'The Missing Jolt' - Starting Assumptions

Further to a short discussion I had recently about Tony Szamboti and Graeme MacQueen's paper, 'The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis' I decided to start a new thread based only on discussing the starting assumptions of the paper. As far as I can tell the paper is divided into two sections; 1. A short discussion on why the authors believe there should have been a jolt observed and 2. The much longer part of the paper which outlines how they looked for this jolt and measured whether it was there or not.

Obviously I'm not suggesting that nobody talk about the second part of the paper (the measuring of whether or not there was a jolt) but that should not be dwelt on in detail. I'm prepared for this thread to be merged with the main thread about the paper here:

http://www.internationalskeptics.com...g+jolt

From the text of this first part of the paper:

Quote:

The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis Graeme MacQueen Tony Szamboti April 22, 2009* In its Final Report on the Collapse of the World Trade Center Towers, the National Institute of Standards and Technology summarizes its three year study and outlines its explanation of the total collapse of WTC 1 and WTC 2. [1] Readers of the report will find that the roughly $20 million expended on this effort have resulted in an explanation of the total collapse of these buildings that is so vague it barely qualifies as a hypothesis. But it does have one crucial feature of a hypothesis: it is, in principle, falsifiable. In fact, it is easy to demonstrate that it is false. In this paper we will, concentrating on the North Tower, offer a refutation that is: easy to understand but reasonably precise capable of being stated briefly verifiable by any reader with average computer skills and a grasp of simple mathematics. NIST’s Hypothesis of Total Collapse: Three essential elements of NIST’s hypothesis of total collapse are made explicit in the Final Report and the companion volumes of the study: 1. Because of damage to stories 93 to 98, and especially because of column buckling due to fire, the top 12 stories of the North Tower (99-110) plus the roof were, in effect, separated from the rest of the Tower and began to behave as a unit. [2] 2. This “rigid block” of 12 stories plus the roof began to move. First it tilted, and then it abruptly fell onto the stories beneath it. [3] 3. The fall of the rigid block caused such damage to the lower structure that “global collapse began.”[4] The rigidity of the upper block of stories is crucial to this explanation. If the upper block were to break, disintegrate or flow on impact it would certainly not threaten the 92 intact floors beneath it. In addition, the rigid block had to fall onto the rest of the building. Although this seems obvious, the NIST authors are often shy about saying it. We hear about the rigid block’s “descent.”[5] We hear of tilting and “downward movement.”[6] We have to look carefully to find the NIST authors using the language of falling. Whatever the reasons for their reticence, it is clear that it will not do for the upper block to ease itself onto the building beneath it, with a gradual creaking of buckled columns and sagging floors. If this were to happen, why would the structure beneath collapse? There was nothing special about the weight of the upper block, rigid or otherwise. The lower part of the Tower had held up this weight without difficulty since 1970. The lower block had 283 cold steel columns, with less than 30% of their total load capacity being utilized for gravity loads, because of the factors of safety designed into the structure and the need to withstand high winds—and gravity loads were essentially the only loads the columns would have been subject to on a day such as 9/11 with little wind. The lower block was not weak, nor (excluding stories 93-98) was it damaged by plane impact or fire. The weight of the upper block posed no threat to it. If there were to be a threat, it had to come from the momentum of the upper block. But momentum is a product of mass and velocity, and since the upper block could not increase its mass it had to increase, if it were to become a threat, its velocity. Since NIST’s theory assumes the only energy at play at this stage of events was gravitational, the upper block had to fall, and the greater its velocity the greater its momentum. The longer and the less impeded its fall, the greater would be its impact on the lower structure. So it is no surprise that the NIST authors, however shy they are about affirming it, eventually come out in favour of the falling of the upper block. [7] Zdenek Bazant and Yong Zhou, with whose September 13, 2001 back-of-the-envelope theory (with subsequent revisions and additions) NIST largely agrees, have never hesitated to say that the upper block fell. [8] Bazant has likewise been frank about the need for severe impact as the upper and lower structures met: he believes the impact may have been powerful enough to have been recorded by seismometers. [9] In his view, collapse initiation of the lower structure required “one powerful jolt.”