911 Debate: Government Derelection, Coverups, Conspiracy Theories

This blog and a Yahoo group, The911Debate, complement each other. Both focus on 9/11 exploitation, culpability, cover-ups, conspiracy theories, and manipulation of public opinion by both the Government and hoax peddlers (a surprising number of whom are former Government officials.) Fantastic theories, such as controlled demolitions destroying the World Trade Center and a guided missile rather than Flight 77 hitting the Pentagon, are drawing attention away from very real Government malfeasance.

My Photo
Location: Seaside, California, United States

Born in 1925, US Navy 1942-1946, retired mathematician (Ph.D. MIT 1958), former Member of Students for a Democratic Society (SDS), of TECNICA (Technical Assistance to Nicaruaga), and of Food Not Bombs.

Friday, July 22, 2005

Critique of Jim Hoffman's Analyses--Part I

Jim Hoffman’s Faulty Analyses of WTC Dust Clouds Clouds Understanding
One of the most widely quoted 9/11 "truth researchers" is Jim Hoffman, a prominent computer graphics programmer. David Ray Griffin, Dean of America's 9/11 conspiracy theory popularizers, quotes him extensively, and Hoffman's critiques of the conventional wisdom on how the WTC buildings collapsed are widely accepted in the 9/11 "truth" movment.
A timeline on Hoffman's 9/11 calculations and speculations follows:
On June 13, 2003 Hoffman published his first article on energy analysis of the collapse of the North Tower. ("The North Tower’s Dust Cloud, Version 1" which can be viewed at
Attempting to apply Boyle’s Ideal Gas Law to the dust cloud which arose from the WTC 1 collapse, he "calculates" that more than 60,000,000 kilowatt hours of energy had to have been dissipated in order to produce what the visual evidence demonstrated. Hoffman erroneously assumed that the available potential energy of WTC 1 was 400,000 KWH, and his conclusion was:
"The amount of energy required to expand the North Tower's dust cloud was many times the entire potential energy of the tower's elevated mass due to gravity. The over 100-fold disparity between this estimate and the gravitational energy is not easily dismissed as reflecting uncertainties in quantitative assessments. The official explanation that the Twin Tower collapses were gravity-driven events appears insufficient to account for the documented energy flows."
It can easily be found in energy tables that 1 KWH of energy is produced by 0.78 Kg of TNT, so the 60,000,000 KWH Hoffman "calculates" were dissipated has the TNT equivalent of 60,000,000 X 0.78 = 46,800,000 Kg or 46,800 tonnes (metric tons) of TNT. This is a lot of shiploads of TNT—a lot more power than the Hiroshima and Nagasaki atomic bombs produced. Apparently Hoffman never gave any consideration to who would be carrying 46,800 tonnes of TNT to the various floors of a 1,386 foot building.
Apparently also, in his critique of the May, 2002 FEMA report on WTC 1 and 2, Hoffman didn’t even read the first sentence of the second chapter:
"Chapter 2: WTC1 & WTC2
" Progression of Collapses
"Construction of WTC 1 resulted in the storage of more than [400,000,000,000] joules of potential energy over the 1,368-foot height of the structure."
This potential energy converted to KWH equals 111,111 KWH, whereas Hoffman estimated the potential energy of WTC 1 to be 400,000 KWH—almost four times the FEMA estimate.
The reason this observation is important is that the common practice of Hoffman and Griffin and most other proponents of the planted-explosive WTC theory is to ignore the work done by both FEMA in its hurried preliminary study and by NIST in its ongoing study. (The FEMA reports on the 9/11 attacks were meant only as quick tentative analyses because the definitive analyses are the responsibility of NIST. FEMA is the Federal Emergency Management Agency, and NIST is the National Institute of Standards and Technology.)
On July 23, 2003 Hoffman published his first revision of his June 13 energy analysis of the collapse of the North Tower. ("The North Tower’s Dust Cloud, Version 2" which can be viewed at
