Needed: More scientists and engineers. And more teamwork. And better peer review.
I just now heard about the following, on 911blogger: A Proposal for Proving Controlled Demolition in a Civil Negligence Suit Against the Security Groups Responsible for the WTC.
In my opinion, this is WAY premature. We are NOT yet anywhere near ready to prove any such thing in a court of law, not even in a civil case.
Too many people in the 9/11 Truth movement think we can prove CD of the WTC buildings via “looks like a CD” arguments plus folklore “physics.” Nothing could be worse for us than to go into a courtroom with those arguments, against a defense attorney who could produce much better expert testimony plus a bunch of photos and videos showing pre-collapse bowing of perimeter columns and (in videos with audio) an absence of explosions loud enough to be demolition charges.
On the other hand, I do believe that Steven Jones is onto something very important, with the spherules and the various temperature discrepancies that have been noted not only by him but by other sources unrelated to the 9/11 Truth movement. (See his latest paper, Extremely high temperatures during the World Trade Center destruction (PDF), especially section 4, “Discussion of relevant previously published data.”)
But his results are, at this point, far from scientifically unassailable yet. He has found enough evidence to raise suspicion, but not much more than that yet. It seems to me that he needs a lot more help than he’s now getting from experts in various relevant fields, including chemistry, metallurgy, structural engineering, and forensic science, in order to produce more definitive results. And he needs that help ASAP, in my opinion.
Do you, dear reader, know any scientists or engineers in the following categories who are sympathetic to the 9/11 Truth movement?
- Chemists and chemical engineers
- Metallurgists
- Forensic scientists
- Structural engineers and other mechanical engineers (especially high-rise structural engineers)
- Explosives experts
- Fire experts (especially forensic fire investigators)
If so, please ask them to contact Scholars for 9/11 Truth and Justice ASAP, and/or to contact Steven Jones at the Journal of 9/11 Studies. I would highly recommend that they also be asked to join Scholars for 9/11 Truth and Justice and participate, at least occasionally, in the “Scientific Analysis” sub-forum of the private forum of STJ911.
It would be desirable to have not just more active researchers, but also a wider variety of peer reviewers for the Journal of 9/11 Studies. (Steven Jones has put out a call for more peer reviewers recently.) So, if anyone reading this happens to know any interested experts in the above categories who don’t necessarily have the time or means to help by doing actual research themselves, but who might be willing to be peer reviewers, that would be very helpful too.
(In the title of this post I use the term “assisted collapse,” because I think that demolition using high explosives is very unlikely, given the lack of videos with sufficiently loud explosive sounds. If only incendiaries were used, and not explosives, then the term “controlled demolition” is not appropriate, because the timing cannot be controlled as precisely as with high explosives.)
Disclaimer: Opinions voiced in this post are solely my own. I’m not speaking on behalf of STJ911 or any other organization.
P.S.: One issue over which there perhaps could be a successful court case, right now, is the question of why NIST didn’t get all the steel from fire-affected areas, contrary to fire investigation protocol. Perhaps the people in charge of the cleanup operation could be sued on behalf of the families?
Further P.S.: I’ll need to do more research on the question of what happened to the steel, and when, and how. Also it has been brought to my attention, elsewhere, that we don’t yet know what, if anything, the FBI (or the NYC police) might have done by way of looking into the possibility of arson, explosives, etc. This should be looked into, if possible, perhaps via FOIA requests.
New York City activist 
One structural engineer (naval) is on STJ forum and is already in contact with Steve, but I don’t know who else. He’s the person who Gurich (a software engineer) spars with disparagingly, despite the common sense points of his posts and clear engineering experience. He is here
http://heiwaco.tripod.com/cv.htm
Comment by victronix — March 12, 2008 @ 2:44 am |
That’s Anders Björkman. Interesting to know that he’s a structural engineer (albeit, apparently, not a high-rise structural engineer). Thanks for telling me. I didn’t know that. Thanks also for pointing me to his website.
It will be interesting to see the eventual results of his sparring with Gregory Urich, whose physical and mathematical arguments make sense to me. I’m still open to the possibility of being proven wrong, but any such proof will need to rely on more than “common sense,” which can be very wrong when applied to things so far outside our daily experience as the collapse of a skyscraper.
Never before in the history of the world have such huge skyscrapers (with such huge gravitational potential energy) collapsed for any reason whatsoever. We cannot assume that they will behave like smaller buildings (or like ships, for that matter).
Do you believe that high explosives were used? If so, how do you account for the absence of loud cracks (as distinct from the roar of the collapses themselves) in those videos with audio?
Comment by Diane — March 12, 2008 @ 9:08 am |
Reports of Assisted Collapse, Controlled Demolition, Molten Steel, Thermite, Electromagnetic Rays, etc.
Many people interpreted the loud sounds and debris being projected out sideways during the Tower collapses as an indication that explosives were used to demolish the buildings. Most of these ‘explosive’ sounds, heard during the collapses were heard after the collapses began. The exterior walls can be seen bending and buckling inward in the videos of both Towers long before any sounds or ground vibrations occurred. In Tower 2, the exterior columns in the east wall were photographed bowing inward up to 10 inches, 18 minutes after the plane’s impact.That’s 38 minutes before the global collapse began. The inward bow was increasing gradually. To be technical, you could say that Tower 2’s collapse began slowly, with possibly some noise or impact sounds from falling floors, about 38 minutes earlier than the official collapse time. The explosive sounds and expanding dust clouds occurred just after the east wall buckled inward and started the collapse, and not before the buckling, as would have happened with controlled demolition.
When the south wall of Tower 1 was photographed it was bowing inward up to 55 inches on floors 95 to 101, about six minutes before these columns were seen buckling inward. In the North Tower “thunder” sounds were heard inturpreted as floors collapsing on the south side 12 to 14 seconds before the top of the building was seen to tilt southward and begin falling as a unit starting the global collapse. Since each section of floor on the long-span side weighed about 500 tons, I would explore these ‘explosive’ sounds in Tower 1 as evidence of a floor or floors detaching and impacting the floors below on the south side which most probably accelerated south wall failure. I believe all the supposed ‘explosive’ sounds can be explained by the impacts made by the collapsing buildings after the columns were pulled in and buckled by the bowing and sagging floors and when the floors themselves began impacting the floors below. The boom, boom, boom, boom, boom repetitive ‘explosive’ sounds reported by firefighters running as Tower 2 was coming down were most likely caused by the sequential collision of impacting floors. The great quantity of air on each floor being compressed in a fraction of a second by great weight and momentum would propel air, smoke, and any concrete dust and debris outward at great velocity.
Initial Collapse Cause
It is clear from the computer studies that the heat from the fires caused differential expansion of the steel parts in the long span, floor trusses with the resulting thermal bowing in some floors directly exerting pull-in forces on the exterior columns or this thermal bowing could have detached a floor which would have impacted the floor below destroying composite action by separating the concrete slab from the trusses and inducing strong tensile (suspension) forces in the double weighted floor. In other floors thermal expansion of the floor against the columns compressed the trusses which along with shear forces within the trusses buckled the diagonal struts collapsing the trusses which went into suspension (catenary action) and helped pull-in and eventually buckle the exterior column walls.
Differential thermal expansion of the concrete and steel has also been shown to disconnect the knuckles from the concrete slab causing loss of composite behavior in the floors. All these adverse floor truss effects were caused by steel expansion which begins immediately as the steel is heated. Bowing and buckling can happen at low temperatures (400 C to 500 C) even before the steel would have weakened excessively from higher temperatures. Thermal contraction caused by cooling of the trusses after the fire burns out can cause strong pull-in forces on the exterior columns. Once the exterior column buckling spread,- possibly assisted by the spandrels,- along an entire wall on one face, the towers began to tilt and the buckling spread around the towers exterior and into the core and with all the columns buckled the leaning top sections of the tower began to fall straight down. There are videos of all these cercumstances.
Although the North tower antenna appeared from some northern angles to have fallen straight down it actually tilted to the south because the south wall buckled first and the cantilevered south side of the building pulled the core and the entire building top over to the south.
