Thursday, April 12, 2007

Physicist Greg Jenkins responds to Morgan Reynolds

Interpreting the Boeing-767 Deceleration During Impact with the WTC Tower: Center of Mass Versus Tail-end Motion, and Instantaneous Versus Average Velocity (April 11, 2007) Gregory S. Jenkins, PhD

This article is mainly a response to Morgan Reynold's Request for Correction to the National Institute for Technology and Standards under the Information Quality Act (or Data Quality Act), found here:

or here:

[Update: I should say that this is a limited response to Morgan Reynolds, because Dr. Reynolds makes a number of points that are not addressed by Jenkins. Jenkins' article is more complete as to me, because I have relied much more heavily on the deceleration issue.]

Jenkins' article also destroys a major premise of several of the articles on this blog, including my first article:

Or maybe it doesn't. I haven't figured that out yet, and it's going to take me some time. The method I used, which was agreed upon by writers on both sides of the debate, was much simpler for someone like me with limited math skills.

So far, I wonder whether Jenkins' comparison with the Sandia experiment is valid, because the plane in that experiment was disintegrated against a reinforced concrete
wall which it did not penetrate at all.

Video of that experiment is here:

True, the tail of the fighter plane doesn't slow, but the plane also is all left outside the wall. This is more like what I would expect to have happened when a Boeing hit the South Tower. I suspect that the answer is that the South Tower is less rigid than the reinforced concrete wall in the Sandia test, which was designed to shield a nuclear reactor from plane impact, but is still quite rigid and would certainly stop the front fuselage of the plane from entering. The big question for me is what would happen when the most massive part of the plane -- the engines and the fuel-laden portion of the wings between the engines -- hit the building. I am thinking of this as partial penetration that would result in a combination of deformation and deceleration, as opposed to the complete fragmentation resulting from a plane dashed to little pieces against a impenetrable concrete wall. I'm thinking there would be a lot more debris outside the WTC tower than observed, and a lot more deceleration than observed, and presumably an explosion.

I also can't understand Jenkin's argument that all the deceleration takes place inside the tower. That's a given if it didn't take place outside, since the plane
did not come through the other side. But I don't see it got inside intact, then disintegrated.

I'm going to try to get further with this by looking at Jenkins' physics and math arguments, but this may be all I can do with it. I've always been grokking this thing the best I can.

Comments on Jenkins' article are most welcome. I begin with my comment on another letter by Eric Salter at Journal of 9/11 Studies on my criticism of him and Steven Jones not citing contrary data. However, I would like comments to focus on the merits of Jenkins' article, which is far more significant. If Jenkins is right, the blatherings of Salter and I mean nothing.


Ningen said...

Eric Salter has also responded to my criticisms of him and Steven Jones for not citing to contrary data.

I was hoping for a response from Steven Jones, from whom I expected more (no offense to Salter, but neither of us are academics like Professor Jones.) I emailed Professor Jones and asked him to respond to my criticism of him for not citing contrary data in the literature, and have heard nothing until now.

In case you are wondering what all this is about, see here:

and the Hoo Fatt article that neither Salter nor Jones cited, here:

Mr. Salter fairly criticizes me for not acknowledging his correction of deceleration in the Fairbanks video , from his original estimate of 18% to 10%. I didn't catch it. Sorry. Perhaps he should have published his revision in a new article, because I did visit his website after writing my article.

But his revision only gives him the benefit of the doubt on my main criticism, the failure to cite the Hoo Fatt article finding far higher loss of kinetic energy during penetration of the external columns of the building than found by the Wierzbicki article cited by Salter.

Salter completely fails to address this criticism, which is far more significant.

I find it odd that the Journal of 9/11 Studies, of which Steven Jones is editor, would publish this Salter letter without addressing the most important point of my article, the failure to address the findings in the Hoo Fatt article.

Salter says the "main point" of my article is the failure of Salter and Jones to address NIST's finding that the Scott Myers video shows 0% deceleration. However, I clearly stated that the Hoo Fatt article raises a question even in comparison to the deceleration that Salter finds in the Fairbanks video. That question is only strengthened by Salter's revision of deceleration in the Fairbanks video to 10%.

Salter says "[T]he smaller measurement also lessens the disparity between my measurement and NIST's."] True, but it increases the disparity between his measurement and the loss of kinetic energy found by Hoo Fatt, which was the main point.

