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The 9/11 Truth Movement: The Top Conspiracy Theory, a Decade Later


Dave Thomas

Skeptical Inquirer Volume 35.4, July/August 2011

After ten years, the pesky 9/11 Truth movement has refined its arguments but still hasn’t proved the attacks were an inside job. Their key claims are refuted on multiple grounds.

The conspiracy theories started flying just days after the September 11, 2001, terrorist attacks on New York and Washington, DC. Over the decade since, several technically elaborate claims have been refined by the “9/11 Truth” movement. Do these intricate arguments—including the rapid collapses of the towers, alleged evidence of thermite usage at Ground Zero, and the collapse of World Trade Center (WTC) 7 (a forty-seven-story building damaged by the fall of WTC 1) “into its own footprint at freefall acceleration”—disprove the mainstream consensus that the September 11, 2001, attacks were the work of al-Qaeda terrorists using hijacked airplanes? In a word: No.

9/11 Truthers

The Players

Dylan Avery and Jason Bermas, the creators of the low-budget documentary film Loose Change, did much to give the 9/11 Truth movement significant momentum in 2005 and in following years. The film, which has undergone several revisions, has been shown on many television stations but is primarily an Internet and DVD phenomenon. Its basic claims are that Flight 77 could not have accounted for the damage at the Pentagon, that the Twin Tower fires were insufficient to cause their collapse, and that cell phone calls from the hijacked airplanes would have been impossible at the time (Avery 2009).

David Ray Griffin is a theologian whose voluminous writings on 9/11 are frequently cited by other 9/11 theorists. NASA scientist Ryan Mackey has written a very thorough critique of Griffin’s claims (Mackey 2008).

Once known as Fleischmann and Pons’s competitor for “cold fusion” research in Utah, Steven Jones has written several 9/11 Truth articles. His work with others (including chemist Niels Harrit of Denmark) on detecting nanothermite in WTC dust is frequently cited as “peer-reviewed research” that proves “inside job” claims.

Physics teacher David Chandler has produced several papers and Internet videos contending that high school physics easily shows that the tower collapses could not have happened from gravity alone. He claims this proves that explosives must have been used.

In the past few years, architect Richard Gage’s group, Architects and Engineers for 9/11 Truth (AE911 Truth), has provided “Truthers” with the ability to claim that thousands of engineering and architecture professionals demand a new investigation into the cause of the attacks. Gage travels the world giving presentations, and his group puts on news conferences and mock debates several times a year (but most often around September 11, the anniversary of the attack) (Thomas 2009; Thomas 2010c).

Hollywood stars who have publicly supported 9/11 Truth claims include Rosie O’Donnell, Charlie Sheen, and Ed Asner. Sheen often talks 9/11 with radio host Alex Jones ( These celebrities frequently cite (and sometimes mangle) claims made by Truther proponents like Griffin and Gage. Former wrestler and Minnesota governor Jesse Ventura has done two 9/11 conspiracy shows on his TruTV series Conspiracy Theory (see “Dave Thomas vs. Jesse Ventura: The Skeptical Smackdown”).

The Claims

As with any well-developed pseudoscience, literally thousands of individual arguments can be advanced in support of the proposition that the United States secretly carried out the September 11 attacks. This report will examine the most enduring and oft cited of these claims: “free fall” of the towers, reports of thermite and molten steel, and WTC 7’s curious collapse. Some of the factions that have developed (such as the “no-planers”) will also be described briefly.

Claim One:
“The Twin Towers collapsed at free-fall accelerations through the path of greatest resistance.”

Perhaps the most bizarre aspect of September 11 was the rapid destruction of both 110-story Twin Towers: after the collapses began due to cascading structural failures at the airplane impact locations, each tower fell completely in just fifteen to twenty seconds. Mainstream scientific analyses, including years of work by the National Institute of Standards and Technology (NIST), generally looked at the cause of each collapse: the intense fires (started by jet fuel and fed by office contents and high winds) eventually caused floor trusses to sag, pulling the perimeter walls inward until they finally snapped. At this instant, the entire upper section of each tower fell the height of one floor, initiating an inevitable, progressive, and utterly catastrophic collapse of each of the structures.

