Sources of the cloud dust and the aftermath

    No masonry was used in the steel construction of the Twin Towers and therefore the mainly 4-inch light concrete floors (40,000 ft2 per floor), fireproofing (5,000 tons), insulation and interior dry walls were the main sources of the dust (Table 1). The initial dust cloud caused a horrendously high concentration of airborne particulate and combustion products, which was both extensive and unforgettable. Within minutes, the air pressure generated by the collapsing tower raised a dust cloud, which bellowed up over 1000 ft (see the American International Building, 70 Pine Street, with a tip height of 952 ft in Figure 2a). In a series of seven photographs taken from the Brooklyn College Campus (seven miles from Ground Zero) over the first eight minutes after the South Towerís collapse the extent of the mixing and the size of the dust cloud are readily apparent (Fig. 2a-g). On a crystal clear day with low wind it rapidly expands, in 8 minutes, to a size sufficient to obliterate any view of Lower Manhattan (Fig. 2g). The dust cloud moved down the street like a wall of volcanic ash (Fig. 3), reaching such a height that no skyscraper (several over 800-ft in height) was visible in Lower Manhattan. After five hours the dust had cleared sufficiently (Fig. 4) for the skyline to be partially visible again, although missing the two tallest and largest buildings in NYC. The mixing indicates the settled dust collected for our study, five days later at several locations more than 8 blocks from the WTC, should be representative of the stable particulate matter in the dust cloud.

Originally posted by jafo72

One final comment. Concrete always retains some trapped moisture. This from my son, a concrete company foreman whose company makes high rise concrete buildings. Is it possible that the concrete, suddenly intensely heated by the exploding fuel, be turned into powder by rapidly expanding steam from such moisture?

Is it possible that the concrete powder is the result of trapped steam? The grinding together of the falling pieces of conctete and steel would contribute powder as well. Just another thought!

Originally posted by Sauron
Billybob, you hit that nail one shot.

Sorry for all the pictures I'm a man of few words, and these pics, say more that I could ever try to write.

People have to wunder what kind on power did this below, please emember that this took place long after the planes hit the Towers.

Originally posted by SMR
Had bombs gone off before the planes hit, I think they would have to be doing some serious explaining to do dont you think?
How would they tell us that terrorists went into the building and placed explosives.It's one thing to drive a truck in with a bomb.But to explain how explosives went off before the planes hit,....they would have to come up with some way of saying somehow known terrorists walked into the buildings, placed explosives during business hours,,,,see where this is going?

Now some might say, well how about the claim of the explosives in the first place.
We know that it was not just five drills but at least 35 drills over at least two months before September 11th.Drills that many floors were emptied out for hours at a time.These drills were un-announced.

Originally posted by HowardRoark
Where did this air go when the towers collapsed?

The claim that the dust cloud represents anything other than the air displaced by the collapse is ridiculous.

Originally posted by wecomeinpeace

Originally posted by HowardRoark
Where did this air go when the towers collapsed?

The claim that the dust cloud represents anything other than the air displaced by the collapse is ridiculous.

I was in Taiwan in 1999 when a major earthquake occured. I was there at the scene of a 20-storey hotel in Taipei that collapsed. The top 16 floors collapsed on top of the bottom four floors. No pulverisation. No dust clouds. No explosive, parabolic jettisoning of glass, concrete and steel. No molten steel. No mysterious squibs. Steel beams mostly in tact. No pancaking, no flapjacking, and no maple syrup. The top section first collapsed straight downward partly crushing the lower floors and then fell over across the street breaking into large chunks, just as the top sections of the WTC towers would have if they had collapsed naturally in the first place. Why did this happen? Because the lower section held once the potential energy of the top part was spent. They rescued survivors from the building. Most of the magical air that you worship so much was still trapped in the building.

Originally posted by wecomeinpeace
Exactly. Finally someone is making some sense. WTC7 was conventional, bottom to top demolition, thus no dust clouds, only squibs as the main supports were blown out and the building collapsed in an instant. WTC1 & 2 were unconventional, top down demolition, thus the outward explosions and pulverisation.

Originally posted by wecomeinpeace
Yes, they did. It's called energy transferance. Every collision loses energy as it is transferred into heat, sound and lateral kinetic vectors. Momentum is transferred into the receiving object and whatever it is connected to (in this case, the Earth).

Originally posted by wecomeinpeace
No, it wouldn't. Energy is lost with each successive collision. If the weakened floors gave way, each successive floor hit below it would cause energy transferance and thus slow and finally stop the collapse.

The Law of Conservation of Energy

Energy in a system may take on various forms (e.g. kinetic, potential, heat, light). The law of conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant.