To add comments or start new threads please go to the full version of: Physics Of 9/11 Events - Part 3
PhysForum Science, Physics and Technology Discussion Forums > General Sci-Tech Discussions > Other Sci-Tech Topics
Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116

David B. Benson
QUOTE (3bodyproblem+Jun 3 2007, 09:23 PM)
2) I was alerted to this last night and posted a response to Pierre this morning. ...

3) ... I believe there is something to be said for the idea of mass from Zone B being ejected once it reaches a critical mass proportional to the plate thickness of the exterior columns.

2) What page? I must have overlooked it.

3) Except that almost all of the mass at Ground Zero lies within or close to the footprint. The exterior sections and columns are the only major exceptions. So the majority of ejection is just the curtain walls...
shagster
QUOTE (3bodyproblem+Jun 3 2007, 09:06 PM)
1) Is it the opposite? I still maintain that the truss connections were vital in maintaining the geometry of the core and exterior. It would seem that their disconnections predicated the collapse at least in WTC 2.


I'm in agreement with you. The core, floors, and perimeter all needed to work together to maintain the overall structure. When any one of those components failed, the whole structure failed. That's the opposite of redundancy.

There should have been some redunancy in the design in that respect, but there wasn't.
Malmoesoldier
[removed]
3bodyproblem
QUOTE (David B. Benson+Jun 3 2007, 09:32 PM)
2) What page? I must have overlooked it.

3) Except that almost all of the mass at Ground Zero lies within or close to the footprint. The exterior sections and columns are the only major exceptions. So the majority of ejection is just the curtain walls...

2) Page 251 At 2:11AM

3) This is where i refer back to the standing core section representing the majority of this mass, at least in WTC 2. Hard to say for sure, perhaps I should look closer at the FEMA report?

Malmoesoldier
QUOTE
To Malmo... have you heard anything at all about that police helicopter,and their warning that the building was unstable and about to go? Can you describe some sort of CD that would produce those results? I mean, there is no super-slow-mo explosives that do that.


Did they get the warning or was it them that gave the warning to others?. There are many that heard explosions in the basement, people that heard explosions from the basement BEFORE the plane crashed into the building, there are many witnesses of explosions. Dont you think explosions from bombs would make the building unstable??. And also giuliani had Pre-Knowledge that the towers was coming down, and then just some days ago he said that he didnt have it, when he for some years ago admitted that he had Pre-Knowledge.
3bodyproblem
QUOTE (shagster+Jun 3 2007, 09:34 PM)
I'm in agreement with you. The core, floors, and perimeter all needed to work together to maintain the overall structure. When any one of those components failed, the whole structure failed. That's the opposite of redundancy.

There should have been some redunancy in the design in that respect, but there wasn't.

Ahh, yes, sorry i misread that.
You hear so much talk of how redundant these building were when there is a substantial amount of evidence to the contrary. After much research I think it is evident that "usable floor space" was of paramount importance when the building was designed. While the engineers and designers contend there was sufficient thought put into "redundancy" with the given range of parameters, I feel may have not been the case. I liken it to my experience in the automotive industry where quality is touted as the most important factor in manufacturing. As a former supervisor, I can assure you "quantity" is the most important factor.
David B. Benson
QUOTE (3bodyproblem+Jun 3 2007, 09:47 PM)
2) Page 251 At 2:11AM

3) This is where i refer back to the standing core section representing the majority of this mass, at least in WTC 2.

2) Thanks.

3) Which mass, in or out? Looks to me that it fell straight down, onto the footprint.
3bodyproblem
QUOTE (David B. Benson+Jun 3 2007, 10:25 PM)
2) Thanks.

3) Which mass, in or out? Looks to me that it fell straight down, onto the footprint.

3) Yep, I believe so for the most part. Which assumption would you make, that this section of the core did not take the same beating as the rest, that this section of the core was stronger than the rest, or some combination of both?
David B. Benson
QUOTE (3bodyproblem+Jun 3 2007, 11:31 PM)
Which assumption would you make, that this section of the core did not take the same beating as the rest, that this section of the core was stronger than the rest, or some combination of both?

Didn't take the same beating. Consider just how asymmetrically the top block fell.
adoucette
QUOTE (Malmoesoldier+Jun 3 2007, 04:39 PM)
In the mid-1990s British Steel and the Building Research Establishment performed a series of six experiments at Cardington to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beams reaching 800-900º C (1,500-1,700º F) in three of the tests (well above the traditionally assumed critical temperature of 600º C (1,100º F), no collapse was observed in any of the six experiments). FEMA

laugh.gif

Were any of them hit by a Jet first?

For those who have the spare time to see if the tests can tell us anything relevant to the WTC fires:

British Steel and the Building Research Establishment

http://www.mace.manchester.ac.uk/project/r...ta/default2.htm

Arthur
3bodyproblem
QUOTE (David B. Benson+Jun 3 2007, 11:33 PM)
Didn't take the same beating. Consider just how asymmetrically the top block fell.

Yes, there was certainly some deflection at initiation that was magnified as the collapse progressed. The core saw less impacts closer to the ground. The natural assumption I beleive would be that the lateral forces were greater.
David B. Benson
QUOTE (3bodyproblem+Jun 4 2007, 12:00 AM)
Yes, there was certainly some deflection at initiation that was magnified as the collapse progressed.

The core saw less impacts closer to the ground.

The natural assumption I beleive[sic] would be that the lateral forces were greater.

(1) Is that is what is actually seen in the videos?

(2) huh.gif How can you know that? What we seem to be sure of is something shagster found in, I believe, a Fox 5 video: the collapse front passing the top of WTC 3 (about 80 meters tall) at 11--12 seconds. I interpret this as indicating a substantial portion of the zone A top block fell apart and simply fell off to the side on its own. I can think of nothing else which would explain this observation of a very long collapse time.

(3) huh.gif
wcelliott
QUOTE
SO?!?! do you think i dont know this????


No, I think you don't. Not based on your prior statements where you constantly link temperatures and time and strength, like you're talking about some annealing process.

Actually, I'm just waiting for you to repeat the same mistake again.

You constantly repeat your errors, even after people repeatedly point them out.

You have yet to grasp the concept that I addressed in one of my first posts on this topic, which is that the buildings were "optimized", which means, by definition, they were "marginal" designs.

The other examples of failed structures you cite weren't optimized, and so weren't marginal designs.

A building can't become one of the tallest structures in the world without being an optimized design, otherwise the excess strength you keep asserting was inherent in the structure would add to the weight needing support from the floors below. "2000%" excess capacity was a figure you cited (demonstrating your complete ignorance). That would mean that they used 20x as much steel as they needed way up there in the upper floors. Which would mean that the structure below would have to support 20x as much steel as necessary, so the floors below would need even more than 20x, and the floors below those would need even more than that. Eventually, you end up with a ground floor that's completely solid steel and concrete, with no room for anyone to access the elevators.

As correctly pointed out, the building was a compromise between strength and floor space. They get to *rent* office space, so that's the key attribute to the design that the building owners are looking for. Safe as needs to be to stay up under all foreseeable circumstances, but as profitable as possible (i.e., maximize the floor space that can be rented out).

Therein lies the key to understanding the collapse - the design was only capable of supporting itself with a reasonable, but small, margin of excess strength. Some of that excess strength was lost when the plane damaged the outer, load-bearing curtain-wall. Some was lost when the plane's debris hit the central core at 450mph. The rest was lost when the fire caused the trusses to reach 600C just long enough to sag (go ahead and make the same boneheaded remark about how many hours, blah, blah, blah, but it's an INSTANTANEOUS response of the steel as a function of TEMPERATURE ALONE). And after they sagged under plastic deformation WHILE the coefficient of thermal expansion was causing it to lengthen (and therefore droop), the fire cooled off and so did the droopy steel trusses, which re hardened faster than they shrank. So they ended up exerting a massive tension on the core and outer curtain walls and the brackets holding them in-place, and at some point, they failed, one after another.

And another concept too sophisticated for you to understand is that the load being supported gets transferred to the remaining trusses when a truss fails. So you get a cascade of failures, starting out slow, but increasing rapidly as each remaining truss gets eliminated one by one. This led to the collapse of the structures.

And I didn't have to read the NIST report to write this, this is just based on my own engineering education and my 30 years' experience as an engineer.

Where my analysis differs from the NIST study is that they assume fire to be a linear phenomenon (implicitly, by the fact that they're comfortable scaling-up a model that was only validated at the 1% level), and that's exactly the same mistake people make when they draw trend lines on stock price histories. It's a classic blunder in modeling, assuming that the chaotic system is obligated to obey linear concepts. Linear models produce expected/nominal values. The real values look more like stock price histories, so when that predicted value is the temperature of a fire, you can guarantee that the actual temperatures will be higher or lower more often than they'll be near the predicted values.

And as I've said before, the steel is sensitive to higher temperatures, so it's the higher temperatures that dominate the phenomenology, not the nominal/expected values.

Other than that, I think NIST did a reasonably good job of explaining what happened, and they managed to do so without invoking non-existent explosives (or invisible Godzillas).

Malmoesoldier
QUOTE
Were any of them hit by a Jet first?


So you dont know what the official story of 9-11 is?. They say that if the fires wasnt that "hot" the towers would still be standing. The fires wasnt hot enough to make the steel fail and collapse, like i showed you. Please wake upp
Grumpy
Timeline for WTC 1 is summarized as follows...

Time Damage and Fire
08:46:30 EDT
(GMT - 4 hours)
A hijacked Boeing 767-200ER airplane crashed into the north face of WTC 1 between the 94th and 98th floors, directly causing
Entry slash on the external columns from the 93rd to 99th floor
Most damage to the 95th and 96th floors
35 external columns cut off, 2 seriously damaged
6 core columns cut off, 3 seriously damaged
43 core columns stripped of insulation on one or more floors
Insulation stripped from trusses covering 5,574 m2 (60,000 ft2) of floor area


08:47 ~ 09:02 Jet fuel erupted into fireballs and immediately ignited a multiple floor fire
Within the first 2 min, fires had burned in the north side windows on the 93rd to 97th floors, the south face of the 96th floor and the east face of the 94th floor
Maximum temperature was estimated about 900 ¨C 1000°C
Smoke emerged from the 104th floor

09:02:59 Another hijacked airplane crashed into WTC 2
09:15 Fire intensified on the 94th and 97th floors
Large fires erupted on the east sides of the 92nd and 96th floors
Fire heated floors had begun to sag

09:30 Vigorous fires on nearly the full perimeter of the 98th floor
Almost no fire on the 99th floor and above

09:58:59 WTC 2 collapsed. The pressure purse generated by the collapse of WTC 2 intensified the fires in WTC 1
10:01 Flames came out of the south side of the west face of the 104th floor

10:18 Jets of smoke ejected from the 92nd and 94th to 98th floors
Fires raged on the south side of the 96th to 99th floors
Floor sagging had increased. The sagging of the south side floors had caused the south perimeter columns bowing inward

10:23 South perimeter columns had bowed inward as much as 1.4 m (55 in.)

10:28 Transmission tower on top of WTC 1 started to move downward and laterally
The entire section of the tower above the crashed zone began tilting as a rigid block toward the south
The upper section of the tower collapsed onto the floors below
Within 12 seconds, the whole WTC 1 collapsed


The timeline for the collapse of WTC 2 is summarised as follows:

Time Damage and Fire
09:02:59 EDT
(GMT +4 hours)

A hijacked Boeing 767-200ER airplane crashed into the east side of the south face of WTC 2 between the 78th and 84th floors, directly causing
Entry slash on the perimeter columns from the 77th to 85th floor
Most damage to the 80th and 81st floors
33 perimeter columns cut off, 1 seriously damaged
10 core columns cut off, 1 seriously damaged
39 core columns stripped of insulation on one or more floors
Insulation stripped from trusses covering 7,432 m2 (80,000 ft2) of floor area

09:03 ~ 09:30 Jet fuel erupted into fireballs and ejected from the 79th, 81st and 82nd floors
Fireballs burned for 10 sec, extending almost 61 m (200 ft) out from the north, east and south faces
Vigorous fires on the east side of the 80th to 83rd floors
Within 18 min of the crash, the east perimeter columns between the 79th to 83rd floors had bowed inward due to floors sagging

09:30 ~ 09:58 Fires continued to burn in the east half of the tower

09:58:59 The top of the tower tilted to the east and south, and WTC 2 collapse


Analysis

The impact of the plane crashes directly caused significant structural damages to both WTC towers. The towers resisted this level of damage and did not collapse immediately showing that the redundancy of the tube-frame structures enabled the redistribution of the loads from the damaged zones to the remaining structures.

