mgod wrote on Tue, 11 September 2007 18:10 |
""One thing that confounded engineers was how falling parts of the structure ploughed through undamaged building beneath and brought the towers down so quickly," said Dr Seffen."
That's got a lot of implications for our recent conversation here, in which it was repeatedly implied that nothing confounded engineers. Thank goodness religious belief in Popular Mechanics doesn't stand in the way of real science.
DS
|
Well I'm not sure which engineers were "confounded", I'd say the "controversy" is being rather overplayed by the BBC, in fact Dr Seffen also says "In all senses, the collapse sequence was quite ordinary and natural."
Try calculating the kinetic energy of the upper sections once they'd fallen a couple of floors... you'll find that the towers collapsing isn't all that confounding after all.
A 14 floor section falling 3.5m (less than one floor's height) releases more potential energy than half a tonne of TNT, it seems highly unlikely that a previously damaged structure is going to withstand that, so it's going to keep going, it loses some of its momentum, but gravity gives it some more, and now it's got an extra 45,000 tonnes of material to work with, by the time you reach the previously undamaged floors they don't stand a chance.
By the way, I'm not referencing Popular Mechanics, and I certainly don't have any sort of religious belief in them, I just use Newton and those who followed him.
I look forward to reading Dr Seffen's paper when it becomes available though, since he's apparantly looked into things in far more detail.