Just drop Anything on Something
Start with a solid rubber ball, mass m (kg) and drop it on the floor from height h = 3.7 meters height = the height that WTC1 upper part is assumed to drop. The ball free falls with acceleration g (9.81 m/s²) due to gravity, makes contact with the floor and normally bounces. The ball was not rigid and deformed upon contact with the floor. Why? The floor applied a force on the solid rubber ball, so that it deformed, absorbed some of the kinetic energy E involved (E = m*h*g) and then released it and bounced up. Evidently the ball also applied a force on the floor that also deformed, absorbed the remainder of the energy involved; maybe the floor vibrated a little. This is Newton's third law at work.
Then do the same thing with a solid sphere of steel. Drop it on the floor. If the floor is strong enough, the same thing will happen as with a rubber ball! The steel sphere bounces. If the floor is not strong enough, i.e. it cannot produce a force big enough to deform the steel sphere, so that it bounces back, the floor will be damaged - maybe a hole is formed in it, and the steel sphere drops through the hole at reduced speed and contacts something else below, or the floor is just partially damaged ... and catches the steel ball, i.e. arrests it.
Finally drop anything weak (an egg or a lemon?) on something strong! PLAFSH! The weak anything (the egg or lemon!) is crushed against the strong something!
Don't forget that!
Try to compress a lemon with another lemon. What happens? Both lemons compress.
Now you have learnt a little what can happen when you drop anything on something and try to compress something. This basic knowledge is used in this paper.
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If the upper, 53 meters tall, 13-15 storeys upper part of WTC 1 actually dropped on the structure below is a matter of semantics. Drop suggests that it was not being held at all. I prefer that it came into contact after local structural failures and downward displacement and that it was prevented from dropping by the connections between the two parts. Anyway, only the velocity at contact is of interest and it was not high in the WTC 1 case. Assuming a 'drop' of 3.7 metres, it does not produce a big velocity; it is around 8 m/s. If the 'drop' is dampened by intermediate connections the velocity is much less.
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Dr Bazant (described below) and NIST suggest that the energy initiating or released at the WTC 1 destruction was enormous but in a serious ships collision it can be up to 10 times bigger!! NIST should learn from ship collisions! Bazant also assumes that the WTC 1 upper part was rigid (!). A rigid object is indestructible and will destroy anything non-rigid. But ships and WTC 1 upper part are not rigid.
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The official explanation(s) of the WTC 1 (photo left) global collapse (sic) is that the alleged release of potential energy (PE), of the mass of an upper part C above all supporting columns after sudden, local deformation and buckling, due to downward, alleged near free fall movement in an initiation zone (indicated by red) and impact of a structure below, exceeds the strain energy (SE) that can be absorbed by the same columns below and above and that all this was due to gravity only.
[SEE THE PICS AT THE LINK]
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Evidently this crush down model and theory is complete nonsense, but it is the official explanation(s) of the WTC 1 destruction on 9/11! A small, fairly weak part C, 95% air, cannot possibly crush a big part A of similar structure only due to gravity and compress it into a 87.3 meters tall tower of rubble on the ground after 10 seconds! Anyone that has just dropped anything on something knows this. Try then to crush this something! You need a big force for that, which gravity alone cannot provide.
http://heiwaco.tripod.com/nist3.htmNote the pic above: There is no upper block crushing the lower sections- it's been obliterated. Furthermore gravity alone will not cause the debris to be thrown out laterally as is seen. Where is that pile-driving mass ? It does not exist. The building here is being ripped apart by forces other than gravity.
