember, the proof need not be complicated.

[Make7]

142. simple scenario for a simple situation

The example of running a certain distance in a certain time can be easily disproven by showing that someone couldn't have covered that distance in that amount of time. That scenario makes sense - you have accounted for the variables involved.

That is not the case with your progressive collapse scenarios - you are leaving important factors out of your calculations. I don't believe your examples demonstrate a reasonable scenario of the physics involved in a progressive collapse. I don't think they prove anything useful at all.

Since you didn't respond to the first part of my post, I'll just have to assume that I was correct at how you arrived at 96.7 seconds - you did not factor in the kinetic energy transfers involved with floor collisions or with the breaking up of the structure of the building.

The proof need not be complicated, but it typically needs to account for the major factors involved with the problem or show that not including them will not significantly alter the outcome.

-Make7

[janedoe]

143. Please read my post #8 again

Pay careful attention to "Case 2."
Pay careful attention to the concepts.
http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=48327&mesg_id=48389

Once you've reviewed that, consider the chart below.


Let's say that we want to collapse the entire building in the time it takes for free-fall of the top floor of WTC1. (Use 9.2 seconds as the time it would take the blue ball to drop from the roof to the street below, in a vacuum.) So, if the entire building is to be on the ground in 9.2 seconds (in a vacuum), the floors below the "pancaking" must start moving before the "progressive collapse reaches that floor, below. To illustrate this, use the concept of the billiard balls. If the red ball (100th floor) is to reach the ground at the same time as the blue ball (110th floor), the red ball must be dropped 0.429 seconds after the blue ball is dropped. But, the blue ball will take 2.779 seconds after it is dropped, just to reach the 100th floor in free fall.

Case 2, in my earlier post, shows the red ball being dropped just as the blue ball passes that point.

Remember, I'm assuming the building was turning to dust, as the collapse progressed, which is essentially what happened.

So, for the building to be collapsed in about 10 seconds, the lower floors would have to start moving before the upper floors could reach them, by gravity alone. Did we see this? I believe it's pretty clear in some of the videos. The "wave" of collapse, progressing down the building, is moving faster than free-fall speed. This would require something like a detonation sequence.

Realizing that, for example, the 40th floor needs to start moving before any of the upper floors have "free-fallen" to that point, why would it start moving? There was no fire there. And, if anything, there is less load on that floor as the upper floors turn to dust.

[Make7]

147. Okay, I believe you.

It takes longer than 9.2 seconds for 11 colored billiard balls to fall to the ground from 1362 ft. when the higher ones cause the lower ones to start falling when they match their height and with no force acting upon them except gravity.

But that does not prove anything at all about how either one of the Twin Towers fell. It is a gross oversimplification.

janedoe wrote:
So, for the building to be collapsed in about 10 seconds, the lower floors would have to start moving before the upper floors could reach them, by gravity alone. Did we see this? I believe it's pretty clear in some of the videos. The "wave" of collapse, progressing down the building, is moving faster than free-fall speed. This would require something like a detonation sequence.

But the buildings did not fall in 10 seconds, therefore you have not proven what you are trying to demonstrate.

I think it is very clear that the wave of collapse is slower than free-fall in the videos. There is clearly debris from the buildings falling faster than the building is collapsing. Plus, they each took longer than 10 seconds to fall - which means they had to be collapsing slower than free fall speeds. (About %60 slower than the rate of free fall for a 15 second collapse time.)

-Make7

[janedoe]

148. I don't understand the point you are trying to make.

Please clarify.

If you understood my demonstration, you would understand I have shown that the 9-11 report cannot be true. Are you now saying I'm wrong because the building actually fell in under 10 seconds?

Please clarify. I'm trying to understand what it is you need.... not that it's my job to serve your needs.

Actually, if you tell me the time you'd like, I can add in a fudge factor and produce that exact time for you. Is that what you want?

Above, I have shown the absolute minimum time it would take to bring the entire building down. Now, do you suppose that time would get bigger or get smaller if you added air resistance?

Note, in the many pictures we've seen, there isn't much of a building above the demolition wavefront. So, there if very little mass to transfer momentum. In addition, with less weight% of design load that the lower floors must carry, they'll require even more force to pulverize them. Gravity can't help the collapse if there's no building above it.

[Make7]

150. I think the collapse times are about 15 to 16 seconds.

You said in 'Case 3.' of post #8 that "the total collapse time must be more than 10 seconds."

I agree, they were longer than that.

My point is that your other examples are not an accurate model of the collapse of a building. I'll use an example with billiard balls:

A ball on the 110th floor falls and hits a ball on the 109th floor. This will cause the ball on the 109th floor to start falling at a rate faster than would be achived by gravity alone. That ball hits the next one and the same thing happens, ball 109 transfers some of its momentum to ball 108. Now ball 108 is falling faster than it would if it had only been influenced by gravity........

So without taking into consideration the force transferred by the momentum of the falling building and how much force is neccessary to cause the remaining intact structure to fail, I think the only thing your scenarios demonstates is how billard balls will fall in your scenarios.

If your point was to prove that the time of 10 seconds that appeared in the 911 Commission Report was wrong, all you had to do was post a video of the South Tower collapsing. As for proving anything else, I think your modeling fails to include enough of the basic parameters that are involved in the collapse to prove or disprove anything.

-Make7

[AlienSpaceBat]

287. Time taken conserving momentum

I've run through this on the same basis - assuming no energy lost crushing supports etc, just the 110 floors floating in mid air and the top one falling onto the one below.

My calculation gives ~15.2 seconds for the 110 floors now combined to hit the deck. I also did a calculation of floors 80-110 falling as a block through the floors below which takes 9.73 seconds to hit bottom (there is the question then of how that block collapses of course).

Each floor takes less and less time to fall as the whole mass accelerates, but particularly in the beginning the conservation of momentum considerably slows the fall.

Here are my graphs, not as pretty as the other ones, but never mind !

Time taken for each floor to collapse into the one below:



Total time taken for collapse



Data table used for graphs

[Make7]

288. Is that you Mr. Hoffman? ( n/t )

[AlienSpaceBat]

289. No such claim to fame !

Just interested to work the figures for myself.

The times given are, of course, the absolute fastest that a progressive pancaking collapse could happen. No energy dissipated to air resistance, crushing and destruction of steel supports, or providing the massive horizontal impulses given to the debris (such as the massive steel piece that hit WTC 6).

[Make7]

290. So if we take your figure of 9.73 seconds....

...for a collapse starting at the 80th floor, add some time for energy used to break up the building - I'll use 4 seconds, that is approximately half the energy dissipated by things other than falling straight down - add another second for the top section to be crushed as it falls into the bottom section, and we get 14.73 seconds. That seems to be reasonably close to the actual collapse time in my opinion.

Wish I had more time to go into more depth on this right now.
____________________

BTW, welcome to DU. :hi: I wasn't sure if you were still around since you only had one post. I'm kinda surprised you haven't found any other discussions to jump into around here.

-Make7

[AlienSpaceBat]

291. it's possible ...

If the top 30 floors did fall that way, without resistance.

I would have guessed that there must be a significant factor to include for air resistance in what is essentially a closed box of each floor being crushed, and the physical breakage of the joints & beams. I'm not an engineer though, and don't know how big or small those factors should be.

Thanks for the welcome. I only started lurking round these parts a short while ago, and hadn't bothered to register to post. I'm away from base for a couple of weeks, but I'll come back then !

[janedoe]

149. Demoliton waves ahead of free fall.

I have provided you with a link to a video, so that you can watch the detonation wave moving ahead of the free-fall of debris.

http://www.911research.com/wtc/evidence/videos/docs/wtc2_demolition_waves.mpg

The following picture shows the detonations ahead of free-fall speed of the particles. If the building is collapsing downward, what are those well-defined narrow clouds moving upward and outward in what appears to be a radial direction?

[Christophera]

159. This Must Have Been Just Before WTC 1 Left The Spire

The spire seems to be just less than half the tower height.



The photo showing the clearly radial expansion at high speed is a littel higher.



That must be the 2 engineering floors that were most concrete where the upper sets of elevators bottomed out. There seems to be more concrete as well as energy involved at that elevation.

[vincent_vega_lives]

186. Time period of any resistance was negligible

Once the collapse initiated either the floor below resisted collapse completely or it didn't. Time would be measured in milliseconds per floor.

[reprehensor]

120. Jane...

I sent you a PM, did you receive it? Not sure if you have enough posts to get PMs.

[librechik]

168. wow. just wow. n/t

[janedoe]

10. Who repealed the laws of Physics?

Check out this video.

http://st12.startlogic.com/~xenonpup/collapse%20update/close-up_north_tower.mpg

The clip playing below looks like the initial segment from the full video.
The full video shows that the radio tower moves to the right, then moves to the left, on its way down. i.e. A clockwise rotation then a counterclockwise rotation. The radio tower appears to stay rigidly connected to the roof, which implies that a correction was probably made in the explosion sequence to keep the collapse motion vertical. I assume they used feedback sensors for this, rather than a visual response (from the helicopter).

Also, I believe the radio tower begins moving, first, before the floors start going down. (This implies that the core columns were destroyed, first, not the outside columns.)



It looks like simultaneous explosions were initiated above the "boundary floor," then the "boundary floor" explodes. (By "boundary floor," I'm referring to that specific floor that is burnt, around the perimeter of the building.) Perhaps the plan was for the plane to hit a few floors lower, in the boundary floor instead of above it. That way, it would look like the part above the damage collapsed into the damaged region, initiating the appearance of a chain reaction. This would be similar to "Case 3" in my post #8, above.

The building face in the foreground (left face) is where the plane went in.

[Make7]

151. The words and picture do not match.

...I turned my attention to steel beams that fell in freefall next to the building as it collapsed. The beams were falling at the same rate that the towers themselves were descending. Familiar with elementary physics, including principles of conservation of energy and momentum, this seemed quite impossible if the towers were indeed "pancaking," which is the official theory. - Dave Heller

http://www.garlicandgrass.org/issue6/Dave_Heller.cfm

Why are there beams below the level of the tower that is still intact? Mr. Heller said they were falling at the same rate - shouldn't they be at the same height?