This time he accepted the FEMA estimate of the available WTC 1 potential energy, 111,000 KWH, he and re-did his earlier calculations, coming up with 11,835,000 KWH dissipated during the collapse. The TNT equivalent of this is 9,231 tonnes of TNT. This is a lot less than the 46,000 tonnes of TNT in his June 13 calculations, and now down to less than the Hiroshima magnitude, but still too much for humans to carry up to the various floors of WTC 1. The wording of Hoffman’s concluding summary remains unchanged from his June 13 summary:
"The amount of energy required to expand the North Tower's dust cloud was many times the entire potential energy of the tower's elevated mass due to gravity. The over 100-fold disparity between this estimate and the gravitational energy is not easily dismissed as reflecting uncertainties in quantitative assessments. The official explanation that the Twin Tower collapses were gravity-driven events appears insufficient to account for the documented energy flows."
On October 16, 2003 Hoffman published his second revision of his energy analysis of the collapse of the North Tower. ("The North Tower’s Dust Cloud, Version 3" which can be viewed at
This time he makes a different assumption of how the energy was dissipated, bringing in the change-of-state of water in the building, including water in the concrete. Again he accepts the FEMA estimate of 111,000 KWH of available potential energy, and calculates that the total amount of energy dissipated had to be approximately 2,817,000 KWH, which is 25.38 times the available potential energy. This time in his conclusions he conservatively reduces this 25 times to 10 times available potential energy in his concluding summary:
"The amount of energy required to expand the North Tower's dust cloud was many times the entire potential energy of the tower's elevated mass due to gravity. The over 10-fold disparity between the most conservative estimate and the gravitational energy is not easily dismissed as reflecting uncertainties in quantitative assessments. The official explanation that the Twin Tower collapses were gravity-driven events appears insufficient to account for the documented energy flows."
Ten times the 111,000 KWH of available potential energy, minus the 111,000, comes out to be 999,000 KWH, or 799 tonnes of TNT the minimum amount of explosive power needed to fit the observed evidence. But 799 tonnes of TNT is still more than could be expected of human beings to covertly carry up to the various floors of WTC 1. Considering that this 799 tonnes of explosives would all have to have been wired up carefully so that the explosives on the various floors are detonated by a computer in a manner coordinated with the building collapse, it remains, even after his drastic reduction in energy calculations, that Hoffman’s theory of controlled demolition of WTC 1 and 2 is not at all plausible.
On an undisclosed date a person going by the pseudonym "TRUTH" tried to rescue Hoffman’s controlled-demolition theory, with a fourth version (third revision) of the June 13 analysis. This is given version 3.0 (as opposed to version 3 above), and is posted on various websites, including on the forum:
In this version the complete title has been changed and for the first time 14 tons of explosives is claimed to be sufficient to fit the observed evidence, but this tonnage is mentioned only in a new section inserted by TRUTH, who indicates that his revision was made in two steps, the last editing being on April 17, 2005. The complete heading and title in the globalresearch forum are:
"Posted: Sat Mar 06, 2004 3:54 am Post subject: CALCULATIONS SAY 14 TONS OF EXPLOSIVE TO BRING DOWN EACH WTC.
"The North Towers Dust Cloud: Analysis of Energy Requirements for the Expansion of the Dust Cloud following the Collapse of 1 World Trade Center by Jim Hoffman, October 16th, 2003 (Version 3.0)" [Note the 3.0 instead of 3 as the version number of the third revision (fourth version).]
At the end of his posting, TRUTH states that "The comment in red has been added to the original article." Since there is much text in TRUTH’s posting in red font (color)—some commentary and one whole new section, all of which is in addition to Hoffman’s Version 3 of October 16—it seems evident that TRUTH meant to say "commentary" instead of "comment".
