Conspiracy theories regarding 9-11 never fail to get my sceptical antennae twitching, and I was particularly appalled at a recent spate of Facebook posts claiming that the supposed victims on board the doomed planes were actually alive and well and living in secret on a government pension. Fair enough for the armchair engineer to claim that the Twin Towers fell this way or that, but what on earth are the families of the dead passengers supposed to feel when they read this kind of nonsense? The clodhopping insensitivity of it is far worse than the stupidity and implausibility of the claims being made.

The claim that the planes were actually missiles (or holograms!?) is fairly clearly absurd on its face, contradicted as it is by such a vast array of video evidence. However, a more common and seemingly more reasonable claim is that the planes did hit the towers, but their eventual collapse was the result of a controlled demolition. On his Neurologica blog, senior sceptic Steve Novella invited one Michael Fullerton to debate the issue. You can read the back-and-forth here but it seems to me that Michael’s whole argument boils down to “I know the Twin Towers fell as a result of a controlled demolition because it kinda-sorta looks like that.” And in both his posts, Steve Novella did an excellent job at seeing past the hand-waving and name-calling and long-word-using to show the emptiness of this claim, while walking us through the basic physics of the situation with admirable clarity,

I posted a comment on the blog explaining that that you don’t even have to bother looking at the physics of the situation to know that the assertion that the Twin Towers fell due to a controlled demolition is absurd, if not actually insane. Anyone who wants to show that this is the case has some very, very hard questions to answer before they even begin to look at the physics involved. Here’s the rest of that comment in full…

Controlled demolition requires explosives – in the case of a building the size of the Twin Towers, massive quantities of explosives, in all likelihood hundreds of pounds. We are not talking about one guy smuggling a briefcase past security, we are talking multiple individuals making multiple undetected trips into and out of the World Trade Center carrying not just explosives but detonators, wiring and other paraphernalia. There is simply no plausible way in which that quantity of explosives could have been smuggled covertly into the buildings, and no evidence that they in fact were. Among the variety of conspirators, deceased and living, on American soil and overseas, none has been identified as playing this role. Nor was any evidence of explosives found in the wreckage. And in all the documents we have regarding the planning of the 9-11 attacks, there is no mention of explosives. Hard question one: exactly how and by whom and when were the explosives introduced?

Some might argue that given the planes and the burning jet fuel had already weakened the structure, less explosives would be required than if the planes had not struck, but this is a slippery slope to giving up the whole game. Once the stalwart Conspiracy Theorist has admitted that collision from a jet plane followed by raging fires burning for many minutes might weaken a building’s integrity, we have to start doing Hard Sums to figure out just how much it might be weakened, and as Steve has shown, the Hard Sums are not in the Conspiracy Theorist’s favour. But, as I say, we don’t need Hard Sums to dismiss this argument.

Even given that explosives could somehow have been introduced into the buildings – hard question two: why the need for a controlled demolition? You are already crashing fully-laden jet airliners into the buildings, which is bound to cause a tremendous amount of damage and loss of life. Why should it be an essential part of the plan to cause those towers to definitely collapse utterly? Remember, that until the planes are minutes away from the World Trade Center, no-one in power will have the slightest clue what the target is. As a terrorist attack it is chillingly perfect, unstoppable. As opposed to spending weeks carefully smuggling explosives into the building, which as soon as they are found, the entire game is up. Why risk the whole operation in that way?

But given that it is a fundamental part of the attack, for reasons unknown, to have the buildings not merely damaged beyond all likely repair but actually razed to the ground, why was the same approach not taken with the other two targets – the Pentagon, which suffered damage only at the impact site, and the Capitol building which was thought to be the target of the fourth plane? Neither of these exploded an hour or two later. Hard question three: why take one approach with one major American landmark and not take the same approach with either of the others?

But, okay, let us grant that for these particularly demented terrorists, and/or their Shadowy Government Overlords, it is tremendously important that the Twin Towers be razed to the ground, and entirely unimportant that the Pentagon and the Capitol building be destroyed completely – it is sufficient to merely damage those. And let us grant once again that our terrorists have the means as well as the desire to covertly introduce, install and detonate at will the prodigious quantity of explosives needed to topple two of the largest buildings on earth in a controlled demolition.

Hard question four: why bother with the planes? As noted, laboriously introducing package after package of explosives risks discovery far more, but if you already have the power to carry out such an operation, likely over several weeks, you now have the power to suddenly and terrifyingly wipe two buildings off the face of the earth. Why do you now bother attempting to hijack a couple of planes? At the very least, why not send them off to two further targets?

Okay, okay, okay. Let us grant – and I’m not sure who still would at this point, but here we go anyway – that our terrorists absolutely must raze the Twin Towers to the ground (but not any other targets); this is such an important part of the plan that they have risked everything to ensure it will happen, and they also have the means to covertly introduce hundreds of pounds of explosive, accurately position it, and detonate it at will; and that it seems sensible to take effectively a belt-and-braces approach by first crashing a plane in to each building, and then setting off their explosives an hour or so later.

Hard question five: why the delay? The purpose of a terrorist attack is to spread terror, to kill innocents and to make the government seem powerless. In the time which elapsed between the planes hitting and the buildings falling, many, many people were evacuated from the buildings and taken to safety. If the explosives had detonated immediately the planes had hit, the result would have been no less spectacular and far more fatal.

Ah, but that might reveal the presence of the explosives. While those who obediently swallow the Official Story might be fooled by the towers collapsing after the fires had raged for an hour, they surely will detect the presence of explosives if the towers fall as soon as the planes hit?

Which brings us to the hardest hard question. Hard question six: why continue to keep the explosives secret? Why on earth would Al Quaeda not be boasting about the bombs? How can it possibly ever, ever, ever advance their cause in any way at all to have secret bombs inside the World Trade Center? Even if the terrorists are acting in cahoots with the government (or secret world government or whomever) pinning the bombs on the terrorists makes their terror even more terrible, whereas keeping the bombs secret achieves nothing whatsoever.

I know that the Twin Towers did not fall due to a controlled explosion because the very idea makes no sense on any level. Adding secret bombs complicates the plan, makes it far more likely to be uncovered, is not necessary, requires a mysterious unmotivated pause in the day’s action and would have been acknowledged by the terrorists, or pinned on them by the government.

That the physics and the video evidence also supports this is welcome, but unnecessary.

Overt planes but secret bombs. For fuck’s sake.