-Make7

[vincent_vega_lives]

167. How does gravity make explosions?

Ever here of kinetic energy? It is quite good at causing violent displacement of matter.

Ever see a nonexplosive cannon projectile hit a concrete wall? Looks a lot like a smaller version of this. Now before you say that the velocity is MUCH lower...it is but then consider the mass.

[pox americana]

169. It doesn't, explosives do.

What the heck do you think fires that "nonexplosive cannon projectile"? Gravity?

[vincent_vega_lives]

187. The propellant charge only acts to impart velocity

Take "nonexplosive cannon projectile" and drop it from 110 stories and the effect is the same.

No take an object that is at least 1,000,000 x the mass and drop it 10 feet.

[Rich Hunt]

263. uh...

How is gravity going to blow pulverized steel across Manhattan?

Uh....like, it has to go somewhere?

Has a building as high as WTC ever come down? No.

We're not talking about everyday conditions here. "Oh, it looks different." Well yeah, the building IS different. Even the most distinguished engineers couldn't have told you what it would look like beforehand. It's an anomaly because it's a huge building that isn't supposed to come down like that.

[pox americana]

276. It's an anomaly alright.

Tenants are usually permitted to leave a building before it's demolished.

[petgoat]

279. "Even the most distinguished engineers couldn't have told you

what it would like like."

Oh? Tom Eagar seemd to feel it was a house of cards--that one
failing truss pulled down the next and they all pulled down zip bang!
zip bang! zip bang! all the way down. And because they building was
90% air inside, there was no way it could fall anywhere but straight
down.

Now NIST tells us that once collapse was initiated it was inevitable.
Those guys seem pretty confident of their theories.

[Kevin Fenton]

5. Good post, thanks (n/t)

[pauldp]

9. Thanks for the post. Great stuff! n/t

[Ezlivin]

11. Enjoying the silence of critics...

Usually topics like this are immediately assailed by True Believers who say things like "Sure, the whole NIST is in on the conspiracy" and the old chestnut "Who could put all those explosives in the building?"

As this whole sordid tale finally is exposed and the hard work of thousands of dedicated, non-paid sleuths who are the true patriots finally comes to fruition, it will be refreshing to finally hear nothing but silence from the True Believers.

Great work!

[janedoe]

12. We'll have to be our own critics, I guess.

"How did the terrorists get access to the buildings in order to plant the explosives?" The response I often get is, "I can't believe anyone could be so evil as to plan a controlled demolition of the WTC."

Umm... the official story has "evil ones" in it, and they supposedly kill themselves in the process. So, if you're going to find "evil ones" in a story, why would they die along with their victims if they are masterminds?

[petgoat]

278. "How did the terrorists get access to the buildings"

By renting office space? Then using it as warehouse space, so they
could move lots of cardoard boxes in through the freight elevator?

[seatnineb]

13. Agreed!

:toast:

[hack89]

61. Not so silent now is it? n/t

[Rich Hunt]

268. a-ha

The old "declare victory" tactic.

Someone posts something logical (and obvious). Flood the thread with cobbled "evidence" until it is too boring to read. Wear down your opposition by making it damn near impossible to follow the thread anymore. Opposition concludes it is a waste of time and energy (or maybe they just took a coffee break).

Declare victory.

I saw this tactic on Usenet time and again.

[realFedUp]

14. Were the explosives built in or added later?

Sorry, I'm sure this has been answered in another
thread, but don't want to search through all
of them.

Were the WTC buildings constructed with controlled demolition
built in?

[pox americana]

15. Good question.

A post here a few weeks ago said that they were placed during "repairs" after the 1993 bombing but I don't remember who said it or in what thread.

[Kevin Fenton]

41. Explosives after 1993

I am one of the few people who pushes this idea, so it might be one of my posts you're referring to. There were a lot of alterations to the building to get it ready to face another terrorist attack. It would have been a good opportunity to place explosives there. However, there's no specific evidence explosives were planted then - it's just a theory.

The bombers' 1993 plan was to destroy the North Tower so that it fell onto the South Tower, which would then collapse (in the direction of Wall Street, although it probably wouldn't have hit the NYSE IMO). There would have been over 100,000 fatalities, many more than on 9/11.

I like the "explosives after 1993" idea because it explains (1) why everybody who knew of them (there must be quite a few) is keeping silent (they think the towers would have fallen over and killed many more people), (2) that the initial intention of the government of not in itself "evil" (it was to protect people who would have been hit by a falling tower) and (3) why the towers were blown up when they did - a few minutes after they started to lean to one side, an indication they might collapse on other buildings.

[pox americana]

73. thanks Kevin

I thought it was you. It's an interesting theory and I'm pretty sure you've got the cover story (if they ever need to use it) nailed.

p.s. I didn't notice or hear anybody mention that either of the towers was leaning -- did you make that up?

[Kevin Fenton]

125. I don't make stuff up

North Tower
"Now, the south side floors had sagged to the point where the south perimeter columns bowed inwards (Figure 2-12). By 10:23 a.m., the south exterior wall had bowed inward as much as 55 in."
Taken from page 86 of the NIST .pdf file, which you can find here:
http://wtc.nist.gov/pubs/NISTNCSTAR1Draft.pdf

South Tower
"The inward bowing of the columns on the east wall spread along the east face." Page 98.
In both cases the bowing became pronounced a few minutes before the towers fell. The NIST has produced photos to back up this claim.
My argument is that a person watching the towers to check for signs of structural instability would have been worried about the bowing (in my view it was not a good reason to demolish the WTC, because it only affected the top 10-30 floors and only a partial collapse was possible, not a complete collapse).

Cover Story?
I'm suggesting that the explosives were placed in the WTC to demolish the towers following a 1993-style bombing (I suppose you could call this a semi-legitimate use of explosives, although I think it's shocking). I am NOT saying that it was a legitimate use of them.
I don't believe in LIHOP or MIHOP (for various reasons, for example, I'm sure that if they'd known in advance they could have thought of a better excuse for POTUS than "I was reading a goat story." or a better one for Myers than "I don't have a cell phone."). Perhaps a majority of people in the world think the attacks were genuine, the government didn't know in advance and that it only started to manipulate them for its own nefarious ends after 10:07 on 9/11 at the earliest. I agree with the first two points, but just have the timing a little different - the most likely explanation to me is that Cheney, et al. started manipulating the attacks while they were in progress.

BTW, if explosives were placed in the WTC after the 1993 attacks (or if a plan to do this was drawn up), that would explain why the democrats are making so little fuss about all this.

[pox americana]

126. hey thanks

for explaining and sourcing it. I'm trying to download that gigantic PDF file now.

I have a feeling they're probably talking about the walls hit by the planes or some damn thing. Frankly this "bowing" business sounds about as plausible as Eagar's "zipper" theory.

As for MIHOP/LIHOP, there is absolutely no doubt in my mind that (a) these were engineered demolitions, and (b) they could have only been achieved with a considerable amount of off-site planning and testing and on-site coordination (including redundancy) and supervision.

[Kevin Fenton]

128. Bowing walls

The walls that bowed were on the sides the NIST thinks were most affected by the fires - the south wall of the North Tower (opposite where the plane hit) and the east wall of the South Tower (which much plane debris seems to have accumulated along). I don't doubt the NIST is right about the bowing and I can see that a large amount of bowing would cause the towers to fall, but I don't think the towers bowed nearly enough to cause them to fall - in the North Tower the maximum was 55 inches - hardly a great deal when you think the towers were supposed to sway in the wind.

I generally believe the NIST when they are describing external phenomena visible from photos and videos, but I disbelieve them when they are guessing at what was going on inside the towers - I don't believe the fires (and therefore the columns) in the North Tower were as hot as the NIST claims or that United 175 took out all those columns in the South Tower's core.

Many people have made the point that there was a minimum amount of death and destruction caused by the fall (i.e. if it had gone sideways, it would have been much worse). Also, when I watch the video, it seems to be obviously an explosive demolition. There seems to be no attempt to hide or disguise it. If the explosives were put in to specifically destroy the towers after they were hit by aircraft, couldn't the bombers have made it look just a little bit realistic? For example, by only partially demolishing one tower, or leaving the bottom part of some steel columns standing? Also, WTC 7 was destroyed differently, which indicates to me that it was destroyed by another person/team or that explosives were planted at a different time.

Bush said he started taking makor decisions on how to respond to the attacks when he took off in Airforce 1, i.e. a couple of minutes before the South Tower fell. I feel there must be a connection. If it was all planned in advance, why does the VP need to call him to get confirmation at all?

[MindMatter]

130. Explosives after 1993

There seem to be two theories: the 1993 planting and the Aug-Sep, 2001 planting.

Regarding the 1993 planting theory, that makes some sense. Officials could have been spooked by the narrow escape they encountered with the basement bombing. They may have concluded that an uncontrolled collapsed of the towers would have been horrendous -- even more catastrophic than the demolition that did occur on 9-11.

The down side of that theory is that there would be a certain danger in having the buildings pre-wired for explosion. On the other hand, this scenario certainly would explain why Silverstein seemed so casual when he made the comment that they decided to pull the building. If the buildings had been so wired since 1993, who would have known? Would Silverstein have known this? I guess the owner is entitled to know it.

The 2001 planting theory seems a lot more consistent with the idea of a greedy new owner looking for a way to make 7 billion bucks in a hurry, but logistically that seems a real tough nut.

If the 1993 theory is correct, it seems like the government would be motivated to come out with it because it would seem to exonerate them from charges of complicity with the terrorists. Their story could be, simply, "We made the decision to demolish the buildings. We regret the loss of life this caused, but had we allowed the buildings to collapse on their own, there would have been much greater loss of life."

This administration is so secretive -- well beyond the point of paranoia -- that they could never make such a disclosure. It is exactly the case of the plane that was evidently shot down in PA, yet the administration persists in telling the fairy tail of the heroic passengers who valiantly battled the terrorists until the bitter end.

But they have a point. A lot of Americans wouldn't really be too comfortable with the idea that the buildings they work in might be wired to implode at the touch of a button. Of course MANY MORE Americans would be horrified to learn that our government has been lying about this for 4 solid years.