However, it was generally believed that the impact also extensively striped off the fire protection materials from structural steel at least in the crashed zones. The multiple floors fires ignited by the jet fuel finally weakened the remaining structures and the towers collapsed.

It is worth noting that in the tube-frame system of the WTC towers, the lateral resistance or stability of the perimeter columns were provided by the composite floor truss system. This lateral restraint is reduced as the floor trusses weaken and sag in the heat. In a multiple floors fire, it was expected the effective length of laterally unrestrained perimeter columns would increase at least twice or triple. In addition to the direct thermal effects, the compressive resistance of these columns eventually reduced until a point that they could not sustain the applied load and buckling occurred.

The video footages showed that in WTC 1, the south perimeter columns of the fire floors had buckled before the top section of the tower tilted to the south and collapsed. On the other hand, in WTC 2, the east perimeter columns of the fire floors had also buckled before the top section of the tower tilted to the east and south and collapsed.

http://www.mace.manchester.ac.uk/project/r...ire/default.htm

Grumpy cool.gif
Daru
It is really really strange... that only small number of steel was recovered from fire zone at the wtc... But what is even more strange is that it show low temperatures. Very low.

This is hard data. Not some speculation. Hard data.

"More than 170 areas were examined on the perimeter column panels...Only three locations had evidence that the steel reached temperatures above 250 °C."

"Annealing studies on recovered steels established the set of time and temperature conditions necessary to alter the steel microstructure. Based on the pre-collapse photographic evidence, the microstructures of steels known to have been exposed to fire were characterized. These microstructures show no evidence of exposure to temperatures above 600 °C for any significant time.
Similar results, i.e., limited exposure if any above 250 °C, were found for two core columns from the fireaffected floors of the towers."


wcelliott
QUOTE
"More than 170 areas were examined on the perimeter column panels...Only three locations had evidence that the steel reached temperatures above 250 °C."


We're talking about the trusses sagging from the intense heat.

The trusses are horizontal, spanning the area between the curtain wall (made up of perimeter columns) and the core. These horizontal trusses were at ceiling-level. Heat rises. These are the structural members that were supposed to be covered with sprayed-on insulation (which in years prior, it was found during inspections that the insulation was falling off in spots throughout the lengths of the trusses).

These are the elements of the structure that sagged, leading to the collapse.

The core steel's temperature probably didn't exceed 250C, and the perimeter columns probably didn't get too hot, either. They didn't have to, in order for the structure to fail as described by the NIST report, and summarized above by Grumpy, and described/modeled in detail by the paper DBB, et al., recently wrote.

My only quibble is with the notion that predicted temperatures expected were the actual peak temperatures, as the peak temperatures would dominate the phenomenology of the collapse.
NEU-FONZE
Just a side comment on some recent posts that have used quotes:

Quote boxes are only useful if the quote is attributed to someone. I don't use quote boxes, preferring to say: Mr X, you said: "..."

Then there is no ambiguity about who said what
Grumpy
NEW YORK CITY—The Commerce Department’s National Institute of Standards and Technology (NIST) today presented its analysis of how the World Trade Center (WTC) towers collapsed after two aircraft were flown into the buildings by terrorists on Sept. 11, 2001. This is the most detailed examination of a building failure ever conducted.

“Like most building collapses, these events were the result of a combination of factors,” said Shyam Sunder, lead investigator for the agency’s building and fire safety investigation into the WTC disaster. “While the buildings were able to withstand the initial impact of the aircraft, the resulting fires that spread through the towers weakened support columns and floors that had fireproofing dislodged by the impacts. This eventually led to collapse as the perimeter columns were pulled inward by the sagging floors and buckled.”

The probable collapse sequences, which update and finalize hypotheses released by NIST last October, were presented by Sunder at a press briefing in New York City.

The specific factors in the collapse sequences relevant to both towers (the sequences vary in detail for WTC 1 and WTC 2) are:

a.) Each aircraft severed perimeter columns, damaged interior core columns and knocked off fireproofing from steel as the planes penetrated the buildings. The weight carried by the severed columns was distributed to other columns.
b.) Subsequently, fires began that were initiated by the aircraft’s jet fuel but were fed for the most part by the building contents and the air supply resulting from breached walls and fire-induced window breakage.
c.) These fires, in combination with the dislodged fireproofing, were responsible for a chain of events in which the building core weakened and began losing its ability to carry loads.
d.)The floors weakened and sagged from the fires, pulling inward on the perimeter columns.
e.)Floor sagging and exposure to high temperatures caused the perimeter columns to bow inward and buckle—a process that spread across the faces of the buildings.
d.)Collapse then ensued.

The sequences are supported by extensive computer modeling and the evidence held by NIST, including photographs and videos, recovered steel, eyewitness accounts and emergency communication records.

http://www.nist.gov/

Or, in other words...


Planes hit buildings, buildings fall down, go boom.

Grumpy cool.gif
Daru
Eh... eh eh... so, now we dont need a hot fire at all !!! What next!!

We know that the trussers were so strong that they pulled the tower down...so to speak... and now we dont even need a hot fire!!

But ofcource it is very simple. It is impossible to explaine the so called "collapse" of the wtc with fire. Period.

And in fact nist admit it... with their own data!
David B. Benson
QUOTE (wcelliott+Jun 4 2007, 12:08 AM)
Where my analysis differs from the NIST study is that they assume fire to be a linear phenomenon ...

Well, I'll not take your assertion as necessarily true.

The firs tests were done to determine how the trusses would behave at various temperatures. That was for the mechanical FEA-style part of the model. Not the NIST fire behavior model. TO model the spread of the fire they divided the square acre of floor into N boxes. They ran their fire model in each box to determine temperatures and likely fire spreading directions and burn-out.

In NCSTAR1-6 or NCSTAR1-6D they discuss how they connected the fire model to the FEA style mechanical model. While I didn't try to follow this part very closely, I certainly obtained the impression that the fire model is quite sophisticated. For example, there only ran it once each simulated 20 minutes and argue that was sufficiently closely based temperature points to determine sag and creep.
David B. Benson
QUOTE (wcelliott+Jun 4 2007, 01:03 AM)
The core steel's temperature probably didn't exceed 250C, and the perimeter columns probably didn't get too hot, either.

In the core of WTC 1, the fire model predicted very hot temperatures for some columns, in excess of 750 F, where NIST arbitrarily cut off the temperature. In any case, the NIST study claims that several, previously intact, core columns creep buckled from a combination of load and temperature.

For the perimeter, most stayed fairly cool, except along part of the south wall.
ChE_n_PhysicsGuy
QUOTE (3bodyproblem+Jun 3 2007, 09:06 PM)
1) Is it the opposite? I still maintain that the truss connections were vital in maintaining the geometry of the core and exterior.  It would seem that their disconnections predicated the collapse at least in WTC 2.

2) Agreed

This is completely false.
David B. Benson
QUOTE (ChE_n_PhysicsGuy+Jun 4 2007, 01:24 AM)
This is completely false.

Maybe not well written, but true. All parts of the towers mutually supported one another. No part could stand on its own.
Grumpy
Daru

QUOTE
And in fact nist admit it... with their own data!


I just posted NIST's opinion, it differs from your characterization of what they said. You see, I've actually read the NIST Reports, and ,if they are not 100% correct on some of the details, their explanations make good sense and they backed all of their conclusions with extensive testing. These people are not elected, nor are they political appointees, these scientists(some 200+) are the best and the most experienced investigative agency on the face of this Earth(in the sciences). They are protected by law from being compelled to testify in lawsuits or be imune to the subpeona power of even Congress. Why?? So they can be free to investigate these kinds of events without fear of harrasment from the people whose ox got gored, because we needed investigations that weren't tainted by influence. There are many more reasons for the existence of NIST, but my point is that NIST is as close as human's can get to the impartial, objective and well researched reports in the event of this type of event and due to the exemplary work they have always done in the past, I accept their word as the scientific truth about this event, until contrary work of equal merit convinces me otherwise, so far not even close.

Grumpy cool.gif
wcelliott
QUOTE
They ran their fire model in each box to determine temperatures and likely fire spreading directions and burn-out.


This is a perfectly valid way to model a linear system.

It's like saying that you can model the Dresden firestorm by applying a building-fire model N times, where N is the number of buildings in Dresden.

That's my complaint. I recognize it's a subtle one, and it probably doesn't matter much in the overall description of what happened, but fires are chaotic processes, not linear systems. The boxes approach will yield nominal values, chaotic processes yield numbers that would appear more like stock price histories. Just like programs that impose a straight-line approximation to a stock's prices is sometimes high, sometimes low. If it's a good model, the highs and lows will average-out to the nominal values that the boxes-approach provides.

But the highs are more significant to the steel under load than the lows.
3bodyproblem
QUOTE (David B. Benson+Jun 4 2007, 12:07 AM)
(1) Is that is what is actually seen in the videos?

(2) huh.gif How can you know that? What we seem to be sure of is something shagster found in, I believe, a Fox 5 video: the collapse front passing the top of WTC 3 (about 80 meters tall) at 11--12 seconds. I interpret this as indicating a substantial portion of the zone A top block fell apart and simply fell off to the side on its own. I can think of nothing else which would explain this observation of a very long collapse time.

(3) huh.gif

1) Certainly for WTC 2 the asymmetrical damage to the exterior and core lead to this deflection. WTC 1 is different.. NIST would seem to indicate that the core failed before the exterior (I believe this was determined by the noticed movement of the radio tower). Personally I find this hard to believe, but I am in no position to go against the professionals. I therefore accept this. I feel however that the video shows the core did not sustain symmetrical damage, it follows therefore that there must have been some deflection. i also believe this is reflected when the damage to the cores of WTC 1,2 are compared, it appears the upper section with the most deflection did less damage to the core during the crush down.

2) That the core remained standing and intact for as long as it did would be my basis. There is a case to be made for the increased thickness of the plate used in the core the further down, but I don't think the plate thickness ramped up with the KE of the upper section. I am not familiar with this video, I will have to look for it.

3) Well this seems to be the natural result of less impacts to the core, more mass ejected laterally. Unless you are under the impression the collapse gained velocity? The energy of the collapse not absorbed by th core had to go somewhere.
wcelliott
QUOTE
"More than 170 areas were examined on the perimeter column panels...Only three locations had evidence that the steel reached temperatures above 250 °C."



Please note: I've re-edited this for clarity, and tried to change it back where it was originally posted, but for some weird reason it's saying I don't have the right to edit my own post. ???

Anyway, the description below is a clearer account of what may have been confusing before.

>>

There are three sets of steel structural members in this discussion: The core steel/concrete structure, the perimeter columns that make up the exterior curtain wall, and the hosizontal trusses that spanned the area between the core and the curtain-wall, holding up the floors.

When we're talking about the extreme-high temperatures that the trusses were exposed to, we're talking about the trusses that support the floors. These are the structures that we're saying were sagging from the intense heat.

These horizontal trusses were at ceiling-level. Heat rises. These are the structural members that were supposed to be covered with sprayed-on insulation (which in years prior, it was found during inspections that the insulation was falling off in spots throughout the lengths of the trusses).

These are the elements of the structure that got the hottest and sagged, leading to the collapse.

The core steel was imbedded in concrete, and that concrete provided insulation, so its temperature probably didn't exceed 250C, and the perimeter columns probably didn't get too hot, either, being exterior to the fire meant that they were half-exposed to the fire inside the structure and half exposed to the outside ambient temperatures. The perimeter columns didn't have to get extraordinarily hot in order for the structure to fail as described by the NIST report, and summarized above by Grumpy, and described/modeled in detail by the paper DBB, et al., recently wrote.

My only quibble is with the notion that predicted temperatures expected were the actual peak temperatures, as the peak temperatures would dominate the phenomenology of the collapse via those temperatures' effects on the horizontal trusses.
Grumpy
wcelliott

One thing. The core columns were not encased in concrete, there was no concrete in the core other than their floors, they were encased with Gypsum board as fireproofing. This gypsum board was blown out of the way even more easily than the spray-on.

Grumpy cool.gif
wcelliott
QUOTE
One thing. The core columns were not encased in concrete, there was no concrete in the core other than their floors, they were encased with Gypsum board as fireproofing. This gypsum board was blown out of the way even more easily than the spray-on.


My error.

That would make it easier for the fires to weaken the cores, which would make it all that easier for the upper sections to tilt and buckle the cores at the impact-damaged floors.

Which is consistent with the observed phenomena, the NIST report, and what all reasonable people agree happened on 9/11.

It would also support the Invisible Godzilla theory, which, like the CDiots' theories of the collapse, is so nebulous that it can't be disproved either way.

Thanks, Grumpy.
SYLVESTER1592
QUOTE (newton+Jun 3 2007, 07:03 AM)

sounds like radiation effects.


Hi there, I'm new to this forum. So I will be reading mostly. I'm not as well equipped in the physics department as most of the members in this forum.

In reaction to the suggestion of radiation effects I would like to add something:

Other causes of multiple myeloma:
benzene exposure: : Chem Biol Interact. 2005 May 30;153-154:65-74

farm animals: J Occup Environ Med. 2003 Aug;45(8):857-68

familial factors: Blood, 15 July 2005, Vol. 106, No. 2, pp. 668-672.

asbestos exposure?:
Suspected but not proven:
Occup Med (Lond). 1999 Nov;49(8):536-9.

Am J Ind Med. 1988;14(6):661-71

Am J Clin Pathol. 1983 Jul;80(1):14-20

Prospective study showing farmers and diabetics as a high risk population:
Int J Cancer. 1989 Apr 15;43(4):554-9

Jumping to radiation is a bit of a stretch… If we were considering Non Hodgkin Lymphoma, maybe…
The asbestos issue was a matter of concern to the EPA, but this was not proven as a risk factor for multiple myeloma. Still it’s interesting, but more from a medical point of view… Radiation is not really a well described factor.
So radiation?... I don’t think so. There would be some other symptoms as well, not predominantly respiratory.

SYL smile.gif
3bodyproblem
QUOTE (SYLVESTER1592+Jun 4 2007, 03:02 AM)

SYL smile.gif

welkom vriend smile.gif
Alan (ex elevator man)
QUOTE (Malmoesoldier+Jun 3 2007, 03:56 PM)

Did they get the warning or was it them that gave the warning to others?. There are many that heard explosions in the basement, people that heard explosions from the basement BEFORE the plane crashed into the building, there are many witnesses of explosions.  Dont you think explosions from bombs would make the building unstable??.

Malmoe,
The policemen in the helicopter gave the warning after noticing the top of the tower starting to lean. The point was, all the firemen inside the tower didn't get that warning because their radios weren't the same frequency as the police radios. As for your other statements about explosions in the basement before the plane impact... that's just silly. The only thing you didn't mention that we've gone over many times before about that is... the 50-ton press that was destroyed. Rodriquez (sp ck) changed his story many times so he's out as far as credibility and any others that jumped on his bandwagon are either dishonest like him, or plain mistaken. There weren't any seismic readings before or after the plane impact, until the building itself collapsed.
Also, I truly wish you'd stop quoting Ryan at the UL. If noone's informed you yet, he was a water tester, not a structural engineer. The UL doesn't test steel... they tested the steel components as a unit, not the steel itself.
There's many other things you've posted that were completely wrong and I don't expect anything from me or the others to get through to you. That's fine, just please be an adult and quit the name calling and cursing.
Also, whether you know it or not, we're all not Republicans or Bush backers, but rather we all back the science, facts, and reality, instead of 'beliefs' and innuendo.

peace

*edited to correct some misspellings
quicknthedead
QUOTE (wcelliott+Jun 3 2007, 09:22 AM)

I'm loving the dark innuendo, but I just wish you'd actually *say* what you keep implying. 

You think they, excuse me, They, **nuked** the WTC, don't you?

C'mon, say it.  Spit it out. 

It isn't like you could lose any more credibility than you already have (trusting Osama bin Laden's word while accusing NIST scientists of being dishonest).

Here is something to spit out, an article that covers past and recent history.

THE TRUE STORY OF 9-11, PART 2 of 2
By Dr. Stanley Monteith, June 3, 2007
http://www.newswithviews.com/Monteith/stanley5.htm

Excerpt:
"They control both political parties, the presidency, the mass media, most major banks, most major corporations, and most of the wealth of the world.[3] If that is true, why hasn't someone told the American people? Because most journalists and most media pundits want to keep their jobs, and don't want to end up like Gary Webb, a Pulitzer prize winning columnist who exposed the CIA's involvement in the drug trade, who shot himself in the head twice to make certain he was dead.

Another excerpt:
"The Joint Intelligence Committee didn't try to determine why Building 7 collapsed because both Senator Bob Graham and Congressman Porter Goss, the co-chairmen of the committee, are members of the CFR. In addition, the Bush administration censored the report.[12]

"The 9/11 Commission didn't determine why Building 7 collapsed because the Chairman, Thomas Kean, the vice-Chairman, Lee Hamilton, two members, Jamie Gorelick and John Lehman, and the Executive Director of the 9/11 Commission, Philip Zelikow, are members of the CFR.[13] Former Senator Max Cleland was a member, but when it became obvious he wouldn't participate in the charade, he was replaced. Again, the Bush administration censored the report.[14] Since there are almost 300 million people living in the U.S., and there are only 4000 members of the CFR, do you honestly believe the CFR's control of both investigations was an accident?"



And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment.
quicknthedead
QUOTE (Alan (ex elevator man)+Jun 3 2007, 01:47 PM)
This article I'm reading sheds some light on the WTC first responders health, and who should be blamed.

Giuliani:  Worse Than Bush


Remember also that the EPA's Whitman declaration of the OK (that the air was safe to breathe) in reality came from the White House.

http://www.ucsusa.org/scientific_integrity...-pollution.html

Excerpt:
"In a series of public statements issued after the terrorist attacks of September 11, 2001, the Environmental Protection Agency (EPA) assured the people of New York that the air around ground zero was safe to breathe. Unfortunately, the agency lacked authoritative information on which to base these claims, and internal agency data conflicting with this reassuring public posture were ignored. The EPA's press releases and public statements after 9/11 were vetted by then-National Security Advisor Condoleezza Rice, suggesting that the White House placed politics over science when communicating about ground zero's air quality."



IN THE BEGINNING GOD CREATED THE HEAVENS AND THE EARTH
wcelliott
QUOTE
Here is something to spit out...


Certainly, nothing I'd care to swallow.

More CT dark innuendo.

You know, there *are* sometimes politically sensitive reasons why certain facts are sometimes left out of reports of this sort that have very little to do with dark conspiracies.

For instance, if the insulation on the horizontal trusses was applied in a shoddy manner by non-union labor, and the inspection job was signed-off by a corrupt building inspector, they may have decided to leave those parts of the story out of the Official Report because there'd be a grassroots demand for sending the corrupt building inspector to prison (also opening up the issue of lawsuits against the city for corruption), which from a political standpoint would tend to diminish the political impact by changing the subject, attributing the WTC damages to NYC corruption and the WTC's hiring non-union/undocumented workers for the insulation job.

It would be the political equivalent of changing the subject before you've made your central point clear.

It would also tend to make scapegoats out of the people who weren't primarily to blame for the attacks, though may have inadvertently made the attacks more devastating than they should've been. If you knew that the building inspector who signed-off on an inadequate fire installation job in exchange for money, would you make him the center of a media feeding frenzy, or would you "spin" the story like we're all absolutely innocent and then, privately, send someone out to deal with the corrupt inspector quietly? Think about it. The "correct" answer isn't always obvious.
newton
QUOTE (SYLVESTER1592+Jun 4 2007, 03:02 AM)

Hi there, I'm new to this forum. So I will be reading mostly. I'm not as well equipped in the physics department as most of the members in this forum.

In reaction to the suggestion of radiation effects I would like to add something:

Other causes of multiple myeloma:
benzene exposure: : Chem Biol Interact. 2005 May 30;153-154:65-74

farm animals: J Occup Environ Med. 2003 Aug;45(8):857-68

familial factors: Blood, 15 July 2005, Vol. 106, No. 2, pp. 668-672.

asbestos exposure?:
Suspected but not proven:
Occup Med (Lond). 1999 Nov;49(8):536-9.

Am J Ind Med. 1988;14(6):661-71

Am J Clin Pathol. 1983 Jul;80(1):14-20

Prospective study showing farmers and diabetics as a high risk population:
Int J Cancer. 1989 Apr 15;43(4):554-9

Jumping to radiation is a bit of a stretch… If we were considering Non Hodgkin Lymphoma, maybe…
The asbestos issue was a matter of concern to the EPA, but this was not proven as a risk factor for multiple myeloma. Still it’s interesting, but more from a medical point of view… Radiation is not really a well described factor.
So radiation?... I don’t think so. There would be some other symptoms as well, not predominantly respiratory.

SYL smile.gif

it might be a stretch if it weren't for elevated tritium levels, and radioactive material at fresh kills landfill.

as it is, fuzzy logic says coincidence theory can only stretch so far.
Oneismany
QUOTE (David B. Benson+May 27 2007, 01:10 AM)
First, there is no such thing as 'free fall speed'. There is free fall, or free fall acceleration, due to the unimpeded force of gravity.


That is disingenuous. The time in which the towers "collapsed" is close to the time for the top floor to fall with nothing but air blocking it, hence "free fall." Speed is distance over time, and this speed was distance over approximately free fall time; hence "free fall" speed. Semantics does not change the time of the fall. However arguing semantics is an easy distraction from the subject.

QUOTE (David B. Benson+May 27 2007, 01:10 AM)
Second, NEU-FONZE posted his measurements for the drop of the tops of the towers for the first few seconds. The best fit to this data for the acceleration is

WTC 1: (2/3) g
WTC 2: (3/4) g

both of which indicate resistance to the fall and neither of which is 'nearly free fall'.

Which begs the question, how did the majority of the debris land in about 10 seconds?

That is the observation and the progressive collapse hypothesis cannot account for it because 10 seconds is about the time it would take the same debris to land if nothing but air was blocking it. Any intervening material would slow the collapse unless there was an outside force, i.e. not gravity. Gravity was part of this system to begin with and the buildings were balanced against gravity. The force of gravity is constant, so how does the momentum of the collapse instantaneously increase?
Oneismany
QUOTE (David B. Benson+May 27 2007, 09:57 PM)
(2) It is a small matter it that once ejected, the exterior columns have nothing further to do with the progressive collapse. Since the distribution at Ground Zero is reasonable well understood, it is possible to give a good estimate of the energy consumed in tossing the exterior wall columns into that pattern. This energy consumption slows the progressive collapse and that is the only effect. So the exact mechanism for this energy consumption is of but small interest, although I will be more satisfied once a physically plausible mechanism is elucidated.

The ejected perimeter columns are irrelevant to the progressive collapse, but the distribution of of the debris is well understood? Maybe the progressive collapse does not explain the ejected perimeter columns because the progressive collapse is an unproved theory but the ejected columns are data about an explosion. If the progressive collapse is not a plausible mechanism for ejecting the perimeter columns but a controlled demolition is, then CD is a better hypothesis.
Oneismany
QUOTE (David B. Benson+May 27 2007, 11:43 PM)
(1) I have offered several times to debate any and all of the B & V assumptions. So far nobody has seriously taken up the challenge.
Anybody who has seen at least one of the videos should seriously doubt that this particular hypothesis is quite a good one. In any case, all that matters in the crush-down equation is that energy consumption is a function of the drop distance, along with the mass, velocity, etc.

Mass is a function of the drop distance and so is velocity? Well then where is this mass coming from? From the lower floors. And if this is a closed system then the total momentum cannot change, by Newton's third law. So, the increase in momentum of the upper part must equal the decrease in momentum of the lower part. The velocity of the whole building cannot increase. If the upper part of the building vacuums up the lower part then how does the velocity of the whole collapse increase? That is akin to saying that if you and your friend are falling and you throw a rope around your friend, then you both will fall faster. In fact, under a constant force, an increase in mass will decrease instantaneous acceleration because a greater mass exerts more gravity of its own and puts up more resistance to motion.
wcelliott
QUOTE
it might be a stretch if it weren't for elevated tritium levels, and radioactive material at fresh kills landfill.


That link I posted showed that pulverized concrete would increase radon levels. Has anyone done a radon count?

Also, since the concrete dust particulates are small enough to enther the lungs, the alpha radiation that's normally not a problem with concrete in a slab becomes a potential problem.

But, let's say for argument's sake that none of these normal-type explanations are the real problem, that it's something specifically radiological that wasn't there to begin with. How far-fetched would it be for the Al Qaida terrorists to have decided to carry along some radioactive material with them with the specific intent of making the WTC attack into a "dirty bomb" assault on the whole of NYC?

If, by some unpredicted mechanism. the radiological isotope got sequestered in the rubble/debris of the site, such as, the concrete dust absorbed the radioisotope, wouldn't that be something that you would keep to yourself for the good of the city as a whole? And wouldn't that explain why they expedited the clean-up operation? They wouldn't want it known that there was a sequestered radiological contaminant in the concrete dust because people would stop coming to NYC and businesses would evacuate NYC out of exaggerated fear. The rumor itself would scare people away and the city would "die" from fright.