The South Tower’s top tilted to the east because its east wall buckled first. With the tower top tilting all the columns were out of alignment. Once the core columns got out of plumb, there would have been little resistance to their buckling at their weak splices. With the incredible weight of the top of the buildings gaining momentum, like a heavy wedge or sledge all it had to do was break the welded, and single bolt connections holding the floors to the columns. This coupled with the fact that the falling top sections momentum increases as the square of the number of floors impacted as the floors were detached and added to the weight of the descending top. There would have been little resistance to slow the top section’s acceleration to the ground. Because this acceleration due to gravity increased the speed and momentum of the collapsing floors and building top, the impacts would have been increasingly violent as shown on the seismic graphs; increasing amplitude until maximum when the mass of accumulated floors hit bedrock seven stories into the cellar.
In order for a column to support the loads they have to be plumb and in line with the columns above and below. If they get out of alignment by 10 to 20 degrees they buckle and can no longer support the weight. The buildings collapsed because the floors first buckled from restrained thermal expansion and from thermal bowing or delamination of the slab and bar joists affecting floor truss stability. The sagging floor trusses pulled in the 59 columns in one exterior wall and they eventually buckled. Once the buildings started to tip over from loss of column support on one side, the tremendous excess eccentric weight began buckling all the columns across the building. Once the tilted building’s tops began descending they hit the floors or columns at eccentric angles which easily detached the floors and buckled the columns. In order for the lower building section to offer any meaningful resistance to the falling building top the columns would have had to hit each other exactly in line and in plumb and this was impossible with the top leaning causing eccentric angles of impact.
The fact is that columns have to be axially (in line and centered) aligned to support the weight of the building above. Once the top building section began tilting the columns on the side that originally buckled did not line up at all. These columns would have been hitting the floors and would have easily detached or buckled them. After the south wall buckled in Tower 1 the adjacent perimeter wall columns buckled from overloads and the columns on the opposite west side of the building, which acted as a hinge would still be bearing on each other but at an eccentric angle which means they also would have also eventually buckled as the top tilted. These columns along with some of the core columns as they buckled are probably what kicked the bottom of the top building section to the west as reported by NIST.
With all the columns across the building buckled the top section began descending at an angle to the building section below. None of the columns would have been axially lined up. As the columns collided they would have hit each other at eccentric angles and easily dislodged, disconnected or buckled each other. Adding the accumulating collapsing floors and you have a release of incredible potential energy changing to kinetic energy and building momentum as the accumulating chaotic mass of debris accelerated into the cellars.
There have been some engineering analyses about the impacting floors slowing down the collapse so that the time to collapse should have been much longer than ‘free fall’ times of an object dropped from the towers tops. Since the Tower’s outer wall columns, especially in Tower 1, pealed out like a banana, they may have been able to break the connections to the floors ahead of the floors being impacted? In other words, with the weight of the wall columns pealing outward from the vertical along with the added horizontal forces of impacting floors projecting debris outwards onto these columns; these columns, while leaning out, might have been able to break the wall-to-floor connections ahead of the level of impacting floors? If this is possible than I believe that the connection failures could could have traveled down the sides of the buildings at a speed faster than free fall times. This might explain the rapid collapses especially in Tower 1. The wall-to-floor connection failures could have traveled down the building sides faster than ‘free fall’ times and in effect started the floors falling before they were impacted by the accumulating mass of impacted floors above.
The heavy exterior wall columns in the 1500 foot high builddings while pealing off could project the column sections outwards a great distance. This distance (500 feet) was proposed as only being made possible by explosive forces. I disagree. If a wall is strong enough and doesen’t break up as it falls it can fall out flat to a distance equal to its height. The Tower walls however did break at the splices as they fell.
Much has been made of the fact that NIST only analyzed the events up to the point where the Towers were poised to collapse before runaway collapse began and failed to pursue the remaining collapse. This was largely because after collapse began the chaotic impacts of the floors, walls and columns colliding could not possibly be analyzed accurately with even the strongest computers. As it was, it was a severe strain on computer capabilities to analyze the mechanism of collapse up to the point of runaway disintegration.
The compression of air in the elevator and air-conditioning shafts by the collapsing upper building section and floors, would project air, smoke, and dust down these shafts and out of the air intake or discharge openings on the lower mechanical equipment floors in the exterior walls. This accounts for the plumes of smoke seen projecting outwards from the buildings well below the collapsing floors. There were quite extensive vertical HVAC shafts built into the building. These shafts are connected to air conditioning exhaust and intake ducts open to the exterior on the mechanical floors. Collapse of these shafts would force the dust and smoke out these HVAC exhaust and intake openings in the side of the building.
The lightweight aluminum cladding’s breaking free from the buckling columns also would have been propelled outward a great distance by this expanding cloud of air and dust. This would account for huge dust clouds and pieces of aluminum seen projected outwards from the upper sections of the collapsing buildings. The light reflected off these aluminum pieces at the north wall of Tower 2 would be interpreted as flashes from explosive ‘squibs’. The flashes below the buckling east wall may have been from the aluminum cladding breaking free from the lower columns as they expanded after being unloaded of axial weight by the buckling of the wall above and their expansion breaking the connections to the cladding. Also explosives leave characteristic tears and fractures in steel, and such indications were not found anywhere in the debris pile.
After any fire in which a building collapses, there often remain deep seated, pockets of fire deep within the rubble pile These pockets of fire sometimes cannot be reached by water streams because of their being covered by debris. Air is sometimes drawn up from the bottom of the pile and feeds these inaccessible fires with air. These fires can last for days and the heat can become intense and can heat any steel in proximity of the fire until the steel is glowing red hot. These pockets of fire are common at burning building collapses and in no way evidence that that explosives or thermite were used to demolish the buildings.
These fires are similar to blacksmith fires where air is blown into the charcoals by a bellows to raise the temperature of the fire to heat a piece of steel or iron. The blacksmith can tell how hot the steel is by its color and can tell when the steel is soft enough to work it with a hammer.
These deep seated fires often have to be dug out by hand tools, back hoes or grapplers in order to expose the burning material for extinguishment. It is common to hold off hitting the fire with water until it is fully exposed in order to prevent the great amount of steam that would be created from obscuring the work area until the fire is fully exposed and can be extinguished. This is what is happening in the picture of a grappler pulling out a piece of glowing hot steel from the debris pile so often described as molten steel. Such fires are incapable of melting steel unless they are supplied with pure oxygen.
Pure oxygen is used in oxyacetylene torches to actually ignite burn and melt the steel when cutting. These torches were used to help clear the debris pile during search and recovery operations. A slag of melted and re-solidified steel and Ferrous oxide is formed on the opposite side of the cut. This slag formation was erroneously reported to be evidence of cutter charges having been used to sever the columns. Small molten pieces of glowing steel cool into spheres as they fly out from the cut.
Much has been made of the presence of molten metal in the debris pile after the collapse. Presumably this molten metal was somehow thought to be connected to explosions or thermite charges, but there were Uninterrupted Power Supply (UPS) battery rooms on some floors of the Towers and Building 7. These battery rooms supplied continuous battery power to computers if the electricity failed for any reason. These batteries contained tons of lead which melts at low temperatures [327 C (621 F)]. The heat from the fires in the debris pile could easily have melted this lead or the aluminum from the plane which were probably the metals that were seen flowing through the pile. There were also quantities of lead, tin, and silver used in the computer circuit boards. NIST reported UPS in the 13th floor of Building 7 and the 81st floor of Tower 2. Additionally the EPA reported over 400 different chemicals in the dust and debris. These chemicals could easily be assembled conceptually to propose any type of chemical reaction imaginable including thermite reactions. In addition thermite reactions are rapid and wouldn’t last the hours or days at which times the molten metal was observed.
