Enough conspiracy theories, already.

The New Pearl Harbor: Disturbing Questions About the Bush Administration and 9/11 By David Ray Griffin. Second edition. Olive Branch Press. 254 pages. $15.

The 9/11 Commission Report: Omissions and Distortions By David Ray Griffin Olive Branch Press. 339 pages. $18.

Christian Faith and the Truth Behind 9/11: A Call to Reflection and Action By David Ray Griffin Westminster John Knox Press. 246 pages. $17. 95.

Debunking 9/11 Myths: Why Conspiracy Theories Can't Stand Up to the Facts By the editors of Popular Mechanics Hearst Books. 170 pages. $14.95.

"Extraordinary claims require extraordinary evidence."--Carl Sagan

"Never ascribe to malice that which is adequately explained by incompetence."--Napoleon

At almost every progressive gathering where there's a question and answer period, someone or other vehemently raises 9/11 and espouses a grand conspiracy theory.

If you haven't had the pleasure of enduring these rants, please let me share.

Here's what the conspiracists believe:

9/11 was an inside job.

Members of the Bush Administration ordered it, not Osama bin Laden.

The Twin Towers fell because the Bush Administration got agents to plant explosives at the base of those buildings.

Building 7, another high-rise at the World Trade Center that fell on 9/11, also came down by planted explosives.

The Pentagon was not hit by American Airlines Flight 77 but by a smaller plane or a missile.

And the Pennsylvania plane did not crash as a result of the revolt by the passengers but was brought down by the military.

I'm amazed at how many people give credence to these theories. Everyone's an engineer. People who never even took one college science course can now hold forth at great length on how the buildings at the World Trade Center could not possibly have collapsed in the way they did and why the Pentagon could not have been struck by that American Airlines jet.

Problem is, some of the best engineers in the country have studied these questions and come up with perfectly logical, scientific explanations for what happened.

The American Society of Civil Engineers and FEMA conducted an in-depth investigation of the World Trade Center. The team members included the director of the Structural Engineering Institute of the American Society of Civil Engineers, the senior fire investigator for the National Fire Protection Association, professors of fire safety, and leaders of some of the top building design and engineering firms.

The investigation concluded that massive structural damage caused by the crashing of the aircrafts into the buildings, combined with the subsequent fires, "were sufficient to induce the collapse of both structures."

The National Institute of Standards and Technology did its own forty-three-volume study of the Twin Towers. It also concluded that a combination of the crash and the subsequent fires brought the towers down: "In each tower, a different combination of impact damage and heat-weakened structural components contributed to the abrupt structural collapse."

Popular Mechanics, first in its March 2005 cover story and now in its expanded book, Debunking 9/11 Myths, takes apart the most popular contentions of the conspiracists. "In every case we examined, the key claims made by conspiracy theorists turned out to be mistaken, misinterpreted, or deliberately falsified," the book says.

I made a few calls myself, including to Gene Corley, who conducted the American Society of Civil Engineers/FEMA study, and to Mete Sozen, structural engineering professor at Purdue, who was one of the principal authors of "The Pentagon Building Performance Report" of January 2003, which was done under the auspices of the American Society of Civil Engineers and the Structural Engineering Institute. I also contacted engineering professors at MIT and other leading universities in the country, and none of them puts any stock in the 9/11 conspiracy theories.

Of course, any conspiracy theorist worth his or her salt will claim that all these people are in on the plot.

And that I, a Rothschild no less, am in on it, too.

Get over it.

The guru of the 9/11 conspiracy movement is David Ray Griffin, an emeritus professor not of engineering but of philosophy and theology at the Claremont School of Theology. First in The New Pearl Harbor and then in The 9/11 Commission Report." Omissions and Distortions and now in Christian Faith and the Truth Behind 9/11, Griffin has peddled his conspiracy theory.

He's not alone, of course. A myriad of websites devote themselves to this subject, and several films are circulating on it, including Loose Change. There's even a group called Scholars for 9/11 Truth, which insists "the World Trade Center was almost certainly brought down by controlled demolitions." Most prominent among these is Steven E. Jones, professor of physics and astronomy at Brigham Young University, whose primary field is not engineering but cold fusion, according to Debunking 9/11 Myths.

The conspiracy theories are particularly popular on the left for a couple of understandable reasons. It's undeniable that Bush has ceaselessly seized on 9/11 to justify his warmaking abroad and his repressive policies at home. And then there's the notorious phrase in a document of the Project for the New American Century, the fount of neoconservativism, whose members included Dick Cheney, Donald Rumsfeld, Paul Wolfowitz, Douglas Feith, and a host of other hawks who flew into the Bush Administration. That line, from the September 2000 study "Rebuilding America's Defenses," argues for transforming the U.S. military posture into a much more aggressive one, and for expanding the Pentagon's budget to reach $500 billion a year. The authors recognized that this transformation would be difficult to achieve quickly "absent some catastrophic and catalyzing event--like a new Pearl Harbor."