So Guiliani goes to the site without a respirator (but mandates that the cleanup workers use them) and declares the air safe to breathe to calm people's (mostly) unreasonable fears.

And the government, which would've known about the true nature of the attack goes all Rambo on Al Qaida and for very good reasons. I think any President who knew that a terrorist organization planned and carried out a radiological attack against the biggest city in the US would feel reasonably justified in declaring war on that organization, and likewise, fully justified in keeping at least part of the real rationale a secret, so as to minimize the collateral damage to the city that was attacked.

Hypothetically speaking.

I cite this as an example of how certain factoids about the US gov't's response that could have very good reasons, even if they are unknown. Not everything the government does in secrecy is out of shame/guilt, sometimes secrets simply are the most appropriate approach to a problem.

Something to keep in mind when looking for villains in this world is that there are more people who hate Americans over there than there are here in the US government.

Osama bin Laden hates America more than George Bush does (What reason would Bush have to hate America, of all people?), and Osama bin Laden is the more-likely person to think up and carry out such an attack.

You have to realize that while you may be convinced that Bush was behind the 9/11 attacks, you can be wrong about that, while one thing is absolutely certain, and that's that Bush himself knows one way or the other whether he plotted it or not, and my belief is that he didn't and has been acting in good faith on behalf of America, dealing with a threat that he's in a better position to understand than the troothers ever could.
wcelliott
QUOTE
If the upper part of the building vacuums up the lower part then how does the velocity of the whole collapse increase?


It's called "gravity".

The top part falls and accelerates as it falls.

If nothing were in its way, it'd hit the ground in less than 10 seconds.

Something is in its way, though, the lower part of the building.

So how much resistance to the upper block's descent does the lower building put up? It puts up about the same amount of resistance with each floor (equal to the structural strength of that floor).

So the energy that the upper block gains when gravity accelerates it is reduced by that energy/floor that the lower part absorbs as it fails. (Think of a stunt man falling on a cardboard box. It takes energy to crush the cardboard box, but if the stunt man weighs more than the energy it takes to crush the box, then he accelerates downward, but at an acceleration that's less than one-g.)

As each floor is crushed by the impact, it goes from zero-g acceleration to a higher speed, determined by that conservation of momentum equation, where the initial velocity*masses separately end up being the combined masses*combined-velocity, so the lower floor accelerates very quickly in the collision (making a huge cloud of concrete dust in the process as it's smashed/accelerated at hundreds of g's for milliseconds until it matches the final speed), then the combined masses continue to accelerate under the pull of gravity less the force it takes to crush the remaining lower structure.

The lower structure can't reasonably sustain the force that would be needed to slow the progressive collapse, as once the upper floors get going, it would take more force to stop them than the structure was designed to provide. If you fall ten feet and land on a two-foot-thick mattress, how many g's do you have to decelerate at in order to come to a stop in those two feet? The answer is 6g's, assuming the best case of constant deceleration. How much force is required to stop 30 floors of the WTC's upper block after it's fallen ten feet in the remaining two feet? The weight of 180 floors. More than the weight of the entire building.

See the problem? The structure of the 70th floor wasn't designed to support another 180 floors above it, so it fails when the maximum load it was designed to carry was exceeded, which was a small fraction of that 180 floors' worth of weight. So the initial velocity of the falling block was diminished only by that fraction of the momentum that was necessary to make the lower floor fail, and that accounts for the difference between the block falling at one g and it falling at the 2/3rds g that the paper cited as the best-fit.

As each floor gets hit, it gets pulverized, and its mass gets added to the falling block, which after a few floors really isn't a block any more, but a block preceded by the crushed-floors debris, so instead of there being a "bang-bang-bang" as each floor is hit by the block you transition to a long steadily-increasing rumble, ending in a big THUD as it all hits the ground in a massive heap.

Just like what the video footage shows happened.

No outside source of energy required, just gravity.
Pierre-Normand
QUOTE (3bodyproblem+Jun 3 2007, 02:11 PM)
Pierre: I see what you are saying and yes when dealing with such a large masses, momentum transfer is key factor. I think however that the "pancaking" (i hate using that term for fear of confusing people) was limited to 3 stories below the upper section at least at the point where the upper section begins to move noticeably. I postulated that there was no reason this did not continue for the entire crush down. Perhaps I was wrong.
  What I have referred to is as a "critical mass" would be Zone B in Mr. Bensons et al. model.  If Zone B was immediately behind the floor wave by 3 stories (I'm holding to 3 stories because of the exterior columns design) the upper section is now exerting a lateral force on the top of the column as the last exterior truss connection is severed. At this point the connection to the next lowest column is subjected to a torque and the bolts are sheared. When the bolts are sheared and the exterior column begins to fall away from the perimeter, Zone B discharges mass proportional to the thickness of the exterior column plate steel. During this discharge the pressure in Zone B is reduced, and perhaps it is reduced enough to allow it to catch up to the floor wave? I'm not sure if it is possible to work out an answer to this postulate or not. In effect the mass in Zone B would oscillating very fast every 3 floors in the decent. This becomes more reasonable later in the collapse when much of the mass has been converted to small particles and is easily discharged.

3bodyproblem,

I don't understand very well your description. I am unsure what you are calling the "floor wave". Are these the floors that are disconnected prior to being hit by the "zone B" falling stack?

I am unsure what you are making of the exterior column design. It is true that the column trees were three story high, but they were assembled in a staggered fashion such that the column splices weren't level in adjacent trees.

One other relevant datum is NIST's sampling of the failures modes of the truss seats. There were random failure modes above the fire/impact zone and, below that, the seats were mainly bent down. This strongly indicates that those floors failed from being hit from above.

I also do not quite understand the unloading process of zone B you describe.
Pierre-Normand
QUOTE (wcelliott+Jun 4 2007, 02:11 AM)
Please note: I've re-edited this for clarity, and tried to change it back where it was originally posted, but for some weird reason it's saying I don't have the right to edit my own post. ???

Wcelliott,

You can only edit your posts within some time limit after they were first posted.
Malmoesoldier
wcelliott

QUOTE
Osama bin Laden hates America more than George Bush does (What reason would Bush have to hate America, of all people?), and Osama bin Laden is the more-likely person to think up and carry out such an attack.


No osama bin laden doesnt hate america more then the NWO does. Bush wasnt behind the attacks alone laugh.gif

And now we dont need a hot fire at all you say?? laugh.gif

QUOTE (->
QUOTE
Osama bin Laden hates America more than George Bush does (What reason would Bush have to hate America, of all people?), and Osama bin Laden is the more-likely person to think up and carry out such an attack.


No osama bin laden doesnt hate america more then the NWO does. Bush wasnt behind the attacks alone laugh.gif

And now we dont need a hot fire at all you say?? laugh.gif

We're talking about the trusses sagging from the intense heat.


The perimeter walls of the twin towers were made up of lightweight sections connected by bolts and welds. If the trusses fail the perimeter walls lose support. The perimeter walls would have had little strength without the bracing of trusses, therefore mass truss failures would have resulted in large sections falling off. If the graphic were factual then Flight 175's impact should have gouged a large hole in the side of the building as masses of trusses would have been obliterated as the plane travelled through the building.

Also, The Windsor Building in Madrid was of similar design to the twin towers, And that fire showed large pieces of structure falling off because trusses were failing in the 800ºC fires on the upper floors of the building.

The Windsor Building fire shows that debris should have rained down from the twin towers as trusses failed, especially toward the time of the collapses, and there should have been gaping holes in the buildings' perimeter walls when the buildings came down. This wasn't the case.

WTC2 showed only minimal aircraft damage in the side of WTC 2 immediately before its collapse, and this indicates the building's internal structure was intact. This is confirmed by firefighters transmissions from the impact area.

The Windsor Building fire demonstrates the structural failures in WTC 2 should have been slow, chaotic and visually progressive, instead they were instantaneous, uniform and visually explosive.

"And while I was still in that immediate area, the south tower, 2 World Trade Center, there was what appeared to be at first an explosion. It appeared at the very top, simultaneously from all four sides, materials shot out horizontally. And then there seemed to be a momentary delay before you could see the beginning of the collapse." Frank Cruthers, Chief (F.D.N.Y.)

This is not the signature a building collapsing through failing trusses.


Another part of the collapse also defies the proposed "truss theory".

The image below is a highly enlarged screenshot.

*www.whatreallyhappened.com/IMAGES/wtc2_arrow_box2.jpg

Point A marks structural damage in the corner of WTC 2

Point B marks a solid piece of structure well above the aircraft impact level.

The "truss theory" dictates that fire destroyed the building's structural integrity in and around the level of point A at the time of the collapse.

The theory is the heat of the fire softened not only the floor trusses but also the walls of the outer skeleton they were attached to. When the steel was sufficiently weakened by the heat the walls and the trusses would have pulled apart and without the trusses to hold them rigid the columns of the outer walls started to bend and then fail.

When the collapse starts the building above the level of point A should plow through the building below because of mass truss failures.

When the top of the structural damage at point A hits the bottom of the structural damage the building's structure breaks in the area of point B, but the corner of the perimeter wall below point A doesn't even buckle when the weight of 25+ floors falls onto it.

If weak trusses and weak bolts were the only things connecting the perimeter walls to the internal core... then the building below the impact area should have visibly disintegrated at the start of the collapse, but it didn't. WTC 2 was held together by something a lot more substantial than trusses and bolts.

"I believe that the building could probably sustain multiple impacts of jet liners because this structure is like the mosquito netting on your screen door - this intense grid - and the plane is just a pencil puncturing that screen netting. It really does nothing to the screen netting." DeMartini

WTC 1 had burned for longer than its twin, so if the "truss theory" is believed then this building should contain more failed trusses than WTC 2, therefore the seismic shockwave generated by the collapsing adjacent building should dislodge numerous pieces of structure from the impact area of the building.

Cary Sheih -WTC 1 Survivor:
"I was a few floors from the ground. Floor,,,,4,,,,then all of a sudden, a loud boom, and the building began to shake unbearably again. People started falling down the stairwell as smoke started to rise from the bottom. The emergency lights flickered and then went out. The building was still shaking, and I could hear the steel buckling." hmm laugh.gif

Cary Sheih on the 72nd floor of WTC 1 when Flight 11 hit the building:

"I heard a loud explosion, which was immediately followed by tremendous building sways and vibrations. As I was thrown out of my chair, I immediately thought that this was an earthquake, but still thinking rationally, I thought that it was abnormal since there are no earthquakes in NYC, especially of this magnitude. I remember thinking that the building felt like it was going to collapse from this initial explosion."

WTC 1 shook and swayed so violently that it threw Cary Sheih from his chair, but it remained standing. This is incredible, especially when you consider the following collapse study:

"The single-bolt connections in the framework of the World Trade Center popped and fell apart during the September 11 terrorist attacks, causing the floors to collapse on top of each other, according to a new study. The analysis, conducted by a team of researchers from the Massachusetts Institute of Technology (MIT), concludes the bolts did not properly secure the towers' steel floor trusses, The New York Post reported yesterday." [CBS News]

If the building was truly held together by weak bolts then the single bolt connections should have "popped and fell apart" when Flight 11 smashed into the inner core of WTC 1, not 1½ hours after the event.

The only way WTC 1 could have survived Flight 11's impact is if the building was solidly constructed.

Below are 2 zoomed images of this WTC construction site photograph. They show steel beams connecting the south tower's outer walls to it's inner core, not trusses:

*www.whatreallyhappened.com/IMAGES/south-spans-marked-zoom_small.jpg
*www.whatreallyhappened.com/IMAGES/wtc_south-hizoom_small.jpg

The buildings were indeed solidly constructed, proof of this lies in the fact they stood for thirty years in winds which sometimes reached hurricane force. Would ¼ mile high buildings which relied solely on the integrity of weak trusses and 5/8" bolts have stood for thirty years?

When Flight 11 flew into WTC 1, one of two things should have happened:

1. If the building was constructed with non-composite steel trusses bolted to the inner core it should have immediately collapsed.

2. If the building was solidly constructed it should have remained standing.

Neither of the above occurred.
Malmoesoldier
And also, NIST contracted with Underwriters Laboratories, Inc. to conduct tests to obtain information on the fire endurance of trusses like those in the WTC towers… All four test specimens sustained the maximum design load for approximately 2 hours without collapsing.” (NIST, 2005, p. 140, emphasis added.)

laugh.gif laugh.gif laugh.gif
adoucette
Moe

The Madrid towers were built around a reinforced concrete core, so NO it was not similar to the WTC and AFAIK, no plane ran into it either.

As for the WTC, there were BEAM framed floors at the lower levels and the mechanical floors. The REST were with trusses.