In TRUTH’s commentary as well as in the whole new section, he refers to Hoffman by name, indicating that Hoffman did not participate in the revision which got the tonnage of explosives down to 14 from the 799 in Hoffman’s Version 3. TRUTH suggests that: "This article by J. Hoffman is a deliberate attempt to divert your attention from the fact that explosives were used to bring down the WTC towers. By presenting a possible explanation for the debris cloud without considering explosives, he is implicitly stating that he, as an expert in the field, does not consider explosives an option, so why should you? He is deliberately pointing you in the wrong direction."
The whole new section apparently written and inserted into Hoffman’s Version 3 of October 16, 2003 begins with:
"The Unexplored Option -- Explosives."
[For some reason TRUTH prefers to use the explosive amatol (80:20)—80% ammonium nitrate and 20 % TNT—instead of the more standard TNT when discussing energy equivalents of explosive tonnage and kilowatt hours. He goes through a lot of chemical calculations which are totally unnecessary because energy conversion between Kg of TNT and KWH are easily found on the Internet, as is the approximation that amatol is 26% more powerful than TNT by weight.] (TRUTH’s relating "hot gasses" to a 200,000,000 liter air expansion seems to me to be lacking validity, but that is not important in this current critique.) TRUTH’s conclusion is that
"Hence the 200,000,000 liter expansion calculated by Hoffman can be explained by the detonation of 200,000,000/16,068 = 12,447 kg = 12.5 tonnes (14 tons) of the high explosive amatol. "Summary "The 200,000,000 liter expansion calculated by Hoffman can be explained by the detonation of 12.5 tonnes (14 tons) of the high explosive amatol." [This ends TRUTH’s inserted section which began with the heading, "The Unexplored Option -- Explosives."]
[Then following this long inserted section, the text of Hoffman’s October 16, 2003 Version 3 resumes with:]
"The dominant energy source assumed to be in play during the leveling of each of the Twin Towers was the gravitational energy due to its elevated mass, whereas the energy sinks included the pulverization of it's concrete, the vaporization of water, and the heating of the concrete and air in the ensuing dust cloud. . . . "Conclusion "The amount of energy required to expand the North Towers dust cloud was many times the entire potential energy of the towers elevated mass due to gravity. The over 10-fold disparity between the most conservative estimate and the gravitational energy is not easily dismissed as reflecting uncertainties in quantitative assessments. The official explanation that the Twin Tower collapses were gravity-driven events appears insufficient to account for the documented energy flows." [The following was in red color—one of TRUTH’s many short inserted comments:] "However, the use of explosives explains all the observed facts, and is thus probably the correct explanation."
where the text in red color is clearly set off from the earlier text by Hoffman.]
Jim Hoffman on "Guns and Butter", KPFA, 1/24/04 and 1/28/04
The transcript of these two interviews is found on:
Edited Transcript of Your Eyes Don't Lie: Common Sense, Physics, and the World Trade Center Collapses
Originally broadcast on KPFA in two parts:Part 1: 1/21/04, 2-3PMPart 2: 1/28/04, 2-3PM
Due to time and space considerations, in this posting it only will be mentioned that Hoffman, perhaps for the first time, referred to a low tonnage of explosives—he used 16 tons instead of TRUTH’s 14 tons above. But in Part 2 of the interview Hoffman states that he doesn’t believe any explosives were used because of the visible evidence, He expounds instead on his new theory that giant masers created the energy which collapsed WTC 1 and 2.
Popular Mechanics Attacks Its"9/11 LIES" Straw Man by Jim Hoffman Version 1.2, February 9, 2005
Is on
Here Hoffman returns to defend the planted explosives and controlled demolition theory, following his abandonment of that theory in his Guns and Butter KPFA interviews above.
Future postings to groups.yahoo.com/group/the911debate and the911debate.blogspot.com will develop further Hoffman’s current views and examine his critique of the Popular Mechanics article debunking major 9/11 conspiracy theories.

