Szamboti's Missing Jolt paper

[Grizzly Bear]

Interesting background there W. D. Clinger. I comprehend and agree with your comments including those which address theoretical situations as opposed to the reality of what happened at WTC on 9/11

When I first engaged Tony over "Missing Jolt" here on JREF I noted for other members the introduction to my first ever post on the Internet. 13 Nov 2007 on the now defunct Richard Dawkins net where my second paragraph was:
It seems once again that nothing changes. I tried some months back to locate the "Engineering Reality" paper but it seems it is no longer available, at least in the original form, So I cannot recall or reconstruct the basis for my objections stated in 2007. However "Missing Jolt" has the same generic problems - whether or not the maths is correct it is not sitting on a valid model of WTC 9/11.

Some of the raw math, at least the simple stuff, seemed correct. I recall looking at one of the things that David Chandler did, which uses the same premise, or from which Tony got his premise and the raw math in those cases was okay, but it was the application, and the way they interpreted it that was whacked out. At the very least, I was able to figure out where he was getting that "no dynamic load" bs... The two were basing that off of the net acceleration if I recall correctly, rather than calculating the amount of force that the upper section mass was exerting.

 

[ozeco41]

Some of the raw math, at least the simple stuff, seemed correct. I recall looking at one of the things that David Chandler did, which uses the same premise, or from which Tony got his premise and the raw math in those cases was okay, but it was the application, and the way they interpreted it that was whacked out....

That is very much my experience and opinion. The theme which I tend to repeat frequently - no point engaging the maths until you understand what you are applying it to.

I could even go further and claim that engaging the maths too early has led to confusion for debunkers also. Take the series of Bazant papers and the confusion they have led to for a lot of discussions here.

I have found that I can explain the Twin Towers global collapse stage easily without resorting to maths. The reason being that all the forces/energies are in the range of "overwhelming". That global collapse was clearly three separate but related mechanisms:
1) pancaking shearing off of the floors inside the outer perimeter. What Major_Tom has termed "ROOSD" but a mechanism which many (? - "several", "a few" ) of us had identified without the acronym; THEN
2) peeling off of the outer perimeter in various sized sheets of columns but none of them end for end crushed/buckled. Again Major_Tom has taken the research further than me (or anyone else AFAICS) FOLLOWED BY
3) strip down of the core - where failure appears to be mainly by shearing of horizontal beams with little if any axial load failure of columns.

So all three dominated by loads which were "overwhelming", no need for the maths AND those who have engaged maths seem to have needed simplifying assumptions which take them away from what really happened. The three mechanisms are not identified anywhere in relation to the Bazant "crush down/crush up" modelling being one example.

Back to your comments:

...At the very least, I was able to figure out where he was getting that "no dynamic load" bs... The two were basing that off of the net acceleration if I recall correctly, rather than calculating the amount of force that the upper section mass was exerting.

That was only one of several "hairy" bits of nonsense physics.

 

[Major_Tom]

Graph of the Femr2 data for the NW corner drop:

Decelerations at 2ft, 6ft and about 18 ft.


This is the movement of the NW corner during that time:

There seems to be a type of discontinuous collision process at this time.
................

I have seen at least 2 other people spot these same decelerations.

 

[ozeco41]

...I have seen at least 2 other people spot these same decelerations.

No doubt. However I need to remember why we are looking for them. The original reason for looking for jolts in the context of the "Missing Jolt" paper was to try to find a "big jolt". That objective a false one arising from faulty extrapolation of a Bazant concept. There was no "big jolt" - I would have been very surprised if there had been. Interesting consequences flow from that but.....another time.

I (and probably "we") always understood that the impact of the falling top block onto the lower tower was an event comprised of multiple collisions therefore lots of little jolts and not one big one. Knowing that much makes the search for examples of small jolts of little interest to me. It adds little if anything to my understanding of the collapse mechanism. Others may find the search of interest.

 

[Grizzly Bear]

So all three dominated by loads which were "overwhelming", no need for the maths AND those who have engaged maths seem to have needed simplifying assumptions which take them away from what really happened. The three mechanisms are not identified anywhere in relation to the Bazant "crush down/crush up" modelling being one example.

Back to your comments: That was only one of several "hairy" bits of nonsense physics.

