Physics and 9/11 truth

``9/11 Truth Movement'' is mostly a sham; excellent antidote at Counterpunch


A sad event featuring 9/11 conspiracy theory sponsored by kpfa and broadcast by C-SPAN 2 over Thanksgiving weekend--and I normally admire both Pacifica and Ray McGovern; David Ray Griffin should be ashamed of his misuse of evidence.

I spend a good bit of time each week teaching introductory physics. Every semester--in the impulse and momentum chapter--I pay special attention to dynamic forces generated by impacts of moving bodies. These are the forces that break things when they fall, contrasted with static conditions where the same objects happily remain intact under the reletively mellow forces due to their own weights. The example I always bring up is how the collapse of the WTC twin towers in New York on 9/11/2001 happened because of the enormous dynamic forces generated once the upper sections began to fall.

Partly I bring up the WTC collapse to counter a load of nonsense on this topic that lives mainly on the Internet, and sometimes on C-SPAN. On many facets of 9/11, a conspiracy industry has emerged to promulgate alternative explanations, calling itself by the misnomer ``9/11 Truth Movement''. It is led by a strange cast of characters also known by the misnomer ``Scholars for 9/11 truth''.

Of the voluminous silliness promulgated by these people, perhaps their lowest appeal to ignorance is their notion that the airplane impacts and subsequent structural weakening did not initiate collapse and bring down the towers. Rather, explosives planted in a government conspiracy did it.

The evidence? None really. There exists no document, no whistle-blower, no witness who has come forward from a diabolical conspiracy that must have involved hundreds of workers to pull off. Oh yes, they have a physicist from BYU, Steve Jones, who has made some unconvincing claims about chemicals that were in the wreckage that suggest explosives were used. But they really go astray when they claim that it is impossible that the towers fell without the help of explosives. Why? Because they fell at ``close to the free-fall time in a vacuum''. Without explosives ``undamaged floors below the impact zone would have offered resistance that is thousands of times greater than air.'' That's the ``proof'' offered.

Now the article at that last link (supplied by Scholars for 9/11 Truth) totally misstates the physics involved in the collapse. Air resistance produces a continuous upward force upon a falling object that increases with velocity until it balances the gravitational force. This is not analogous to what happened during the collapse of the twin towers.

A Tuesday article in Counterpunch by physicist Manuel Garcia supplies the facts to counter this asinine rubbish in a slightly technical but totally coherent explanation of the fall times of the towers. It includes discussion of the disastrous effect of dynamic loading on the structures resulting from rapid momentum changes and stress waves--essential discussion completely left out of ignorant conspiracy literature.

Certainly there are mysteries about 9/11. The relationship of US intelligence and the shadowy networks that are referred to as ``al-Qā`ida'' deserve much more investigation. I would like to be able to appreciate the writing of some of the ``9/11 Scholars'' on these issues. But their embrace of asinine silliness and misuse of physics really taints their work.

I support Alexander Cockburn, Matt Taibbi, Noam Chomsky, and Matt Rothschild in their efforts to expose the intellectual bankruptcy of the ``9/11 Truth Movement''. This bankruptcy is no more well illustrated than in the rabid accusations flung by conspiracy adherents when faced with skepticism about their wild, unsupportable claims. They scream incoherently about ``left gatekeepers'' surpressing their version of the truth.

Like Chomsky has written, ``One of the major consequences of the 9/11 movement has been to draw enormous amounts of energy and effort away from activism directed to real and ongoing crimes of state, and their institutional background, crimes that are far more serious than blowing up the WTC would be.'' It's time to focus our attention away from conspiracy mongering and towards building a movement to stop the continuing crimes of state that are costing the lives of tens of thousands of people every week.