Griffin and other leftwing conspiracy theorists put the two together, and voila. The attacks "were orchestrated in order to pave the way for launching unprovoked wars on two countries that provided no threat, whether imminent or long-term, to the people of the United States," he writes in Christian Faith and the Truth Behind 9/11. "The Administration and its Pentagon even planned to use 9/11 as a pretext ... to attack still more countries. The U.S. government was planning, therefore, to use the deaths of some 3,000 people (whom itself had killed) to justify wars that would most likely kill and maim many hundreds of thousands of people, perhaps millions."

Before taking some of the major conspiracy claims one by one, let's examine how outlandish the conspiracy theory is on its face.

First, Osama bin Laden has already claimed responsibility for the attack several times and boasted of the prowess of the suicide bombers who hijacked those planes. Why not take him at his word? And if bin Laden were working in cahoots with the Bush Administration, why was the President warned on August 6, 2001, in a Presidential daily briefing that Osama bin Laden was about to attack the United States? Wouldn't that risk exposing the conspiracy?

Second, if the Bush Administration plotters carried out 9/11 to justify attacking Iraq, why didn't they have Iraqi hijackers do the deed? In actuality, there was not a single Iraqi hijacker, and Bush propagandists had to do all sorts of gymnastics to link Iraq to the actual attackers.

Third, for this conspiracy to have succeeded, it would have had to have been amazingly vast: not only the high level members of the Bush Administration (including the head of the Secret Service, Griffin says in Christian Faith) and the explosives teams, but also many others.

Griffin, in Pearl Harbor, for instance, alleges that Mayor Rudolph Giuliani may have been involved. Griffin quotes Giuliani telling ABC News, "We were operating out of there [Building 7] when we were told that the World Trade Center was gonna collapse." Griffin says Giuliani had no obvious way of knowing that, and concludes: "Giuliani's statement provides, therefore, evidence someone, perhaps he himself, knew something that the firemen in the buildings did not know--which was perhaps that explosives had been placed in the buildings and were about to be set off." Is that really evidence? Isn't it much more likely that the firefighters told the mayor to leave because the fire itself was jeopardizing the building?

Griffin also alleges that Larry Silverstein, who leased the World Trade Center complex, was in on the deal so he could collect the insurance. (This claim--which he might as well have called "The Jew Cashed In"--dovetails with the anti-Semitic conspiracy theory popular in the Middle East that the Mossad blew up the towers and warned the thousands of Jews who would have been working there to stay home.)

In Pearl Harbor, Griffin quotes Silverstein in a 2002 PBS documentary recalling a conversation from the fire department commander on September 11 "telling me that they were not sure they were gonna be able to contain the fire, and I said, 'We've had such terrible loss of life, maybe the smartest thing to do is pull it.' And they made that decision to pull and we watched the building collapse." Griffin, who writes that Silverstein "made almost $500 million in profit from the collapse of Building 7," says by "pull it" Silverstein was recommending that the building be demolished by explosives. Silverstein has flat-out denied that. By "pulling it," he has said that he meant giving up on the firefighters' efforts to save the building.

Two books later, Griffin removes any ambiguity. Silverstein's "assertion that Building 7 was brought down by explosives, whatever the motive behind it, explains why and how it collapsed," Griffin writes in Christian Faith and the Truth Behind 9/11. But Silverstein never made such an assertion, and for Griffin to claim he did is, to say the least, a distortion.

The problems with a vast conspiracy theory are obvious. There's the likelihood that someone along the chain would squeal. Members of the government have been engaged in far less treasonous plots, and whistleblowers have managed to get the information out to the likes of Seymour Hersh over at The New Yorker. And, on top of that, we're supposed to believe that this incompetent Administration, which brought you Katrina, was somehow able to execute this grand conspiracy?

Finally, in Pearl Harbor, Griffin acknowledges one enormous, unfillable hole in the conspiracists' theory: If Flight 77 did not hit the Pentagon, where did it go? And where did all sixty-four people on board go? Griffin pathetically answers: "One cannot expect that the revisionists, being independent researchers with limited budgets and no power to subpoena testimony, could answer all the questions raised by their alternative scenario."

On to some of Griffin's most oft-cited questions, and the answers to them.

Why did dust clouds shoot out of the Twin Towers as they fell?

Or, as Griffin poses it in Pearl Harbor. "What other than explosives could turn concrete into powder and then eject it horizontally 150 feet or more?"

Corley, who headed up the investigation for the American Society of Civil Engineers and FEMA, gives a quick response to that. "That is simply the air pressure being pushed down," he says. "Once the collapse started, then you had roughly a twenty-story building and roughly a thirty-story building acting as a very large mass to push everything down. The air pressure gets quite something, and the windows on the lower floors break, and you see puffs of smoke coming out of them." Debunking 9/11 Myths offers the same explanation and cites structural engineer Jon Magnusson, who says this expulsion of air and debris is fairly common when buildings collapse.

Why did the tower that was hit second fall first?