About the concrete destruction into dust; F.R. Greening did a paper called Energy Transfer in the WTC Collapse in which he says “the energy required to crush concrete to 100 μm particles is 1.9 × 1011 J, which is well within the crushing capacity of the available energy. Hence it is theoretically possible for the WTC collapse events to have crushed more than 90 % of the floor concrete to particles well within the observed particle size range.”
http://nistreview.org/WTC-REPORT-GREENING.pdf I would also investigate the possibility that the concrete was sub par due to freezing during curing or too much air or water having been added during construction.
Do you think the architect or engineers who built the Towers would want to admit the deficiencies in design, fireproofing and other construction weaknesses after their buildings collapsed? Do you think they will get any other jobs after 5 of their buildings collapsed from fire? (Building 5 had a serious interior multiple floor collapse.) Do you know that they didn’t have to follow any building codes? The reason the columns broke at the splices was that they had serious weaknesses due to lack of reinforcing plates or even welds on the exterior column bolted splices. The long span truss floors were never tested at their design length. I would think the builders would be looking for any excuse to divert attention from themselves even the wild idea that explosives were involved. Why do you think it took so long to get the plans for the buildings while the building engineers had them all along.
About the eye witnesses; there are many reasons that loud sounds can be produced at a fire. There can be smoke explosions particularly in fires that have a flammable liquid involved. There were fuel explosions in the elevator shafts. Most of the people in tower 1 did not know that tower 2 had collapsed but they all heard the noises and even felt the rush of air up the stairs. There could have been floor detachments impacting the floors below and producing loud sounds before any general collapse began. Most of the people in tower 2 did not know tower 1 had been struck by a plane but they heard the explosion and felt the impact. Explosives produce loud distinctive pressure waves that can leave people deaf of blow out eardrums. This kind of sound was not heard.
The windows broken out and marble wall panels detached on the interior of the first floor lobby were probably because of torque forces experienced on the lower floor columns from the plane impacts many floors above. The reports of “explosions” in the cellars were also probably from such column displacements or from jet fuel ignitions in the elevator shafts. If you stick a stick into the ground and hit it with another stick most of the deformation will be in the ground around the bottom of the stick. There were reports of split walls and ceiling collapses on many floors after the planes hit. The one elevator shaft that extended into the cellars had a fuel explosion from the jet fuel spilling down the shaft.
In conclusion I think the reports of controlled demolition can be explained by sounds or sights produced by the plane impacts and jet fuel and air explosions; the sounds of the Towers collapse, – remember most of the people in Tower 1 did not know Tower 2 had collapsed and attributed the sounds of that collapse to be happening in the building they were in. When the interior of building 7 collapsed it would have produced explosive sounds before the exterior walls began collapsing.
Arthur Scheuerman
Comment by scheuerman — March 12, 2008 @ 8:46 pm |
I’ve worked for the architecture/engineering firm that participated in the NIST reports, as a junior designer (highrises). Anders’ positions are what make sense to me, while Gurich’s often strike me as verbatim defenses of the official story without the complexity of reality.
While we cannot assume the events will be like smaller buildings, as I’ve said, dozens and dozens of floors of intact steel structure doesn’t just fail. A witness I knew at the scene across the street, who came away with PTSD, heard the roar of that destruction in her head for years. Literally. In a traumatic situation like that with everything shaking, windows blasting inward, and a roar so loud it lasted for years in her head, it seems unlikely that we can make any solid determinations without audio recordings proving that the roar of the destruction, the vibrations and simultaneous destruction of everything in the vicinity to the event, and the chaos and terror of it all, could not mask and sounds of explosives for those in the vicinity, were they used. It’s not a strong point.
This is what I’m talking about when I refer to the real life complexities that don’t fit nicely into simple formulas found online or brought from a JREF forum post.
Comment by reader21 — March 12, 2008 @ 9:02 pm |
reader21 wrote:
Indeed, without any audio recording, this would be quite difficult. But we do have videos with audio. Have you listened to these? If so, what do you think of them?
Comment by Diane — March 12, 2008 @ 10:01 pm |
To Arthur Scheuerman:
What do you think of the high-temperature anomalies reported in Steven Jones’s latest paper, Extremely high temperatures during the World Trade Center destruction (PDF)? (See especially section 4, “Discussion of relevant previously published data”.) See also my blog post He oughta know better: Mark Roberts and the iron spherules.
Also, what do you think of Abolhassan Astaneh-Asl’s findings? (See Engineer Sees Evidence of Extreme Temperatures in WTC Steel.)
Of course, we do need to distinguish between (1) signs of extremely high-temperature events during and before the collapses themselves and (2) high temperatures in the pile after the collapse. I’m aware that high temperatures in the pile, days or weeks after the collapse, don’t necessarily imply anything about temperatures before and during the collapse.
Anyhow, I would be interested in your comments on the following posts of mine:
– WTC 7: FEMA report and NIST prelim report: What about pre-collapse leaning and the transit???
– Richard Gage’s avowed enemy, part 2 – and my thoughts about WTC 7 (which refers to your paper about WTC 7)
– WTC 7 fire weirdness, taking FEMA and NIST at their word
Note: In accordance with my comment policy, please post comments on those posts underneath those posts themselves, rather than here on this page. Note that all recent comments, including those on older posts, are listed under “Recent Comments” on the side panel.
Comment by Diane — March 12, 2008 @ 10:22 pm |
A somewhat relevant news story . . .
Astaneh-Asl does not advocate demoltion, but is a potentially credible voice exposing at least some of the corruption and misrepresentation of the effort.
Engineer society accused of cover-ups
http://news.yahoo.com/s/ap/20080325/ap_on_re_us/embattled_engineers
Excerpt:
In 2002, the society’s report on the World Trade Center praised the buildings for remaining standing long enough to allow tens thousands of people to flee.
But, the report said, skyscrapers are not typically designed to withstand airplane impacts. Instead of hardening buildings against such impacts, it recommended improving aviation security and fire protection.
Abolhassan Astaneh-Asl, a structural engineer and forensics expert, contends his computer simulations disprove the society’s findings that skyscrapers could not be designed to withstand the impact of a jetliner.
Astaneh-Asl, who received money from the National Science Foundation to investigate the collapse, insisted most New York skyscrapers built with traditional designs would survive such an impact and prevent the kind of fires that brought down the twin towers.
He also questioned the makeup of the society’s investigation team. On the team were the wife of the trade center’s structural engineer and a representative of the buildings’ original design team.
“I call this moral corruption,” said Astaneh-Asl, who is on the faculty at the University of California, Berkeley.
Gene Corley, a forensics expert and team leader on the society’s report, said employing people with ties to the original builders was necessary because they had access to information that was difficult to get any other way.
Corley said the society’s study was peer-reviewed and its credibility was upheld by follow-up studies, including one by the National Institute of Standards and Technology.
“I hope someone looks into the people making the accusations,” Corley said. “That’s a sordid tale.”
Comment by reader21 — March 26, 2008 @ 7:04 pm |
It think it is impossible for the World Trade Center to have collapsed that soon after impact just because of a 175 ton airliner and to have done it in less than 15 seconds once it started. The annoying thing is that most high school kids should be able to understand why, much less a judge. But the obvious information needed for this is the TONS of STEEL and TONS of CONCRETE on every level of the buildings. I don’t understand why people weren’t screaming for that data within six weeks of 9/11.
Now here is data from Urich’s spreadsheet. It is from the column “core column steel tons”. These are the six basement levels. As far as I know the columns were 36 feet long and and each level was 12 feet high. But not only is every level different but they get lighter as you go down. Now how is that possible?
B1 469,32
B2 461,57
B3 453,81
B4 446,06
B5 438,31
B6 430,56
http://911research.wtc7.net/papers/urich/calcMassAndPeWtc1.htm
Now if you check you will notice that each level is different by 7,75. That looks like some kind of interpolation with the lightest on the bottom. ROFL
But on floors 1 thru 6 are all an identical 477,07.
That makes absolutely no sense to me. So though I admire Urich’s effort I am inclined to be suspicious of the details and wonder how he got such weird numbers. So as far as I am concerned there is no reliable data to base a DEBATE on. We can’t tell with any precision what the plane hit.
