This column makes some great points.
I will repeat some of them below in case the link goes away.
First, al-Qaida has repeatedly admitted planning and executing the 9/11 attacks. In a captured videotape recording of a private meeting in November 2001, bin Laden talks in detail about the 9/11 plot, comparing his expectations in advance to what actually occurred.
End of discussion, right? Nope. The 9/11 conspiracy peddlers reply that bin Laden is –today – on the payroll of the CIA and the Israeli Mossad. To explain away al-Qaida's proud admission, they "out" bin Laden as a CIA agent. (Where is Joe Wilson when you need him?) Some also insist that Al Jazeera is a television network operated by Israel, because Qatar lacks technical skills.
Second, of the World Trade Center, professors Fetzer and Jones insist "there was not enough kinetic energy to cause one floor to bring about the collapse of the floor below it." Yet about 29 floors tilted and fell onto the crumbling floor where the aircraft gouged out and removed support structure. Why would a university professor talk about "one floor" falling when everyone knows that 29 floors, plus 140 tons of aircraft and cargo, fell? Fetzer is intentionally deceiving the gullible. (But I am Jewish, he says, for disagreeing with him.)
Third, Fetzer and Jones argue that the Twin Towers could not have collapsed so neatly without a controlled demolition. Architects clarify that any such building is designed to load-shift. The failure of part of a floor causes other parts of that structure to compensate and take up the load. This means that each floor must always fail symmetrically. As long as any part of the floor remains intact, it is designed to pick up the remaining load. Thus, it was inevitable that the towers collapsed symmetrically and down the center. Furthermore, controlled demolitions start from the bottom up. The WTC collapse bears no resemblance to that whatsoever.
Fourth, many conspiracy peddlers insist that no airplanes ever hit the World Trade Center or Pentagon. The airplanes never existed. They refuse to acknowledge that tens of thousands of eyewitnesses went outside and watched the WTC burn before the second airplane hit. News footage was faked, they say, but they do not explain how thousands of journalists and New Yorkers all watched the airplane hit or how dozens of cameras all show the same thing. They ignore how American Airlines crash investigators verified their airplanes from the wreckage in order to file insurance claims and prepare for lawsuits. They do not explain why hundreds of civilian air traffic controllers and airport radar operators confirm the official explanation (indeed, are the sources for much of it). They assume that hundreds of local police and firefighters crawling over the wreckage covered up for the murderers of their fellow firefighters and cops.
Fifth, conspiracy mongers claim that no steel building has ever collapsed from fire alone, so the Twin Towers couldn't, either. However, the heavy-steel-construction McCormick Place Exhibition Hall collapsed after only 30 minutes of an ordinary fire in Chicago. No physical damage. No jet fuel. Just an ordinary fire softened the steel to the point of structural collapse. And that steel was not carrying the load of 110 floors above it. A dozen other fires in steel buildings have also collapsed floors because the steel softened and buckled. The Hotel Windsor lost its entire upper half in a fire. Clearly, the temperature of an ordinary fire can make a steel structure fail.
But, of course, the WTC towers did not collapse from fire alone, but from the severe physical damage of a 140-ton aircraft traveling at 540 mph shredding the support structures, not to mention the weight of the planes themselves. Incredible temperatures resulted from approximately 30,000 kilograms of jet fuel. But the fireball itself was an enormous, cataclysmic bomb, shattering the building's interior. They ignore how this fantastic bomb of jet fuel damaged the building. During the ensuing fire, the expansion of steel in 1,500 degree fires distorted the building and sheared off bolts and connectors, as the steel expanded, buckled and warped. Later, a "fuel air bomb" from jet fuel leaking down the elevator shaft shook the entire structure.
Sixth, conspiracy mongers engage in pure science fiction about whether the WTC buildings should have collapsed as they did. Such calculations are meaningless because we can never know the actual circumstances: What was the temperature inside? We will never know. Was there substandard construction material? Was the construction perfect? Was there corrosion from the salt air of the ocean during 35 years? Was the architectural design as good as the architects thought?
All such calculations are pure science fiction because there are a hundred variables we can never know. The mythmakers ignore the structural damage from the 1993 bombing. Islamic terrorists had calculated that their truck bomb in the basement garage would bring down the Twin Towers completely. The towers stood, but with what damage?
Similarly, the mythmakers claim that the towers fell at the same rate as objects in free fall. Actually, the towers fell in a span of between 12 and 20 seconds, whereas free fall is 9.22 seconds. Dr. Frank Greening's exhaustive paper demonstrates brilliantly that the Twin Towers collapse is entirely explainable from gravity alone. Furthermore, how the government can make buildings fall faster (consistent with the news footage) is never well explained.
Seventh, engineers at the Pentagon measured the hole from Flight 77 at 90 feet wide. Yet the fiction-peddlers claim that the hole was only 16 feet wide, based on a French author who apparently has never visited the United States. Conspiracy peddlers argue that a Boeing 757 would have made a hole wider than 16 feet. It did. Yet vast arguments, websites, books and careers are based on the hole being only 16 feet, instead of the actual 90 feet.
Eighth, other mythmakers point to lists of victims on each flight. They claim that the hijackers are missing from the passenger manifests, which proves that the government slipped the hijackers past security gates. But lists of victims obviously do not include the murderers who killed them.
Ninth, the 9/11 conspiracy peddlers all contradict each other. Collectively, they will claim that there is "overwhelming evidence" against the official explanation of 9/11. However, what is "overwhelming" is a mish-mash of contradictory and mutually exclusive scenarios. Each of the conspiracy peddlers proves the others wrong. Moreover, the conspiracy theories keep changing. When confronted by the falsehoods and contradictions, they simply change their story. This proves that they are not seeking the truth, but any excuse to bash Bush.
In general, conspiracy theorists point to elements of the official explanation they find hard to believe – but then adopt infinitely less believable, preposterous scenarios. Their scenarios do not answer their own questions any better than the official explanation (or even as well). These activists are simply intent on bending the truth, not finding it, to bash George Bush.