[Kevin Fenton]

224. Silverstein, etc.

I guess a few people at the towers would have known, including the owner. Also, the recently hired head of security at the WTC, John O'Niell, had worked on the 1993 investigation at the FBI and even headed the USS Cole investigation. He would have known if there were explosives in the towers anyway, so maybe that's why they hired him.

I think if the government had said at the time, it would have driven a coach and horses through any attempt to create national unity (the same goes for the shooting down of United 93) - just think of all those lawsuits. Saying now is even more unacceptable - how could they justify covering it up for four years? Also, this is assuming it was the right thing to do and the towers would have collapsed anyway, which is in dispute. There's also the small matter of the several hundred first responders trapped inside the towers when they fell. Bushco would have to say that not only did it have to demolish the towers, but it had to do so at that moment and couldn't give the firemen time to get out.

[Christophera]

216. Thermite Added In Remodel After 1993 Bombing, Basement.

The tower core and floors had to have been built with high explosives placed optimally in the center of cast concrete to cause this effect.



Only the most optimally placed and distributed explosives can cause this breakage. Otherwise you end up with many big chunks.

The thermite was initiated when the demo was down to about 20 floors and it took out the base of the exterior box columns and most of the interior box columns leaving the elevator pits int he basement filled with molten steel.

[janedoe]

17. No.

Somebody might push the "red button" by mistake. If they want to bring it down, they do the engineering work for that, then. Afterall, some portions of the building may not be as originally designed. (like having an airplane parked on upper floors or other remodeling)

[hack89]

19. Were there explosives on every floor?

How many tons of explosives did it take and how long did it take to prepare the building for demo?

[spooked911]

21. I have an idea-- now that we've convinced you it was controlled demo

why don't you work towards getting a new 9/11 investigation from our government, and then we can find the people who blew up the towers and you can ask them that.

Okay?

[hack89]

25. No..

if you can't even advance a reasonable theory on how it could be done than what do you have? I say it was impossible to wire the WTC for demo and your reply only reinforces my opinion.

[OmmmSweetOmmm]

36. Do you really think it would be so difficult to wire them? They were

huge buildings and I wouldn't be surprised that anyone dressed in workmen clothes could have done the job. I worked in the Chrysler Bldg for years and there were always maintenance people all over the place.

I also seem to recall that there a few weekends when the towers were closed for some work? Can anyone help me on this?

[petgoat]

37. Difficult to wire them?

Many of the businesses in the WTC used their offices to warehouse
product, so people moved boxes up the freight elevator all the time.

A "toxic tenant" could have planted the charges in the core simply by
picking a few locks. Radio control would allow detonation without
unsightly wires. And if the zipper theory and the pancake theory are
correct, the building was a house of cards and wouldn't take much
exploding to collapse.

The theory that the buildings were pre-wired with explosives makes a
certain kind of sense when you remember that the mayor's
disaster-control bunker was in WTC7. Imagine a 200-year hurricane
that bends the tower so it threatens to fall over. Under those
circumstances the ability to quickly bring it down would be desirable.
So it's not completely loony to think that the towers were secretly
rigged for demolition.

[hack89]

50. Then please fill in the blanks

It required xx tons of explosives and xx radio receivers

These explosives filled xx semi trailers

It took xx people xx days/weeks/months to do it

All of this was hidden from xx people who worked at the WTC

[pox americana]

54. That's what the 9/11 Commission was supposed to figure out

so ask them.

[hack89]

55. So if I understand correctly...

when you really get to the bottom line, you are unable to formulate a remotely plausible theory on how it was actually done. Beyond your hatred and mistrust you have what? Nothing from the looks of it.

You have also admitted (though I am sure you will not agree) that the BFEE will never face justice for 9/11 because they are the only people smart enough to figure out how it was done!

[pox americana]

58. Sorry, I'd love to believe the official fairy tale

but I lost faith in the 9/11 Commission the day they released their report.

[hack89]

60. So articulate a detailed and reasonable alternative! n/t

[pox americana]

62. Okay I'll spell it out one more time, just for you.

Listen carefully now. Here we go: all currently available evidence, including photographs, video footage, live reporting, witness testimony, thermal imaging, seismographic records, scientific analysis, and more, indicate that the cause of failure for WTC buildings 1, 2, and 7 was three controlled demolitions using pre-placed professionally engineered high-powered explosives.

Was that clear enough?

[LARED]

63. I don't think that met the criteria of

articulate, detailed, and reasonable.

[hack89]

65. Can you take it one step further?

and demonstrate an understanding of what is actually required to make all that happen? If it is such a proven fact why is it that no one in the CT "researcher" community is willing to go out on a limb and offer something more than a superficial analysis of what happened. Where is that analysis that says : "in order for the building to fall as observed, x charges were place on beams x, y and z and detonated in this sequence."? Demolition is a science - calculating and publishing what is required would be easy. Yet no one has even attempted anything beyond superficial analysis of internet pictures and video. Could it be that there are no real engineers in the "researcher" community?

I got a particular chuckle over the scientific analysis - show me a single engineering organization that has challenged the FEMA and NIST reports.

[janedoe]

66. Ummm... don't you remember the demolition expert who said

it was clearly controlled demolition. I think he said this on Sept. 12, 2001. (He was from New Mexico Tech.) Shortly after that, he apparently was threaten by the powers that be and changed his story about a week later. Shortly after that, he got a big promotion.

Hmmm.. why do you suppose he was promoted? If he was "wrong" on 9-12-01 and published it, doesn't that show incompetence? So, why do you think they promoted him? Also, his department received a huge financial contribution ($85 million, as I remember, but not sure of the exact number). The contribution came from either the Bush administration or the RNC, I forget which.

[hack89]

67. No, I don't remember - name and link please. n/t

[Name removed]

68. Deleted message

Message removed by moderator. Click here to review the message board rules.

[janedoe]

69. Here's his reward

http://www.angelfire.com/ny5/tradecencrimes/Van.htm

VP Van Romero Named Chairman of Domestic Preparedness Consortium

SOCORRO, N.M., January 11, 2002 -- Van D. Romero, vice president for research and economic development at New Mexico Tech, recently was appointed national chairman of the the National Domestic Preparedness Consortium (NDPC), a partnership of public and private organizations committed to serving emergency first-responders by training them to respond efficiently and safely to incidents involving weapons of mass destruction.
<snip>

[janedoe]

70. He's even listed on the White House site!-No child left behind

Presidential Advisory Commission on
Educational Excellence for Hispanic Americans

http://www.yic.gov/paceea/adcom/bios.html

Hmm... when do you think he was awarded that position?

[hack89]

71. When I don't know who says what and what story to believe...

I use logic and my own understanding of physical concepts.

This has served me well. bye bye

[pox americana]

72. Don't worry, nobody's trying to interfere with your beliefs.

Note however that the thread topic is "science."

[hack89]

76. Inside joke...

Janedoe gets it.

[rman]

75. does the unbelievability of the official story not worry you?

-

[hack89]

77. So we two unbelievable stories instead of one,

You still have to prove your theories - the fact that the government story could be wrong does not mean your story is automatically right.
And unless you can move beyond what happened and prove how it happened you are not going to convince anything. Look at this thread - it is nothing more than amateur analysis of internet video and pictures plus nitpicking of government evidence and reports. It is as shallow an analysis as you can imagine.

[rman]

78. You do not answer my question.

Does it not worry you that the official story is (by your own admission) unbelievable (which is rather different then "could be wrong")?

And does it not imply that the government seems to be satisfied (and seems to expect us to be satisfied) with a story that is (by your own admission) not based on proof?
Does that not worry you also?

If anyone would have the means to "prove" what really happened, would it not be the government with its vast resources, rather then the numerous non-government mandated commissions created by civilians who are -much like you- not satisfied with the official story?

[hack89]

80. Didn't mean to confuse you...

I was speaking hypothetically - I accept the government story.

I am not asking you to prove anything as much as I am asking you to go beyond the superficial and advance a potential scenario that displays a deeper understanding of explosives, demolition and engineering.

[rman]

81. The official story does not explain the collapse of WTC7

Why do you hold me to a higher standard then the government?

FEMA (Federal Emergency Management Agency) http://www.fema.gov
World Trade Center Building Performance Study http://www.fema.gov/library/wtcstudy.shtm
Chapter 5 - WTC7 http://www.fema.gov/pdf/library/fema403_ch5.pdf

5.7 Observations and findings (page 31)
(...)
"The specifics of the fires in WTC7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence. Further research, investigation, and analyses are needed to resolve this issue."


Note that no further investigation can be done, since all the debris has been removed and much of it sold for scraps to various 3rd world nations.

[hack89]

83. The NIST report expalins more about WTC 7

http://wtc.nist.gov/pubs/June2004WTC7StructuralFire&CollapseAnalysisPrint.pdf

[rman]

85. If it does,

then we have conflicting stories from the official sources.
Not exactly reassuring.

[hack89]

87. I don't hold you alone to a higher standard..

as much as I do the entire community of 9/11 "researchers".

[rman]

89. But you do hold 'us' to a higher standard then you do the government?

Interesting.

[hack89]

91. But the CT community doesn't even meet the government standard

take the NIST report for example - it is full of engineering details that, if wrong, should be easily rebutted. Where is the point by point rebuttal of the NIST report? Surely there is someone in the 9/11 community that could do it -how about Dave Heller? Instead of sprouting questionable physics, why isn't he attacking the government case at its roots? Why has no one factually undermined the very documents that the government says proves their case then it brings into question?

[pox americana]

93. Good grief, where have you been?

Thread after thread here has provided links to sites rebutting the government reports point by point and more. Haven't you been paying attention?

[hack89]

95. I guess not..

can we start with the NIST report first? Thanks and look forward to your reply.

[pox americana]

96. Start here:

http://www.saunalahti.fi/wtc2001/nistcomm.htm#R2

I believe your last comment in the thread that discussed it was:

"Can't argue with "logic" like this.. so I won't. Have a nice evening."

Couldn't have said it better myself!

:)

[Christophera]

162. Hack Convienently Ignores Fear Of Experts

Anybody capable of confronting the ugly truth doesn't nee NIST to know the towers were demolished. Meaning the NIST report is useless, worse, a deceptive distraction.

