Comment: Physics is not simplistic but it doesn't lie.

(See in situ)

Physics is not simplistic but it doesn't lie.

Sorry, but physics is just not as simple as 'it is possible to weaken a piece of steel enough to lose enough strength' for this to happen. I get so tired of people trying to explain things they don't know the first thing about by over simplifying.

Steel beams have numerous 'strengths', each to be considered separately. This is the scientific discipline called Finite Element Analysis (FEA). There is tension (stretching it's length), compression (pushing it shorter), bending moments, twisting moments and sheer moments (kind of like a jog in a highway).

Each beam was placed there to stop a specific force from causing displacement. The infamous generic 'beams' that are often discussed were there to carry the vertical load on their compressive strength. This assumes that the beams were braced to resist significant buckling at the time, which they were. To add to that, beams in buildings like that have their skins work-hardened which further resists these problems. Then, outside of that hard shell, they were placed inside columns of concrete to further add compressive strength (concrete is extremely hard in compression) and thermal insulation.

The interesting thing about compressive strength is that it's harder to compress something like steel than it is to bend it. On top of that, a great amount of compression can occur before the yield point is reached (where the beam would fail in this scenario).

Combine those facts with the fact that the entire building could have been supported and even caught from falling a 100' above on less than half the number of beams and we get some interesting conclusions. The majority (like 80%) of the beams would have had to all reach their softening (working) temperature (not their 90% loss of bending strength) all at the same time. Heat 20% and then let them cool while you heat another 20% and that's not enough. Even if you cleaned all the concrete shell from 80% of the beams and then heated them to 1200 deg F simultaneously, the other remaining beams would have held them in place and forced them to hold the weight up to the working temperature of steel. Depending on what type of steel it was, that could be 2200-2600 deg F.

THEN... we have the other problem of the floors below still remaining in tact. If you had a martian disintegration gun and could vanish floors 50-80, allowing 80-110 to drop down on floor 50, you would only get a few floors of damage. The lower 45 or so floors would be left holding the wreckage nearly 500' off the ground. (Assuming they didn't fall off to the side.)

And lastly, assuming that the beams were all completely exposed, all heated to 2500 deg F and all failed simultaneously, there is still no way the entire building would fall at free-fall speed or into it's own footprint. Each floor it encountered on it's way down would present it's own unique set of circumstances increasing the odds that it will be stopped, it will careen off to one side or that it will demolish one of the falling floors from above. Should any of those occur on even one floor, we could not possibly get the scenario we did.

In short, ALL of the beams must have been demo'd simultaneously (per floor) and for nearly all the vertical height of the tower and that REQUIRES nano-thermite (barring some other unknown explosive just like it). The existence of molten steel and the 6 week's duration of that state also prove it. There is zero doubt left about it.