Monday, July 18, 2005

Excerpts From Popular Mechanics 9/11 Myth Debunking Article

911 Debate: Government Derelection, Coverups, Conspiracy Theories


Below is an annotated collection of excerpts from the widely disseminated Popular Magazine article debunking some of the major conspiracy theory myths on 9/11. Graphics are omitted and some of what I consider to be relatively unimportant details are trimmed or excised. The original March 2005 PM article can be found at

The major conspiracy theory myths not included in the PM article pertain to those put out by the US Government which try to show that the 9/11 and other Islamic terrorist attacks are motivated by hatred which radical Muslims have for democracy, women’s liberation, women’s rights, and so on, or by the goal of radical Muslims to forcefully convert us to Islam, etc, etc. These are very important conspiracy theories and will be addressed later on in the building up of both my blog, http://the911debate.blogspot.com and its companion Yahoo group, http://groups.yahoo.com/group/the911debate.

Not all conspiracy theories are false: e.g., clearly a group of Muslims conspired to mount the 9/11 attacks, and most experts believe that members of the US Government conspired to exploit the 9/11 attacks in order to invade Iraq for oil and bases in the Middle East.

Annotated excerpts of the March 2005 PM article follow, with all annotations in square brackets:

9/11: Debunking The Myths

PM examines the evidence and consults the experts to refute the most persistent conspiracy theories of September 11. [Published originally in the March,2005 issue.]

FROM THE MOMENT the first airplane crashed into the World Trade Center on the morning of September 11, 2001, the world has asked one simple and compelling question: How could it happen?

Three and a half years later, not everyone is convinced we know the truth. Go to Google.com, type in the search phrase "World Trade Center conspiracy" and you'll get links to an estimated 628,000 Web sites. More than 3000 books on 9/11 have been published; many of them reject the official consensus that hijackers associated with Osama bin Laden and Al Qaeda flew passenger planes into U.S. landmarks.

Healthy skepticism, it seems, has curdled into paranoia. Wild conspiracy tales are peddled daily on the Internet, talk radio and in other media. Blurry photos, quotes taken out of context and sketchy eyewitness accounts have inspired a slew of elaborate theories: The Pentagon was struck by a missile; the World Trade Center was razed by demolition-style bombs; Flight 93 was shot down by a mysterious white jet. As outlandish as these claims may sound, they are increasingly accepted abroad and among extremists here in the United States.

To investigate 16 of the most prevalent claims made by conspiracy theorists, POPULAR MECHANICS assembled a team of nine researchers and reporters who, together with PM editors, consulted more than 70 professionals in fields that form the core content of this magazine, including aviation, engineering and the military.

In the end, we were able to debunk each of these assertions with hard evidence and a healthy dose of common sense. We learned that a few theories are based on something as innocent as a reporting error on that chaotic day. Others are the byproducts of cynical imaginations that aim to inject suspicion and animosity into public debate. Only by confronting such poisonous claims with irrefutable facts can we understand what really happened on a day that is forever seared into world history.--THE EDITORS

The widely accepted account that hijackers commandeered and crashed the four 9/11 planes is supported by reams of evidence, from cockpit recordings to forensics to the fact that crews and passengers never returned home. Nonetheless, conspiracy theorists seize on a handful of "facts" to argue a very different scenario: The jets that struck New York and Washington, D.C., weren't commercial planes, they say, but something else, perhaps refueling tankers or guided missiles. And the lack of military intervention? Theorists claim it proves the U.S. government instigated the assault or allowed it to occur in order to advance oil interests or a war agenda.

[“Where’s the Pod” section omitted in these excerpts.]

No Stand-Down Order
CLAIM: No fighter jets were scrambled from any of the 28 Air Force bases within close range of the four hijacked flights. "On 11 September Andrews had two squadrons of fighter jets with the job of protecting the skies over Washington D.C.," says the Web site emperors-clothes.com. "They failed to do their job." "There is only one explanation for this," writes Mark R. Elsis of StandDown.net. "Our Air Force was ordered to Stand Down on 9/11."

FACT: On 9/11 there were only 14 fighter jets on alert in the contiguous 48 states. No computer network or alarm automatically alerted the North American Air Defense Command (NORAD) of missing planes. "They [civilian Air Traffic Control, or ATC] had to pick up the phone and literally dial us," says Maj. Douglas Martin, public affairs officer for NORAD. Boston Center, one of 22 Federal Aviation Administration (FAA) regional ATC facilities, called NORAD's Northeast Air Defense Sector (NEADS) three times: at 8:37 am EST to inform NEADS that Flight 11 was hijacked; at 9:21 am to inform the agency, mistakenly, that Flight 11 was headed for Washington (the plane had hit the North Tower 35 minutes earlier); and at 9:41 am to (erroneously) identify Delta Air Lines Flight 1989 from Boston as a possible hijacking. The New York ATC called NEADS at 9:03 am to report that United Flight 175 had been hijacked--the same time the plane slammed into the South Tower. Within minutes of that first call from Boston Center, NEADS scrambled two F-15s from Otis Air Force Base in Falmouth, Mass., and three F-16s from Langley Air National Guard Base in Hampton, Va. None of the fighters got anywhere near the pirated planes.