This is either sloppy and illogical , or it is dishonest.

I also find it odd that the Journal of 9/11 Studies is publishing the Jenkins letter which questions my method, which I adopted from Salter and Jones in the first place.

Shouldn't there be some consistency on this point by peer reviewers? If my argument is seriously flawed according to Jenkins, why is it worth addressing by Salter? If it is worth addressing, why not address it fairly on my real main

I don't want to take away from Jenkins article, which is much more significant and has to be addressed on its own merits. But I want to comment on Salter's letter, so I'm doing it in this comment rather than as a separate post. I would appreciate if you could restrict comments to Dr. Jenkins' article.

spooked said...

I frankly don't have time to go critically through Jenkin's piece, but I can imagine his argument.

I think the problem is that in isolation, each of these points, such as deceleration, can be argued to fit the official story, though the fact is ANYTHING can be spun by someone smart.

A big problem is that if the plane entered and then disintegrated, as they would have us believe, then there should have been an explosion right as the plane impacted. But the explosion is delayed, and you can clearly see the fireball devleop on the other side of the building. This would indicate that the plane made it most of the way through before exploding, which is absurd, I think, since almost nothing of the plane penetrates out the other side.

But in total, there are many different problems with the official 2nd hit story. The thing that ultimately convinced me that the 2nd hit was bogus was the realization of how the "plane" in each video was significantly different from a bona fide 767-200-- each plane is mutated in some way suggesting a poorly made CGI. Then there are the unbelievable camera shots-- the amazing pans and perfectly timed zooms, etc. It all adds up to something extremely fishy.

I don't think the deceleration argument is going to prove anything in itself, and even worse, it gives the "debunkers" some oxygen.

Though realistically, I don't ever expect video fakery to become public knowledge, there are too many powerful people covering it up.

Anonymous said...

first, why do they always post their reports on a pdf file which one cannot simply copy/paste snippets of in order to remark about?
this jenkins report is about deceleration and velocity - are these the only factors that have any bearing on whether the images of ua175 and aa11 striking the towers, that were presented to the world by the media, are false or not?
the very first sentence:
""many people who support the notion that airplanes did not collide with the wtc towers erroneously apply physics to substantiate their claim""
erroneously apply physics?
if jenkins or any other know-it-all including reynolds wishes to bandy the word "physics" about simply as a means of cowing the average john Q into believing that said know-it-all actually does know-it-all as pertaining to say ua175 striking the wtc2 then they must start with the very instant that the aluminum 767 with a plastic nosecone touches the massive hardened steel/concrete of the wtc.
does the plastic 767 nosecone pierce thru the side of wtc like an arrow?
or does the plastic 767 nosecone bludgeon thru the side of wtc like a hammer?
or does the plastic 767 nosecone flow between and around the massive hardened steel columns like mercury?
these considerations are the beginning of the actual physics of an aluminum/plastic 767 striking the massive hardened steel/concrete of the wtc.
calculations of velocity, deceleration, center of mass, etc. are all well and good and no doubt jenkins' math is spot on since he lists them so emphatically but they only serve to distract.
they are reminiscent of the greening collapse time calculations as pertains to the wtc "collapse".
"wow look how smart i am with my mathematics! and never mind what you can see with your own eyes."

consider jenkins' reference 7-34b - here we see that the aluminum/plastic 767 has pierced the side of wtc (like an arrow?) but has not yet broken into the million pieces that we see in 7-34c.
one needs only say "as if!"
we don't even need to use math to see how foolish this is.
i stand by my previous comment:
a 767 is nothing more than a giant flying beer can. did you know that when a 767 is way up there - say 35k' or so - they only pressure the cabins to an atmospheric equivalent of 8k' because a sea level pressure would put too much strain on it's fragile beer can seams.

the very instant when the 767 nosecone - which is made of plastic - encountered the massive steel columns - placed @ 2' centers and fully backed up by the horizontal concrete floor slabs which were in turn tied into and fully backed up by the even more massive core columns - it would begin to crumple into a big cushiony wad of aluminum, preventing itself from entering the wtc.
stomp a beer can onto a BBQ grill placed upon bricks and see how much of the beer can goes thru said BBQ grill.
is my size 11 clownshoe stomp on a beer can an equivalent force of 500mph on a 767?
maybe not. try a sledgehammer stomp on said beer can. it will still not penetrate said BBQ grill.
crash "physics" (get to the real physics!) aside, that there was TV fakery regarding the images of ua175 is well established.
as if! jenkins. as if.