I think what Tony lost sight of is the fact that one of the hairy bits of his writings was taking Bazant's paper literally. What Bazant does math wise is on a way higher level than I'm qualified to critique, but the basic concept of his model and the limitations at least seemed apparent from what he [Bazant] was writing. As with comparing different buildings like we do with case studies you can make certain assumptions provided that the author & reader understands the scope and limitations of the comparables. Tony, from the exchanges I've had with him kept thinking of that model as an interpretation of the real thing. It's one of the weirder cases I've personally run into, but then, beyond this site I don't engage with this topic elsewhere so I don't have the wide variety exposure that you probably have had.

I think a lot of the confusion you're referring to is with many talks about the Bazant papers being scoped onto just the limiting case he used rather than also taking into account the real life factors in addition. I always think about issues of load eccentricity, in addition to literal overloading of the structure, since failures aren't always a problem of the structure losing strength, but sometimes stability too; not in all cases however. Just my 0.02.

 

[ergo]

For bedunkers to try pin the failure of crush down, crush up on those who provided common sense critiques of it is pretty rich. As a so-called "limiting case" model, it doesn't even come close -- to anything. The notion of "limiting case" seems to have been seeded in after the fact. In any case, its "limiting case" not only doesn't match what occurs, but isn't even the best case model for survival, as Bazant claims. So what is its purpose? The closest it comes to reality is the first two seconds of collapse, but even there it fails. Yet last time I checked, it still stands as the only official global collapse explanation.

So now that some here can acknowledge that it's been debunked (while others will continue on their wiggy tangents long into some lost future), what official model do our 9/11 bedunkers want us to believe? Because you're kind of playing games here. You want to have your maggot-filled cake and pretend to eat it, too. You can't reconcile your newfound ROOSD with Bazant's "limiting case". Either we have a useful, realistic and officially endorsed model of the collapse progression, or we don't. Which is it?

 

[newton3376]

For bedunkers to try pin the failure of crush down, crush up on those who provided common sense critiques of it is pretty rich. As a so-called "limiting case" model, it doesn't even come close -- to anything. The notion of "limiting case" seems to have been seeded in after the fact. In any case, its "limiting case" not only doesn't match what occurs, but isn't even the best case model for survival, as Bazant claims. So what is its purpose? The closest it comes to reality is the first two seconds of collapse, but even there it fails. Yet last time I checked, it still stands as the only official global collapse explanation.

So now that some here can acknowledge that it's been debunked (while others will continue on their wiggy tangents long into some lost future), what official model do our 9/11 bedunkers want us to believe? Because you're kind of playing games here. You want to have your maggot-filled cake and pretend to eat it, too. You can't reconcile your newfound ROOSD with Bazant's "limiting case". Either we have a useful, realistic and officially endorsed model of the collapse progression, or we don't. Which is it?

Epic Fail.

Sorry ergo....your uninformed....and unqualified "opinion" about any of Bazants papers mean nothing to the Engineering community.

Once again....you are ignored by the world.

Carry on

 

[GlennB]

...
In any case, its "limiting case" not only doesn't match what occurs, but isn't even the best case model for survival, as Bazant claims.

Wrong. Square - theoretical - column-end-on-column-end impact is the best possible case for collapse arrest.

Tell us, ergo, what could be better?

 

[ozeco41]

I think what Tony lost sight of is the fact that one of the hairy bits of his writings was taking Bazant's paper literally.

Yes.

Remainder of your comments broadly agree with my view onthe vtopic.

 

[pgimeno]

For bedunkers to try pin the failure of crush down, crush up on those who provided common sense critiques of it is pretty rich. As a so-called "limiting case" model, it doesn't even come close -- to anything. The notion of "limiting case" seems to have been seeded in after the fact. In any case, its "limiting case" not only doesn't match what occurs, but isn't even the best case model for survival, as Bazant claims. So what is its purpose? The closest it comes to reality is the first two seconds of collapse, but even there it fails. Yet last time I checked, it still stands as the only official global collapse explanation.

So now that some here can acknowledge that it's been debunked (while others will continue on their wiggy tangents long into some lost future), what official model do our 9/11 bedunkers want us to believe? Because you're kind of playing games here. You want to have your maggot-filled cake and pretend to eat it, too. You can't reconcile your newfound ROOSD with Bazant's "limiting case". Either we have a useful, realistic and officially endorsed model of the collapse progression, or we don't. Which is it?

I already answered that to you more than a year ago.