Why couldn't ATC find the hijacked flights? When the hijackers turned off the planes' transponders, which broadcast identifying signals, ATC had to search 4500 identical radar blips crisscrossing some of the country's busiest air corridors. And NORAD's sophisticated radar? It ringed the continent, looking outward for threats, not inward. "It was like a doughnut," Martin says. "There was no coverage in the middle." Pre-9/11, flights originating in the States were not seen as threats and NORAD wasn't prepared to track them.

[“Flight 175’s Windows” claim and debunking omitted here.]

Intercepts Not Routine
CLAIM:"It has been standard operating procedures for decades to immediately intercept off-course planes that do not respond to communications from air traffic controllers," says the Web site oilempire.us. "When the Air Force 'scrambles' a fighter plane to intercept, they usually reach the plane in question in minutes."

FACT: In the decade before 9/11, NORAD intercepted only one civilian plane over North America: golfer Payne Stewart's Learjet, in October 1999. With passengers and crew unconscious from cabin decompression, the plane lost radio contact but remained in transponder contact until it crashed. Even so, it took an F-16 1 hour and 22 minutes to reach the stricken jet. Rules in effect back then, and on 9/11, prohibited supersonic flight on intercepts. Prior to 9/11, all other NORAD interceptions were limited to offshore Air Defense Identification Zones (ADIZ). "Until 9/11 there was no domestic ADIZ," FAA spokesman Bill Schumann tells PM. After 9/11, NORAD and the FAA increased cooperation, setting up hotlines between ATCs and NORAD command centers, according to officials from both agencies. NORAD has also increased its fighter coverage and has installed radar to monitor airspace over the continent.

The collapse of both World Trade Center towers--and the smaller WTC 7 a few hours later--initially surprised even some experts. But subsequent studies have shown that the WTC's structural integrity was destroyed by intense fire as well as the severe damage inflicted by the planes. That explanation hasn't swayed conspiracy theorists, who contend that all three buildings were wired with explosives in advance and razed in a series of controlled demolitions.

Widespread Damage
CLAIM:The first hijacked plane crashed through the 94th to the 98th floors of the World Trade Center's 110-story North Tower; the second jet slammed into the 78th to the 84th floors of the 110-story South Tower. The impact and ensuing fires disrupted elevator service in both buildings. Plus, the lobbies of both buildings were visibly damaged before the towers collapsed. "There is NO WAY the impact of the jet caused such widespread damage 80 stories below," claims a posting on the San Diego Independent Media Center Web site (sandiego.indymedia.org). "It is OBVIOUS and irrefutable that OTHER EXPLOSIVES (... such as concussion bombs) HAD ALREADY BEEN DETONATED in the lower levels of tower one at the same time as the plane crash."

FACT: Following up on a May 2002 preliminary report by the Federal Emergency Management Agency (FEMA), a major study will be released in spring 2005 by the National Institute of Standards and Technology (NIST), a branch of the U.S. Department of Commerce. NIST shared its initial findings with PM and made its lead researcher available to our team of reporters.

The NIST investigation revealed that plane debris sliced through the utility shafts at the North Tower's core, creating a conduit for burning jet fuel--and fiery destruction throughout the building. "It's very hard to document where the fuel went," says Forman Williams, a NIST adviser and a combustion expert, "but if it's atomized and combustible and gets to an ignition source, it'll go off."

Burning fuel traveling down the elevator shafts would have disrupted the elevator systems and caused extensive damage to the lobbies. NIST heard first-person testimony that "some elevators slammed right down" to the ground floor. "The doors cracked open on the lobby floor and flames came out and people died," says James Quintiere, an engineering professor at the University of Maryland and a NIST adviser. A similar observation was made in the French documentary "9/11," by Jules and Gedeon Naudet. As Jules Naudet entered the North Tower lobby, minutes after the first aircraft struck, he saw victims on fire, a scene he found too horrific to film.