Anonymous said...

perhaps the engines of a real 767 could punch thru the side of the tower as they are relatively heavy compared to any other component of a 767 but while being somewhat heavy they are also very brittle.
they would be no match for the massive hardened steel perimeter columns and certainly no match for the even more massive core columns. the fuel load would probably be the heaviest single component in a real 767 but it is liquid not a solid like the landing gear assemblies so it's impact would be diffused, or splashed, some around the perimeter columns and some against the side of the tower.
500mph would be very fast and while the front fuselage is being squashed like the beer can that it actually is the wings would still be heading for the tower so they shouldn't actually break off at the wing root as some no-planers have posited - at least not until the engines themselves actually contacted the tower - and the engines would actually meet up with a mass of squashed fuselage acting as a cushion between them and the tower so their impact on the perimeter columns would be lessened.
look, i could go on about this all day from the tip of the plastic nosecone to the very end of the fragile tail assembly's fragile wingtips - wingtips! why do we observe them actually penetrating the side of the massive wtc in the CNN video? were the wingtips made of some kind of a super material or is it far more likely that the CNN video does not depict an actual event? - but to no avail - until all the "smart guys" like jenkins et al take a good hard look at themselves and their motives and face the truth that the official vids are nothing more than fakery, all their calculations of deceleration etc are meaningless.

Ningen said...

Spooked said:

I don't think the deceleration argument is going to prove anything in itself, and even worse, it gives the "debunkers" some oxygen.

And anonymous, among many other things, says something similar.

I am sure I have oversimplified things, and may have stepped into a trap of sorts by focusing on this deceleration issue. The analysis I used is what I learned from Salter, and I assumed that since physics professor Jones adopted it, it is valid. It's a lot more complicated and I may not be able to answer Jenkins on this point.

But I just read Reynolds' request for correction and he is raising so many points beyond this, including the penetration of the fuselage which makes no sense. Spooked, I've not been good at the video analysis so I haven't focused on that, but it is definitely strange.

Thanks for the comments.

Anonymous said...

ningen, sir,
i agree that this deceleration issue is a trap - but i don't believe you are guilty of oversimplifying.
rather, in and of itself it is a very complicated matter involving several layers of mathematics.
forget about reynolds as he is denying the official claim that what we see on vid is an actual 767 actually hitting a wtc and focus on jenkins who insists that a real 767 did really penetrate the wtc.
on what vid does jenkins base his deceleration calcs?
i submit that it does not matter which vid because ALL vids of ua175 hitting AND ENTERING wtc2 are false.
i need only say that they are fakery based on my prior 2 comments comparing a 767 to a beer can.
jenkins on the other hand submits as support for his deceleration calculations a simple diagram by NIST that depicts the entire front portion of a 767 already inside the wtc AS IF BY MAGIC.
jenkins needs to explain how it is exactly that a smooth rounded plastic 767 nosecone was able to penetrate the side of the extremely strong and massive hardened steel/concrete of the wtc.
THAT my friends, will be the actual physics of this matter - not any calculations of deceleration based on a vid that i say is phony to begin with.
the onus of proof of fakery is not on us but rather the proof of authenticity is is on the smart guys suck as jenkins et al.
now i reiterate my previous comparison of jenkins' deceleration calculations to that of greening's collapse time calculations:
no doubt the math is correct but it would seem to have no bearing on what was actually recorded for posterity by vids.
h is for ha.

Ningen said...

a simple diagram by NIST that depicts the entire front portion of a 767 already inside the wtc AS IF BY MAGIC.

Thank you, ha. I've been wondering about this. Karim and Hoo Fatt also simply assumed this penetration of the front fuselage. It seems that it has to be assumed, so that the first real impact is the engines and the center of the wings, opening up a space for the tail to go in. (I also can't imagine how the stress of the deceleration when the engines hit would not rip the tail up.)

It seems hard for me to believe that Jenkins really believes what he is saying. The whole thing is so counterintuitive.

Ningen said...

try a sledgehammer stomp on said beer can. it will still not penetrate said BBQ grill.

This makes a lot of sense. Thanks!

Ningen said...

greening's collapse time calculations Greening has recanted, it seems.