That is reason to criticize every architectural and engineering school in the United States. Why isn’t every engineering school in the country demanding a table specifying the TONS of STEEL and TONS of CONCRETE on every level of the WTC.
[Video link, prohibited by comment policy, edited out by blog author Diane.]
psik
Comment by psikeyhackr — April 26, 2008 @ 2:10 am |
You’ve asked some very good questions here. Why don’t you ask Greg Urich yourself directly? He posts in the JREF forum, so you should be able to find him there.
Comment by Diane — April 26, 2008 @ 7:07 pm |
I’m a member of JREF now and found a thread that Urich has posted to in the last month. I put up that info from his spreadsheet.
Somebody said that just because Urich is wrong that doesn’t mean the NIST is. I told him that the NIST doesn’t even specify the TOTAL AMOUNT OF CONCRETE.
Comment by psikeyhackr — May 1, 2008 @ 4:14 am |
I’m a member of JREF now and found a thread that Urich has posted to in the last month. I put up that info from his spreadsheet.
Somebody said that just because Urich is wrong that doesn’t mean the NIST is. I told him that the NIST doesn’t even specify the TOTAL AMOUNT OF CONCRETE.
Comment by psikeyhackr — May 1, 2008 @ 4:16 am |
Diane,
You are doing great work. Thanks for your contribution!
I would like to respond to two points above.
First reader21 suggests that I use verbatim defences of the official story. I have to assume he is not very familiar with my work. For example, I have posted articles based on my own analyses showing that Bazant and Zhou’s overload ratio (WTC1) should be closer to unity than the value of 31 that they give. I am still working on writing that up but my preliminary results give a value around 2 which indicates collapse continuation. I have also done my own momentum and energy analysis showing that the Ross and Kuttler analyses of WTC1 are fatally flawed. I have posted drafts for comment at both the Scholars for 9/11 Truth and JREF forums. If reader21 has any criticisms of those drafts I would appreciate if he would them rather than erroneously characterizing me as a NIST/Bazant parrot.
Second, psikeyhackr was wondering why the core column data for the basement is strange. I responded on JREF with the following:
“The column size data was extracted from the NIST SAP2000 model and released based on a FOIA request. Lon Waters has published shapes and dimensions along with the original data which is available in spreadsheet format on that (his) site. I was pretty surprised by the lowest columns being somewhat smaller that the ones above. There could be some mistake, but there are a few possible explanations.
The structure is different below grade in that there are no “open” floors as in the rest of the building. Thus there are extra columns spread out over the entire floor area. Also the floor height is 10′ instead of 12′ which raises the buckling strength because of the length factor so they could use slightly smaller members. It is also possible that the lowest columns were all of higher grade steel.
I do use linear interpolation based on the SAP2000 data. All the sources and methods are explained in the article which is a separate file. (See 4.3.3 Variation of Core Column Steel). Note that original steel contracts had more steel than the SAP data. This could be those extra columns so there is surely room for refinement in my calculation. Unfortunately, the amount of information in NIST’s NCSTAR reports regarding the lower levels is pretty limited.”
It appears Lon Waters has found some errors and corrected that data on his site. I will send a correction to the Journal of 9/11 Studies as soon as I get a chance. Lon Waters web site is here: http://wtcmodel.wikidot.com/nist-core-column-data
My article explaining the calculation (in painful detail) is here: http://www.journalof911studies.com/volume/200703/GUrich/MassAndPeWtc.pdf
It should be noted that the magnitude of the error is not significant either for collapse analyses or in relationship to the total mass and potential energy.
Comment by gregoryurich — May 18, 2008 @ 2:25 am |
Hi, I have a question, well two if you don’t mind 🙂
1. What does the paper mean- I mean in terms of its impact on the official story?
2. I noticed the ‘recovered debris mass’ was as you noted matching the calculated debris mass- but what about all the missing concrete that blew away up the eastern seaboard- all the concrete dust? Wouldn’t that have led to a lesser amount of recovered debris- since there was almost no concrete in the debris- and there should have been if the buildings weren’t vaporized with explosives or whatever?
Kudos on that paper- looks like some serious work man, I’d buy you an ice cold beer if I lived close by.
😉
Comment by realitydesign — May 18, 2008 @ 6:29 pm |
To realitydesign:
I originally got interested in the mass and energy for two reasons. I was trying to check a number of separate independent analyses done by Bazant and Zhou (“Simple Analysis”), Gordon Ross, Frank Greening, Kenneth Kuttler and “Newtons Bit” (JREF handle). I was also trying to do collapse time calculations which are dependent on the strength of the structure relative to the mass and especially the mass distribution.
So to answer your first question, what does the paper mean? That we can do momentum, energy and collapse time analyses with a reasonable amount of certainty regarding the mass and potential energy.
Nonetheless, after recalculating the above mentioned analysis (and fixing the errors in Ross and Kuttler) the results show that once the collapse was initiated, it would continue to the ground. Also, the observed collapse times do not appear to be in violation of any physical laws, at least within the bounds of the uncertainty in the measurements and the uncertainty inherent on the modeling.
Regarding the dustified concrete. Over at the Scholars for 9/11 Truth and Justuce forum, Tony Szamboti, Greg Jenkins and I calculated the amount of concrete crushed to dust as having an upper bound of around 15%. Personally, I believe it is closer to half that. The huge amounts of dust observed during the collapse were likely mostly cementitious SFRM (fire proofing) and gypsum from wallboard as these are much more easily dustified than concrete. There were roughly 46,000 tons of these materials in the towers. It is interesting to note that the SFRM and gypsum alone would account for 10 lbs of dust per sq ft over a 200 acre area.
I am currently of the opinion that there was nothing strange about the collapses of WTC1 and WTC2 with the possible exception of collapse initiation. Unfortunately, I don’t have enough expertise to judge the NIST fire modeling with regards to steel temperature. As you probably know, Steven Jones has found some rather disturbing evidence in the dust including chips (having a chemical composition similar to thermite) which burst into white hot flame when ignited. There could be some rational explanation for those materials being in the towers, but I haven’t seen any.
Comment by gregoryurich — May 19, 2008 @ 10:50 pm |
I don’t know about this 15% number- there was just no concrete in any sizable form anywhere in the aftermath. Workers couldn’t even find it per NIST and all the photos we have don’t show antyhting but dust. Now, with one hundred and ten floors and the so called ‘pile driver effect’ that they say ’caused’ the many visible squibs- I’m going to need floors or at least big macro chunks to do that- but everything dustifies in mid air and goes outward…there is no pile driver, no concrete, yet we see squibs galore.
Comment by realitydesign — May 20, 2008 @ 5:31 am |
gregoryurich:
{{{ So to answer your first question, what does the paper mean? That we can do momentum, energy and collapse time analyses with a reasonable amount of certainty regarding the mass and potential energy. }}}
Doesn’t it take energy to crush all of the columns on a given level? Greening used the variable E1 to represent this. But he assumed it was constant throughout the building. That does not make any sense. As the amount of steel in the columns per level increases going down the building the amount of energy required to crush that steel should increase. I don’t see how computing potential energy gets you that information. Potential Energy comes from mass falling from a height without resistance. The whole point is that the building would have resisted a fall.
This supposed gravitational collapse involves the top crushing the intact mass below. Where in that paper is the energy required to CRUSH each level? Wouldn’t there have to be two separate calculations, one for each tower, since the mass above the impact was different for each tower?
Comment by psikeyhackr — May 20, 2008 @ 2:28 pm |
To reality design regarding #15:
We calculated it based on the chemical composition of the dust. If you are not a member of the Scholars for 9/11 Truth and Justice (STJ911), you may want to consider joining. Our discussions are on that forum but you need to be a member to see them.
The majority of the concrete (of everything really) ended up in the footprint. I am convinced that there was a piston effect of the damaged building materials falling down within the outer tube. See the article by Greg Jenkins at the Journal of 9/11 Studies which describes a lower bound for material remaining in the footprint. Also, there are photos of rather large pieces in the debris which I have posted at the STJ911 forum. Keep in mind that most of the energy was dissipated in the final impact with the bedrock which contributed to further comminution.