While the mainstream explanation (dismissed as the “official story” by 9/11 Truthers) usually ends with the initiation of these unstoppable collapses, the 9/11 Truth movement’s attacks begin there. Gage of AE911 Truth says on that group’s website, “Destruction [of the Twin Towers] proceeds through the path of greatest resistance at nearly free-fall acceleration” (Gage 2011; emphasis added). Many 9/11 Truther pundits drop the “nearly” and say simply that the collapses were at free fall. Truthers then insist that free fall acceleration indicates a complete lack of resistance, proving that the structures were demolished with explosives. We are also told that the sheer mass of the towers, “80,000 tons of structural steel,” would simply resist collapse.

How could the buildings fall so quickly? It’s been explained very well in the technical literature by Northwestern’s Zdenek Bazant, PhD, and others (see, for example, Bazant 2008). I’ve developed a simpler physics model of the progressive collapses that agrees quite well with the main points of Bazant’s more rigorous results (Thomas 2010b). Here are some of my findings:

Claim Two:
“Nano-thermite and military-grade explosives were found in dust from the towers. Tons of melted steel were found in tower debris.”

thermite burningThe thermite reaction is very hot, but it is also very slow compared to high explosives.

Real controlled demolitions commonly use explosives to topple large buildings. However, the hallmarks of actual demolitions (the characteristic “boom-boom-boom-boom” sounds and the flashes of high explosives) were completely absent in Manhattan on the morning of September 11, 2001. Many 9/11 Truth advocates, including architect Richard Gage, insist that high explosives must have been used to bring down the Twin Towers, as they say this is the only process that can possibly explain the “ejection of debris hundreds of feet from the towers.” However, they simultaneously insist that thermite or a derivative (thermate, nanothermite, etc.) was used instead, so as to topple the towers quietly. (This is but one of many instances in which 9/11 Truth claims flatly contradict each other.) Thermite itself fails as an explanation for the destruction of the Towers on many levels:

Claim Three:
“Tower 7, which wasn’t hit by a plane, collapsed neatly into its own footprint.”

World Trade Center Building 7Courtesy of the Prints and Photographs Division, Library of Congress

The enigma of WTC 7 is becoming increasingly popular in Truther circles. We’re told that it wasn’t hit by a plane and was subjected to just a few “small office fires.” Yet it collapsed anyway, late in the afternoon of September 11, “falling neatly into its own footprint at freefall acceleration, just like a normal controlled demolition.” In particular, Truthers point to a brief period of freefall (2.25 seconds) that was confirmed by NIST in its WTC 7 final report (Sunder 2008; NIST 2010) as proving that the building was purposely imploded. However, WTC 7, too, fails to prove 9/11 was an “inside job”:

Factions within 9/11 Truth

Early on, it was mainly MIHOP (“Made it happen on purpose”) versus LIHOP (“Let it happen on purpose”). Nowadays most serious Truthers down-pedal the “no-planers,” who say no plane hit the Pentagon or even the Towers. There is considerable friction between some groups, with certain 9/11 Truth groups attacking others as “disinformation agents.” However, 9/11 Truth is mostly a big tent. Many “serious” groups such as AE911 Truth quietly champion “no-planers” such as former pilot Dwain Deets, engineer Anders Bjorkman, and Craig Ranke of Citizen Investigation Team (CIT) (Gage 2011). Gage formally withdrew his support of CIT in February 2011, even as his website touted 9/11 articles in Foreign Policy Journal, an online publication notorious for its frequent forays into Holocaust denial.


As Ted Goertzel pointed out in his recent Skeptical Inquirer article “The Conspiracy Meme: Why Conspiracy Theories Appeal and Persist,” “When an alleged fact is debunked, the conspiracy meme often just replaces it with another fact” (Goertzel 2011). In another ten years, will the 9/11 Truth movement have developed new arguments, or will it stick with the polished claims discussed here? Either way, it appears this American conspiracy theory classic is here to stay.