As soon as the report fails to explain the concrete plumes rocketing upeards and outwards from the core by describing high explosives in use, it's credibility is gone.

Realistically, why would anyone of authority bother. If the the high authorities of law enforcement decide to turn their back on the Constitution an dthe principles of the nation, who is to assume a duty to expose the truth?

[pox americana]

94. Van Romero

JaneDoe, you must have linked to an off-limits site. But that is an exceptionally instructive article, so here's a summary with a link to the original publication (the Albuquerque Journal):

Summary:

Romero is a building demolitions researcher and administrator at New Mexico Institute of Mining and Technology.

He watched the events on TV on 9/11, and was of the opinion that the plane crashes weren't capable of producing such methodical collapses, and were simply diversions to cover demolitions triggered by explosives inside the buildings.

Romero offered this analysis to reporter Olivier Uyttebrouck, who wrote the article which was published on September 14, 2001.

link: http://www.abqjournal.com/aqvan09-11-01.htm

[nomatrix]

74. Hack, why it is inconsistant to think explosives?

• September 6, 2001 - A two week heightened security alert at the WTC is lifted and bomb-sniffing dogs there were abruptly removed.

"The World Trade Center was destroyed just days after a heightened security alert was lifted at the landmark 110-story towers, security personnel said yesterday.
Daria Coard, 37, a guard at Tower One, said the security detail had been working 12-hour shifts for the past two weeks because of numerous phone threats. But on Thursday, bomb-sniffing dogs were abruptly removed.
"Today was the first day there was not the extra security," Coard said. "We were protecting below. We had the ground covered. We didn't figure they would do it with planes. There is no way anyone could have stopped that."
Security guard Hermina Jones said officials had recently taken steps to secure the towers against aerial attacks by installing bulletproof windows and fireproof doors in the 22nd-floor computer command center." Newday 09/12/01

Why was security looking for explosives? Why did they stop?
Maybe this question should have been asked of security by the 9-11 commission.

It has always been the MO of terrorists to use explosives so why would you question that? Or how much, how many people, etc. like it was inconceivable.....

I am also one of those who believe a fail safe *could have* been designed after the 1993 bombing plot revealed the planned outcome of toppling one structure into the other. It would have been irresponsible not to have reviewed steps to prevent a 110 story domino disaster.
i don't think it's a great stretch of the imagination.

[hack89]

79. Here is my issue with explosives..

Everyone glosses over the fact that wiring the buildings for demo is a major industrial activity involving tons of explosives, miles of cables, hundreds of people and a lot of time. It beggars the imagination to think this was done in front of tens of thousands of witnesses daily and no one saw anything. Show me a single person saying after the fact "now that I think about it, I do remember a couple of guys doing something in the wall."

When I mention this, the conversation veers into weirdness like having the explosives build into the building. Your failsafe scenario is another example - you can't postulate a reasonable explanation so you pull this out of thin air even though:

1. you have absolutely no proof.
2. you can't explain in technical terms how it was done.

If someone was to post a 10 page white laying out how it could have been done that included an analysis of the buildings structure, where the explosives were planted and how it would produce the observed collapse then perhaps I would consider the idea.

[rman]

82. The official story doesn't explain much either.

The cause of the collapse of WTC7 is unexplained by the official story (see http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=48327&mesg_id=48640)

The pancake *theory* (supposedly) explaining the collapse of WTC 1 and 2, is proposed by a materials expert, not by a structural engineer, and that theory is highly contested by structural engineers.

I may not be qualified to explain what the government can not explain, but i am qualified to point out that the government can not explain it.
So although i do not exactly know what actually happened, for me the official story is enough ground for suspicion that something else happened then what the government wants us to believe.

The red flag for me is the fact that the government seems to be satisfied with, and seems to expect us to be satisfied with a story that does not explain shit.
Just look at the official motive for the attack; "they hate us for our freedoms". Give me a f'in break.

If you are interested to learn what allegedly has been omitted by the official investigation and the resulting report, have a look a this video recording from a non government-mandated 9-11 commission.
http://911busters.com/video/WMV/CC6_John_Judge_911_Omission_Report.wmv (wmv).
More:
http://911busters.com/911-Commission.html
http://www.reopen911.org/freedvd.php

[hack89]

84. The NIST report has more details

there is also enough detail for a point by point rebuttal if you can.

http://wtc.nist.gov/pubs/June2004WTC7StructuralFire&CollapseAnalysisPrint.pdf

[rman]

88. How about a point by point rebutal by you, of the points presented

in the video, if you can. And how about the points presented by other witnesses and commissioners in the other video recordings.

Are you even aware of the story of Indira Singh and role of Ptech in the FAA, and its connections to Saudi financers who are linked to the Bush family?

And how about you address my comment on the official motive for the attack.


Maybe i should start presenting only one point at a time, as to not make it easy for you to simply ignore most of what i put before you.

[hack89]

86. Can you show a single structural engineer ..

who questions the pancake theory? Can you provide the name the materials expert? Can you show a single engineering organization who has questioned the conduct and results of the NIST and FEMA reports?

Thanks in advance.

[rman]

90. see the OP

you're welcome

[janedoe]

98. I'm a single structural engineer and a materials expert...

and I've questioned the results of the NIST and FEMA reports, right before you.

But, it's obvious that is not what you are looking for...

[hack89]

100. Do you believe that your views are in the mainstream of your profession?

and if so, could you direct me to others in your profession that share your views?

Edited to remove offensive comment. Sorry Janedoe if you saw it before I deleted it.

[pox americana]

102. You asked, "Can you show a single structural engineer"

who questions the pancake theory, and you got one. Now you're trying to move the goalposts.

You could at least say thank you.

[hack89]

104. I was hoping that Janedoe

would use her profession background and direct me to the various profession journals and discussion boards that she frequents - then we could very quickly see what the majority of her material science and structural science colleagues think. I am puzzle that she has failed to link to a single professional engineering site so I thought i would give her the opportunity.

[AZCat]

137. There is one guy I know of...

He writes a column for Plumbing Engineer magazine (accessible online at www.plumbingengineer.com) titled "Fire Protection" and his name is Richard Schulte. He has been openly critical of the NIST investigation, although not in the same manner as most of the posts in this forum. It might be worth checking out if you're interested in seeing what the professional community is saying - just go to the archives section of their web page.

I've been reading his articles for a while but since our office doesn't do any fire system design it has been more of a hobby than a professional interest.

[hack89]

138. Thanks n/t

[LARED]

114. That 's great , the forum now has a structural engineer and

materials expert.

I have a question. I'm a mechanical engineer and have come across eutectic based corrosion a number of times while investigating high temperature steel alloy failures. I'm not an expert and typically defer to hired materials experts for help in determining the precise mode of failure.

As you are a materials expert I'm sure you had great interest in the corroded steel found in the WTC debris that was attacked by sulfur compounds and analysed by the NIST guys. They can't say for sure what or why this happened, so I was wondering what's your opinion regarding this corrosion.

[Make7]

249. Apparently that information is difficult to find with GOOGLE. ( n/t )

[pox americana]

92. There were 80 elevator technicians working in WTC 1 and 2 on 9/11

all privately contracted from ACE. No survivors that I know of have said "Come to thing of it, there were an awful lot of elevator guys around that morning," but you can let me know if I'm wrong.

This says two things:

1) Huge corps of building technicians (and their gear) were a routine sight, and

2) Since at least some were privately contracted, unfamiliar uniforms, faces, equipment and vehicles were also routine.

In other words, they could have taken all the time they wanted to rig the buildings in broad daylight without anybody giving it a thought.

Incidentally, all those elevator technicians left the buildings immediately after the first plane struck, in violation of emergency procedures, and survived. People stuck in the elevators weren't so lucky.

edit: typo

[pox americana]

97. p.s.

and since the elevator shafts were in the structural cores, which had to be blown apart to bring the buildings down, I wouldn't be surprised if that's where the above-ground explosives were placed, however many tons they needed.

[janedoe]

99. Any maintenance work replacing light bulbs in a dropped ceiling

would have produced excellent access to placing explosives anywhere they wanted to put them.

[demodewd]

101. where's your proof?

You have absolutely no proof of your position and far far less scientific logic to go with it.

[hack89]

103. Well, heres a chance to convert me..

you know what information I am looking for - is it your position that it doesn't exist?

Besides, there take no position in my post - it is a criticism of yours (or at least the CT community)

[demodewd]

105. can't support these theories

Maybe you should start providing a feasible scientific explanation for your position. Of which I haven't seen any. Sorry if I don't buy into the total collapse of the buildings within 14 seconds theory,the sufficient amount of energy to provide the massive pulverization of non-metallic materials and still have sufficient energy to reduce the entire building into a pile of steel and dust in 14 seconds theory,or the causation of collapse by exposed steel beams that had lost their asbestos fire proofing theory. Or the fires burnt hot enough to compromise the entire steel columns on one floor that thusly fell simultaneously and met absolutely no resistance from the floor(s) below theory.

[hack89]

106. I never asked you to believe the official story

Pretend I have no position.

All I would like is for you to show me, in a detailed and comprehensive manner, how you think it happened. Not another endless list list of cherry-picked nit picky discrepancies in the government story, no more superficial analysis of internet videos and pictures, no more "smoking guns" based on anonymous sources - just an articulate, well thought out presentation of what you think happened. I am tired of wading in the shallow end - show me some depth to your thoughts.

[petgoat]

108. official story

Asking for proof is beside the point. There isn't going to be any
proof. The evidence has been suppressed. The steel was destroyed, the
blueprints are secret. There's no proof of the official story either.
There wasn't any proof of the Eagar "zipper" theory or the "pancake"
theory, but they were accepted as the truth--but I guess NIST didn't
find them credible because it doesn't mention them.

Look at the Executive Summary of the NIST report on project 3:
Mechanical and Metallurgical Analysis of Structural Steel.

http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

Their steel samples show only "limited exposure if any above 250
degrees C." (See p. 6)

There's no proof of anything. But the collapse of WTC7 and the
destruction of evidence and the gag orders on the firemen all look
very suspicious. As do the free-fall speed collapse, the failure of
the NIST computer model to examine the collapse of the lower part of
the structure (do you really believe the lower core was taken down by
a bunch of falling debris?), and the unexplained conversion of
concrete to dust.

