Recently I heard about an online article at Popular Mechanics that debunked all the myths regarding the events of 9-11. Since I've encountered a few folks (even some who stand on street corners with signs) who try to convince me that it was all a hoax, a conspiracy, a government planned operation, I wanted to see what Popular Mechanics had to say about it. It's a fascinating article and well worth the time to read, even if you have to do it in installments as I did.
One of the conspiracy theorists' claims is that the WTC towers were not brought down by planes as we have seen on video but by explosions planted by government and military officials at the base of the buildings and timed to go off when the planes hit them. (uh huh. And what about all the people on the planes who never came home and were never seen again? What about all the people who were on their cell phones while they were being hijacked telling people, family and friends what was happening?)
One reason some believe there was a bomb is because of all the dust and smoke that came out of the buildings as they collapsed. The PM article answers this. Another support for this weird contention (of government planted explosives) is that there was fire in the lobby minutes after the planes crashed. How could this be unless there were explosives set off at the bottom?
This too is answered. And what's cool is that my recent inquiry into the construction of skyscrapers gave me the perfect frame of reference to understand what they were talking about. I now know what a skyscraper's core is -- a hollow tube in the middle formed by strong weight bearing columns. It is there that the elevators run, and also where the ducts and wiring and so forth are placed. When the jets hit, burning jet fuel barrelled down those shafts all the way to the bottom in a matter of seconds, thus causing the fires there.
From this article I also learned that steel doesn't melt until 2750 degrees F, a temperature burning jet fuel cannot reach. (another piece of info the conspiracists use for their arguments) However, it does lose 50% of its strength when it reaches about 1100 degrees F, well within the range of temps for burning jet fuel. And at 1800 degrees, which is about hot hot they figured the fires got, it's down to 10% of its original strength. Hardly enough to hold up those buildings...
Another question I've had people pose me is "Where's the plane in the Pentagon? Why is there no evidence of a passenger plane having crashed there?" (there is). "Why did a 275 ft wide plane make only a 75 foot hole?" PM answers these questions as well.
As I said, it's somewhat long, but a fascinating article, as much for how misstatements and misinformation are seized upon and distorted into an entire network of speculations, as for all the answers that are presented as to why exactly the towers collapsed, why there are no signs of wings in the damage to the Pentagon, and what the explanation is for that engine from Flight 99 in PA that supposedly ended up miles from the wreckage site with "with damage comparable to that which a heat-seeking missile would do to an airliner."
If you'd like to read it, you can find it by clicking here.