"Melted" Steel
CLAIM: "We have been lied to," announces the Web site AttackOnAmerica.net. "The first lie was that the load of fuel from the aircraft was the cause of structural failure. No kerosene fire can burn hot enough to melt steel." The posting is entitled "Proof Of Controlled Demolition At The WTC."

FACT: Jet fuel burns at 800° to 1500°F, not hot enough to melt steel (2750°F). However, experts agree that for the towers to collapse, their steel frames didn't need to melt, they just had to lose some of their structural strength--and that required exposure to much less heat. "I have never seen melted steel in a building fire," says retired New York deputy fire chief Vincent Dunn, author of The Collapse Of Burning Buildings: A Guide To Fireground Safety. "But I've seen a lot of twisted, warped, bent and sagging steel. What happens is that the steel tries to expand at both ends, but when it can no longer expand, it sags and the surrounding concrete cracks."

"Steel loses about 50 percent of its strength at 1100°F," notes senior engineer Farid Alfawak-hiri of the American Institute of Steel Construction. "And at 1800° it is probably at less than 10 percent." NIST also believes that a great deal of the spray-on fireproofing insulation was likely knocked off the steel beams that were in the path of the crashing jets, leaving the metal more vulnerable to the heat.

But jet fuel wasn't the only thing burning, notes Forman Williams, a professor of engineering at the University of California, San Diego, and one of seven structural engineers and fire experts that PM consulted. He says that while the jet fuel was the catalyst for the WTC fires, the resulting inferno was intensified by the combustible material inside the buildings, including rugs, curtains, furniture and paper. NIST reports that pockets of fire hit 1832°F.

"The jet fuel was the ignition source," Williams tells PM. "It burned for maybe 10 minutes, and [the towers] were still standing in 10 minutes. It was the rest of the stuff burning afterward that was responsible for the heat transfer that eventually brought them down."

Puffs Of Dust
CLAIM:As each tower collapsed, clearly visible puffs of dust and debris were ejected from the sides of the buildings. An advertisement in The New York Times for the book Painful Questions: An Analysis Of The September 11th Attack made this claim: "The concrete clouds shooting out of the buildings are not possible from a mere collapse. They do occur from explosions." Numerous conspiracy theorists cite Van Romero, an explosives expert and vice president of the New Mexico Institute of Mining and Technology, who was quoted on 9/11 by the Albuquerque Journal as saying "there were some explosive devices inside the buildings that caused the towers to collapse." The article continues, "Romero said the collapse of the structures resembled those of controlled implosions used to demolish old structures."

FACT: Once each tower began to collapse, the weight of all the floors above the collapsed zone bore down with pulverizing force on the highest intact floor. Unable to absorb the massive energy, that floor would fail, transmitting the forces to the floor below, allowing the collapse to progress downward through the building in a chain reaction. Engineers call the process "pancaking," and it does not require an explosion to begin, according to David Biggs, a structural engineer at Ryan-Biggs Associates and a member of the American Society of Civil Engineers (ASCE) team that worked on the FEMA report.

Like all office buildings, the WTC towers contained a huge volume of air. As they pancaked, all that air--along with the concrete and other debris pulverized by the force of the collapse--was ejected with enormous energy. "When you have a significant portion of a floor collapsing, it's going to shoot air and concrete dust out the window," NIST lead investigator Shyam Sunder tells PM. Those clouds of dust may create the impression of a controlled demolition, Sunder adds, "but it is the floor pancaking that leads to that perception."

Demolition expert Romero regrets that his comments to the Albuquerque Journal became fodder for conspiracy theorists. "I was misquoted in saying that I thought it was explosives that brought down the building," he tells PM. "I only said that that's what it looked like."

Romero, who agrees with the scientific conclusion that fire triggered the collapses, demanded a retraction from the Journal. It was printed Sept. 22, 2001. "I felt like my scientific reputation was on the line." But emperors-clothes.com saw something else: "The paymaster of Romero's research institute is the Pentagon. Directly or indirectly, pressure was brought to bear, forcing Romero to retract his original statement." Romero responds: "Conspiracy theorists came out saying that the government got to me. That is the farthest thing from the truth. This has been an albatross around my neck for three years."

