What phenomenon is at work here?

[yodermon]

Video: http://italy.indymedia.org/uploads/2005/03/wtc2-demolition-3.avi



The picture annotation asserts that these are "squibs". I am not ready to agree with that, and am not asserting it here.

However I'm very interested as to what could cause these "puffs" of "air" ~50 stories below the currently collapsing floor?

If it's a "compression wave", how fast would such a wave have to have traveled to create the "puff" at that floor?

Does the official explanation account for these things?

(images from http://www.abovetopsecret.com/forum/single.php?post=1556994 )

[greyl]

1. compressed air

There's an error in your reasoning above. Air would not have to travel 50 floors on it's way out the windows. (and since when does a demo blow out windows and not supports?)

4. Weren't the puffs of smoke that were seen, as the collapse of each WTC tower starts, evidence of controlled demolition explosions?

No. As stated in Section 6.14.4 of NIST NCSTAR 1, the falling mass of the building compressed the air ahead of it—much like the action of a piston—forcing smoke and debris out the windows as the stories below failed sequentially.

These puffs were observed at many locations as the towers collapsed. In all cases, they had the appearance of jets of gas being pushed from the building through windows or between columns on the mechanical floors. Such jets are expected since the air inside the building is compressed as the tower falls and must flow somewhere as the pressure builds. It is significant that similar “puffs” were observed numerous times on the fire floors in both towers prior to their collapses, perhaps due to falling walls or portions of a floor. Puffs from WTC 1 were even observed when WTC 2 was struck by the aircraft. These observations confirm that even minor overpressures were transmitted through the towers and forced smoke and debris from the building.
http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm

[petgoat]

2. Right, air would not have to travel 50 stories.

The pressure wave would have to travel 50 stories. So what's yer point?
How did the pressure wave travel 50 stories?

I used to believe the air-pushed-down-the-elevator-shafts-canard. If
somebody can identify the specific floors of the squibs and provide
floor plans for those floors and explain why specific isolated windows
blew out and what elevator shaft was involved I might believe it.

Since most of the elevator shafts stopped at the sky lobbies at 44 and 78,
most of the squibs should be there. Since the mechanical floors at 41/42
and 75/76 were reinforced, early collapses of floors underneath them would
be puzzling.

since when does a demo blow out windows and not supports?

When it's in the core.



These issues could be clarified by a rigorous examination of particular
squibs. Instead all we get is a lot of handwaving.

[greyl]

3. Yes, I read that wrong. However,

I don't think anything would have to travel 50 stories to explain the "squibs". (is 50 stories accurate?) You'd have to figure the initial air volume in all floors above the squib, and including the already collapsing floors to really get a detailed handle on what's going on. Are the squibs only coming out of already broken windows? I think so.

Free of detailed maths, think of this: Fill a 50 ft garden hose with smoke. Blow on one end.
Did a pressure wave travel to the other end of the hose to force the smoke out? No.

[mhatrw]

4. Good question. n/t