Avery, Dylan. 2009. Loose Change 9/11: An American Coup. Distributed by Microcinema International. Released September 22.

Bazant, Dzenek, J. Le, F.R. Greening, and D.B. Benson. 2008. What did and did not cause collapse of World Trade Center Twin Towers in New York? Journal of Engineering Mechanics ASCE 13(10): 892–906. Available online at

Blanchard, Brent 2006. A critical analysis of the collapse of WTC Towers 1, 2, and 7 from an explosives and conventional demolitions viewpoint. Journal of Debunking 911 Conspiracy Theories 1(2). Available online at

Chandler, David. 2010. Destruction of the World Trade Center North Tower and fundamental physics. Journal of 9/11 Studies 28 (February). Available online at

Fana, Run-Hua, Hong-Liang Lü, Kang-Ning Sun, et al. 2006. Kinetics of thermite reaction in Al-Fe2O3 system. Thermochimica Acta 440(2) (January 15): 129–31.

Gage, Richard. 2011. Architects and Engineers for 9/11 Truth. Available online at

Goertzel, Ted. 2011. The conspiracy meme: Why conspiracy theories appeal and persist. Skeptical Inquirer 35(1) (January/February): 28–37.

Harrit, Niels H., Jeffrey Farrer, Steven E. Jones, et al. 2009. Active thermitic material discovered in dust from the 9/11 World Trade Center catastrophe. Bentham Open Chemical Physics Journal 2: 7–31. Available online at

Hoffman, Thomas. 2009. Bentham editor resigns over Steven Jones’ paper. Danish Science News Service (April 28). Available online at­_artikel_om_911. (Translation available online at

Mackey, Ryan. 2008. On debunking 9/11 debunking: Examining Dr. David Ray Griffin’s latest criticism of the NIST World Trade Center investigation. Journal of Debunking 911 Conspiracy Theories 1(4). Available online at

NIST. 2010. Questions and answers about the NIST WTC 7 investigation (updated September 17). Available online at

Roberts, Mark. 2008. World Trade Center building 7 and the lies of the ‘9/11 Truth movement.’ Available online at

Sublette, Carey. 2006. Complete list of all U.S. nuclear weapons. Nuclear Weapon Archive Organization. Available online at

Sunder, Shyam, Richard G. Gann, William L. Grosshandler, et al. 2008. NIST Final Report on the Collapse of World Trade Center Building 7. Available online at

“Sunstealer.” 2011. The sad case of Niels Harrit. JREF forum. Available online at

Thomas, Dave. 2009. How I debated a 9/11 Truther and survived. Skeptical Briefs 19(4) (December). Available online at

———. 2010a: The video Jesse Ventura doesn’t want the world to see! NM Skeptic Blog (March 24). Available online at

———. 2010b. Institute of Theoretical and Experimental 9/11 Physics 9-11 ‘Truth’ resources. New Mexicans for Science and Reason (August). Available online at

———. 2010c. 9/11 truth: The Coast-to-Coast AM debate. Skeptical Briefs 20(4) (December).

Young, Jeffrey R. 2007. A Berkeley engineer searches for the truth about the Twin Towers’ collapse. Civil and Structural Engineers on WTC Collapse. Available online at

9/11 Internet Resources

The James Randi Educational Foundation (JREF) Forum, 9/11 Conspiracy Theory area.
If you need every single 9/11 Truth claim sliced and diced a 
thousand ways, this is your site.

Mark Roberts (“Gravy”)

Screw Loose Change blog

AE911Truth.Info (Joseph Noble)
“Answering the questions of Architects and Engineers for 9/11 Truth”

9/11 Myths: Reading between the Lies

Dave Thomas

Dave Thomas, a physicist and mathematician, is president of New Mexicans for Science and Reason and a fellow of the Committee for Skeptical Inquiry. He is currently a scientist/programmer at IRIS/PASSCAL in Socorro, New Mexico, and also teaches classes in physics, psychology, and critical thinking at New Mexico Tech.