Moderated WTC 1 features list, initiation model / WTC 2 features list, collapse model

[Carll68]

Am I the only one here who finds it extremely entertaining, that, in all this time, Femr2 (in all his incarnations) still can not understand what the NIST study reveals, and constantly misrepresent what it states?

Please tell me I am not alone in finding his idiotic ramblings hilarious.

No one takes his gibberish serious, do they?

Do they?

Do They?

 

[femr2]

When, is when millions of tons of debris slammed downward onto it from the first collapse

But the point of the *feature* is the description of fire ejections from the fire floors of WTC1 right back at WTC 2 initiation and the couple of following seconds, long before any debris slammed downward onto basement areas. Are you describing......air from WTC2 upper floors travelling, via C6, 7 & 50, 1000 feet down WTC2, bypassing any available venting, especially that around the lobby, increased pressure in the whole basement complex, which then traversed through openings in C6, 7 & 50 in WTC1...in order to push fire out up-top ? Is that what you are describing ?

The tilt angle started at zero.

Of course...

Then, at some later time (after which it could no longer be measured), it was about eight degrees.

Not quite true. NIST didn't measure it beyond that, sure. I've measured it to well over 12 degrees.

It therefore stands to reason (and is also easily observed) that at various times in between, it must have been half a degree, then one degree, then two degrees and so forth.

Of course...

I'm not aware of any issue related to the collapse causality that depends on precisely what time a given tilt angle occurred, relative to other events.

The most immediate implication is that of timing. To clarify what I mean, take the following NIST statement...

The entire section of the building above the impact zone began tilting as a rigid block (all four faces, not only the bowed and buckled south face) to the south (at least about 8º) as column instability progressed rapidly from the south wall along the adjacent east and west walls.

Regardless of whether you conclude core-led or south-perimeter-led, the process described above by NIST does not occur over an angle of at least about 8º, but over an angle of less than 1 degree. The time, described above as rapidly is indeed that, very rapid.

Once the entire upper section is descending vertically, which it is following the small amount of rotation I illustrated earlier, column instability progression is done and dusted. Rotation continues, but initiation is over.

As I cautioned you long ago, you're applying instantaneous time marks to processes that had durations. Instantaneous time marks are arbitrary and do not necessarily indicate, with any reliability, the exact timing of unobservable causal events occurring fractions of a second apart.

Eh ? I'm not stating absolute timings. As accurate as I can, when I do, sure.

Overloaded columns can deform slowly or quickly, in unison or out of unison, and there is no displacement, speed, or acceleration value at which one can definitely say, for instance, that deformation became "release" at that precise moment.

Would you agree that it is valid to say that after rotation of < 1 degree that column instability progression (in context) has completed ? I certainly would. From that point on, the upper section is *dropping* as far as I'm concerned.

So in sum, I agree with your assertion that there was a time when the tilt angle was about 0.6 degrees. Indeed, it would be very surprising otherwise, such as if it had skipped directly from 0.5 to 0.7.

Is there really any need for you make make comments like this ?

So far I do not agree with any particular significance you might be ascribing to that event.

Respectfully,
Myriad

The purpose is to describe what happened as accurately as possible. Does my response above clarify your viewpoint ?

 

[tfk]

femr & MT,

OK, I looked thru your first 5 references.
Absolute garbage waste of time.
___

Ejection from 75th Fl, E Side During AA11 Impact:
It's there. The effect is completely unsurprising.
I see absolutely nothing here related to collapse initiation.
Please now tell me what this tells YOU about collapse initiation.

Damage to Basement and Lobby
It's there. NIST documented it.
The effect is not only unsurprising, but expected.
I see absolutely nothing here related to collapse initiation.
Please now tell me what this tells YOU about collapse initiation.

Fire, Smoke Ejections as WTC2 is Struck
It's there.
The effect is completely unsurprising.
I see absolutely nothing here related to collapse initiation.
Please now tell me what this tells YOU about collapse initiation.

Strong Fire Ejections As WTC2 Collapses
It's there. NIST documented it.
The effect is completely unsurprising.
I see absolutely nothing here related to collapse initiation.
Please now tell me what this tells YOU about collapse initiation.

Inward Bowing of the S Perimeter
Zero surprise to anybody.
It's there. NIST documented it.

Except this segment is enlivened with numerous, totally unsupported, and comical (IMHO), assertions:

The NIST claims that floor sagging pulled in the south perimeter to the point of failure. The south wall failure overloads the core, causing progressive column failures from south to north over a tilt of 8 degrees.

>>>>>>>>>>>>>>>>>>>

"But if the core went first at a tilt angle of less than 1 degree, all this seems like bunk."