FYI, Bazant's model is not an "official collapse theory" and is not a "Bazant/NIST model".

Bazant conclusively proved that once started, the collapse was unstoppable, because even in his "best case scenario" the towers would collapse. His paper is not "official" in any way I can think.

NIST used that conclusion to stop right after collapse initiation, because it was already conclusively proved (by Bazant) in a reputable journal that once the collapse started, there was no stopping until the total destruction. NIST didn't give a model of progressive collapse at all.

The only official organization I know that gave an explanation of the actual collapse sequence is FEMA. Note that NIST contended their collapse initiation mechanism, not their collapse sequence.

If I understand it correctly, there are at least two truthers here that agree with a good part of FEMA's sequence. You can read about it here:

http://www.internationalskeptics.com/forums/showthread.php?postid=6133565#post6133565

ETA: By the way, FEMA's explanation is here: http://www.internationalskeptics.com/forums/showthread.php?p=6133238#post6133238

 

[tfk]

From the mechanical point of view, in order for jolts of the size that Tony requires, the ends of columns must land square onto each other & stick. Tony agrees with this statement.

[It's a work-density argument. The work required to slow the upper block significantly is enormous. The columns are the only components of the structure that could possibly generate even a fraction of this amount of work without instant failure. And all of that work has to pass thru the columns-to-column interface area.]

This end-to-end "stick the landing" contact is, to all intent, impossible.

Tony denies that this end-to-end contact is impossible. He believes that it is likely.

I challenge anyone to drop a couple hundred tons of column assembly 12', 24' or 36' IN AIR & have the ends stick.

Now, try the same thing thru a roiling, churning mass of debris.

Good luck.

 

[Dave Rogers]

From the mechanical point of view, in order for jolts of the size that Tony requires, the ends of columns must land square onto each other & stick. Tony agrees with this statement.

It's even more stringent than that. In order for jolts of the size Tony requires [1], the upper block must not rotate as it falls (which both upper blocks were observed to do), and all the initial failures must remove equal lengths of column. Failure to satisfy either of these conditions must result in a series of smaller jolts separated in time. Tony repeatedly refused to acknowledge this, despite the fact that I modelled the effect of rotation and demonstrated that a half-degree rotation would result in no jolts above 1G; his response was to imply that I'd made up the results.

Dave

[1] Incidentally, Tony originally calculated a dynamic loading of 31x for the initial impact, and deduced from this that a 31G jolt should therefore be observed. It took a long time to talk him out of this egregious piece of stupidity; I'm not sure he was ever really convinced.

 

[Hokulele]

It's even more stringent than that. In order for jolts of the size Tony requires [1], the upper block must not rotate as it falls (which both upper blocks were observed to do), and all the initial failures must remove equal lengths of column. Failure to satisfy either of these conditions must result in a series of smaller jolts separated in time. Tony repeatedly refused to acknowledge this, despite the fact that I modelled the effect of rotation and demonstrated that a half-degree rotation would result in no jolts above 1G; his response was to imply that I'd made up the results.

His later response was to make the claim that all of the rotation seen happened several seconds after the collapse initiation.

 

[Dave Rogers]

His later response was to make the claim that all of the rotation seen happened several seconds after the collapse initiation.

Yes, even after I posted a picture that showed about 2º of rotation of the top block of WTC1 before the top corner had dropped through a full storey. But who am I going to believe, Tony or my own lying eyes?

Dave

 

[ozeco41]

Yes, even after I posted a picture that showed about 2º of rotation of the top block of WTC1 before the top corner had dropped through a full storey. But who am I going to believe, Tony or my own lying eyes?

Dave

It is actually even more basic than the geometric issues of rotation causing misalignment.

Recall that the instant of time we are discussing is as the top block starts to fall.

At that moment all the columns not previously severed by aircraft contact have either failed (most of them) OR are in the process of failing (relatively few). That failure and the fact that the top block is falling means that all the top block column ends are already bypassing their lower tower other part (or for the few still failing are in process of folding/buckling/bending to bypass).

It is interesting how many people miss that simple fact. And, naturally, there are no square ends with vertical gaps for the top block to fall through to allow the possibility of end for end axial contact. And that whether or not there was rotation.

