1. I believe I heard recently that there was something like 3-4 tons of nano thermite involved. How was this determined? Was this derived from the mass of the iron micro spheres or was this extrapolated from the mass of the red gray chips? Is there a reliable calculation of how much energy 3-4 tons of NT would release? Is there any understanding about how it is "detonated" or used? Is the current thesis that the material was "painted" on surfaces and ignited to then release the energy? Was it applied to the steel connections? Was it applied to the hung ceiling or painted on the slabs or the steel joints? Would it explode simultaneously or was it used more as an incendiary to burn away the structure at the joints? Do we know how NT actually works?

Do all dust samples contain the same percentage / proportion of iron micro spheres to volume or weight of the samples? That is are dust sample uniform or do they differ in their make up? What can we tell from this?

There appears to have been at least one massive explosive event in each of the twin towers after the top sections had been completely destroyed. This shows steel being thrown radially very much like a typical explosive event. It produced enormous dust and debris and appears to have been located in the core area if one traces the origin of the debris plumes. However, even a massive explosion, blowing up the top of the structure would likely not facilitate the lower section to then collapse as there was little left to crush down through the structure. There would have been material exploded downward which would destroy part of the structure below that massive explosion, but even this would like not have enough downward directed energy to destroy the entire core. And this is evidenced by some of the core remaining as seen in the Siegal videos and stills taken from Hoboken NJ.

2. The massive destruction of twins and bldg 7 seems to have destroyed almost all the light gauge steel - metal slab decks, truss joists and wall framing and somehow all the contents. The larger steel sections seemed to have remained largely intact, with some peculiar damage... such as bowing inward of the box columns at the ends or bending some of them like a noodle. Clearly the connections/ends of the massive columns show signs of being attacked. This was of course the weakest part of the structure - where the columns and girders were bolted and welded together... and much of the massive 36' long steel was found intact indicating that the joints failed and this makes perfect sense. So what destroyed all the metal decks, light gauge trusses, and metal framing and all the contents but left so much paper?

3. Lower Manhattan was covered in dust, up to a million tons perhaps as the three buildings and contents weighed in at about 1.5 - 2 million tons in total. A quick calculation of the mass of concrete in the 3 building is in the order of ~300,000 tons. The dust included not only concrete, but glass, drywall, stone, interior finishes, fixtures, equipment, furniture and other contents and of course human remains. With so little recognizable at the end, what would account for everything turning to dust? This seems to indicate an almost universal destruction throughout most of the buildings. What we do see remaining is ejected material and large strong sections of steel which resisted the explosions and fell down from gravity.

4. Why did the destruction of the south tower not damage the north tower which stood less than 200 feet away? I suspect that the facades contained the massive explosions in the core - like blast curtains, but were broken apart and forced to fall away perpendicular... like a playing card standing on edge... they fell over and split apart. The plan of the twins would allow the falling south towers facades to miss the north tower as they peeled away. Was the massive hole in WTC 6 the result of a large section of the facade membrane steel falling through it from 1000 feet above - (that's a lot of kinetic energy)?

5. The almost free fall acceleration of the twin towers cannot be explained by destruction of large amounts of the structure at the base. This was not seen. I would suggest that what might have happened is that almost simultaneous destruction took place at the perimeter of the core at perhaps 30 story separations in height. It was like a simultaneous stacked (3 or so) explosive destructions. Once the initiation began with the first "CD" of the top... the others then went off almost at the same time. The massive explosion above the crash zone would provide the "cover" ... the reason.. the so called crushing down excuse of the top through the structure... and the literal cover of dust clouds to conceal the building's outer core blowing up 30 and 60 stories down through the areas unaffected by fire. I suspect many of the floor systems did drop when released from the core (first). Several of them were exploded and destroyed with shock waves which pushed the facade away at the 3 or so locations. The corners were destroyed and cut away...which held the facades together and would enable the facades to stand without the floor or the core lateral support absent high wind loads. Released from lateral support the facades toppled away.

6. There were only 24 perimeter core columns and they were the only ones which needed to be attacked and dismantled to topple the structure and the core corner columns of the perimeter alone each supported as much as ~4% of the static load each or ~16% (rough calculations) in the aggregate. You can see how vulnerable this structure was to attack at only 4 places in the core.

7. The perimeter which carried ~40% of the static load were like massive planes of steel made from bolted and welded pre fab steel assemblies (10'w x 36'h x ~1.5' d) and ~192' wide and ~1300' tall. The facade membranes were secured obviously on their interior side and this also provided most of their lateral support. The perimeter was self supporting IF the corners remained intact. The corners enabled each faced to support the adjacent ones laterally and resist the wind loads. Even with the entire interior of the building destroyed the perimeter would stand as a hollowed out square tube. But with the corners destroyed the building facade's four sides would topple over and away like a house of cards. So here again you can destroy the entire perimeter's ability to support the floor system and themselves by attacking the 4 corners. This was observed.

8. The remaining central core was the likely undermined by several cutter charges and explosives to push the columns out of alignment at their joints and this structure the last to stand was unable to without continuity of force vectors and being of such a high aspect ratio... it collapsed down. The entire core was obviously not destroyed in the scheme... at least for the main destruction of the floor and perimeter... it came at the conclusion and it only supported "itself" and some of the floors and equipment within the core which was mostly open space and vertical shafts.

My unanswered questions are:

What was the mechanism to destroy all the light gauge metal... trusses, metal studs, equipment, ducts etc.?
Could the lightweight fly ash concrete turn to dust from a collapse? If not what turned it to dust?
What was the mechanism which turned all the other materials... glass, furniture etc. to dust?