Which is why some of us want a new investigation.

[hack89]

109. You don't get it - do you?

To get another investigation, you need to convince the US public that there is a reasonable alternative to the official story. People accept government incompetence so just pointing out holes in the official story will not get their attention. You have to be able to say "this is what really happened and this is how they did." It doesn't have to be accurate, it just has to be plausible enough to engage peoples imaginations and get them thinking.

So, for example, it is not enough to say that tehe WTC were brought down by controlled demolition - you need to advance a detailed and plausible story on how it was done.

[pox americana]

111. For the imagination challenged, try this:

1. BushCo heard from Tenet (and everybody else) about 9/11 plans.

2. Buscho contacted Marvin (Bush brother who directed firm in charge of WTC security) and said "Marv, wire the buildings for demolition, just in case we have to bring them down in an emergency, but keep it secret so as not to worry Wall Street."

3. Presto.

[hack89]

112. 2a : And the guy who wired the buildings did..... n/t

[pox americana]

113. I hate to give away the ending, but here's a clue:

Maybe all those elevator technicians weren't really fixing the elevators.

[hack89]

115. Ok - if you say so. n/t

[pox americana]

117. Thanks, I thought you'd like it. n/t

[vincent_vega_lives]

154. Maybe

all the office furniture was actually made of C4?

[Rich Hunt]

262. So pancaking is a "theory" now?

Next thing you know, gravity will be a "theory" to some of these people.

Should I bother telling them that pancaking is what buildings normally do when they collapse? What IS the point of placing bombs in a building that is going to collapse anyway?

You can make disinformation, you can fake credentials...you can create an illusion in all kinds of ways, but you can't fake a building collapsing the way it normally does when the top floors can't sustain the weight.

Come on - I had a few architecture classes and even I know that.

This is disinfo, people.

[petgoat]

273. "So pancaking is a "theory" now?"

Yes, Rich. It's a term of art. The prevailing theory of the collapse
came from Thomas Eagar and combined his "zipper theory" with his
"pancake theory" to explain the collapse.

Under the zipper theory, weak truss "clips" at the exterior column
gave way and each pulled down the next and the floor gradually
unzipped from the exterior walls. Then under the "pancake theory" the
weight of the fallen floor floor was too much for the (presumably
fire-weakened) floor beneath it, so that gave way, and the two floors
together tore down a third, etc. etc. etc. Without the lateral
support of the floor membranes, the exterior columns are believed to
have buckled outward.

The obvious absurdity of this theory was that it required that the
clips at the exterior be unbelievably flimsy, and yet the clips at
the core side were so strong that the collapsing floors took down the
core with them. But this was the official dogma until NIST realized
that its obviously wouldn't do.

So now the external clips are incredibly strong. So strong that
floors sagging from excess heating are able to pull on the external
columns strongly enough to buckle them inward. Now when ASCE
presumably had the run of the scrap pile why they couldn't pick out
exterior columns that show which way they buckled I don't know. It
looks like no matter where we turn, we run into the "incompetence
theory".

Now don't forget that under NIST's theory, the steel was overheated,
but they haven't got one piece of core steel that shows heating above
250 degrees C.

If a politically ambitious former federal prosecutor had not ordered
the destruction of the physical evidence, maybe we wouldn't have all
these pesky questions.

[philb]

133. The week end before 9/11 they closed the building for major renovations

and also removed the bomb sniffing dogs that were usually there due to the prior threats to WTC in the fall of 2001.

I understand whoever did the renovations also locked the exits to the roof, resulting in much increased deaths from 9/11
and also cut off the security cameras on the roof that usually have continuous feed; but weren't working on 9/11.

I've seen discussion of this; likely on DU, but don't have the URL.

[vincent_vega_lives]

153. detonators

Anyone handling explosives know that the detonators involve the most risk. A relatively minor jostle or static charge can set one off.

The risk is high enough when safety is the only factor, let alone the need for absolute secrecy.

[janedoe]

157. Doesn't it depend on the type of explosive used? (n/t)

[vincent_vega_lives]

158. Not if we are talking about

military or commercial demolition explosives. If you want to set off a charge electrically, you need a detonator.

[janedoe]

160. No kidding!

Really?

[vincent_vega_lives]

163. So then why did you ask? (n/t)

[Rich Hunt]

269. I suppose

...but people aren't looking at the big picture.

What would be the purpose of adding extra explosives to a building that would likely collapse on its own?

What would be the purpose of that?

What is the purpose of terrorism? It's....to destroy or damage the target and terrorize the witnesses. Mission accomplished, with or without explosives.

What would be the purpose of adding explosives to a building whose upper stories are already destroyed? Can we start asking the larger questions now?

[petgoat]

277. Why add explosives? Because every movie needs explosions.

If the 9/11 event is to make the whole world different now, it has to be
spectacular. Simply crashing planes into towers is not enough. The
towers must fall. Everyone who works in a tall building (or has family
who works in a tall building) must be made to feel very very vulnerable.

That only happens if the towers fall.

[Kevin Fenton]

42. Impossible

I don't think it could be impossible to wire a building for demolition. Surely every building can be wired, it's just a question of time, money and manpower?

[petgoat]

107. Impossible?

Who needs wires? Couldn't detonation have been handled wirelessly?

I find the proposition reasonable that the building was prepared for
demolition as a disaster-readiness program. Imagine a 200-year
hurricane. First of all, they'd tell everybody to stay home that day.
Then, if the building got bent so it threatened to topple, they'd
dynamite it. The fact that the mayor's disaster bunker was installed in
WTC7 is consistent with this idea.

For which, admittedly there is no evidence. But if there were charges
in the building, that would have been a secret. Even more so after
9/11.

[mikelewis]

122. They didn't rig the buildings when they built them....

First of all, if a 200 year hurricane hit New York, they'd have a lot more to worry about than the Trade Center or any other building for that matter. A hurricane with enough force to blow those buildings over would destroy the east coast. That's the point really. That's why the thought of a plane full of jet fuel knocking them over is so completely absurd. Buildings don't simply explode unless there is a cataclysmic reason for them to do so; such as a 200 year hurricane or a shit load of explosives. They're not going to plant bombs in buildings when there is a chance something could go wrong and the bombs explode by accident.

The explosives could have been wireless. The explosives could have been planted at any point. The explosives could have been planted without being seen. While this would be difficult, it is possible. What is not possible is the fact that the buildings fell as fast as they did and pulverized themselves into dust. That is not possible. Truthfully, when they planted them is irrelevant because we know for fact they were there. The peddlers of the OCT are the one's who have to explain when and how they got there or they have to come up with an explanation as to how those buildings defied the laws of physics. The balls in their court and they don't seem to want to play.

Which leads me to something that could be possible but is next to impossible to prove. The command bunker was built for 9/11. I believe it was where the attack was coordinated. I also believe flight 93 was supposed to have struck this building after the towers collapsed giving no doubt as to why WTC7 collapsed. Since it failed, they decided to "pull it" anyway and "we watched the building collapse". Again, this is possible, to me it even seems logical. The reason I believe this is very simple. If I were going to bet which building flight 93 was going to hit had it not stopped flying, I would bet it was the only other building to mysteriously collapse but was not hit by a plane. I believe WTC7 is the smoking gun for 9/11. It's the smoking gun because it died but was never hit by a bullet and flight 93 was the bullet that missed it's mark. Something killed that building and it wasn't the silver bullet that was scattered over 8 miles of pennsylvania.

[petgoat]

127. 2 Planes 3 Buildings is Intellectually Dissonant

When the explosives were planted is irrelevant to someone who already
believes explosives were planted.

For someone who will argue that planting explosives was impossible
because it would require a massive conspiratorial labor force and the
smuggling of tons of explosives into the building and the laying of
miles of control wire the notion that the building was pre-wired might
open a cognitive window.

Your "Flight 93 Was Meant for WTC7" theory is an interesting one. The
question it raises for me is... why WTC7? Why not a symbolic target
like the Capitol or the Liberty Bell or the Statue of Liberty?
Perhaps the answer lies in computers and records destroyed in the
offices in the WTC7, offices of the SEC, the IRS, the FBI, and the
CIA.

One of the striking things to me about the destruction of WTC7 is that
it provides a perfect excuse for keeping the local FBI agents off the
case. "Yeah, normally you would handle it, but hey Bud, you have no
office. So let the guys from Washington handle it, okay? In fact,
until we can build you some new offices, maybe we'll just reassign you
to South Dakota."

I have no evidence for this scenario of course.

[mikelewis]

131. First of all, you wouldn't need tons and tons of explosives...

nor would you need miles or wire. Demolitions are small charges places in key locations that cause a loss of structural integrity resulting in a collapse. The explosions don't control the collapse, the timing and placement of them does. Always remember, it's not the size that matters, it's how you use it.

Flight 93 was alledgedly headed for the White House. Support for that theory comes from a Secret Service transmission to the Air Force pilots over D.C. to protect the White House at all costs. Because there is no earthly way they could have known it's destination, it is misleading to assume this was it's actual target.

[petgoat]

132. you wouldn't need tons and tons of explosives

If the zipper/pancake theory is correct, you need only blow one floor
truss loose from the exterior column and that tears loose the next and
the next and the next, and the tumbling floor tumbles the next and
the tower comes tumbling down.

Who needs explosives? If that theory is correct, a guy with a crowbar
could have brought the towers down!

Of course, NIST's failure to endorse the pancake and zipper theories
pretty well shoots holes in it IMHO.

[Christophera]

191. Not For Ordinary DEMO Where Big Pieces Are Found, Or Free Fall Seen

What you say is true mikelewis, for an ordinary demolition. Placement is everything, as well as distribution.

What we see here,



if it were a collapse caused by minimal charges, would be comprised pf many big pieces that were separated by a loss of structural integrity.
What is seen at the top of the descending tower is sand and gravel arcing up and out. This is essentially a continuous series of explosions that continued to the ground.

[vincent_vega_lives]

221. which would call for literally several tons of explosives

planted throughout the building.

There is plenty of energy in that building to smash the concrete in the floors to fine grain "sand & gravel".