To help put this in perspective, Imagine what it would look like if the 23,000 tons of SFRM and gypsum per building were ejected as dust and distributed over a 200 acre area such that the result was 10 lbs per sq ft over the entire area. Also keep in mind that this dust starting obscuring observation of the collapses early in the collapses.
Comment by gregoryurich — May 21, 2008 @ 12:44 pm |
To psikeyhackr regarding #16:
Yes it does take energy to buckle the columns on each floor (or more likely every three floors). Greening’s calculation is a first order approximation which doesn’t take the columns strength variance or mass distribution into account. Here is a spreadsheet for WTC1 which does:
http://www.cool-places.0catch.com/docs/calcCollapse.xls
If you adjust the energy parameter at the top to around 300MJ, you get a fall-time which is pretty close to a realistic observed fall-time (15+ sec according to Jim Hoffman). The energy parameter represents the plastic buckling energy per floor and is scaled by a factor of 10 from top to bottom to account for increasing strength of the columns.
My mass and potential energy paper gives us only some of the information that we need. The actual buckling energies could be calculated floor by floor from the SAP2000 data. So far, I am satisfied with my linear approximation. Actually the 300MJ I am suggesting is a significant over-estimate for buckling only. The inelastic collision assumes that the floor is immediately dissociated from the structure and any concrete comminution energy is included in the energy loss associated with the inelastic collision. In reality there was alot of other structural damage above and beyond column buckling (e.g. fracture of horizontal members and connections, etc.) which I assume is the reason the energy parameter value must be somewhat higher than only the plastic buckling energy for columns in order to arrive at the “correct” fall-time.
The spread sheet also takes debris ejection into account ramping up to 20% after a number of floors. One thing you may want to do is adjust the energy value during the inital buckling to somewhat less than 300MJ. The reason I suggest this is that assuming the columns were heat weakened (the extent is clearly up for debate) the buckling energy would be less. This will give a slightly faster fall time.
Of course the real situation is much more complicated than this model, but it does help us understand the energy requirements and general collapse dynamics somewhat. We have gone into greater detail in terms of what really is happening in the core at the STJ911 forum (you may want to consider joining). Not everyone agrees on the failure sequence but the discussions are pretty helpful for refining ideas and testing hypotheses.
Separate fall-time calculations could be done for WTC2 but WTC1 is the less severe case and that is why people have been focusing on it. Basically, if WTC1 collapsed due to plane impact and damage, there is no question about WTC2. By the it is important to remember that the oft quoted fall-times given by NIST are up until the first debris starts hitting the ground. If you watch some of the videos, it is easy to see that collapse completion (not counting the spire) acually took at least a few more seconds. This is why I use Jim Hoffmans estimate.
Comment by gregoryurich — May 21, 2008 @ 1:32 pm |
Is that energy loss in column G the result of levels being crushed in the lower intact portion or does it include the effect of the bottom of the falling mass being crushed?
If you tape a bottle cap to the business end of a hammer and slam the hammer down on a bottle cap on the sidewalk it won’t just be the cap on the sidewalk that will be flattened. So will the cap on the hammer.
This crush down – crush up makes no sense. The two pieces will crush each other simultaneously. Does that spreadsheet include both of those energies. Is there a document explaining each ot the columns in that spreadsheet?
Comment by psikeyhackr — May 22, 2008 @ 2:02 pm |
To psikeyhackr regarding #19:
I agree that the crush down – crush up is unrealistic and that there was damage to the upper portion as well. In fact I have posted some powerpoint slides, which were spread all over the internet, showing just that. However I don’t think most interpretations of those slides are correct.
If both the upper and lower columns fail, the next fall is 2 stories (24 ft) instead of one which gives twice the PE -> KE of the first impact. Gordon Ross has attempted to show that the collapse will arrest during the first collision. Frank Greening and Newtons Bit have shown problems with Ross analysis which when taken into account show that even if both floors (columns) fail the collapse will most likely progress. Keep in mind that the upper columns are only slightly weaker than the intact columns directly below and the core was damaged and heat-weakened to some extent. Also, keep in mind that the primary assumption they are all using is from the Bazant simple analysis: that of evenly distributed, axial column-column collision. This is the most optimistic assumption for survival of the structure.
What actually happened is much more complicated. My understanding (WTC1) is that the upper part started to tilt southward giving the appearance of the antenna (and core) dropping viewed from the north. There are a number of video analyses which show “tilt first” and I have replicated that result myself. Theoretically the hinge of the tilt (the north exterior columns) should fail at around 8 degrees, which it appears that they do. This is followed by a drop of the entire upper part. Due to the tilt, the impact is not column-column or evenly distributed. This means horizontal members impact horizontal members and columns punch throught the floors. The horizontal components clearly will fail as they cannot even support the static load let alone the dynamic load. When the horizontal members fail, the column become unshored. This means that the columns’ effective length increases and they most likely somewhat distorted, both factors which contribute to making buckle more easily. At the point where the core columns are unshored to the welded joints they are extremely vulnerable and sheared horizontal member will even act as levers causing moments which will easily break the welded connections. Major Tom (a poster at JREF) has a site where he has analyzed the debris photographs and his conclusion that the majority of core columns broke at the welds is pretty convincing.
Comment by gregoryurich — May 23, 2008 @ 9:29 am |
{{{ This means horizontal members impact horizontal members and columns punch throught the floors. The horizontal components clearly will fail as they cannot even support the static load let alone the dynamic load. When the horizontal members fail, the column become unshored. This means that the columns’ effective length increases and they most likely somewhat distorted, both factors which contribute to making buckle more easily. At the point where the core columns are unshored to the welded joints they are extremely vulnerable and sheared horizontal member will even act as levers causing moments which will easily break the welded connections. }}}
So columns from the bottom portion will be punching holes through the floors of the falling upper portion and vice versa. A mass of randomly configured crushed up junk will accumulate between the two pieces. So how could the falling upper floors possibly stay balanced on that junk? Why didn’t it fall off the side? And yet we are supposed to believe this happened twice. Once on each tower. Without falling off the side.
YEAH RIGHT!
So does that spreadsheet have energy loss estimates for all of that hole punching and bending and breakage of columns?
Comment by psikeyhackr — May 24, 2008 @ 7:36 pm |
The argument about falling of to the side just doesn’t make sense to me. The only forces acting on the top section are downward (gravity) and upward (resistance). I can’t see where the force required to displace the 32,800 tonne chunk of building (to the extent that it could fall off) would come from. Do you have any suggestions?
Regarding energy loss, as I mentioned above in #18:
“Actually the 300MJ I am suggesting is a significant over-estimate for buckling only. The inelastic collision assumes that the floor is immediately dissociated from the structure and any concrete comminution energy is included in the energy loss associated with the inelastic collision. In reality there was alot of other structural damage above and beyond column buckling (e.g. fracture of horizontal members and connections, etc.) which I assume is the reason the energy parameter value must be somewhat higher than only the plastic buckling energy for columns in order to arrive at the “correct” fall-time.”
I have not rigorously calculated punch through energy, but it has to be less than the buckling energy, otherwise buckling would occur. If you are willing and able to do so, I know alot of people who would be interested.
I thought of an interesting question while thinking about your comment. Did the tilting make the top section more vulnerable to structural dissociation?
Comment by gregoryurich — May 25, 2008 @ 6:41 pm |
{{{ The argument about falling of to the side just doesn’t make sense to me. The only forces acting on the top section are downward (gravity) and upward (resistance). }}}
Things can work perfectly in mathematics. Objects like planets in a vacuum that interact via gravity can be predicted with near mathematical perfection. But when huge massive objects start colliding and crushing each other then get much more messy. It is extremely improbable that the crushing top portion would remain perfectly centered for 1000 plus feet while crushing thousands of tons of steel and concrete all of the way. Once it got off center it would crush the lower portion unevenly which would tend to force it more off center and the cycle would repeat until it fell off the side.
Now things are even worse for the south tower since we have pictures of the top tilted at 20 degrees. So how could it crush the resistance of the lower intact portion without getting more and more tilted until the inevitable occurred?