The very language of "...dropped through a full storey..." seems to imply that there was a missing bit of column with the top block falling through a space or gap. Whether you intended it or not that issue has underpinned quite a bit of confusion about how the transition from initial collapse (top block starts to fall) to global or progressive collapse i.e. "ROOSD" for those who don't object to the authorship of the acronym.

 

[Dave Rogers]

The very language of "...dropped through a full storey..." seems to imply that there was a missing bit of column with the top block falling through a space or gap. Whether you intended it or not that issue has underpinned quite a bit of confusion about how the transition from initial collapse (top block starts to fall) to global or progressive collapse i.e. "ROOSD" for those who don't object to the authorship of the acronym.

Yes, the language was misleading - it might be better to rephrase it as "dropped through a distance equal to the height of a single storey". There's no reason, of course, why the failure of any specific column should occur over the height of a single storey, quite apart from the rather obvious fact that no such failure would be expected to leave clean, square ends.

Dave

 

[ozeco41]

 

[Major_Tom]

Yes, even after I posted a picture that showed about 2º of rotation of the top block of WTC1 before the top corner had dropped through a full storey. But who am I going to believe, Tony or my own lying eyes?

Dave

Dave, why not just use the work already done by R Mackey and Greg Urich who get their tilt description for WTC1 straight from the NIST report?


Greg Urich's rendition of the NIST description of WTC1:

This seems like a good likeness of the NIST description.


R Mackey offers another rendition of the NIST description:

In the following interview at 11:35 and 14:50: http://www.youtube.com/watch?v=kDvDND9zNUk

R Mackey at 11:35 and 14:50, "We are talking 8 degrees of tilt. That is what the NIST reports. They report 7 or 8 degrees rotation about 1 axis and 2 to 3 degrees about another."

Note that this is almost exactly how the NIST describes WTC2, as 7 or 8 degree tilt eastward and about 3 or 4 degrees southward.


R Mackey: "At 8 degrees rotation, this is the point at which the hinge is completely broken and the upper block will start to fall straight down....this is what we see on the video".
......................


How did you measure 2 degrees when the professional engineers at the NIST describe the movement as shown in the R Mackey and Urich illustrations? Why do you feel you need measurements to cross-check the claims of the true professionals? Hey, is this measurement stuff even allowed in this sub-forum?
...................................


The following images are from around the moment that Dave measures a 1 fl drop and 2 degrees of tilt, but from the south.

What about the obvious light grey ejections leaving the building from around fl 88, 89 at this time? There seem to be failures much lower than the NIST had noticed during the collapse initiation sequence. Wouldn't it be important to also factor this lower failure into the potential jolts? This could also be an argument against Tony, that the initial failures were not limited to floor 98.

 

[Dave Rogers]

Dave, why not just use the work already done by R Mackey and Greg Urich who get their tilt description for WTC1 straight from the NIST report?

[...]

How did you measure 2 degrees when the professional engineers at the NIST describe the movement as shown in the R Mackey and Urich illustrations?

This is the most totally daft objection to a trivial point that I've ever seen, even on this forum. I posted a picture for Tony that clearly showed a rotation of 2º visible in one specific projection of the upper block of WTC1 before it had fallen a significant distance. Please explain to me, how is this inconsistent with NIST's finding that it rotated a total of 8º before falling a significant distance?

Let me make it clear: I wasn't trying to measure the exact rotation of the upper block prior to its descent. I was, very specifically, refuting Tony's implication that it cannot have rotated by as much as half a degree before descending, and I chose a very clear and easily-measured picture in order to do so.

Dave

 

[Major_Tom]

This is the most totally daft objection to a trivial point that I've ever seen, even on this forum. I posted a picture for Tony that clearly showed a rotation of 2º visible in one specific projection of the upper block of WTC1 before it had fallen a significant distance. Please explain to me, how is this inconsistent with NIST's finding that it rotated a total of 8º before falling a significant distance?

Let me make it clear: I wasn't trying to measure the exact rotation of the upper block prior to its descent. I was, very specifically, refuting Tony's implication that it cannot have rotated by as much as half a degree before descending, and I chose a very clear and easily-measured picture in order to do so.

Dave

But how did your measurements end up contradicting the G Urich, R Mackey and the NIST?

Do the posters here have a standard group of measurements they use or does each person just guess on his own? When I presented a set of measurements they were not considered worthy of this forum. Yet, I can see each person guessing even 10 years after the event.

Why not use the NIST measurements like R Mackey and G Urich do?