Each floor is 200' to a side and 4-5" thick. 40,000 sqft of concrete per floor. The part of the building above the collapse point weighed around 100,000 Tons, falling 12' on to the floor below.
Instantanious velocity after falling 12' = 8.4m/s

KE = (.5)*(95,238,095kg)*(8.4m/s)sqd

KE = 3,359,999,991.6 joules (3360 MJ)

3,360 MJ = from 1,570 to 1,721 lbs of TNT depending on source

[Christophera]

259. Minimum Explosives = 14 Tons & There Is No Gravel In Floors

Posted by vincent_vega_lives

There is plenty of energy in that building to smash the concrete in the floors to fine grain "sand & gravel".

The floors were lightweight concrete which contains NO gravel. It is comprised of vermiculite, flyash or pumice with fine silica sand and portland cement.

Jim Hoffman calculates 14 tons of high explosives would be needed to create the dust and propell it into the massive clouds that existed.

I think more than 25 tons was used. And of course if that went off without optimum containment and distribution, the detonation would have looked a lot different than what we saw.

The energy contained in the falling mass is enough to break a lot of concrete, but the notion that high strength structural concrete would be crushed is non sense. Lightweight concrete yes, but not structural.

[vincent_vega_lives]

280. 82.5 tons of explosives

That is the approx equivalent energy released during the collapse if one considers that the buildings weighed 500,000 tons.

[MindMatter]

136. "When the explosives were planted is irrelevant"

"When the explosives were planted is irrelevant to someone who already
believes explosives were planted."

Hardly. If the explosives were installed in 1993, this suggests that Giuliani, perhaps in consultation with Cheney, made the decision to pull the buildings as a lesser of evils scenario. Their crime in that case is one of massive cover-up and of lack of attentiveness to the "gathering" terrorist threat.

If the explosives were placed in the weeks leading up to 9-11, this suggests active participation by this administration in the planning and execution of the 9-11 event.

Timing makes all the difference. Two different scenarios. Two entirely different crimes.

[spooked911]

231. Welcome to DU!!!!!!!!!!!!!!!!!!!!!

:toast: :party: :toast: :party:

and yes, good point.

[philb]

134. They have some pretty powerful explosives in small packages these days

and there is a lot of controlled demolition going on and lots of people with expertise in how to do it.
This didn't have to be the usual precise, careful job.
Just get enough explosives in the right places to bring the towers down.

[spooked911]

230. Yep, exactly.

[janedoe]

39. I'll second that.

Wouldn't it be nice if the "PATRIOT ACT" included accountability?

[mikelewis]

118. I'm sorry, but I don't believe we need to answer that question...

You're argueing that the towers could not have been wired by explosives because this would have been impossible to do. People would see the workers wiring the buildings and someone would have noticed men placing explosives in the buildings. What you fail to take into consideration is the fact that the buildings could not have simply pulverized themselves at that speed. That is impossible. So, either we are all completely wrong about how long the buidings took to hit the ground or some other explanation must exist to account for the speed of collapse. Since the OCT states the speed of collapse and that is impossible without some other force acting to move that building down faster, the burden of proof is not on us. The burden of proof is on those who say it the building naturally destroyed itself according to the laws of physics. Is the time it took to collapse wrong? Is the equation for calculating the freefall speed wrong? If none of these calculations are wrong, the burden of proof lies on the shoulders of those who say this is inaccurate. It was impossible for those buildings to fall without an outside force such as controlled demolitions. It's irrelevant to the arguement as to when they were placed, it could not have acted that way without them. And you know it.

[petgoat]

121. NIST Computer Modeling

The computer models NIST generated to explain the collapse were
truncated at floor 91 (WTC1) and floor 77 (WTC2) (see p. 27 of the .pdf)
and the time of the modeling ended when the collapse started. (see p.
29 of the .pdf)

ht tp://wtc.nist.gov/pubs/NCSTAR1-6ExecutiveSummary.pdf

Thus NIST neatly sidestepped the most glaring question about the
collapse: why did the towers come down at nearly freefall speed, with
no resistance by the lower structure?

[Christophera]

110. What Collapse? I Only Saw A Demolition.....

We Don't Need No Stinking Badges..........

to know this.

Good to see a thread about the WTC towers in the 9-11 forum instead of current subterfuge of secret, distractive origin and media.

[hack89]

116. A classic, incoherent Christophera post - we missed you! n/t

[rman]

123. classic ad hominem

[hack89]

124. Yep n/t

[Old and In the Way]

119. How much explosives would be needed?

Here's a clue from a post a made back ilast November-

I got this special US News and World Report last Christmas. The Magazine was called "Secrets of the Master Builders". The last article, whose title is noted above was quite interesting. It's been sitting in the bathroom and I finally got around to reading this article today.

Anyway, there were 2 interesting paragraphs I thought I'd share.

"The tools of the destructor's trade range from standard dynamite, used to shatter concrete, to linear shaped charges that concentrate the force of the blast. Shaped charges use a high explosive called RDX, slicing through steel with millions of pounds pf pressure per square inch. In 2001 project, for example, a New York gas storage tank built with 5 million pounds of steel took a mere 80 pounds of shaped charges to come down.

[philb]

135. So a little RDX does a lot of destruction. is this commonly used

and to whom would it be available?

Sounds like this would be a candidate for a job like the towers.

What other options seem plausible?

[vincent_vega_lives]

152. Hmmm a gas storage tank?

You mean a huge hollow tank? Hardly the same, just an outer wall to compromise.

The WTC towers had over 200,000 TONS of steel. Thats 80 times more than the gas storage tank. So in your comparision you would require 6,400 lbs of shaped charges,

[philb]

145. New witness reports explosion before WTC2 collapsed

Witness to WTC destruction from a neighboring roof:
“There was a crowd of my neighbors gathered on my roof, most with cameras. As we watched, the South Tower exploded and then collapsed.”

“Screams of Horror were heard from people all around the area as people watched the second tower implode and collapse”

http://www.melomane.org/nine_eleven/tragedy.htm

[philb]

146. What caused the huge wall of heat reported by many witnesses?

College student 5 blocks from WTC
All of us on the roof were paralyzed with shock and didn't notice the enormous cloud of ash coming towards us until it was too late to escape. Then it hit us. It felt like a hard wall of hot smoky breath. Our eyes were immediately caked and our clothes saturated with itchy dust.
I'm writing this story from the 25th story of my building overlooking downtown New York City, where I live five blocks from the World Trade Center towers http://www.sckans.edu/campus/southwesterner/2001winter/swtrnr_terror.html

[philb]

161. Firemen and survivors report basement explosion at WTC2 before

the tower "collapsed"

When the fire rescue team reached an area directly in front of Tower Two, Antonio said he'd take over the equipment cart Will had pushed from Building 5. ... The team moved ahead. Scant minutes passed. Suddenly the hallway began to shudder as a terrible deafening roar swept over them. That's when Will saw the giant fireball explode in the street.
Seconds later the team's entire world began to crumble. It was precisely 9:59 a.m. The Trade Center's South Tower had just collapsed. http://www.bowhunter.com/feature_articles/BN_FromTheRubble/


United Airlines Flight 175 struck the 78th through 84th floors of the south tower at almost 9:03 a.m., 16 1/2 minutes after a jet hit the north tower.
Brian Clark, executive vice president of Euro Brokers on the 84th floor, was standing against the west wall when the higher wing of the Boeing 767 hit his floor. "It felt like the building was going to fall," he recalls. Five Euro Brokers colleagues walked with Clark into the hall, turned left and entered Stairway A. Clark and co-worker Ronald DiFrancesco continued down. Clark heard banging from inside Fuji Bank's wrecked office. "Help! I'm buried! Can anybody help?" yelled Stanley Praimnath, a loan officer. Clark pulled him from the rubble and they walked down together.
As he left the building, saw a fireball rolling toward him. He put his arms in front of his face. He woke up three days later at St. Vincent's hospital. His arms were burned. Some bones were broken. His lungs were singed. But he was alive.
http://www.usatoday.com/news/sept11/2001/12/19/usat-escape.htm

[philb]

170. Hundreds of firement statements released under FOIA- explosions reported

http://www.flcv.com/firemen.html

[spooked911]

173. Here's another article saying that the speed of the towers collapse

is proof of demolition:
http://www.attackonamerica.net/proofofcontrolleddemolitionatwtc.htm

As your eyes will tell you, the World Trade Center collapses looked like controlled demolitions. Here's the proof.

The proof. According to the law of gravity, it is possible to calculate the time it takes for an object to fall a given distance. The equation is H=(1/2)at2, where H is the height, a is the acceleration of gravity (10 meters per second squared) and t is time in seconds. Plug in the height of the building at 1350 feet (411 meters) and we get 9 seconds. That is just about the length of time it took for the very top of the World Trade Center to fall to the street below. According to all reports, the whole thing was over in just about ten seconds.

It is as if the entire building were falling straight down through thin air. As if the entire solid structure below, the strong part which had not been burned or sliced or harmed in any significant way, just disappeared into nothingness. Yet this (within a small tolerance) is what we would expect to find if there had been a controlled demolition, because the explosions below really do leave the upper stories completely unsupported. Like the Road Runner after he runs off the edge of the cliff, the entire building pauses a moment, then goes straight down.

Any kind of viscous process or friction process should have slowed the whole thing down. Like dropping a lead ball into a vat of molasses, or dropping a feather into the air, gravitational acceleration cannot achieve its full effect if it is fighting any opposing force. In the case of the World Trade Center, the intact building below should have at least braked the fall of the upper stories. This did not happen. There was no measurable friction at all.

This proves controlled demolition.

The only thing is he got the Roadrunner and WilE Coyote mixed up. :P

[LARED]

174. Serious question

Why do you cling to the falsehood that the towers collapsed in about nine seconds. It is obviouly false.

[spooked911]

176. Huh? When did I ever cling to this?

I don't know how long it took, in fact the exact time is hard to know. But I assume it was somewhere between 9 and 16 seconds. Certainly not longer than 16 seconds.

By the way, how do you like this quote?
the gravitational potential energy of a skyscraper is nowhere near sufficient to destroy its own frame.