Seismic Spikes
CLAIM:Seismographs at Columbia University's Lamont-Doherty Earth Observatory in Palisades, N.Y., 21 miles north of the WTC, recorded the events of 9/11. "The strongest jolts were all registered at the beginning of the collapses, well before falling debris struck the earth," reports the Web site WhatReallyHappened.com.

A columnist on Prisonplanet.com, a Web site run by radio talk show host Alex Jones, claims the seismic spikes (boxed area on Graph 1) are "indisputable proof that massive explosions brought down" the towers. The Web site says its findings are supported by two seismologists at the observatory, Won-Young Kim and Arthur Lerner-Lam. Each "sharp spike of short duration," says Prisonplanet.com, was consistent with a "demolition-style implosion."

FACT:"There is no scientific basis for the conclusion that explosions brought down the towers," Lerner-Lam tells PM. "That representation of our work is categorically incorrect and not in context."

The report issued by Lamont-Doherty includes various graphs showing the seismic readings produced by the planes crashing into the two towers as well as the later collapse of both buildings. WhatReallyHappened.com chooses to display only one graph (Graph 1), which shows the readings over a 30-minute time span.

On that graph, the 8- and 10-second collapses appear--misleadingly--as a pair of sudden spikes. Lamont-Doherty's 40-second plot of the same data (Graph 2) gives a much more detailed picture: The seismic waves--blue for the South Tower, red for the North Tower--start small and then escalate as the buildings rumble to the ground. Translation: no bombs.

WTC 7 Collapse
CLAIM:Seven hours after the two towers fell, the 47-story WTC 7 collapsed. According to 911review.org: "The video clearly shows that it was not a collapse subsequent to a fire, but rather a controlled demolition: amongst the Internet investigators, the jury is in on this one."

FACT: Many conspiracy theorists point to FEMA's preliminary report, which said there was relatively light damage to WTC 7 prior to its collapse. With the benefit of more time and resources, NIST researchers now support the working hypothesis that WTC 7 was far more compromised by falling debris than the FEMA report indicated. "The most important thing we found was that there was, in fact, physical damage to the south face of building 7," NIST's Sunder tells PM. "On about a third of the face to the center and to the bottom--approximately 10 stories--about 25 percent of the depth of the building was scooped out." NIST also discovered previously undocumented damage to WTC 7's upper stories and its southwest corner.

NIST investigators believe a combination of intense fire and severe structural damage contributed to the collapse, though assigning the exact proportion requires more research. But NIST's analysis suggests the fall of WTC 7 was an example of "progressive collapse," a process in which the failure of parts of a structure ultimately creates strains that cause the entire building to come down. Videos of the fall of WTC 7 show cracks, or "kinks," in the building's facade just before the two penthouses disappeared into the structure, one after the other. The entire building fell in on itself, with the slumping east side of the structure pulling down the west side in a diagonal collapse.

According to NIST, there was one primary reason for the building's failure: In an unusual design, the columns near the visible kinks were carrying exceptionally large loads, roughly 2000 sq. ft. of floor area for each floor. "What our preliminary analysis has shown is that if you take out just one column on one of the lower floors," Sunder notes, "it could cause a vertical progression of collapse so that the entire section comes down."

There are two other possible contributing factors still under investigation: First, trusses on the fifth and seventh floors were designed to transfer loads from one set of columns to another. With columns on the south face apparently damaged, high stresses would likely have been communicated to columns on the building's other faces, thereby exceeding their load-bearing capacities.

Second, a fifth-floor fire burned for up to 7 hours. "There was no firefighting in WTC 7," Sunder says. Investigators believe the fire was fed by tanks of diesel fuel that many tenants used to run emergency generators. Most tanks throughout the building were fairly small, but a generator on the fifth floor was connected to a large tank in the basement via a pressurized line. Says Sunder: "Our current working hypothesis is that this pressurized line was supplying fuel [to the fire] for a long period of time."

WTC 7 might have withstood the physical damage it received, or the fire that burned for hours, but those combined factors--along with the building's unusual construction--were enough to set off the chain-reaction collapse.

At 9:37 am on 9/11, 51 minutes after the first plane hit the World Trade Center, the Pentagon was similarly attacked. Though dozens of witnesses saw a Boeing 757 hit the building, conspiracy advocates insist there is evidence that a missile or a different type of plane smashed into the Pentagon.