So seemingly we have two extremely improbable straight down gravitational collapses within minutes of each other. Yet the self proclaimed “world renowned experts” at the NIST can’t provide us with a human readable table of the tons of steel and tons of concrete on every level. That is a good trick for the nation that put men on the moon.
Comment by psikeyhackr — June 7, 2008 @ 8:55 pm |
Reply to psikeyhackr regarding #23,
The videos and photos of debris patterns show that neither WTC1 or WTC2 remained perfectly centered.
For me to buy your argument you will need to demonstrate those mathematical probabilities (i.e. extremely improbable). A simple force diagram would be a good start. If you don’t have the background to do that, we can agree to disagree on that point. Some things you may want to consider:
1. How far can it rotate before it starts falling downward? (most structural engineers say max 8 degrees)
2. How fast was the top rotating?
3. Har far down would it fall before the center of gravity reaches the perimeter?
4. Do the very strong exterior columns (safety factor >5), which formed a Verendiell truss, contribute to funneling broken material down into the building?
5. Where are the horizontal forces coming from? (Here my understanding is that once the top part stats to fall their are none, and that the leading edge is the first to encounter resistance which counteracts the effect of the angular (rotational) momentum.
There are clearly inadequacies in the NIST reports which should be addressed. Metamars has started an excellent thread over at JREF regarding NIST’s Black Boxes. Nonetheless, I think your concerns about the mass are dealt with pretty well in my paper, which includes comparisons to other buildings as well as the amount of debris removed from the site. Again if you do have any more corrections or suggestions regarding my paper I’ll be glad to consider them and make any needed corrections.
Comment by gregoryurich — June 9, 2008 @ 10:30 am |
Reply to gregoryurich regarding #24,
{{{ The videos and photos of debris patterns show that neither WTC1 or WTC2 remained perfectly centered. }}}
Of course that is relevant if only the airliners and resulting fires were solely responsible for the collapses.
We have video of the top of the south tower tilted at 20 degrees. We KNOW it was off center. The question is; “How could it possibly not have fallen down the side of the building?” How could it crush everything below straight down being off center from the start? This looks like rationalizing the “supposed collapse” after the fact with mathematics and trying to use that as proof the collapse made sense.
{{{ For me to buy your argument you will need to demonstrate those mathematical probabilities (i.e. extremely improbable). A simple force diagram would be a good start.
There are clearly inadequacies in the NIST reports which should be addressed. Metamars has started an excellent thread over at JREF regarding NIST’s Black Boxes. Nonetheless, I think your concerns about the mass are dealt with pretty well in my paper, which includes comparisons to other buildings as well as the amount of debris removed from the site. Again if you do have any more corrections or suggestions regarding my paper I’ll be glad to consider them and make any needed corrections. }}}
Your paper says this:
{{{ The calculated mass of 288,100 metric tons (317,500 short tons) is found to correspond with two other comparable structures in
terms of mass per unit floor area, NIST’s SAP2000 model, and the reported amount of recovered debris. The calculated mass refutes the popular notion that the building weighed 500,000 tons. }}}
It disagrees with but I don’t know that it refutes.
Many sources say the WTC towers had 200,000 tons of steel and 425,000 cubic yards of concrete. The NIST report confirms the quantity of steel but never specifies the quantity of concrete. That by itself is extremely odd. Now that would come to 212,500 cubic yards per building which at 100 lb per cu. ft. is 286,875 tons. Now that says nothing about the fact that there were two types of concrete and the normal type is 50% heavier. It appears that the 425,000 cubic yard specification was used long before 9/11 by the Port Authority and IF it is correct then your numbers must be off.
There are reasons other than the collapse for wanting correct information about the distribution of mass on the towers. The NIST says the south tower oscillated for 4 minutes after impact. Suppose the 81st level moved 6 inches as a result of that impact. Doesn’t it take more energy to move 400 tons 6 inches than 300 tons? The kinetic energy of the aircraft had two effects on the tower. The structural damage and the oscillation. How can the structural damage be computed without knowing how much energy went into the oscillation? How can that be computed without an accurate distribution of mass? In SIX YEARS I haven’t seen this question addressed by EXPERTS. What is the point of doing complex collapse calculations if the collapse should never have happened? Why do complex collapse calculations if you are not CERTAIN the data you are working with is correct? Why shouldn’t it be easy for the NIST to get and provide that data in human readable form? Why are we making excuses for the NIST?
Why isn’t everyone screaming BLOODY MURDER about the NIST not having supplied accurate TRUSTWORTHY data by now? Why even talk about an investigation without that?
Comment by psikeyhackr — June 10, 2008 @ 4:19 pm |
psikeyhackr we will never bring these people to justice because they are above the law- they fucking own all the muscle. Look at all the convicted FELONS from Iran Contra who not only had convictions overturned- but who have gone on to run some of the highest level progrmas- untouched. There will never be any 911 justice these people are so bold they are untouchable.
This back and forth about the towers collapse can go on forever- just like JFK analysis. We know the truth. Counterintelligence wants the debate to go on and on forever and it looks like it will.
Pack your shit and get out of the usa while you can.
Comment by realitydesign — June 10, 2008 @ 7:07 pm |
{{{ This back and forth about the towers collapse can go on forever- just like JFK analysis. We know the truth. Counterintelligence wants the debate to go on and on forever and it looks like it will. }}}
The trouble is, this is a grade school physics problem. It is not like JFK. How do you run a hi-tek society without people that can’t solve a grade school physics problem? People need to refuse to think in terms of REAL PHYSICS to not solve this.
Physics this simple really isn’t a debate. It is a matter of how long people don’t demand accurate data. The nation that put men on the moon can’t tell the entire world the tons of steel and tons of concrete on every level of buildings designed before the moon landing. Why aren’t the Iranians pointing that out to the world?
This kind of makes all of the engineering schools in the US accomplices after the fact. They should know to demand such data.
Comment by psikeyhackr — June 10, 2008 @ 9:50 pm |
To psikey,
NIST provides photocopies of the ORIGINAL DESIGN DOCUMENTS which specify the thickness and type of concrete on every floor. How much better can the data be? This is the data I use in my analysis. I have to wonder if you have actually read the paper.
Did you think about the questions I posed in #24? If it’s high school physics, do a force diagram, do a little math and help me understand what you are talking about. I aced “solid mechanics” (statics and dynamics) in engineering school and I don’t think it’s as easy as you say.
The CD theory is the best thing that ever happened to Bush and Cheney. It is most likely false, which will make the truth movement look like a bunch of fools, and it is taking all the energy away from the real issues. The real dope is what Dennis Kucinich presented last night.
Comment by Gregory — June 10, 2008 @ 11:35 pm |
To Greg:
1. Bush and Cheney have nothing to worry about- even if CD was proven beyond a reasonable doubt…who would listen? No one. The 911 criminals will NEVER be caught. I think the closest anyone came was Marvin Bush’s maid who was ‘backed over’ in his driveway in D.C. because her e-brake ‘failed’ when she walked around the back of her car. I wonder what she stumbled across in the house or what she heard….
2.Are you of the impression that wt7 was not CD?
Comment by realitydesign — June 11, 2008 @ 3:41 am |
You need a force diagram to wonder how the top of the south tower got tilted 20 degrees long after the plane impact.
So where did the number 425,000 cubic yards of concrete come from?
And why can’t they tell us something as simple as the number and weights of each type of wall panel?
But then they can write a report about shocks to suspended ceilings and that is the only one where they use the term “center of mass”. They never mention the center of mass of the top of the south tower. Are you claiming the falling mass of the south tower was centered?
Where have the people with the degrees in this area of expertise discussed the energy needed to shake the south tower on impact by the plane much less calculated it. And how could they calculate it without distribution of mass? Is the objective here to solve the problem or make everybody do lots of idiotic busy work? In 3 years and with $20,000,000 the NIST couldn’t make an accurate table without interpolation? Don’t we have enough computing power to do that compared to what was available in the early 60s to design the buildings?