:) :o :D :) :o :D :):P :7 :o :D :)

[LARED]

177. Not clinging you say? So how about advocating?

You stated

Here's another article saying that the speed of the towers collapse is proof of demolition:

You are stating it is proof, yet the proof requires that the towers fall at free fall speed. Obviously if the towers did not fall at free fall speed the proof in not a proof, it is just nonsense.


the gravitational potential energy of a skyscraper is nowhere near sufficient to destroy its own frame.

is a fine and dandy quote. It's not quite as good as

"Guard with jealous attention the public liberty. Suspect every one who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are inevitably ruined." (Patrick Henry)

and it would be real nice if the author states why he feels this way. There is no reason I can think of to believe it's true. BTW, I do think the quote from Henry is true, maybe that's why it's famous

[spooked911]

179. All I said here was that the article claims

the speed of the fall is proof of controlled demolition. I didn't say he definitively PROVED it, I was just reporting what the article claimed-- he said it was proof. He also said the collapse was over in about ten seconds, which is what many people say.

As far as your quote, it is a good one.

But are you somehow accusing me of trying to take away the public liberty? Lowly little me? Why aren't you more suspicious of the Bush administration? They are the ones that have the control over public liberty, and there is ample reason to suspect they know a lot more about 9/11 than what is in the official record.

[LARED]

182. Ok

So why did you post the article if you don't think it proves anything?

BTW, the quote was not directed in any way torwards you, I just like it.

[vincent_vega_lives]

189. This begs the question

IF the building had somehow failed at the point of impact/fire (as impossible as that may seem :eyes: ) how would you expect the building to behave and over what period of time?

[spooked911]

196. It would collapse much much slower, and maybe not collapse completely

Janedoe has posted nice graphs here somewhere that show how each floor should start free-fall separately, thus lengthening the overall collapse time to over a minute. If you assume that momentum from the falling floors sped things up a bit, then it should still take a good thirty seconds. But these calculations are calculating free-fall in a vacuum and not accounting for air resistance, so the collapse would probably take something like a minute.

Also, the upper chunk of the south tower should have stayed intact longer and should have fallen off at more of an angle instead of just turning into dust.

[vincent_vega_lives]

198. In order to know this

One would have to know the ability of the structure to resist lateral stresses to remain intact during tipping, the amount of force applied to each floor, and the ability of each floor to withstand the transmition of impulse energy.

[spooked911]

200. You don't have to know that in order to know that it doesn't make sense

for that upper structure to turn to dust within seconds of tipping.

Besides, we have an explanation for why it disintegrated-- explosives:

[vincent_vega_lives]

201. Perfect - mystery solved!

We can disband the FBI, we have spooked911. :eyes:

The upper structure hardly turned to dust...or are there some type of explosives from a different dimension that can turn steel beams to dust?

People here continue to underestimate the forces involved. KE when involving the mass that is in motion here can easily be greater that that provided by CE from explosives.

[spooked911]

202. Oh yeah, the FBI. They certainly left no stoned unturned in their

neverending quest for the truth about 9/11.


:crazy: :crazy: :crazy: :crazy: :crazy: :crazy:


And just ignore those multiple explosive jets coming out of the side of that building. :)

[vincent_vega_lives]

208. Explosive jets

do they involve pods of some sort?

Go watch some more movies dude and tell me some more about "explosive jets".

[spooked911]

214. Denial is a wonderful thing.

watch this video if you dare:
http://www.terrorize.dk/911/wtc2dem10/911.wtc.2.demolition.south.air.mpg

In particular watch carefully for the first second as the top tilts.

How many puffs of smoke are coming out the west (unaffected) side?

[Christophera]

217. In Above Ground Blasting It's Referred To As "rifle shot".

Occasionally when blasting stone formation high pressure gasses will escape through one crack causing large jets of gas and fine particulate, old timers referred to it as "rifle shot" because it often had pebbles in it.

The below is not that. It is a series of floor panels of one floor, detonating prematurely.



Some have said they though it was compressed air from the above collapse. Nonsense. The windows woun't contain enough pressure to have a breach like that.

I do not think spooked9-11 is a pod person, but your point about "movies" is well made in reference to much of what happens in this forum.

[janedoe]

212. You mean these?

So, the official explanation for these explosive jets was... to ignore them? I wonder why. :think:



It's amazing how perfectly symmetrical and centered they are.
What creative explanation do you think they could have come up with if they tried to explain these?


:nuke:

[petgoat]

215. Those isolated puffs are disturbing;

I've always explained in my own mind the puffs-in-a-row as windows
blowing out because air was forced down an elevator shaft to an open
elevator door or something.

Given the open floor plan those isolated puffs make no sense.

[vincent_vega_lives]

220. If those were explosive blasts

Then they obviously had nothing to do with the building collapse

1. You would expect to see them moving in a wave down the building.
2. These blast appear to have no effect as the progression still has a way to go before reaching them.

A good explanation would be that the floors are collapsing internally, and sending air explosively down stairwells, elevator shafts, perhaps even sections of the floors coming down. The collapse was an extremely violent event, even without explosives.

[petgoat]

225. "A good explanation would be that the floors are collapsing internally

and sending air explosively down stairwells, elevator shafts"

That's not a good explanation, because only one window blows. If the
air was coming down the elevator shafts, all the windows on the floor
should blow if the floor remained inits oringinal open plan. Was there
interior remodeling that might put a hallway leading from the core to
the window? I guess that might do it.

[Christophera]

226. "Then they (EXP.) obviously had nothing to do with the building collapse"

Seeing as the building was demolished and did not collapse, the statement is true and it is true that since they are separate, they are not a actual part of the demolition with their mis timing.

In the photo below the progressive wave or chain of delayed explosions is seen over the premature detonations, explosions or "jets/puffs" created by erroneous installation of delays. This becomes very clear when the "puff" of explosion is a horizontal line or floor line.



How can windows hold enough air pressure to rip apart lightweight concrete and create dense jets of particualte?

[petgoat]

227. "How can windows hold enough air pressure?"

Good point. While a horizontal row blowing out is consistent with the
elevator shaft theory, the air should be clean--with ejected office
debris, maybe, but where would that dust come from?

What's that confetti under the red arrow near the bottom of the picture?

[janedoe]

228. Windows? What windows?

Did you notice that the floor by the red arrow (with confetti ) is on a floor where there are no windows! That's the floor 41-42 mechanical level. Compare it to WTC1 at that height, then look back at WTC2, and you'll see it's that same level.

[spooked911]

229. Whoa-- that is a really important find. That simply screams planted

explosives.

Great work!!!!!!!
:toast: :toast: :toast: :toast: :toast: :toast: :toast:
:yourock: :yourock: :yourock: :yourock: :yourock: :yourock: :yourock: :yourock: :applause: :applause: :applause: :applause: :applause:

[Make7]

232. It "screams planted explosives?" How so? ( n/t )

[spooked911]

233. In that there wouldn't be windows blowing out at that part of the building

so the smoke puffs probably come from explosives detonating prematurely.

Now, it is possible that there are a row of vents there blowing out the concrete dust from the collapse above. It's possible. On the other hand, those mechanical floors would be a perfect place to plant explosives without being seen by too many people.

[Make7]

235. I guess it's possible there are vents.

Aesthetics concerns
____________________

Most mechanical floors require external vents or louvers for ventilation and heat rejection along most or all of their perimeter, precluding the use of glass windows. The resulting visible "dark bands" can disrupt the overall facade design especially if it is fully glass-clad. Different architectural styles approach this challenge in different ways.

In the Modern and International styles of the 60s and 70s where form follows function, the vents' presence is not seen as undesirable. Rather it emphasizes the functional layout of the building by dividing it neatly into equal blocks, mirroring the layout of the elevators and offices inside. This can be clearly seen on the World Trade Center twin towers and the Sears Tower.

picture
The former World Trade Center twin towers. The "dark bands" are vents for the mechanical floors.

http://en.wikipedia.org/wiki/Mechanical_penthouse

-Make7

[vincent_vega_lives]

238. I guarantee you won't get a response to this...

Nothing to see here!

:rofl:

Good one.

[Name removed]

241. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Make7]

244. I think you may have jinxed it. ( n/t )

[seatnineb]

247. Golly..........I must have jinxed the base of WTC2 aswell!.............

Here is the base of WTC2 JUST BEFORE it collapses.

You can see that amorphouse mass of dust swirling towards the firemen who are gathered at the north-west corner ,relative to WTC2.



The cameraman then pans his camera upwards to catch the initiation of the collpase of the top portion of WTC2..........

[Make7]

250. Umm...I was responding to vincent_vega_lives.

I replied to Post #238.

It gets all goofy when there are so many responses it ends up with all the messages lined up in a row.
____________________

Do you know where there is a video clip that the first screenshot is from? It's difficult to tell what that is from just the one frame. I have a somewhat stupid idea of what it might be, but don't care to venture a guess without some neighboring frames for comparison.

And the lighting on the last one is strange. It almost looks like it's glowing white with a hint of blue in it. What do you think that could be?

-Make7

[seatnineb]

253. O.K

Go to this web page:

http://terrorize.dk/911/wtc2dem4/wtcwestblow.php#westbelow

And click on this link at the top.............

Video: 911.wtc.2.demoltion.west.below.wmv -- 320 x 240 pixels, 20 fps, 0m14s, 558KB

[Make7]

254. Thanks for the link.

I just might have to learn Danish one of these days. :)

Anyway - unfortunately that didn't clarify it for me. In fact, I'm not really sure what that is in the first screen capture. Two observations about it though:

1. It doesn't really appear to be moving as far as I can tell.
   
2. The lighting in that area seems to be brighter than the area just to the left of it.
   

____________________

The last screen capture looks like it is happening on the mechanical floors. It looks like it might be water to me. Notice, in the video, how it seems to fall quickly after exiting the building? What do you think it could be?

-Make7

[seatnineb]

255. Where there is smoke at the base ......there is a collapse........

As for this:



It is clearly moving.....as far as I can tell.........

With regards to your second question.....

I'm not sure what that is either.....It would be nice to see the unedited video of this segment...as opposed to a few seconds of a WMV.

[Make7]

256. I believe the saying is:

Where there's smoke, there's fire.
____________________

I just watched the video again and I don't see any obvious movement of that...that... whatever it is.