Big Plane, Small Holes
CLAIM: Two holes were visible in the Pentagon immediately after the attack: a 75-ft.-wide entry hole in the building's exterior wall, and a 16-ft.-wide hole in Ring C, the Pentagon's middle ring. Conspiracy theorists claim both holes are far too small to have been made by a Boeing 757. "How does a plane 125 ft. wide and 155 ft. long fit into a hole which is only 16 ft. across?" asks reopen911.org, a Web site "dedicated to discovering the bottom line truth to what really occurred on September 11, 2001."

The truth is of even less importance to French author Thierry Meyssan, whose baseless assertions are fodder for even mainstream European and Middle Eastern media. In his book The Big Lie, Meyssan concludes that the Pentagon was struck by a satellite-guided missile--part of an elaborate U.S. military coup. "This attack," he writes, "could only be committed by United States military personnel against other U.S. military personnel."

FACT: When American Airlines Flight 77 hit the Pentagon's exterior wall, Ring E, it created a hole approximately 75 ft. wide, according to the ASCE Pentagon Building Performance Report. The exterior facade collapsed about 20 minutes after impact, but ASCE based its measurements of the original hole on the number of first-floor support columns that were destroyed or damaged. Computer simulations confirmed the findings.

Why wasn't the hole as wide as a 757's 124-ft.-10-in. wingspan? A crashing jet doesn't punch a cartoon-like outline of itself into a reinforced concrete building, says ASCE team member Mete Sozen, a professor of structural engineering at Purdue University. In this case, one wing hit the ground; the other was sheared off by the force of the impact with the Pentagon's load-bearing columns, explains Sozen, who specializes in the behavior of concrete buildings. What was left of the plane flowed into the structure in a state closer to a liquid than a solid mass. "If you expected the entire wing to cut into the building," Sozen tells PM, "it didn't happen."

The tidy hole in Ring C was 12 ft. wide--not 16 ft. ASCE concludes it was made by the jet's landing gear, not by the fuselage.

Intact Windows
CLAIM:Many Pentagon windows remained in one piece--even those just above the point of impact from the Boeing 757 passenger plane. Pentagonstrike.co.uk, an online animation widely circulated in the United States and Europe, claims that photographs showing "intact windows" directly above the crash site prove "a missile" or "a craft much smaller than a 757" struck the Pentagon.

FACT: Some windows near the impact area did indeed survive the crash. But that's what the windows were supposed to do--they're blast-resistant. [REMAINDER OF THIS SECTION OMITTED HERE.]

Flight 77 Debris
CLAIM:Conspiracy theorists insist there was no plane wreckage at the Pentagon. "In reality, a Boeing 757 was never found," claims pentagonstrike.co.uk, which asks the question, "What hit the Pentagon on 9/11?"

FACT:Blast expert Allyn E. Kilsheimer was the first structural engineer to arrive at the Pentagon after the crash and helped coordinate the emergency response. "It was absolutely a plane, and I'll tell you why," says Kilsheimer, CEO of KCE Structural Engineers PC, Washington, D.C. "I saw the marks of the plane wing on the face of the building. I picked up parts of the plane with the airline markings on them. I held in my hand the tail section of the plane, and I found the black box." Kilsheimer's eyewitness account is backed up by photos of plane wreckage inside and outside the building. Kilsheimer adds: "I held parts of uniforms from crew members in my hands, including body parts. Okay?"


REPORTING: Benjamin Chertoff, Davin Coburn, Michael Connery, David Enders, Kevin Haynes, Kristin Roth, Tracy Saelinger, Erik Sofge and the editors of POPULAR MECHANICS.
SOURCES: For a list of experts consulted during the preparation of this article, click here.

PM consulted more than 300 experts and organizations in its investigation into 9/11 conspiracy theories. The following were particularly helpful.

[List omitted here, but a partial list is displayed if you press the "here"button above in the SOURCES line. Alternatively, the list is displayed when you read the first comment to this posting. Consulted experts include Van Romero, Ph.D. vice president, New Mexico Institute of Mining and Technology, whose views conspiracy hoaxers consistently misrepresent.]