This shows clearly the relative size of the truss material.

User posted image

http://i117.photobucket.com/albums/o72/ard...ionimage017.jpg

As to the point of how the towers were built.
They were STRONG, but they weren't overbuilt. Read wcelliott's apt description of what it takes to optimize design in order to build the two tallest and voluminous buildings in the world.

User posted image

http://i117.photobucket.com/albums/o72/ard...eshilouette.jpg

Arthur
SYLVESTER1592
QUOTE (newton+Jun 4 2007, 07:14 AM)
it might be a stretch if it weren't for elevated tritium levels, and radioactive material at fresh kills landfill.

as it is, fuzzy logic says coincidence theory can only stretch so far.


If we assume this is true , there still is no clear relation between multiple myeloma and radiation. Although a good hypothesis, I haven’t seen any studies on it yet. Even for workers in nuclear reactors there should be some relation… I can’t find it. I think other clinical presentations are more likely, other types of lymphoma’s have been described, but this is an odd one to relate to radiation.

I remember an article which showed the possibility of natural nuclear reactions in the earth’s upper mantle and crust and the products of this, published by J.M. Herndon in PNAS (PNAS 2003;100;3047-3050 and PNAS 1996;93;646-648). I can’t post the link yet, but you can find it using Google Scholar.

Are you sure that this phenomenon is not what they are referring to when they talk about radioactive material?... Are they suggesting a radioactive bomb or something like that? What radioactive material was present? I’m interested in these elevated tritium levels and radioactive material at fresh kills landfill… Can I get a link or pdf or something with a little more details?

SYL smile.gif
wcelliott
Malmoesoldier,Jun 4 2007, 01:03 PM

>>If the graphic were factual then Flight 175's impact should have gouged a large hole in the side of the building as masses of trusses would have been obliterated as the plane travelled through the building.
<<


You mean to say you think it didn't?

blink.gif

My point was that the building was supported by three main structural elements, and if any one of the three failed, the structure as a whole would've failed.

The horizontal trusses were the most vulnerable of the three to fire, they would heat up the fastest and they would fail the quickest. When they go, the structure goes.

The collapses weren't sudden, they started when the planes hit, and progressed slowly but inexorably from there. It wasn't noticeable at first, but if you want to track its progress, measure the angle between the top part of the building and true vertical. It will progress slowly, then faster, then faster, then the building collapses. If it were a CD, there would be no angle-rate at all. zero. and when the explosives went off, then it would've collapsed. That's not what happened. The fact that there was a non-zero angle rate at the time of the collapse means that the building was on its way down.

Arthur, My Thanks to you for those pictures, they truly are worth at least a thousand words apiece.

biggrin.gif
3bodyproblem
QUOTE (Pierre-Normand+Jun 4 2007, 11:38 AM)
3bodyproblem,

I don't understand very well your description. I am unsure what you are calling the "floor wave". Are these the floors that are disconnected prior to being hit by the "zone B" falling stack?

I am unsure what you are making of the exterior column design. It is true that the column trees were three story high, but they were assembled in a staggered fashion such that the column splices weren't level in adjacent trees.

One other relevant datum is NIST's sampling of the failures modes of the truss seats. There were random failure modes above the fire/impact zone and, below that, the seats were mainly bent down. This strongly indicates that those floors failed from being hit from above.

I also do not quite understand the unloading process of zone B you describe.

Hi Pierre:

1) Yes. What I have envisioned as the floor wave is the pancaking of the floors prior to the arrival of Zone B. I beleive this is really pronounced in the video footage of the south wall of WTC 2.

2) Yes, the exterior was staggered and all trees were three stories. Even though they were staggered I believe that most would fail at the bolted connection a this was the weakest point. Due to the velocity of the collapse the sequential failure of the exterior staggered trees would appear to be seamless, and happening approximately every three stories.

3) I also believe my analysis concurs with the NIST data. Imagine the proceeding edge of Zone B is acting laterally on the top of the 3 story tree. The floor trusses, being slightly ahead of Zone B are severed. The lateral forces on the top of the tree exert a moment about the bolt connections on the bottom and shear them off. The tree is now free to fall away from the perimeter of the building. At this point there would be a substantial drop in pressure of Zone B as the exterior is no longer containing it inside the footprint and material is ejected. In the next instant it is again contained and the pressure in Zone B again begins to build during the next three stories.


After explaining this again, I realize my model relies on one key thing. I need to prove that the floor "pancaking" system was returning to equilibrium every three floors ie: slowing down. If this can be shown, then it would be safe to assume that the pancaking relied on Zone B to sever the exterior columns.
metamars
QUOTE (SYLVESTER1592+Jun 4 2007, 03:02 AM)

Hi there, I'm new to this forum. So I will be reading mostly. I'm not as well equipped in the physics department as most of the members in this forum.



Ha! You are new. biggrin.gif
Grumpy
3bodyproblem

QUOTE
After explaining this again, I realize my model relies on one key thing. I need to prove that the floor "pancaking" system was returning to equilibrium every three floors ie: slowing down. If this can be shown, then it would be safe to assume that the pancaking relied on Zone B to sever the exterior columns.


This is where I part company with your hypothesus. I believe the "pancaking/bagelling" was a self sustaining phenominon in it's own right and proceeded to completion once started. Since this was going on within the still intact outer structure the shedding of mass was at a minimum and most of the floors went straight to the basements.

Now, zone B may have started out lagging by ~10 floors but it probably accelerated faster than the floor collapse and may have caught up with it later in the sequence, melding zone B and the floor "wave" but the signs of floor collapse ahead of zone B are pretty plain early in the sequence.

Grumpy cool.gif

wcelliott
QUOTE
believe the "pancaking/bagelling" was a self sustaining phenominon in it's own right and proceeded to completion once started. Since this was going on within the still intact outer structure the shedding of mass was at a minimum and most of the floors went straight to the basements.



I agree with this, with a slight caveat, that I don't think that the floors maintained their integrity post-impact from the floor-debris from above.

In a prior rant, I pointed out that each floor, when hit from above, had to accelerate to the upper floors' materials' velocity as it "stacked up", I realized that the accelerations would be huge and brief, and that would explain the generation of so much concrete dust.

The other point to remember is that there's office-junk in between the colliding floors, which would mostly get crushed immediately, but would contribute to an uneven distribution of forces on both the floor below and the material falling from above. This unequal distribution of high forces would, IMO, shatter the floor below into a million pieces (and a huge cloud of concrete dust), so the floor below that would be struck by a non-solid mass of debris hitting it all at approximately the same instant. Not exactly pancaking, but so close that the distinction would be academic.
3bodyproblem
QUOTE (Grumpy+Jun 4 2007, 04:24 PM)
3bodyproblem



This is where I part company with your hypothesus. I believe the "pancaking/bagelling" was a self sustaining phenominon in it's own right and proceeded to completion once started. Since this was going on within the still intact outer structure the shedding of mass was at a minimum and most of the floors went straight to the basements.

Now, zone B may have started out lagging by ~10 floors but it probably accelerated faster than the floor collapse and may have caught up with it later in the sequence, melding zone B and the floor "wave" but the signs of floor collapse ahead of zone B are pretty plain early in the sequence.

Grumpy cool.gif

Well I can't say as I blame you. This relies on an almost balanced system to work. The overpressure from Zone B would have to be sufficient to propagate the "pancaking".

In the self sustained bagel collapse I can't see the upper section catching up, as the floor truss connections appear to be relatively constant the entire height of the building. This would propagate much like Mr. Greening described in his original paper, minus the core and exterior mass. Wouldn't then the floor wave arrive noticeably ahead of the upper section?
3bodyproblem
QUOTE (wcelliott+Jun 4 2007, 04:49 PM)

I agree with this, with a slight caveat, that I don't think that the floors maintained their integrity post-impact from the floor-debris from above.
[snip]
Not exactly pancaking, but so close that the distinction would be academic.


Yep. I believe this is also substantiated by the photos in NCSTAR1-3 fig. 5.1 of balled up floor trussing.

I hate using the term pancaking as well, as this phenomenon is almost exclusive to steel reinforced concrete slab cascade failure. The term is properly used to describe the appearance of the collapse after it has occurred.
newton
QUOTE (SYLVESTER1592+Jun 4 2007, 03:42 PM)

If we assume this is true , there still is no clear relation between multiple myeloma and radiation. Although a good hypothesis, I haven’t seen any studies on it yet. Even for workers in nuclear reactors there should be some relation… I can’t find it. I think other clinical presentations are more likely, other types of lymphoma’s have been described, but this is an odd one to relate to radiation.

I remember an article which showed the possibility of natural nuclear reactions in the earth’s upper mantle and crust and the products of this, published by J.M. Herndon in PNAS (PNAS 2003;100;3047-3050 and PNAS 1996;93;646-648). I can’t post the link yet, but you can find it using Google Scholar.

Are you sure that this phenomenon is not what they are referring to when they talk about radioactive material?... Are they suggesting a radioactive bomb or something like that? What radioactive material was present? I’m interested in these elevated tritium levels and radioactive material at fresh kills landfill… Can I get a link or pdf or something with a little more details?

SYL smile.gif

here's someone else picking up the same breadcrumbs

i just did a google search, 'radiation fresh kills'. this is not an area i'm really that interested in, yet, but it is interesting, and i have seen every theory at some point in my tireless search for....
.....zzzzzzzzzzzzzz.

however, the more people who find out the truth behind THAT debacle, the better. so, if you're qualified, and maybe have taken the hypocratic oath, even, this aspect of 911's coverup might benefit with your helping hand.

QUOTE
This is the story of 9-11 and cancer.

To date, 75 recovery workers on or around what is now known as "the Pile"—the rubble that remained after the World Trade Center towers collapsed on the morning of September 11, 2001—have been diagnosed with blood cell cancers that a half-dozen top doctors and epidemiologists have confirmed as having been likely caused by that exposure.

Those 75 cases have come to light in joint-action lawsuits filed against New York City on behalf of at least 8,500 recovery workers who suffer from various forms of lung illnesses and respiratory diseases—and suggest a pattern too distinct to ignore. While some cancers take years, if not decades, to develop, the blood cancers in otherwise healthy and young individuals represent a pattern that experts believe will likely prove to be more than circumstantial. The suits seek to prove that these 8,500 workers—approximately 20 percent of the total estimated recovery force that cleared the rubble from ground zero—all suffer from the debilitating effects of those events.


http://www.villagevoice.com/news/0648,lombardi,75156,2.html

QUOTE (->
QUOTE
This is the story of 9-11 and cancer.

To date, 75 recovery workers on or around what is now known as "the Pile"—the rubble that remained after the World Trade Center towers collapsed on the morning of September 11, 2001—have been diagnosed with blood cell cancers that a half-dozen top doctors and epidemiologists have confirmed as having been likely caused by that exposure.

Those 75 cases have come to light in joint-action lawsuits filed against New York City on behalf of at least 8,500 recovery workers who suffer from various forms of lung illnesses and respiratory diseases—and suggest a pattern too distinct to ignore. While some cancers take years, if not decades, to develop, the blood cancers in otherwise healthy and young individuals represent a pattern that experts believe will likely prove to be more than circumstantial. The suits seek to prove that these 8,500 workers—approximately 20 percent of the total estimated recovery force that cleared the rubble from ground zero—all suffer from the debilitating effects of those events.


http://www.villagevoice.com/news/0648,lombardi,75156,2.html

"In the end," Worby declares, "our officials might be responsible for more deaths than Osama bin Laden on 9-11."


newton
here's the report on elevated tritium...

7. Conclusions (this is a link to the entire report)

QUOTE

34{.3} Ci of tritium were released from the two Boeing 767 on impact with the Twin
Towers at the World Trade Center. The limited measurements and modeling are consistent with
an instantaneous (catastrophic) creation of HTO from the aircraft emergency signs, deposition of
a small fraction of it at ground zero and water-flow controlled removal from the site. The
modeling suggests that the contribution from the aircraft would imply the HTO deposition
fraction of [3]%, a value which is judged somewhat too high. Therefore, the source term from
the airplanes alone is insufficient to explain the measurements and modeling.
Several weapons were present and destroyed at [the]WTC. The modeling is also
consistent with the second tritium source from the weapon sights (plus possibly tritium watches)
where tritium was slowly released from the debris in the lingering fires, followed by an oxidation
and removal with the water flow. Such a limiting case would require a minimum of 115 weapons
and a quantitative capturing of tritium. Therefore, such a mechanism alone [seems in]sufficient,
which indicates that the weapon/watch source complemented the airplane source.
adoucette
Re cancer risk:

All from same article.

http://www.villagevoice.com/news/0648,lombardi,75156,2.html

Number of rescue workers: ~40,000

Of the 8,500 people now suing the city, 400, or about 5 percent, have cancer.