I would think if it was caused by explosions, it would be moving at a fairly rapid rate. Maybe it's smoke from a fire.
____________________

I agree, it's sometimes difficult to tell what is going on in these somewhat less than optimal quality computer video clips on the internet.

-Make7

[Name removed]

257. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Make7]

258. I could've swore that I read FDNY interviews that mentioned...

...flaming debris falling from Flight 175's impact and also numerous accounts of vehicles on fire after the buildings collapsed.

I wonder if flaming debris starts fires....

I wonder if vehicle fires generate smoke....

-Make7

[seatnineb]

260. I stand corrected...here is your fire........BEFORE WTC +WTC2 fell........

(Thanx to K-Robjoe)

Looks like this fire was in the south west corner of the complex....


So your analysis is correct.....and my demo theory is wrong.

[Make7]

261. I'm still curious about what's going on in this picture:

I think it looks like water when I watch the video, but it is so far below the collapse I'm wondering what's going on.

-Make7

[Rich Hunt]

270. actually it doesn't

Other than the fact that we're looking at buildings being destroyed.

The top two are a lot cleaner and, um, the buildings are a hell of a lot smaller. WTC destruction was a huge mess.

No, to my eyes, it doesn't look like a standard demolition. What's more, "planted bombs" would not have been necessary. The targets were taken out and people were duly terrorized by the spectacle. Mission accomplished, I'd say.

[seatnineb]

272. You might be right....but you might be wrong.....

Fox 5 News:

“There is an explosion at the base of the building….white smoke from the bottom …something has happened at the base of the building… then, another explosion. Another building in the World Trade Center complex….”

[petgoat]

274. "doesn't look like a standard demolition." But Van Romero said it did n/t

[seatnineb]

281. Mod......You seem to have a problem with this photo?

What is wrong with posting this photo?

[Make7]

283. Perhaps it is because of the website hosting the image. ( n/t )

[seatnineb]

284. Yes......that it is what I thought too.........but.....

....I have always assumed that image itself has been lifted from mainsteam media by W****************d .com

So what is the big deal?

[Make7]

285. I don't know.

There is nothing about the picture itself that should cause a problem. Maybe you could find another source, or just put that picture on a free image host and see what happens when you post it. Like this:



Hopefully, you will get an answer from the moderators as to what exactly the issue is.

-Make7

[Kevin Fenton]

240. Ejecta

What are you saying is being ejected through the louvers? Dust that's fallen down an elevator shaft?
How come it's only coming out of from middle section of one face of one the mechanical floor?
Are you saying that such "squibs" are only visible from mechanical floors?

btw, Do you agree with NIST that United 175 destroyed 10 core columns in the South Tower?

[Make7]

245. I was just saying that there are vents for air circulation.

What is being ejected could be a number of things, but seeing as how it's happening on a mechanical floor it could be dust that has gotten into the building air handling system. Or it could be part of the floors internally collapsing before the collapse of the perimeter walls. Or dust coming down the elevator shafts. Or.....

It might be localized to the middle of that face because that's where the air handling system is, or there is heavy machinery blocking the path from the elevator shafts except for at that particular point, or maybe there was a partial floor collapse right there.

I really don't know what is causing it to happen. I don't know that anyone really does, we can't see what's happening inside the building.

To tell you the truth, I haven't looked into it that much, but I seem to recall seeing "venting" on floors other than the mechanical floors.

Once again, there is no footage of the inside of the building at the impact area, so we can't really know how many columns were destroyed. 10 seems a little high to me, but no one can say for certain. It may actually have been more. I do believe that the plane took out the corner core column, which is significant because the corner columns share a larger portion of the load per column than any of the other columns.
____________________

You've read the NIST report right? In their modeling, did they factor in the load the wind would put on the buildings?

-Make7

[Kevin Fenton]

246. Various

I also seem to recall venting on floors which are not mechanical floors.

Localisation
Generally the claim is that there were rows of explosives, so if this is a squib from an explosive, then it must be firing both out of sequence regarding the fall of the towers and indpendently of the other explosives on the row (unless there were no other explosives there because it was a mechanical floor, which might also explain why it was firing out of sequence, although I'm not sure how exactly).

If it's venting, should the venting be going down the towers as they fall, or both up and down?

Is there any reason to think that if the towers were demolished by explosives that there would be no venting?

Although I have not read every single page of the NIST report (didn't bother with the recommendations, etc.), I don't recall much (if anything) about wind load. They said the collapse was preceded by bowing in both cases. Why do you think the wind load is significant for the two towers, given the collapse initiation was supposedly different for both of them? Or do you think it might have been significant for just one of them?
I checked the seven factors decisive for the collapse of WTC 1 on page 34/88 and wind load is not mentioned there. Neither is it mentioned for WTC 2 on page 45/99. So they either didn't think about it or did think about it, but thought it was not significant.

The point with the 10 severed core columns in the south tower core is that the collapse (if it is a "natural" collapse) is a product of various factors (I'm aware this is a simplification): primarily the external impact damage to the perimeter columns and flooring (which is discernable from evidence), the damage to core columns and other members, fireproofing knocked off members and the heaping of combustibles (the last two factors help determine how the fire acts on the steel). NIST seems to have arrived at what I'll call "values" for these four factors given which the tower collapses after 56 minutes. If you think one of these "values" is too high, then surely you must think one of the others is too low, otherwise the tower would not collapse after 56 minutes, but after a longer time. For example, if less core columns were severed than NIST claims (but its claims regarding the other factors influencing the collapse are correct), it should follow that the tower would have stood for longer - say 10 minutes more for each extra column, for the sake of argument. So if you think 10 is a little high, which NIST estimate do you think is a little low? For example, do you think they underestimated the amount of fireproofing knocked off members?

Elements of the plane (e.g. engines and landing gear) clearly retained their ability to sever some columns even after crashing through the perimeter, but the right wing of United 175 (enigne and landing gear) only severed 2 further columns (in the permieter on the other side). NIST claims American 11 severed 6 columns in the north tower core (which it hit head on in the middle). United 175 was travelling faster than American 11 at the moment of impact and the core was closer to the south wall of the south tower than the north wall of the north tower, but the core columns got thicker the lower down they went. The figure of 10 seems more than a little high to me.

Why is the corner core column more significant? Because it's bigger than the others?
Why do you believe it was taken out by the plane? Which bit of the plane?

btw, According to NIST in addition to severing 10 core columns, United 175 also stripped 39 of them of their insulation, in some cases on multiple floors.

[Make7]

251. Yes, it did happen on other floors too.

I think venting would generally go downward although there may have been other causes which might have created anomalies.

If explosives were used, I am reasonably certain that venting would occur.

I actually brought up the wind loads because I think that may have had an effect on the South Tower. The wind was blowing in a southeast direction which could have put additional stress on the damaged southeast corner of the building. The wind load probably was not constant either - a changing load probably would have had more of an effect than a static load from a consistent wind speed.

I know I sound like a broken record, but since we don't have pictures or video of the inside of the buildings at the core area, we probably will never know for sure how much damage was caused by the impacts, and where that damage occurred.

The corner column is significant because I remember reading in a NIST report somewhere that the 4 corner columns of the core handled close to 20% of the entire gravity load of the core.

I think the southeast corner core column got taken out because a FEMA report indicated that, based on the trajectory of Flight 175, the fuselage was likely to impact that area of the core. Maybe it didn't, I could never really effectively determine the plane's path into the building from the video footage. (Although I must say I didn't work too hard at it.)

Obviously, if someone were to definitively prove exactly what happened there would not be nearly as many theories to explain the collapses. However, that does seem unlikely to happen.

-Make7

[petgoat]

252. Did UAL 175 Destroy 10 Core Columns?

Good catch, Kevin. The 911research debunking of NIST points that out--
175 hit at an angle and could not have destroyed 10 columns.

[spooked911]

242. Okay, guess I got a little over-excited there.

[Make7]

243. No problem - it happens to all of us. ( n/t )

[Christophera]

248. If Compresed Air From Vents, Why Only Some? Windows Above Unprotected.

If the dust and particulate is coming out of vents, why only on one side of the building? And still, for the vent to be passing that kind of expansion of air frmo the compression of falling debri inside the building, windows above would burst outwards and they are not.

[Christophera]

234. Wow, You're Right, Nearly Solid Concrete. There Are Windows above and ...

that makes my point rebutting the contention that the jets of particulate are caused by compression of air inside the tower below the downaward advancing debri mass, even stronger.

What kind of air pressure do the windows above contain that blows solid concrete out the side of the building below?

It is the ovious evidence, that by simple inference, begins to prove the demolition by showing what can only happen with optimum, adequate and uniform placement of high explosives achieving total pulverization in place, that will show America the truth.

[petgoat]

236. Good Eye, Jane. I just noticed those bands today, wondered what they

were. One possibility then: that the dust is being blown out the air
intake from a heating system? It's dust from the ductwork? Otherwise,
yes, the mechanical room seems an ideal place to plant explosives--
except that a sharp-eyed engineer from Berkeley might look at some
pictures four years later....

I'll repeat my question. What's the confetti down near the bottom of
the picture? Under the red arrow.

[janedoe]

178. Wait, didn't I see a post, somewhere,

with a model of the collapse, claiming that it only required 1/3 of the building's potential energy to destroy the building ...and in 16 seconds or less!

Hmmm... it appears that we can't trust any of their "engineering" judgement. It's null and void. Time to move on.

So, where did that quote come from that you posted?

[Make7]

190. Actually 16 seconds for 1/3 PE was your calculation.

It would be 2/3 PE for a 16 second collapse time.

 collapse time | rate of acceleration | compared to gravity
------------------------------------------------------------
     9.22358            32.1601               0.0%
    11.29650            21.4402             -33.3%
    16.00000            10.6875             -66.7%

That quote came from the article he linked to:
http://www.attackonamerica.net/proofofcontrolleddemolitionatwtc.htm

From Post #173.

-Make7

[philb]

282. NY Firemen & Policemen- lots of reports of explosions at both WTC building

before they collapsed. Both upper level and ground level explosions reported by hundreds.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=51793&mesg_id=51793
http://www.flcv.com/firemen.html
http://www.flcv.com/nypolice.html