The "impossible fire induced collapse" claim

[I Ratant]

I don't understand why some people are unable to grasp why the towers collapsed the way they did.

[qimg]http://northerngoodies.com/site_files/WTC_SUN_PICTURE.jpg[/qimg]

.
Lordy!
Great picture!
Really a good data point.

 

[jaydeehess]

What difference does it make how thick the columns were at the bottom? The stuff didn't fall on the columns, it fell between them.

BINGO, phunk wins the prize for identifying Mikeys most glaring inaccuracy in his determination as to why the towers should still be standing.

The upper falling mass impinged PRIMARILY on the floor pans of the levels below initial collapse.
Those floors are all designed the same (except for a few mechanical floors) to transfer a floor load to the columns via the truss seats. Each floor is expected to take approx the same load BUT the columns of course are taking the additive load of all structure above.
The caveat of course is that no column can stand upright and stable on its own, it requires lateral support to resist buckling. Build a column long enough and without lateral suport it will buckle under its own weight.

So what happens if a vast greater load than designed for, is applied dynamically to a floor pan? Answer is of course that the trusses and/or the truss seats fail immediatly offering little to no delay to the falling mass which then falls another 3 meters gaining more velocity and thus applying even greater dynamic load on the next floor pan.
However, the lateral support for the core columns is the connection, via the floor trusses, to the perimeter columns.
No lateral support = buckling

Mikeys believes that somehow, by some unknown and unseen and unexplainable mechanism, the dynamic load of the falling mass was applied to the columns and perhaps that the floors do not contribute to the system by which the structure remains upright.

Here's a primer for Mikeys;
Place a 1/4 nut on your head. You can barely percieve its weight (force) on your skull (especially if young and in possession of a full head of hair)
Now have someone take that 1/4 nut to the top of a 6 foot ladder and drop it upon your head.
Note the difference in being able to percieve the force applied to your head by the static load in the first place and the dynamic load in the subsequent case.

Second experiment;
Support and staple a 3ftX3ft piece of cardboard between four 2X4s on the ground(cardboard is about 1 3/4 inches off the floor) Now slowly load it with pennies until the cardboard fails(buckles , tears loose from staples or tears and drops pennies)
Remake the cardboard panel and fill a paper bag with 1/4 the mass of pennies that failed the cardboard and drop it on the cardboard from various heights starting at 1 meter above. How high does one need to get to have 1/4 the original failure mass cause failure in a dynamic situation?