[10] Of course, if there was a powerful jolt to the lower structure there must also have been a powerful jolt to the upper falling structure, in accord with Newton’s Third Law. In order to keep a sense of reality as we discuss NIST’s theory it may be useful to label the three interacting parts of the North Tower, as they are pictured by NIST, as RB-12+, DS-6 and RB-92. Where RB stands for rigid block, DS stands for damaged structure, and the numbers following the letters refer to the number of stories in each structure. The upper block comprised the 12 stories of 99-110 as well as the roof structure with antenna and hat truss; the intermediate area was damaged by plane impact and fire and was six stories high (93-98 inclusive); and the lower block was rigid and comprised, in addition to subterranean levels, the first 92 stories of the building. These designations actually underestimate the contrast between RB-12+ and RB-92, because the latter was not only largely undamaged by fire but was more massive per story. It was also stronger: the Tower’s columns tapered as they ascended. [11] Yet the fall of RB-12+, we are supposed to believe, put a catastrophic end to DS-6 and RB-92. What NIST essentially says, agreeing with Bazant, is that the lighter and weaker part initially fell with a powerful jolt onto the heavier and stronger part, which could not withstand its momentum, and that this caused a progressive collapse to initiate smashing the lower block to bits all the way to the ground. The NIST Final Report does not tell us what happened to RB-12+ after its impact with the two structures beneath it. Did it fall through them all the way to the ground (that is, to the rubble heap on the ground), maintaining considerable mass and rigidity the whole time--as Bazant argued in 2001 and has continued to argue? [12] On this the NIST authors are silent. NIST also does not tell us how far RB-12+ fell before its impact with intact structure. Did it fall one story (roughly 12 feet), or several stories? We are left in the dark. Once again Bazant comes to the rescue. It fell “at least one story,” he says. [13] To his credit, Bazant is willing to state the essential elements of the hypothesis. If this hypothesis is to hold any water at all there must be substantial impact: RB-12+ has a lot of work to do, so it had better fall at least one story. As we will show, for the purposes of the present refutation it does not matter whether RB-12+ fell one story, six stories, or somewhere in between. The Necessary Jolt: As Bazant has said, when the top part fell and struck the stories beneath it, there had to be a powerful jolt. While a jolt entails acceleration of the impacted object it requires deceleration of the impacting object. Even a hammer hitting a nail decelerates, and if the hammer is striking a strong, rigid body fixed to the earth its deceleration will be abrupt and dramatic. Although NIST does not explicitly speak, like Bazant, of a “jolt”, and may therefore be thought to evade this paper’s refutation, it is impossible for NIST to escape the implications of its own assertions. The NIST report speaks of a strong, rigid structure (the upper structure or rigid block) falling freely onto another strong, rigid structure (the intact part of the building below the damaged area): the jolt cannot be avoided. [14] This was a necessary jolt. Without it the required work could not have been done.

I noticed two statements that have no substantiation:

1. If the upper block were to break, disintegrate or flow on impact it would certainly not threaten the 92 intact floors beneath it.

2. ...the rigid block had to fall onto the rest of the building...it is clear that it will not do for the upper block to ease itself onto the building beneath it, with a gradual creaking of buckled columns and sagging floors. If this were to happen, why would the structure beneath collapse?

(For the second point I refer to the implied assertion that the structure beneath would not collapse)

From my reading of the first part of the paper and this post by ozeco41:

http://www.internationalskeptics.com...5&postcount=82

I'm pretty convinced that there is no reason to expect a jolt in the situation present on 9/11.

If one floor of the tower had been magically and instantaneously removed, then the top block falling would create the jolt that is being looked for in the second part of the paper. Is that right?

I'm hoping that Tony Szamboti and/or Graeme MacQueen will respond to this thread.

via International Skeptics Forum http://ift.tt/1Ve4LCP