The physics of tower collapse part II

[Bushwacker]

[marky 54]

theres a lot stuff promoted by j.woods and tv fakery npt etc, that is shockingly misleading.

it is hard to see how the errors could be missed or how certain conclusions can be drawn. i cannot hope feeling alot of it is delibrately misleading, ie: knowing it is wrong but promoting it to fool people anyway.

theres a world of difference between not understanding something, or disagreeing on the conclusions of the same evidence and purposily making up evidence that comes out of nowhere and is simply blatent lies.

[spiv]

[pepik]

I was going to make a remark about the truth movement and the conservation of stupidity but then I had second thoughts.

Spiv might want to note, however, that when the newton's cradle ball strikes the other balls, it is moving horizontally, i.e. it is not accelerating due to gravity any more. How does this compare to the vertical stacking of WTC floors?

[spiv]

Oh deary me Pepik, have you ever studied physics? Maybe you could answer your own question.

[pepik]

I have high school physics. How much have you studied?

[Bushwacker]

[mr freedom]

Bushwacker, you may find this article of interest.

http://journalof911studies.com/articles/W7Kuttler.pdf

[sam]

[mr freedom]

Sam, you may find this article of interest.

http://journalof911studies.com/articles/W7Kuttler.pdf

[Bushwacker]

[spiv]

The context of the question on this post was to do with conservation of momentum, and the equation for momentum is mass x velocity = momentum. Now imagine the situation a tiny fraction of a spilt second before the upper floor hit a lower floor (time = t and δt->0), and I mean a fraction of a second, such that we can, effectively for our purposes, ignore the effect of acceleration due to gravity. After all, momentum does not rely on gravity, it relies only on mass and velocity.

If m1 and m2 are the masses of the top and lower floors respectively, and v1 and 0 are the velocities of the upper and lower floors prior to impact, and v2 is the velocity of the two floors a split second after contact.

Prior to contact (m1 x v1) + (m2 x 0) = M where M is the combined momentum of the two floors.

The split second after impact, δt->0 and (m1 + m2 ) x v2 = M (momentum conserved)

So the momentum M equals both equations, therefore (m1 x v1) = (m1 + m2 ) x v2

As m1 + m2 > m1, it follows that v2 < v1, does it not?

[sam]

[pepik]

What is the ratio of M1 to M2? And what happens to this ratio as the collapse progresses?

[Alex_V]

If we were to totally ignore the effect of acceleration due to gravity, no collapse could ever even start.

I'm no mathematician, but surely your illustration of conservation of momentum actually shows how inevitable progressive collapse is once one floor has given way. The momentum conserved (presuming the floor doesn't halt the fall) will insure that a greater mass (m1) is starting at a greater velocity (v1) as it accelerates towards the next floor.

The great mistake (or deception) of the truth movement is in believing that the slowing that takes place after a floor is hit means that the collapse must eventually stop - a schoolboy error. v2 will almost certainly be less than v1, but as long as it is more than 0 (the velocity from which the initial collapse began) then it will be greater than v1 was by the time the increased mass hits the next floor. Basically your v1 and your m1 go up floor by floor, increasing the mass and velocity of the collapse.

On that basis, all that needs to be proven is that the first floor that the collapsing material hit gave way. After that collapse is inevitable on these terms.

[spiv]

Momentum does not rely on gravity, and don't forget δt->0. Study your physics fellas.

[Bushwacker]

[mr freedom]

[sam]

[Bushwacker]

[mr freedom]

[Bushwacker]

Mr Kuttler actually shows no signs whatsoever of acknowledging that it was not in fact a top down pancake collapse, either in his introduction, calculations or conclusions, rather he indicates that he thinks that was exactly what it was.

No doubt other relatively straightforward calculations could be made of scenarios that did not occur, and they would be of as little use as this woeful effort.

There is no bias towards a shorter collapse time in his assumption of a top down collapse, exactly the reverse, because the initial momentum he starts with is that of the top floor falling on to the one below, a single floor whose vertical velocity would be halved by the collision. In contrast, consider what actually happened: the entire building (less the penthouse) fell as more or less a solid body, a momentum 47 times greater. It encountered nothing else, but simply hit the ground and disintegrated, there was therefore no transfer of momentum. Ignoring air and crushing resistance, as Kuttler does, the top would be free-falling and would hit the ground in 6 seconds.

Producing work based on transfer of momentum when no such transfer took place is simply perverse, at best, and Kuttler's calculations have no value at all, as far as I can see.

[mr freedom]

[Bushwacker]

Yes, Kuttler does indeed say that, but I take that to be a disingenuous attempt to leave an opening for his friend Jones to come in and say that the reason for a lack of resistance was that key parts of the structure had been attacked with thermite, thermate, super nano thermate, or superduper imaginery thermate which might have been developed with convenient properties. Nowhere does he say that the building did not fall in a pancake collapse, starting from the top, the collapse mode he assumes for his calculations. Reading his paper with no other knowledge of the event, one would naturally draw the inference that a pancake collapse was what happened, and take his calculation at face value. At best, his omission to mention the actual collapse mode of the building was ill-advised, at worst it was dishonest.

I cannot agree that his model is biased towards a shorter collapse time, he starts with the momentum of a single floor, which builds up floor by floor until all the floors are moving, and they all move together only at the end. What actually happened was that they all started moving together, the maximum momentum achieved under Kuttler's model, and momentum was lost as floors were successively crushed. This is what happens in a controlled demolition, so it is not surprising that it should look similar or take a similar time.

However, you are correct in that what is difficult to understand about the collapse is not actually the time it takes, but why failure should take place apparently across most of the width of the building virtually at the same time. It was always considered that probably the unique design of the building was responsible in some way, and an article in a recent issue of Structure magazine, by someone who sounds like an informed insider to the NIST investigation, suggests a mechanism. LINK. This sounds like the best theory put forward to date.

[sam]

[Bushwacker]

[Dallas]

[Dallas]

[Bushwacker]

[Micpsi]

Dallas's remark still applies to the South Tower. But then you are notorious for cherry-picking those parts of an argument you can rebut and ignoring those that you cannot in order to create the illusion that your rebuttal is comprehensive, whereas it still misses the point, as it did here.