Conspiracy theory challenged (911 of course)

[Main Street]

Not that I would think its going to change anybodies opinion. I found this to be very interesting.
The author is well qualified and demonstrates originality of thought. He has come up with previously unknown scientific rationale for
an engineering-related event that clearly puzzled some engineers.
The researcher Dr. Keith A. Seffen, has impressive credentials in precisely the relevant field. Besides a load of
academic diplomas he is an engineer who specializes in structural design, particularly
steelwork (and not a biologist or a conspiracy theory writer, for example).

http://news.bbc.co.uk/2/hi/science/nature/6987965.stm

"The study by a Cambridge University engineer demonstrates that once the collapse of the twin towers began, it was destined to be rapid and total.

After reviewing television footage of the Trade Center's destruction, engineers had proposed the idea of "progressive collapse" to explain the way the twin towers disintegrated on 11 September 2001.
This mode of structural failure describes the way the building fell straight down rather than toppling, with each successive floor crushing the one beneath (an effect called "pancaking").

Resistance to collapse
Dr Keith Seffen set out to test mathematically whether this chain reaction really could explain what happened in Lower Manhattan six years ago. The findings are to be published in the Journal of Engineering Mechanics."

[nifan]

I wasnt aware there was a conspiricay theory here, to my knowledge there has been a fairly good understanding of what happened for some time - im not even sure what this research adds too much, other than it doesnt seem to talk about the effect of the fire on the central core of the building (at least in the bbc article, not sure of the paper)

[Gnevin]

I wasnt aware there was a conspiricay theory here, to my knowledge there has been a fairly good understanding of what happened for some time - im not even sure what this research adds too much, other than it doesnt seem to talk about the effect of the fire on the central core of the building (at least in the bbc article, not sure of the paper)

THe theory is they used explosive NIfan

One of many conspiracy theories proposes that the buildings came down in a manner consistent with a "controlled demolition".

He'd proved this is not the case

[Main Street]

I wasnt aware there was a conspiricay theory here, to my knowledge there has been a fairly good understanding of what happened for some time - im not even sure what this research adds too much, other than it doesnt seem to talk about the effect of the fire on the central core of the building (at least in the bbc article, not sure of the paper)

The good understandings were based on probabilities, this brings a higher level of engineering science to the explanation.

"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.
Conspiracy theorists see evidence of a "controlled detonation"
He added that his calculations showed this was a "very ordinary thing to happen" and that no other intervention, such as explosive charges laid inside the building, was needed to explain the behaviour of the buildings.