mardi 25 août 2015

Was there a reason to expect a powerful jolt in the towers?

Since Tony Szamboti made his paper "The Missing Jolt" public, he has moved the goalposts somewhat, to the point of asserting the necessity for a powerful jolt even in a more realistic situation than the one he proposed in said paper.

Mainly, he has asserted that axial column-to-column impact was unavoidable. I didn't see any clear flaw in his reasoning.

The intention of this thread is to focus the discussion not on the paper's starting assumption of rigid blocks, but on the question of whether a powerful, measurable jolt was expectable in the actual situation and whether there was / why there wasn't one.

This has been discussed in other threads, and I admit to my initial confusion as to the contents of the paper (due to having forgotten about its actual contents and focusing on Tony's latter claims). So, given that my ideas are now hopefully clearer, and that what I was discussing all that time was not the paper's contents but what is to be the topic of this thread, I wanted a more specific discussion on the subject. It keeps confusing me to see every so often the claim that a macroscopic jolt was not possible, since it isn't accompanied by any reasoned explanation as to why. I hope this thread will help put this issue to rest once and for all.

Clearly, after the fall of several floors, the tilt of the top block was enough for the columns to be out of alignment. The question is, when not all columns had failed yet, and one side of the core had fallen the height of one story while the opposite side of the building still managed to hold it enough to make it pivot, whether it was expected that an axial column-on-column impact happened.

I've received several answers to this question. I remember the posters, but I'd have a hard time finding the posts right now. Newton's Bit said that unless the impact was perfectly square, which is basically discarded, the border-on-border impacts (don't remember the exact terms he used) would not oppose nearly as much resistance because of the reduced impact surface. I agree, but I objected that the bent web would provide an additional surface for impact. I didn't get an answer as to whether that objection held any water, so I'm still unsure about it. Here's an example of a column bent that way:

http://ift.tt/1PQrkcA

Special emphasis in the "Fractured end near the 100th floor level". The bent web would provide a greater surface to squarely impact the bottom surviving part of the column. Detailed view here:

http://ift.tt/1PQrkcJ

Note the "three elbows" structure of the failure, except that the bottom "elbow" is actually a broken connection in this case. Unfortunately, we don't have any core columns from the impact area belonging to the side that failed first.

Grizzly Bear has shown a pretty convincing picture of WTC2 showing how the building's tilt induced a rotation over a pivot higher than the impact zone, causing a displacement backwards that would be a plausible explanation for the misalignment. He also provided another picture for WTC1 that I could not interpret as a potential cause of misalignment.

Ozeco41 has said that there never was an opportunity for a big jolt, but it's not clear to me whether in every occasion he mentioned it, he referred to the assumptions in Szamboti's paper or not. To my knowledge, he has never explained how they would be avoided at the point in the process outlined above.

Worth mentioning is that, regardless of whether Tony's paper had a wrong assumption to start with, it contains measurements that he later claimed should have shown a jolt. I disagree, for a number of reasons, mainly related to the data acquisition and treatment methods he used. But I still think that the overall idea that a jolt should be present (even if not of a magnitude big enough to be shown in his data) has merit.


via International Skeptics Forum http://ift.tt/1hZm0Z9

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