"Those numbers seem quite outrageous," is how Hesdorffer puts it. Now at Johns Hopkins, Hesdorffer directed until last year the tumor immunotherapy program at Columbia University Medical Center, where he treated two recovery workers who got cancer post–9-11. He notes that the average healthy adult person has a 20 percent risk of having cancer over a lifetime. Calculate that risk over five years—the time frame from the events of 9-11 until today—and it drops to about 1 percent.


Except 400 is exactly the same EXPECTED 1 percent of the TOTAL workers, so the numbers don't appear out of line.

Without knowing the type of cancers one can't really tell if there is an over abundance of a specific TYPE of cancer, but the OVERALL cancer numbers don't jump out like the large number of respiratory problems.

Unlike the respiratory problems I would be surprised to find much of a spike in overall cancer rates given the relatively short time the workers were exposed to toxins in the pile.

Arthur
Alan (ex elevator man)
QUOTE (Malmoesoldier+Jun 4 2007, 07:03 AM)
"And while I was still in that immediate area, the south tower, 2 World Trade Center, there was what appeared to be at first an explosion. It appeared at the very top, simultaneously from all four sides, materials shot out horizontally. And then there seemed to be a momentary delay before you could see the beginning of the collapse." Frank Cruthers, Chief (F.D.N.Y.)


The key phrase there is "...what appeared to be at first ..."
Then, please explain how he could see all four sides at once. At MOST, he could see 3, but 4 sides is impossible.
So anyways, I checked the rest of his statement, but he didn't expound on it. But a few pages later, he DID mention WTC 7.

QUOTE
Early on, there was concern that 7 World
Trade Center might have been both impacted by the
collapsing tower and had several fires in it and there
was a concern that it might collapse. So we instructed
that a collapse area --
Q. A collapse zone?
A. Yeah -- be set up and maintained so that when
the expected collapse of 7 happened
, we wouldn't have
people working in it. There was considerable
discussion with Con Ed regarding the substation in that
building and the feeders and the oil coolants and so
on.


Read it yourself at : Chief Caruthers interview
SYLVESTER1592
QUOTE (newton+Jun 4 2007, 06:36 PM)
i just did a google search, 'radiation fresh kills'.  this is not an area i'm really that interested in, yet, but it is interesting, and i have seen every theory at some point in my tireless search for....
.....zzzzzzzzzzzzzz.

however, the more people who find out the truth behind THAT debacle, the better.  so, if you're qualified, and maybe have taken the hypocratic oath, even, this aspect of 911's coverup might benefit with your helping hand.

OK,
I think this is in line with my first post. They refer to the most likely cause as benzene or even other chemicals such as dioxin and asbestos among others. Benzene as a well proven one, and if you look at the questions asked by the doctors to the patients, that would be exactly what I would ask. These are the most likely (known) occupational causes. As far as the reference to the atomic bomb goes, they are referring to the postponed effects of exposure to carcinogens. Of course if there would be an access of other types of lymphoma’s (Non Hodgkin Lymphoma), you could consider radiation as one of the possible causes in a differential diagnosis, but in this stage I think I’ll stick with benzene.

I think you are right when you claim the EPA should have been more careful in their recommendations. I always thought it was a rather bold statement that there were no health risks. I think they figured this out too. The medical follow up of patients will reflect this, but the EPA works with large populations instead of the individual patient and has to look ahead. As a result their risk assessment can be quite off the mark and sometimes is, as in this case for this specific type of cancer…
To what extent they could have predicted this is hard to say, but I have to agree that the overal cancer risk can only be evaluated over time and it's a bit early to say right now. To what extent there will be a spike is still uncertain, maybe we'll know in about 15 years...

Thank you for the links,

SYL smile.gif
SYLVESTER1592
QUOTE (newton+Jun 4 2007, 06:48 PM)
here's the report on elevated tritium...


I'm sorry didn't check the tritium link yet.
I just read it. It says on page2 that All the levels were well below the level of concern to human exposure. It doesn't support clinical presentation of possible radiation effects in workers, but still I agree it is an interesting find.

Thank you,

SYL smile.gif
Malmoesoldier
Alan

QUOTE
Read it yourself at : Chief Caruthers interview


Yes so?.

"I--I went down to the scene and we set up headquarters at 75 Barkley Street, which was right there with the police commissioner, the fire commissioner, the head of emergency management, and we were operating out of there when we were told that the World Trade Center was going to collapse. And it did collapse before we could actually get out of the building, so we were trapped in the building for 10, 15 minutes, and finally found an exit and got out, walked north, and took a lot of people with us." Giuliani

And then some days ago he said that he wasnt told that the building was going to collapse and that he didnt have any pre-knowledge.

http*://www.wnbc.com/politics/13404578/detail.html?dl=mainclick
http*://www.prisonplanet.com/articles/may2007/290507giulianiconfronted.htm

And there was big explosions in WTC 7

Explosions heard a hour later...From below the WTC 7 http:*//www.youtube.com/watch?v=JW_jm3EEHLQ

Here you can hear two BIG explosions from WTC 7 http*://www.youtube.com/watch?v=CcRs1fv8i3I

At 02:15 in this video you hear a big explosion from WTC 7 http*://www.youtube.com/watch?v=Hj0vq69jmSo&mode=related&search=

People that was inside WTC 7 that could FEEL and heard explosions http*://www.record-eagle.com/2001/sep/11scene.htm
Malmoesoldier
adoucette and wcelliott i debunked you about the trusses but i will do it one more time laugh.gif

So what happens when world trade center type trusses are heated?

Well,... from the evidence, the answer is: Not that much happens.

We consider two examples from fires that were known to be very hot.

The June 1990 Broadgate Phase 8 fire.

Cant post pictures so here's a link. http*://guardian.150m.com/wtc/trusses-broadgate.jpg

The above photo shows a number of trusses and a buckled steel column after the Broadgate Phase 8 fire.

Note that the fire was hot enough to buckle the steel column.
Note that even though the trusses were obviously in the same fire, they show no sign of buckling

"On the 23rd June 1990 a fire developed in the partly completed fourteen storey building in the Broadgate development. The fire began in a large contractors hut on the first floor and smoke spread undetected throughout the building. The fire detection and sprinkler system were not yet operational out of working hours.

The fire lasted 4.5 hours including 2 hours where the fire exceeded 1000°C (1832°F). The direct fire loss was in excess of £25 million however, only a fraction of the cost (£2 million) represented structural frame and floor damage. The major damage was to the building fabric as a result of smoke. Moreover, the structural repairs after the fire took only 30 days. The structure of the building was a steel frame with composite steel deck concrete floors and was only partially (fire) protected at this stage of construction. During and after the fire, despite large deflections in the elements exposed to fire, the structure behaved well and there was no collapse of any of the columns, beams or floors.

The Broadgate phase 8 fire was the first opportunity to examine the influence of fire on the structural behaviour of a modern fast track steel framed building with composite construction."

The trusses used in the Broadgate phase 8 construction had a 45 feet (13.5m) span.
The World Trade Center Tower construction used trusses with both 35 and 60 foot spans.

And note that, the sprinkler system and other active measures were NOT operational at the time of the fire and most of the steel was not fire protected.


The February 1975 World Trade Center North Tower Fire.

"This 110-story steel-framed office building suffered a fire on the 11th floor on February 23, 1975. The loss was estimated at over $2,000,000. The building is one of a pair of towers, 412 m in height. The fire started at approximately 11:45 P.M. in a furnished office on the 11th floor and spread through the corridors toward the main open office area. A porter saw flames under the door and sounded the alarm. It was later that the smoke detector in the air-conditioning plenum on the 11th floor was activated. The delay was probably because the air-conditioning system was turned off at night. The building engineers placed the ventilation system in the purge mode, to blow fresh air into the core area and to draw air from all the offices on the 11th floor so as to prevent further smoke spread. The fire department on arrival found a very intense fire. It was not immediately known that the fire was spreading vertically from floor to floor through openings in the floor slab. These 300-mm x 450-mm (12-in. x 18-in.) openings in the slab provided access for telephone cables. Subsidiary fires on the 9th to the 19th floors were discovered and readily extinguished. The only occupants of the building at the time of fire were cleaning and service personnel. They were evacuated without any fatalities. However, there were 125 firemen involved in fighting this fire and 28 sustained injuries from the intense heat and smoke. The cause of the fire is unknown."

The WTC North Tower suffered no serious structural damage in this fire. In particular, none of the trusses needed to be replaced.

So, here is a very serious fire (which spread over eleven floors) in World Trade Center North Tower. The very same building that "collapsed" on 9/11. Although the 1975 fire lasted about 4 hours, it caused no serious structural damage. However, according to the government/media fairy tale on 9/11, the 2001 fire, which lasted only 45 minutes, caused not only serious structural damage, but the entire building to collapse.

There should be a law against telling such fairy tales as these government/media fables.

Anyway, in both of the above mentioned pre-9/11 fires, the trusses survived the fires without replacement and supported the buildings for many, many years after the fires were put out.

So did truss failure cause the "collapses" of the World Trade Center buildings? Of course not.

And NIST contracted with Underwriters Laboratories, Inc. to conduct tests to obtain information on the fire endurance of trusses like those in the WTC towers… All four test specimens sustained the maximum design load for approximately 2 hours without collapsing.” (NIST, 2005, p. 140, emphasis added.)

laugh.gif
NEU-FONZE
Sylvester1592:

Benzene air concentrations as high as 30 ppm were recorded at Ground Zero in the period immediately after 9/11. The OSHA permissible exposure limit for benzene is 1 ppm for an 8-hour time-weighted average.

Toluene, ethyl benzene, xylene, styrene were also present .... all of which are potentially carcinogenic.
SYLVESTER1592
QUOTE (NEU-FONZE+Jun 4 2007, 08:22 PM)
Sylvester1592:

Benzene air concentrations as high as 30 ppm were recorded at Ground Zero in the period immediately after 9/11. The OSHA permissible exposure limit for benzene is 1 ppm for an 8-hour time-weighted average.

Toluene, ethyl benzene, xylene, styrene were also present .... all of which are potentially carcinogenic.

I didn't know it was that high. I guess that strengthens the idea the cause for a relative rise in the incidence of multiple myeloma could be contributed to the presence of aromatic substances.
Did that info come from the EPA or a published article I could reference? If you can post a link that would be very much appreciated. Thanks NEU-FONZE.

SYL smile.gif
NEU-FONZE
Sylvester1592:

You are welcome!

There is a ton of data on air quality at the WTC on the EPA site:

http://www.epa.gov/wtc/benzene/

Data for other species are at:

http://www.epa.gov/wtc/monitoring/index.html

I hope these links work.... if not google on words like WTC EPA Response
adoucette
I've been debunked?

Not likely, and certainly not by anyone as ill informed as you are.

laugh.gif

For the Broadgate fire

Note: the building was a partly completed fourteen storey building in the

Meaning it had ZIP LIVE load and ZIP cumbustible fuel load.

Ooops.

Oh and it wasn't HIT BY A FRIGGIN JET PLANE.


Why is it that you don't understand that a FIRE would not have hurt the towers either?

It was the effects of the fire AFTER the jet plane hit it at 500 mph that was the issue.

Go ahead MOE, tell us again how the PLANE'S IMPACT DID LITTLE DAMAGE.

laugh.gif

Arthur
David B. Benson
QUOTE (wcelliott+Jun 4 2007, 01:53 AM)
This is a perfectly valid way to model a linear system.

Its also a valid way to model a non-linear system. In this part of campus, the fluid mechanics consists mostly of research in water, air, materials, and some combustion work. Over there is the shock physics group. Everybody grids their models into boxes or cubes. I've tried to con vice the air quality guys to try Voronoi griding, so far without success.

NIST has had a building fire safety group since 1923. That's a longer institutional history than for liquid-fueled rockets.

The are whole journals of fire safety engineering. Don't you think all those people, including NIST, are aware of the effects you mention? They don't come around complaining about the way you approximate Naiver-Stokes. I don't think you are in a position to complain about the way they approximate the same equations in the regime they have studied for so long.
David B. Benson
QUOTE (3bodyproblem+Jun 4 2007, 02:05 AM)
1) WTC 1 is different.. NIST would seem to indicate that the core failed before the exterior (I believe this was determined by the noticed movement of the radio tower).

3) Unless you are under the impression the collapse gained velocity?

1) NO! NCSTAR1-6 and NCSTAR1-6D both clearly state that three walls failed first. The antenna tower appears to sink in one video due to the tilting. Another video, taken more from the west, clearly indicates the tilt.