Why are you bringing up Bush and Cheney? I haven’t said a thing about them and don’t give a damn. I didn’t say anything about controlled demolition either. If the planes did it then it should be possible to explain it at every step. So why don’t we have people separating the impact energy into what shook the building and what did structural damage? That happened long before the collapse.
Comment by psikeyhackr — June 11, 2008 @ 9:47 am |
Psikey,
I thought we were discussing the blog entry which is titled “Time to Get Serious about Proving Assisted Collapse…”. The controlled demolition theory is one of the most common theories regarding assisted collapse.
Where does that 425,000 cubic yards of concrete you cite come from? Do they describe how it was used. Maybe it was used in the slurry wall (bathtub?
When designing buildings, the exact weights of each component is never used. They use allowances (e.g. 12 psf for partitions) to take account things that will often be changed depending on the occupancy.
Spend a little time with the NIST reports. I don’t think they are as bad as you do. They are not written for laymen and they are by no means complete. I don’t think $20M is alot of money considering the amount of work they did, so they had to make priorities of what they focused on and how much detail they provided. I run into this all the time in my work.
The center of mass of tops of towers were not centered, but they weren’t displaced enough to topple off. This is where I would need the force diagram to convince me otherwise. That the tops leaned doesn’t make me suspicious. When I started all of my work on this I thought the collapse times were suspicious. I no longer think so because I did the math.
Alot of physics is counter intuitive especially when you get into dynamic situations with impact.
I bring up Bush and Cheney because I think that is where the real conspiracy lies. Have you looked into Kucinich’s impeachment bill?
Comment by Gregory — June 11, 2008 @ 2:23 pm |
Reality,
I’m undecided on the WTC7 collapse because I have done collapse time calculations and there is nothing really strange about it. A bottom up collapse dissipates far less energy so it doesn’t slow the collapse much. I also have not heard a convincing motive, but still, it sure looks strange when I watch the videos! I am waiting for the NIST report to see what they come up with.
Comment by Gregory — June 11, 2008 @ 2:28 pm |
(This comment is an edited pingback.)
Pingback by Dennis Kucinich’s articles of impeachment of President George W. Bush « New York City activist — June 13, 2008 @ 9:24 pm |
The reported collapse time of WTC 7 according to the seismic readings was 18 seconds:
http://www.firehouse.com/tech/news/2002/0121_terrorist.html
There’s nothing strange about that. What many people have done is to depend upon video images which create the appearance of a collapse occurring in 6.5 seconds and then to subsequently turn that number of 6.5 into a holy grail. A good practice to follow is to use both video images and seismic readings to obtain estimates of collapse time and always choose the larger number, whichever it is. In that article from FIREHOUSE magazine they give estimates of collapse times of 10, 8, and 18 seconds for WTC 1, 2, and 7. On this page Jim Hoffman attempts to claim, based upon videos, that the collapse of WTC 7 occurred in only 6.5 seconds:
http://wtc7.net/videos.html
But on this other page Hoffman argues on the basis of videos that the collapse times of WTC 1 & 2 were greater than 15 seconds:
http://911research.wtc7.net/essays/demolition/seismic.html
The safest approach to take is that where seismic readings give us the larger estimate for collapse time (WTC 7, 18 seconds, not 6.5 seconds) that estimate should be used. Where videos give the higher estimate (WTC 1 & 2, more than 15 seconds, not 10 seconds or less) this estimate should be invoked. It has to be expected that different methodologies of estimating the collapse time will sometimes give a higher or lower estimate but that whichever one gives the higher estimate is more likely to be accurate. Many 911-activists have followed a practice of choosing the lower estimates (10 seconds for WTC 1, 8 seconds for WTC 2, 6.5 seconds for WTC 7) and attempting to build arguments which depend upon this usage of the lower estimate. That’s not a good procedure in general.
Comment by patricksmcnally — June 13, 2008 @ 9:49 pm |
For WTC 7, the final global collapse took 6.5 seconds.
The 18 seconds includes interior local collapses before the final global collapse.
Comment by Diane — June 13, 2008 @ 10:44 pm |
Yes, but those local collapses are indeed part of the total collapse and arguments which attempt to segregate off a final global collapse and present it as if it were the total collapse are misleading and wrong-headed. The whole point is that the number 6.5 seconds is often presented as an automatic proof of demolition, whereas it ceases to be such the moment that we realize that there was a broader collapse phenomenon which took up to 18 seconds.
Comment by patricksmcnally — June 13, 2008 @ 11:34 pm |
What I’m calling the “final global collapse” did involve the entire outer wall.
So there’s still the question of whether it’s reasonable to expect the entire outer wall to collapse, in an almost straight-down manner, in only 6.5 seconds.
I don’t claim to know the answer to that question, which would probably require some detailed quantitative analysis and knowledge of the mechanical properties of the outer steel frame.
Comment by Diane — June 14, 2008 @ 3:01 am |
> So there’s still the question of whether it’s reasonable to expect the entire outer wall to collapse, in an almost straight-down manner, in only 6.5 seconds.
Fair enough.
> I don’t claim to know the answer to that question, which would probably require some detailed quantitative analysis and knowledge of the mechanical properties of the outer steel frame.
But that obviously is very different from what is claimed at the majority of 911-activist sites about WTC 7 and the alleged 6.5 second collapse.
Comment by patricksmcnally — June 14, 2008 @ 2:58 pm |
Response to GUrich #31
{{{ Where does that 425,000 cubic yards of concrete you cite come from? Do they describe how it was used. Maybe it was used in the slurry wall (bathtub? }}}
Just using Google to search on +wtc +425000 +”port authority” will get hundreds of hits. I presume many of these are quotes from other sources. But since they are associated with the 200,000 tons of steel which was in the towers I am inclined to think the 425K is just for the towers however I do not KNOW.
That is the problem with this entire mess. This is going on SEVEN YEARS. It did not take that long to design the towers. The nation that put men on the moon should not have trouble telling the entire world the tons of steel and concrete on every level of buildings designed before the moon landing. But I have seen enough professionals make things unnecessarily complicated often enough to not be impressed by it. The NIST made a report about suspended ceilings which was the only place they used the term “center of mass” which is why I found that report. It looked like a total waste of money to me.
The tilted top of the south tower should have crushed one side of the tower more than the other thereby increasing the tilt until it inevitably fell down the side. So why didn’t the obvious happen? The video is taken as proof that what happened is what should have happened strictly on the basis of the planes and fires but there is too much missing but simple information. FEMA has a map with X’s for material hurled from the towers but does not specify the weights or where the material came from on the towers. How did dozens of tons of material get hurled 600 feet to the Winter Garden by a gravitational collapse started by a fire?
Comment by psikeyhackr — June 15, 2008 @ 8:04 pm |
Sorry, forgot to mention. I’m really not paying attention to the politics that may or may not be related to this. Personally I think the physics should settle whether or not the planes could bring the buildings down in less than two hours. I personally doubt it but until a large percentage of Americans UNDERSTAND THAT I see no point in discussing the politics.
Comment by psikeyhackr — June 15, 2008 @ 8:09 pm |
Collapse One
Clear Thinking
psik
Comment by psikeyhackr — June 20, 2008 @ 5:43 pm |
Response to Psikeyhackr #39:
NIST provides the original design documents indicating the amount of concrete on each floor. I fail to see the significance of the discrepancy with older generalized internet sources.
Ryan Mackey has decribed in detail why the upper parts did not fall off. There is currently a thread about this at JREF. You have provided no support for your hypothesis that they would. If you do, I would be glad to consider it.
It didn’t get hurled. Since the somewhat intact exterior section (originally 1400ft long) peeled outwards, it is not surprising that the reached 600ft away. Watch the videos carefully. This can be seen especially well in the case of WTC1 where nearly the entire side peeled off and impacted the World Financial Center. Major Tom has some interesting info about this on his site.
Comment by Gregory — June 22, 2008 @ 9:15 am |
{{{ It didn’t get hurled. Since the somewhat intact exterior section (originally 1400ft long) peeled outwards, it is not surprising that the reached 600ft away. }}}
“PEELED”
You call what you see in those videos peeling? LOL
If it had peeled it could hardly have gone 200 feet from the building.
