Cues and frameworks affect our perceptions so strongly. This afternoon, I reach the last mile and a half or so of a run around a lake. I have to go to the bathroom. Pretty urgently. Not only that, I somehow get off the right path. I know the bathroom is at the campground where I’m parked, but I’m not sure how far away the campground is.
At that point I come out onto a road. It looks like Doane Hill road, the way back to the campground. I’d like to make sure, though, because if it’s not the right road and I actually become lost, I’m cooked. At that moment I see a woman squatting by a tree on the other side of the road. Three cues tell me she’s probably a ranger from the campground. First, she’s wearing a shirt that is just the khaki color that rangers wear. The fabric isn’t the same, but the color matches. Second, a white, fairly large van sits up the road about thirty-five feet. It must be her vehicle, as no one else is around. On a previous hike somewhere, I saw a white van just like it. It was an official vehicle for the Department of Natural Resources or something similar. Third, she seemed to be checking something on the ground, at the base of the tree. That’s the kind of thing rangers do. They’re interested in nature, and they take extra interest in the grounds they’re responsible for.
So I strode across the road to ask my urgent question, “Is this Doane Hill Road?” She did not respond as a ranger would. She said, “No,” or perhaps “I don’t know,” and began to move away awkwardly. By this time I was across the road, still in a hurry. When I realized the truth, my perception that she was a ranger checking something on the ground fell apart just as quickly as it had formed. She was taking a pee! Whoops. I veered off to head up the road. I saw a man behind the wheel as I passed the white van. He must have thought, “What a jerk – he couldn’t even leave her alone.”
Now, it’s a long way from this mishap to perceptions about 9/11, but you know I’ve thought about the subject a good deal lately. Cues and frameworks affect our perceptions so strongly. The difficulty is, we don’t have much of a framework for what we saw when the Twin Towers came down. Airliners don’t crash into one hundred story buildings – until that day. We certainly had not seen skyscrapers that high explode progressively from the top down before that day. Consequently, our minds were open to suggestion from people who customarily speak with authority.
The authoritative explanation did not take long to come. Heat from jet fuel fires weakened the steel columns and trusses that formed the skeleton of each tower. When these structural columns and their associated joints gave way, the entire tower collapsed in a pancake effect. That is, each story failed after the one above it failed, due to the unnatural amount of weight coming down on top of it. Thus both towers fell straight down.
It sounded just plausible enough. Evidence for this kind of collapse was scanty, but no competing theories came forth in the days that followed the catastrophe. The wreckage would not yield good evidence, so before long we had computer models to show how the pancake effect would have worked. You can’t argue with a computer.
The pancake theory has a couple of difficulties that make it implausible after all. First, the weight from the upper stories did not come straight down. The upper stories exploded into dust and pieces of steel. The concrete disappears and the structural steel is ejected outward. The explosions start at the top of the buildings, above the crash sites, and continue past the crash sites as they advance toward the ground. Clearly the structural steel does not bear more weight than it did while the buildings were whole. The explosions remove weight from the top of the structure – they do not add to it.
I know, to describe the destruction at the top and all the way down the towers as explosions begs the question. They look like explosions, but perhaps pancaking, which we’ve never seen before, looks like a progressive explosion. Pancaking could not turn all of that concrete to dust, but we can leave that point for now. Let’s take a look at the second difficulty.
The rate of collapse does not beg any questions about what we are seeing. Each tower comes down in about twelve seconds. For comparison, Usain Bolt’s Olympic time in the 100 meter sprint is 9.63 seconds. At one hundred stories, each story pancaked in 0.12 seconds, or just over one-tenth of a second each. Mr. Bolt takes just over four steps per second when he runs, which means each step requires about 0.24 seconds. The pancake theory requires us to accept that, by weight alone, the structural steel in each story of these gargantuan buildings collapsed in half the time Mr. Bolt requires for one step, when he sprints at a world record pace. We have seen how fast he runs.
Suppose each floor takes only one half second to collapse. Then the building requires fifty seconds, not twelve, to come down. Twelve seconds to destroy a one hundred story building is awfully fast. We know that each tower contained 78,000 tons of structural steel. Below the crash sites, each tower was structurally sound. If the architects designed a building that could collapse that fast – whatever trauma it might have suffered – they designed a catastrophically unsafe building. The idea that towers that size could collapse in twelve seconds by gravity alone is not plausible.
My mistake at Doane Hill Road caused me momentary embarrassment, though I’m sure the poor woman felt worse about my intrusion than I did. It was interesting to analyze why I made the mistake: I misinterpreted the cues in front of me because I placed them in an incorrect framework. For 9/11, we should recognize our mistake in accepting the pancake theory, understand why we erred, then work toward an explanation that is accurate. We have to consider another theory.
An alternate theory proposes that the buildings exploded, from the top down, and that explosions removed the core columns at the base as well. Can controlled explosions explain how the Twin Towers fell in twelve seconds – at 0.12 seconds per floor – better than the pancake theory? Architects and structural engineers who have studied this problem closely believe the pancake theory is inferior. In light of the evidence and explanations they have presented, can we reinterpret existing cues and fashion new frameworks for what we saw on 9/11? Can we rethink what we saw?