Interesting about the trap. I may have stuck my foot in some doo doo that will be hard to wipe off, since I've been presenting this as conclusive proof. I've always thought it was strange to be relying on faked videos to prove the videos were faked, but the deceleration argument is what did it for me.

I think you have the better answer -- the experts have assumed out of their models the behavior of the fuselage. Karim and Hoo Fatt simply assumed it into the towers, by magic, as you say.

I'm still going to try and understand Jenkins' arguments about average velocity and center of mass, if only so I don't get suckered again.

Anonymous said...

first, i thank you for posting my comments here!
i have long awaited some place to say what i have to say (whether right or wrong) where someone actually considers it.
second, if you have "put your foot in some doo-doo" it is not hard to wipe off simply because you have a mind-set that is open to all considerations - in short, if you realize that you are incorrect about something then you would be the first person to admit such, ya? spooked is the same, as am i.
this aspect, IMO, is what denotes a truly evolved member of humanity.
i know that you see what i am saying.
i am certainly no scientist and i am easily defeated by even the simplest of math but it is obvious to me that jenkins and hoo fat and everyone else who are supposed smart guys have simply skipped a step so to speak.
this begs the question:
are they simply not as smart of guys as they would like to believe or have they actually made their minds up and are simply trying to manipulate the perceptions of others to fit their (official?) foregone conclusions?
i have to say that since i (a relative moron compared to the likes of these "geniuses") can see thru all the bullshit to the actual crux of the matter then i can't believe for even a moment that they have been fooled either.
therefore they can be nothing more than official distractors.
anyway thanx again for this blog.
h is for ha!

Anonymous said...

Greening has recanted!?
to what extent has he recanted?
to the extent that he acknowledges prof. wood's claim that the NIST/911 commission's (and by extension greening et al's) explanation for the wtc collapse are not physically possible?
this claim of prof. wood would seem to render any collapse time calculations null and void would it not?
if any of these supposed "smart guys" were to actually have an honest discussion of all of this then perhaps their calculations might actually apply to what can be readily observed simply by watching a vid of said.
until this happens re: wtc "collapse" i will put my faith in prof. wood.
however i am not holding my breath.
IMO the same can be said as re: ua175 vs. wtc2 - until the likes of jenkins et al actually step up and begin at the beginning then i will put my faith in what my own eyes can observe.
until even 1 of these "smart guys" even attempts to pretend that he actually believes what he is positing then i will simply dismiss them entirely.
do you see what i am saying "smart guys"?
always, ha.

Ningen said...

Check back tomorrow, but I will tell you now what I recall. He said that his assumption of a free fall of one floor height to start the progressive collapse process was not realistic. He said some other things, too.

Ningen said...

Here it part of it, but now I can't find his comment about the initial free fall assumption being unrealistic. I'll keep looking.

According to Screw Loose Change, here,

Greening posted as Apollo20 here

and here

He's stirred things up there because he was kind of a hero among those who believe the official story.

Recant may be too strong a word, but if I can find the free fall quote I think it is justified. He's an interesting character.

Anonymous said...

no doubt that greening is very smart.
don't worry about digging up any links to his work.
i suspect that he realizes what is up re: wtc demolition, and that his calculations, however accurate, do not reflect what really happened.
if he is wise enough to put his integrity over his apparent allegiance then he will soon come out with another posit.
next time, ha.

Anonymous said...

apparently all of this deceleration nonsense is based on the evan fairbanks video, ya?
salter and jenkins and jones and anyone else who bandies about the word "physics" and who pretends as if they should be taken seriously should be made to explain exactly in what manner did the smooth, rounded plastic nosecone of a real 767 penetrate the massive hardened steel/concrete of the wtc.
go ahead salter, jenkins and jones! you are the smart guys are you not?
it is unfortunate that you cannot be forced to put up or shut up!

Ningen said...

Thanks, ha.

I'm trying to get an answer on this from Jenkins, here:

It begins with ---

"The media fakery"

My last comment is "I've read it" -- I'm waiting for his reply

Anonymous said...

and here is the evan fairbanks clip from which jenkins has derived his deceleration nonsense.

stand up straight jenkins!
when you can actually explain the physics of what we see then maybe you will be taken seriously.

i will get you started:
would an actual smooth rounded plastic 767 nosecone pierce thru the massive hardened steel/concrete wtc like an arrow?
or would it bludgeon thru like a hammer?
or would it flow between and around said hardened steel columns and horizontal concrete floor slabs like a liquid mercury perhaps?