"All other things being equal, then, the tower that was struck first should have collapsed first. And yet, although the South Tower was struck seventeen minutes later than the North Tower, it collapsed twenty-nine minutes earlier," writes Griffin in Pearl Harbor. The fact that the South Tower fell first, he concludes, "suggests that the collapse of these buildings was caused by something other than the fires."

But all things weren't equal. "The damage done to the second building was more serious than the damage done to the first," says Corley.

The National Institute of Standards and Technology concurs. Its "Final Report on the Collapse of the World Trade Center Towers" notes that ten core columns were severed in the South Tower, whereas only six were severed in the North. And 20,000 more square feet of insulation was stripped from the trusses in the South Tower than the North. The report "found no corroborating evidence for alternative hypotheses suggesting that the WTC were brought down by controlled demolition using explosives planted prior to September 11, 2001."

What about Building 7?

This is a favorite of the conspiracy theorists, since the planes did not strike this structure. But the building did sustain damage from the debris of the Twin Towers. "On about a third of the face to the center and to the bottom--approximately ten stories--about 25 percent of the depth of the building was scooped out," Shyam Sunder, the lead investigator for the National Institute of Standards and Technology, told Popular Mechanics.

What's more, the fire in the building lasted for about eight hours, in part because there were fuel tanks in the basement and on some of the floors. "The building was designed for a fire duration of no more than about three hours," says Corley. "Eight hours was way more than what that building was designed for."

The National Institute of Standards and Technology is still studying the collapse of Building 7, but its initial report says: "NIST has seen no evidence that the collapse of WTC 7 was caused by bombs, missiles, or controlled demolition."

What about the Pentagon?

Conspiracy theorists will bend your ear explaining that the American Airlines Boeing 757 couldn't possibly have made such a small hole in the Pentagon. Griffin in Pear/Harbor: "The orifice created by the impact ... was at most eighteen feet in diameter. Is it not absurd to suggest that a Boeing 757 created and then disappeared into such a small hole? ... Can anyone seriously believe that a 125-foot-wide airplane created and then went inside a hole less than twenty-feet wide?"

First of all, the hole was actually ninety feet wide, according to the "Pentagon Building Performance Report" of January 2003, which the American Society of Civil Engineers and the Structural Engineering Institute put out. And Professor Sozen of Purdue, one of the authors of that report, has an explanation.

"The reinforced columns of the Pentagon destroyed the wings," says Sozen. "That's why the hole is smaller. It had to be smaller." Since working on that report, Sozen has designed simulations at Purdue, and his results correspond with what happened to Flight 77, he says. Sozen, who identifies himself as a progressive, says it is "ridiculous to deny" that the American Airlines plane hit the Pentagon. And, he adds, if Flight 77 didn't hit the Pentagon, where did it go and "what happened to the people in that plane"?

But we know what happened to them. They died at the Pentagon. "All but five of the 189 people who died on the aircraft and in the Pentagon were later identified through DNA testing," according to Debunking 9/11 Myths.

Finally, was Flight 93 shot down?

Griffin and many other conspiracists allege that Flight 93, which crashed in Pennsylvania, was brought down not by the passengers struggling with the hijackers but by a U.S. missile. But we know from cell phone conversations that passengers on board that plane planned on confronting the hijackers. And, as Debunking 9/11 Myths notes, "a Cleveland air traffic controller assigned to Flight 93 heard signs of a struggle in the cockpit, followed shortly by screaming."

Tapes of the conversations at the northeast regional headquarters for the North American Aerospace Defense Command (NORAD) confirm this, as Michael Bronner has shown in his August article for Vanity Fair entitled "9/11 Live: The NORAD Tapes." Major Kevin Nasypany was the facility's mission-crew commander that day, and the tapes show him frantically trying to figure what was going on and whether he had orders to shoot Flight 93 down.

"Gimme the call sign," he says at 10:07. "Gimme the whole nine yards.... Let's get some info, real quick. They got a bomb?"

But, as Bronner reports, by then "everyone on board is already dead. Following the passengers' counterattack, the plane crashed in a field in Pennsylvania at 10:03 a.m."

The man who headed up the crash site investigation there was Matthew McCormick, a thirty-three-year veteran at the National Transportation Safety Board. "From my investigation there was no pre-impact stress to the airplane," he told the Debunking authors.

To be sure, there are discrepancies and omissions in The 9/11 Commission Report, and the Pentagon and FAA appear to have not been fully truthful and forthcoming about what happened that day. Not every riddle that Griffin and other conspiracists pose has a ready answer. But almost all of their major assertions are baseless. And their own theories have such gigantic holes and require such monumental leaps of logic that they discredit themselves.

At bottom, the 9111 conspiracy theories are profoundly irrational and unscientific. It is more than passing strange that progressives, who so revere science on such issues as tobacco, stem cells, evolution, and global warming, are so willing to abandon science and give in to fantasy on the subject of 9/11.

The 9/11 conspiracy theories are a cul-de-sac. They lead nowhere. And they aren't necessary to prove the venality of the Bush Administration. There's plenty of that proof lying around. We don't need to make it up.