3) The collapse proceeded at a ever increasing speed during crush-down. Diagrams are given in Greening's "Energy Transfer" and also in Bazant & Verdure. NEU-FONZE's measurements also directly demonstrate this.
David B. Benson
QUOTE (Oneismany+Jun 4 2007, 07:16 AM)
The time in which the towers "collapsed" is close to the time for the top floor to fall with nothing but air blocking it, hence "free fall."


Which begs the question, how did the majority of the debris land in about 10 seconds?

Not true.

Not true again.

WTC 1 took 18 seconds to collapse. The Heath video (audio portion) absolutely established this. The majority of the debris came to a smashing halt in the lowest sub-basement at about 13 seconds. The recent, careful calculation in Bazant/Le/Greening/Benson states 12.8 seconds and I'll not quibble about a mere 0.2 seconds, as the determination of 'about 13 seconds' is rather approximate in any case.

A Fox 5 video shows the bottom of the crushing from passing the top of WTC 3 (about 80 meters) after about 11-12 seconds of collapse with about 2 more seconds to go to reach the lowest sub-basement.
adoucette
QUOTE (NEU-FONZE+Jun 4 2007, 03:22 PM)
Sylvester1592:

Benzene air concentrations as high as 30 ppm were recorded at Ground Zero in the period immediately after 9/11. The OSHA permissible exposure limit for benzene is 1 ppm for an 8-hour time-weighted average.

Toluene, ethyl benzene, xylene, styrene were also present .... all of which are potentially carcinogenic.

But generally speaking you have to be exposed to these chemicals over a reasonably long period of time to see an increase in cancer.

Levels like 30 ppm for a short time (a few hours to few days) are much more likely to be directly toxic to your liver than to be carcinogenic.

Put it in perspective, the OSHA limit allows you to get 1 ppm over an 8 hour time weighted average.

That generally indicates you can have a greater exposure for shorter periods of time, thus for example 8 ppm for just one hour might be acceptable as would 16 ppm for 30 minutes (those might not be exactly correct but you get the idea).

As far as the EPA statement, she made a STUPID statement that has come back to bite her. The air WAS remarkably good shortly after 9/11, mainly because the pit fires were being suppressed by a lot of water and BECAUSE IT HAD RAINED.

Still, many THOUSANDS of people had already been exposed to some of the WORST possible particulates/gases etc on the day of the collapse. Many of them residents of the area. These people were already "done in" by the initial dust cloud following the collapse and the fact that the AIR got so much better within a few days was not going to help them at all.

Secondly, as the studies showed, while the AIR was fairly good in lower Manhattan, there was LOTS of settled dust around and a lot of it was in the size range you don't want to be breathing. Clearly this dust had to be cleaned up before LIVING in the area because otherwise it would result in periodic inhalation of toxic dust.

Then there were the fires that burned all the way till December. So, clearly her remark was a tad premature in that as the pile burned the toxins released would change and the hazard would change based on wind speed and direction. Though IN GENERAL the air might be good (i,e only 1 of 10 stations reporting bad air), if you were living downwind of the fire for several days you could get a fairly decent dose of potentially toxic smoke.

Finally, AFAIK she was not talking about working on the PIT itself. It clearly had its own issues.

Arthur
David B. Benson
QUOTE (Oneismany+Jun 4 2007, 08:22 AM)
Mass is a function of the drop distance and so is velocity?

It is clearer, I hope, to state that the mass of each story depends upon the story number. In general, as the story number increases, the mass decreases. There were several exceptions to this generality, notably the mechanical floors and the excess mass at the top due to the hat truss.

The drop speed is easily determined by the drop data that NEU-FONZE measured. The speed increases during the collapse, at least for the first few seconds of measurement.

For the correct physics without calculus, see Greening's "Energy Transfer" paper.
For the correct physics using the calculus, see Bazant & Verdure's paper, obtainable from Professor Bazant's web site.
Malmoesoldier
adoucette. Haha you are debunked real hard! laugh.gif

The fires in WTC was not hot enough to make the trusses collapse

Ooops.

Oh and Underwriters Laboratories All four trusses tests specimens sustained the maximum design load for approximately 2 hours without collapsing.

Ooops.

READ my two posts about trusses again and maybe EVEN you will understand laugh.gif

WTC2 showed only minimal aircraft damage in the side of WTC 2 immediately before its collapse, and this indicates the building's internal structure was intact. This is confirmed by firefighters transmissions from the impact area.

9-11 was an inside job. You believe in lies that a 10 year old can see trough. FEMA even says that the buildings didnt have a CORE!!! LOL laugh.gif. They lie like that so they can laugh at people like you that believes in their BS.
David B. Benson
QUOTE (3bodyproblem+Jun 4 2007, 03:59 PM)
What I have envisioned as the floor wave is the pancaking of the floors prior to the arrival of Zone B.

NO!

By definition, zone B IS the crushing front, both the crushed trusses and the crushed core. See Bazant & Verdure's paper.

If you insist upon distinguishing between bageling trusses and the destruction in the core, call the former Bf and the latter Bc.
3bodyproblem
QUOTE (David B. Benson+Jun 4 2007, 09:12 PM)
1) NO! NCSTAR1-6 and NCSTAR1-6D both clearly state that three walls failed first. The antenna tower appears to sink in one video due to the tilting. Another video, taken more from the west, clearly indicates the tilt.

3) The collapse proceeded at a ever increasing speed during crush-down. Diagrams are given in Greening's "Energy Transfer" and also in Bazant & Verdure. NEU-FONZE's measurements also directly demonstrate this.

1) OK, losing my mind. I knew this from NCSTAR and then got confused with a video I saw. Yes "Probable Collapse Sequence" in 6D I believe. I knew there was a reason I found it hard to believe.

3) Yes indeed. I was referring to the point where the core was suffering from less damage and remained intact. The energy of the collapse not going into damaging the core must have manifested in other forms ie: the collapse picked up even more speed, the debris was ejected even further, or the pulverization was increased. I was just curious what your thoughts on this were. It was my contention that the debris would be ejected even further.
David B. Benson
QUOTE (3bodyproblem+Jun 4 2007, 09:46 PM)
I was referring to the point where the core was suffering from less damage and remained intact. The energy of the collapse not going into damaging the core must have manifested in other forms ie: the collapse picked up even more speed, the debris was ejected even further, or the pulverization was increased.

All three. The ejection speed ought to depend upon the collapse front speed (I think). The pulverization and air resistance clearly do.
3bodyproblem
QUOTE (David B. Benson+Jun 4 2007, 09:53 PM)
The ejection speed ought to depend upon the collapse front speed (I think). .

My thoughts were that the increasing plate thickness would have some effect on this.

My apologies, I have never read this Bazant Verdure paper. I thought I had. But, I am right now, it is very interesting and answers a few of my questions. (It appears I have read some of this paper smile.gif)

And yes B floor and B core I was trying to figure that out all day, it took me less time to figure out what AFAIK, Newbie smile.gif
Daru
Researcher Jim Hoffman estimated in a January 2004 interview with Bonnie Faulkner that about 80 to 90 percent of the masses of the Towers ended up outside of their footprints www.studyof911.com/articles/BsB092306/

Eh... "progressive collapse" eh eh.

User posted image
David B. Benson
QUOTE (Daru+Jun 4 2007, 10:23 PM)
... about 80 to 90 percent of the masses of the Towers ended up outside of their footprints ...

Nope. A reasonably careful inspection of Ground Zero photographs, especially the aerial ones, demonstrates that about 80% lies within, or in very close proximity to, the footprints.

Goes to show you should not trust Hoffman... wink.gif
SYLVESTER1592
QUOTE (adoucette+Jun 4 2007, 09:36 PM)
But generally speaking you have to be exposed to these chemicals over a reasonably long period of time to see an increase in cancer.

Levels like 30 ppm for a short time (a few hours to few days) are much more likely to be directly toxic to your liver than to be carcinogenic.

Put it in perspective, the OSHA limit allows you to get 1 ppm over an 8 hour time weighted average.

That generally indicates you can have a greater exposure for shorter periods of time, thus for example 8 ppm for just one hour might be acceptable as would 16 ppm for 30 minutes (those might not be exactly correct but you get the idea). 

As far as the EPA statement, she made a STUPID statement that has come back to bite her. The air WAS remarkably good shortly after 9/11, mainly because the pit fires were being suppressed by a lot of water and BECAUSE IT HAD RAINED.

Still, many THOUSANDS of people had already been exposed to some of the WORST possible particulates/gases etc on the day of the collapse. Many of them residents of the area. These people were already "done in" by the initial dust cloud following the collapse and the fact that the AIR got so much better within a few days was not going to help them at all.

Secondly, as the studies showed, while the AIR was fairly good in lower Manhattan, there was LOTS of settled dust around and a lot of it was in the size range you don't want to be breathing. Clearly this dust had to be cleaned up before LIVING in the area because otherwise it would result in periodic inhalation of toxic dust.

Then there were the fires that burned all the way till December. So, clearly her remark was a tad premature in that as the pile burned the toxins released would change and the hazard would change based on wind speed and direction. Though IN GENERAL the air might be good (i,e only 1 of 10 stations reporting bad air), if you were living downwind of the fire for several days you could get a fairly decent dose of potentially toxic smoke.

Finally, AFAIK she was not talking about working on the PIT itself. It clearly had its own issues. 

Arthur

Noted, good point.

I think the OP referred to “blood cancer in 911 rescue workers” and I also think she wasn't talking about them specifically but rather about the general public.

When I look at the info supplied by NEU-FONZE it shows a exposure to volatile organic compounds to be 4000 times higher in the air at ground zero then in the surrounding streets. How this would work out for benzene is something I'm not sure of yet. I think the EPA made an average over a year of exposure and came to a number lower then 20 ppm, but this is an average for a year of continues exposure, so that's quite a lot. Even though you would not expect these amounts to be immediately carcinogenic, higher amounts on the site itself and failure to comply with the recommendations of the EPA, could amount to much higher levels of exposure. I'm just guessing here, since I have no way to know for sure at this time. The measurements were taken at the outer edge of the work zone, so it it can be expected that at the actual site the levels would be a lot higher. If it is true, it would explain an increase in the incidence.

When you consider 20.000 ppm is fatal, this is getting me interested. I think the main immediate effects would be neurological, so the “advice” to use protection would be rather inadequate. If they are really exposed and influenced by the effects of benzene, you can’t expect them to follow advice or a recommendation. A requirement would be more appropriate.

Benzene is lipid soluble, it sticks around for a while. It is easily absorbed through the lungs and skin and can reach a steady state in about 4 hours (about 40-50% will be taken in). It will take a long time to get rid of it and about 60% of the absorbed amount remains, the rest is excreted in urine metabolized by the liver or exhaled.

I agree it requires a reasonable time to get an access amount into your body, but the carcinogenic effects are dose related, so I’m not sure at this time if a short term high exposure would not get you the same effect. I would have to look it up.
I also agree that an acute toxic effect would be very likely, but the neurological or cardiac effects seen at that day is also something I would have to look into.

I have to check much of these things to be absolutely sure, but I have to admit that the numbers shown by the EPA got me interested. I really don’t know for sure at this point. If you check TOXNET or HSDB (Hazardous Substances Data Bank) at the National Library of Medicine, I think there is some information, but I don’t remember anything on short term single dose exposure and carcinogenic effects of chemicals. There may be some more information out there…

If I find out more I’ll get back to you on this.

SYL smile.gif
Malmoesoldier
A web search reveals most references to progressive collapse involve one or more of four cases:

The WTC North Tower
The WTC South Tower
WTC Building 7
The Murrah Federal Building in Oklahoma City (bombed in 1995).

Why does this phenomenon only show up in terrorist incidents? laugh.gif
adoucette
QUOTE (Malmoesoldier+Jun 4 2007, 06:04 PM)
A web search reveals most references to progressive collapse involve one or more of four cases:

The WTC North Tower
The WTC South Tower
WTC Building 7
The Murrah Federal Building in Oklahoma City (bombed in 1995).

Why does this phenomenon only show up in terrorist incidents? laugh.gif

Because its often related to STRUCURAL DAMAGE.

You know, the damage to the towers that you seem to KEEP FORGETTING ABOUT.

Arthur
David B. Benson
QUOTE (adoucette+Jun 4 2007, 11:25 PM)
Because its often related to STRUCURAL DAMAGE.

Which, on rare occasion, is just due to age-induced creep:

Venice Campanile, 1902;
Goch cathedral;
Pavia Civic Cneter, 1989.
3bodyproblem
QUOTE (Malmoesoldier+Jun 4 2007, 11:04 PM)
A web search reveals most references to progressive collapse involve one or more of four cases:

The WTC North Tower
The WTC South Tower
WTC Building 7
The Murrah Federal Building in Oklahoma City (bombed in 1995).