Do a search in Youtube on DavidSChandler to find his analyses of videos ejecting that material. So all of that old information got the steel correct and the concrete wrong but it is the macroscopic concrete that disappeared from the WTC but you have decided to accept what the NIST says.
We can all see videos of the top of the south tower tilting but we aren’t supposed wonder how far the center of that mass deviated from the vertical center of the building and why it didn’t crush one side more and fall off that side?
YEAH RIGHT, you go along with Mackey.
Comment by psikeyhackr — June 22, 2008 @ 2:52 pm |
Are you suggesting that the original design documents presented by NIST were fabricated? Can you show that any of the floor thicknesses given are non-standard?
For the mass of concrete you are suggesting, the floors would need to be 12″ thick just about everywhere and 16″ thick in mechanical and high traffic areas.
I’ve watched the Candler analysis a number of times. He assumes that the debris is falling at terminal velocity which is a mistake. The reason he gets a straight plot is that the leading edge is accelerating horizontally because of the peeling. Check out Major Toms site: http://www.sharpprintinginc.com/911/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=62&MMN_position=149:149
By the way, I have seen photos of the nearly intact exterior stretching from WTC1 all the way to WFC.
I don’t go along with anybody. See my latest thread on JREF regarding the fire proofing to see if I go along with Mackey. I consider the evidence and take each analysis at it’s own merit. I think Major Tom is right about the peeling and Ryan Mackey is right about the tilting. If you want to convince me, you’ll have to show how they are wrong.
Comment by Gregory — June 25, 2008 @ 8:38 pm |
Don’t hand me this “are you suggesting” like I made up the 425,000 cubic yards out of thin air.
I have heard two different stories about people trapped in elevators in the WTC. In one people were able to dig through drywall with the end of a squeegy. In the other they came up against a concrete wall. I am encountering contradictory information about whether or not there was any concrete enclosure going up the core. Maybe it only went part way.
But you can forget about me trusting the NIST when they can’t do something as simple and obvious as tell us the number and weights of each of the 12 types of perimeter wall panels. They can tell us the original design called for 14, like that is supposed to matter. It gives the impression they are doing a really thorough job though. Tell people unimportant information while leaving out what matters.
Comment by psikeyhackr — June 26, 2008 @ 10:42 pm |
{{{ I’ve watched the Candler analysis a number of times. He assumes that the debris is falling at terminal velocity which is a mistake. }}}
I have done the trajectory calculations a number of times. Assuming the fall takes place as if in a vacuum requires a higher initial horizontal velocity. That simply begs the question, “What gave that many tons of material that much velocity?”
Ht. sec @ horz-vel
1350 = 9.2 @ 44.5 mph
1300 = 9.0 @ 45.5 mph
1250 = 8.8 @ 46.5 mph
1200 = 8.7 @ 47.0 mph
1150 = 8.5 @ 48.1 mph
1100 = 8.3 @ 49.3 mph
1050 = 8.1 @ 50.5 mph
1000 = 7.9 @ 51.8 mph
950 = 7.7 @ 53.1 mph
900 = 7.5 @ 54.5 mph
850 = 7.3 @ 56.0 mph
800 = 7.1 @ 57.6 mph
750 = 6.8 @ 60.2 mph
700 = 6.6 @ 62.0 mph
650 = 6.4 @ 63.9 mph
600 = 6.1 @ 67.1 mph
550 = 5.9 @ 69.3 mph
500 = 5.7 @ 71.8 mph
450 = 5.3 @ 77.2 mph
400 = 5.0 @ 81.8 mph
350 = 4.7 @ 87.0 mph
300 = 4.3 @ 95.1 mph
250 = 4.0 @ 102.3 mph
200 = 3.5 @ 116.9 mph
150 = 3.0 @ 136.4 mph
100 = 2.5 @ 163.6 mph
50 = 1.8 @ 227.3 mph
Terminal velocity would mean more time to fall and less horizontal velocity required to reach the Winter Garden. It is a pity that FEMA doesn’t tell us where those panels came from on the building. Now what possible reason could there be for not providing that information? Why wouldn’t they want to know? What kind of totally screwed up investigation was this.
Of course the farther down the tower a wall panel came from the heavier it had to be so that would require even more force to obtain the required velocity.
Comment by psikeyhackr — June 26, 2008 @ 11:12 pm |
Based on Chandlers straight line plot, either the vertical and horizontal components of the velocity are constant OR they are both changing such that Vh/Vv = 1/3. If I have understood the data you provide, it shows that there was horizontal acceleration. What could have caused that?
Comment by Gregory — June 28, 2008 @ 7:24 pm |
I am not suggesting that you made up anything. I have seen that 425,000 cu yds all over the place too. Either the original design documents provided by NIST are false (and therefore fabricated) or the 425,000 cu yds is false, possibly due to being quoted out of context. Since the NIST documents make sense and there is zero evidence for concrete used anywhere other than the floors and as fireproofing, I believe the NIST documents.
Would people digging with a squeegy be able to tell the difference between drywall with a four foot wide box column behind it and concrete? Otherwise, the only thing I can imagine is that the elevator pits may have been concrete.
Have you considered joining the Scholars for 9/11 Truth and Justice? Their forum has tons of information and even one member who is convinced the cores were concrete. He is the only person I have met on any forum who thinks there was a concrete core.
Comment by Gregory — June 28, 2008 @ 7:42 pm |
{{{ If I have understood the data you provide, it shows that there was horizontal acceleration. What could have caused that? }}}
Sorry, I wasn’t clear enough about that.
1350 = 9.2 @ 44.5 mph
1000 = 7.9 @ 51.8 mph
The 1350 and 1000 are heights from which a mass might fall.
The 9.2 and 7.9 are the times it takes for the mass to reach the ground.
The 44.5 and 51.8 are the horizontal velocities necessary for the mass to travel 600 feet to the Winter Garden in that time.
Obviously the farther down the less available time so the greater velocity required. So the question is, “What caused it to have the necessary velocity to reach the Winter Garden?”
It is a pity FEMA didn’t record the ID numbers off that material so we could know where it came from.
Comment by psikeyhackr — June 29, 2008 @ 2:29 am |
Chandler says the fall was at terminal velocity (i.e. constant speed). We need to see if there was vertical and/or horizontal acceleration. I’m sure there was both, but you should check for yourself. The reason I am sure is because that would be the result of the exterior peeling outward, for which there is other supporting evidence.
Comment by Gregory — June 30, 2008 @ 8:16 am |
{{{ Chandler says the fall was at terminal velocity }}}
What are you referring to by “fall”.
I have watched one of his videos where he tracked some material flying away from the tower and the vertical to horizontal movement was very linear. That would indicate that the downward movement was constant. It is not like he just made a claim or came up with a formula. That is what his source data seems to indicate.
He did not create the original video.
Comment by psikeyhackr — July 7, 2008 @ 12:28 pm |
What is terminal velocity for a falling heavy object? Was the horizontal velocity the same as terminal velocity?
There are at least two explanations for the linear trajectory. Chandler’s doesn’t make any sense.
Comment by Gregory — July 10, 2008 @ 7:57 pm |
I have another video on Youtube.
It is of a top down gravitational collapse. Guess what?
Mass slows it down and brings it to a stop.
Just search on: WTC MIToo
psik
Comment by psikeyhackr — March 26, 2009 @ 2:02 pm |
It has been kind of dead around here. What has happened to the Truth Movement in New York?
Economic Crisis?
Comment by psikeyhackr — March 26, 2009 @ 2:04 pm |
My, my this was long ago. And still such a simple problem not resolved. I made a mistake back then by not modifying Gregory Urich’s spreadsheet. It is so curious that he does not specify the height at each level but has the mass and potential energy. All you have to do is divide the potential energy by the mass to get the height.
Try it and you will get a really peculiar number for the roof. LOL
Comment by psikeyhackr — November 10, 2015 @ 9:08 pm |