Why does this phenomenon only show up in terrorist incidents? laugh.gif

Because terrorists are the #1 cause of buildings collapsing? (Other than by demolition)
David B. Benson
QUOTE (3bodyproblem+Jun 5 2007, 12:06 AM)
(Other than by demolition)

World-wide, the primary cause is earthquakes.
FactCheck
QUOTE (Malmoesoldier+Jun 4 2007, 09:40 PM)
adoucette. Haha you are debunked real hard! laugh.gif

The fires in WTC was not hot enough to make the trusses collapse

Ooops.

Oh and Underwriters Laboratories All four trusses tests specimens sustained the maximum design load for approximately 2 hours without collapsing.

Ooops.

READ my two posts about trusses again and maybe EVEN you will understand laugh.gif

WTC2 showed only minimal aircraft damage in the side of WTC 2 immediately before its collapse, and this indicates the building's internal structure was intact. This is confirmed by firefighters transmissions from the impact area.

9-11 was an inside job. You believe in lies that a 10 year old can see trough. FEMA even says that the buildings didnt have a CORE!!! LOL laugh.gif. They lie like that so they can laugh at people like you that believes in their BS.

Err... who said the trusses "Collapsed"? Not the NIST...

The trusses sagged and pulled the columns in over time which is an effect impossible for explosives achieve. Not even thermite...
metamars
QUOTE (adoucette+Jun 4 2007, 11:25 PM)
Because its often related to STRUCURAL DAMAGE.

You know, the damage to the towers that you seem to KEEP FORGETTING ABOUT.

Arthur

Doubtless there have been thousands of such cases in Bagdad. Right?

Could this be why there are no Iraqi 911 Truth groups? (AFAIK)
quicknthedead
QUOTE (wcelliott+Jun 3 2007, 10:46 PM)

Certainly, nothing I'd care to swallow. 

More CT dark innuendo.

You know, there *are* sometimes politically sensitive reasons why certain facts are sometimes left out of reports of this sort that have very little to do with dark conspiracies.

For instance, if the insulation on the horizontal trusses was applied in a shoddy manner by non-union labor, and the inspection job was signed-off by a corrupt building inspector, they may have decided to leave those parts of the story out of the Official Report because there'd be a grassroots demand for sending the corrupt building inspector to prison (also opening up the issue of lawsuits against the city for corruption), which from a political standpoint would tend to diminish the political impact by changing the subject, attributing the WTC damages to NYC corruption and the WTC's hiring non-union/undocumented workers for the insulation job.

It would be the political equivalent of changing the subject before you've made your central point clear.

It would also tend to make scapegoats out of the people who weren't primarily to blame for the attacks, though may have inadvertently made the attacks more devastating than they should've been.  If you knew that the building inspector who signed-off on an inadequate fire installation job in exchange for money, would you make him the center of a media feeding frenzy, or would you "spin" the story like we're all absolutely innocent and then, privately, send someone out to deal with the corrupt inspector quietly?  Think about it.  The "correct" answer isn't always obvious.


"More CT dark innuendo"?

This was historical information presented -- and origins of the CFR is something you apparently need to study so you might know what you are dealing with.

We should never "spin" a story. It should only be the truth and nothing but.

Next time try reading the article instead of blowing smoke.



MOREOVER THAT EVERY MAN WHO EATS AND DRINKS
SEES GOOD IN ALL HIS LABOR
IT IS THE GIFT OF GOD
3bodyproblem
Han anyone seen what Gordon Ross has to say about the new paper? It's available over at 911 Blogger.
wcelliott
QUOTE
I don't think you are in a position to complain about the way they approximate the same equations in the regime they have studied for so long.


I'm pretty sure that I've used words like "quibble" when discussing this one and only criticism I have of the NIST version of 9/11.

I didn't intend for this to be a major issue, I only felt it necessary to point out that just because a computer model of a fire says reaches a maximum temperature of X, that doesn't mean that there weren't places that got hotter than the model indicates.

It's one of the most common subtle errors that otherwise intelligent people make. People talk about "trends in stock prices", pasting straight lines over fractal curves (chaotic systems have fractal states), and use the lines as if they meant something.

In virtually every encyclopedia, one of the statistics provided for islands is the lengths of their coastlines. Unless their coastline is a man-made levee, it's a fractal curve that has no definite length.

Meteorologists also use grid/box approaches to predict the weather, that's how Chaos was discovered. Perhaps you know the story, but a computer model of the earth's weather was being tested, using a set of random but reasonable initial values as input, and the program predicted the weather several days in advance. The programmer saved the initial conditions and made a slight change in the program and tested the program using the saved input data, and found that the weather predictions changed slightly, deviating more and more, until after the fourth day or so, the two runs didn't look anything alike. The programmer undid the slight modification and re-ran the same program using the same saved data, and found, again, that the predictions were different from the first time the program ran using that data. After a lot of debugging, the programmer realized that the only difference between the first run and the subsequent runs was that the temperature data was originally generated internally, so had the full precision available, and the stored data was truncated after the sixth decimal place. The differences in the predictions were due to temperature differences on the order of a millionth of a degree. Weather, being a nonlinear system, was sensitive to differences in initial conditions of a millionth of a degree. This is where "The Butterfly Effect" got its name, the notion that a butterfly would be capable of changing the temperature by a millionth of a degree by flying or not.

I'm not saying that weather predictions are worthless, but that their numbers, no matter how well-crunched, are expected values and that the real values will tend to fall in a range about the predicted numbers.

In other words, when attempting to predict a nonlinear system, like fire is, the predicted values should be taken with a grain of salt.

The NIST report admitted that the model they used was empirically validated at 1% of the scale of the WTC fire(s), but never mentioned any sort of "grain of salt" acknowledgment that there might be a problem applying the model to a fire 100x as big. (I don't have the report in front of me, but as I recall, they actually seemed rather proud of the fact that they'd scaled it up by a factor of 100x.)

As I said before, you don't get Dresden by modeling a building fire and multiplying the results by the number of buildings in Dresden. You could do that with rigor if fire was a linear system, but it isn't, and you can't.

The two main points are: 1) Fire is a chaotic process, and, 2) Models of chaotic processes don't scale-up reliably.

Sorry if that offends you, but both of those statements are true, regardless of who states them.
wcelliott
QUOTE
Next time try reading the article instead of blowing smoke.


I read the article, it was a pile of cr@p.
adoucette
QUOTE (DBB+)
I don't think you are in a position to complain about the way they approximate the same equations in the regime they have studied for so long. 


QUOTE (wcelliott+Jun 4 2007, 10:35 PM)

I'm pretty sure that I've used words like "quibble" when discussing this one and only criticism I have of the NIST version of 9/11. 

I didn't intend for this to be a major issue, I only felt it necessary to point out that just because a computer model of a fire says reaches a maximum temperature of X, that doesn't mean that there weren't places that got hotter than the model indicates.


I think you are both right.

Models by their nature don't typically do well at predicting the extremes. i.e. as wcelliot contends that in the fire of this scale there would invariably be sets of unusual conditions like a draft that creates a vortex which is by a puddle of jet fuel which ends up creating a blow-torch effect and resulting in temps that may have been hundreds of degrees hotter than the FDS model would predict.

But David is also right in that the models have been developed and tested and refined such that the OVERALL results do a very good job of modeling reality because in the end, the likelyhood of the unusual vortex lasting long enough in that environment to have a significant effect on enough of the structure to make a substantial difference in the mechanism of collapse is very small.

So for instance there could be spots hot enough to cause some steel to melt, even though the model does not predict temps that high, but again, the model is most likely correct in that there would not be enough of those hot spots or melted steel to alter the overall heat absorbtion rates and the general collapse mode of the structure.

Arthur
wcelliott
QUOTE
So for instance there could be spots hot enough to cause some steel to melt, even though the model does not predict temps that high, but again, the model is most likely correct in that there would not be enough of those hot spots or melted steel to alter the overall heat absorbtion rates and the general collapse mode of the structure.


That's mostly my point.

I'll put more trust in a fire model when someone produces one that shows what flames look like. I've yet to see a fire that looked like colored boxes.

biggrin.gif
newton
flames emit light.
Alan (ex elevator man)
Malmoe, I watched your posted videos, even though they were all full of crapola. One even claimed it was a nuclear weapon that destroyed the towers. With statements like 7000-degrees, and 99% of concrete turned to dust. You should be embarrassed and ashamed for believing this stuff. All of it has been covered here repeatedly. As always happens, CT's bring up something 'proving' a conspiracy, and when proven wrong with facts, they just change the topic to something else and say yet again they have proof. It goes around and around, and in this instance it has come around again with your video having quotes about 'molten metal', but it was in the elevator pits. First note, it said "metal", not steel. Now, look again at my name. Google "babbitt", or "babbitt metal". Note also that each elevator cable has about a cup of babbitt poured on each end. With each elevator having 6-8 hoist cables, and 6-8 compensating cables, and one governor cable... you can see there can be alot of babbitt in each pit. The stuff gets shipped out in bars and is melted on site, close to the pour, with a propane pot. Here's a picture of one with a ladle-full ready for pouring, except this is from a site that explains pouring babbitt in bearings. In that case, it looks like they heated just a ladle-full, instead of a bowl you then dipped out of... which makes sense, since it wouldn't take much to pour a bearing.

User posted image

Oh yeah, we used to heat it until it would char or ignite either a piece of the rope core of the cables, or a rolled up piece of paper when dipped into the bowl. It was liquid way before it got even that hot... so we're not talking about a high temp.
Alan (ex elevator man)
Small correction to previous post. Most elevators in the towers had 2 governor cables. Any elevator that terminates above an existing floor, meaning there were occupied areas under the elevator pit, then those elevators had governors on the counterweight frames as well as the cars. K, for a bigger picture of that propane/ladle, hit this link... the picture that posted shows up smaller.

propane tank heating up babbitt
newton
interesting.

should i post the picture again of the claw with the glowing metal in it's grasp?

it is not stretch to imagine that 'molten' means 'glowing, running, like lava' to most people when they are trying to communicate ideas. 'silver, running metal, like mercury' would better describe molten babbit.

interesting.
reasonwhy
QUOTE (3bodyproblem+Jun 4 2007, 07:25 PM)
Han anyone seen what Gordon Ross has to say about the new paper? It's available over at 911 Blogger.

He did on his website before the paper was submitted:

QUOTE
The following graphics obtained from the excellent terrorize.dk site show this very clearly.  These photographs in and of themselves destroy the arguments of Dr. Bazant and his fellow advocates of the "crush-down crush-up" theory of collapse.  They demonstrate that the first storeys to undergo crushing were those between the two planes indicated.  The lower collapse front did not accelerate at the same rate as the roof line.

User posted imageUser posted image
User posted imageUser posted image

This makes is obvious the paper is not dealing with reality (and I am sure that doesn't bother DBB as long as it gets past the reviewers )! laugh.gif
Alan (ex elevator man)
QUOTE (newton+Jun 4 2007, 11:59 PM)
interesting.

should i post the picture again of the claw with the glowing metal in it's grasp?

it is not stretch to imagine that 'molten' means 'glowing, running, like lava' to most people when they are trying to communicate ideas. 'silver, running metal, like mercury' would better describe molten babbit.

interesting.

I'm not sure what you're trying to say Newt. I noticed tho, that you know the difference between glowing and molten. Also, babbitt looks silver in daylight, but orange if it's dark. It'll look brown actually, until you scrape and pour out the impurities that come to the top when it's melted. So, in the elevatoer pit, I doubt it would look silver at all... orange if still hot and halfway clean, or brown if it picked up trash on the way down.
Malmoesoldier
Alan

QUOTE
One even claimed it was a nuclear weapon that destroyed the towers


When did i say something about nuclear weapons? i dont believe in that, i said look at the explosion at 02:15 in the video. Good, then if you looked at the videos/links you know that there was big explosions in WTC 7. And that Giuliani lied.

wcelliott and adoucette your trusses theory is debunked hard! lol laugh.gif

9-11 was an inside job
PhysOrg scientific forums are totally dedicated to science, physics, and technology. Besides topical forums such as nanotechnology, quantum physics, silicon and III-V technology, applied physics, materials, space and others, you can also join our news and publications discussions. We also provide an off-topic forum category. If you need specific help on a scientific problem or have a question related to physics or technology, visit the PhysOrg Forums. Here you’ll find experts from various fields online every day.
To quit out of "lo-fi" mode and return to the regular forums, please click here.