Perhaps the cause of the IB has more to do with the large fireballs that emerge from the center of the IB region only a few minutes before IB was first reported?

Pure comedy gold.

"All [unspecified something] seems like bunk."
Because … uh … because … uh … just because.

And then the stunningly brilliant touch that "OUTWARD blowing fireballs caused INWARD bowing…"

Don't get much funnier.
___

Now, instead of wasting more of our time, why don't you please tell us exactly what YOU guys believe these 5 pieces of irrelevant trivia tell you about collapse initiation.

NOW would be good a good time for that information.

5 weeks ago, as requested multiple times, would have been better…


tk

 

[femr2]

Two Deceptions-

This should be interesting...

femr2’s edited video of the west wall nearly perpendicular to the fall south.

femr2's segment of the following clip from the NIST Cumulus database...

.\NIST Cumulus Video\CNN Aircheck Eric Levin\CNN Aircheck Eric Letvin Cli24.avi

Deception 1) At the start of femr2’s edited about half second clip

It's not edited. It's a brightened segment and is cropped to reduce the filesize of the GIF, sure. Grab the file directly from the Cumulus database.

the top appears to stop rotating at ¼ second and then falling vertically for the other ¼ second.

Take a piece of paper and mark the following:
a) The drop of the NW corner at upper left of west façade (window wash platform) about 5/16” on my 19” monitor.
b) The drop of the floor at the smoke/flame line, lower left corner of west wall, about 3/16”
c) The drop of the flame up at right side of west wall, about 6/16” indicating a tilt in the south direction including deception 2)

The net drop of the NW corner, a) minus b) is actually 2/16” not the 5/16” illusion of the edit, a 40% distortion.

Deception 2) Place your pointer at the bottom left corner of the NE wall at the start of the video and note the shift of this point to the right at the end of the clip, reducing the apparent tilt of the rotation.

Could these two effects have been in the original video.

Go download it

No, from femr2’s own other video where this clip is edited from, we don’t see the two deceptions above. Throughout the edited portion, the original video actually shows a tilt to the right of vertical. The deceptions were intentional.

Compare Femr2’s original video (at 1:15)
http://www.youtube.com/watch?v=wjnJ7CPIoFA

Well there's your problem. That's not the same video. I'll upload a copy of the file (CNN Aircheck Eric Letvin Cli24.avi) for you, though I request that you apologise for making such ridiculous accusations.

Combine the vertical fall distortion and the righting of the tilt angle and you get -

Angry.

You angry ? No, sir, you are mistaken.

Ridiculous.

 

[dafydd]

Am I the only one here who finds it extremely entertaining, that, in all this time, Femr2 (in all his incarnations) still can not understand what the NIST study reveals, and constantly misrepresent what it states?

Please tell me I am not alone in finding his idiotic ramblings hilarious.

No one takes his gibberish serious, do they?

Do they?

Do They?

Comedy gold.Long may he post.

 

[femr2]

femr & MT,

OK, I looked thru your first 5 references.

I've just given my opinion on those items to Myriad.

 

[beachnut]

Before I *do the math*, here's a quick NW view...

... Now, who thinks that the fire near the SW corner descents about 29 feet before the release of the NW corner ?

Math? Now, who thinks the WTC was not destroyed by impacts and fire? That is the only question worth asking, and those who can't come up with this correct answer are doomed for infinite failure.

 

[femr2]

BasqueArch,

Here y'are...


Might want to pause it at 0:20 and compare the the GIF I posted...

...then have a think about your ridiculous accusations.

 

[tfk]

Here is an image taken from NCSTAR1-5A
chapter 8, pg 266 (pdf 362)

~2 sec after start of collapse

North side on the right (in shade)
East side on the left (in sun)

Figure 8-105. This frame taken from a video recorded at 10:28:24 a.m. shows WTC 1 from the northeast.

Figure 8–105 shows a frame taken from one of the long-range videos roughly two seconds after the collapse of WTC 1 began. The fire expelled from the 98th floor on the southern side of the east face is very bright. There was no apparent expulsion of fire from lower floors on this face. This supports the conclusion that the fire on the 98th floor was the largest fire present on this face at the time of collapse.

The tilt angle should be taken as approximate. In order to be precise, one would have to check all the video & printing x-y aspect ratios, of course.

But, assuming that they are close to 1:1, this shows AT LEAST a 4.4° tilt about 2 seconds after start of collapse. Again, this is the minimum tilt angle, because, if it is not tilting exactly in the plane of the image, then the real 3D tilt angle will be larger.

Just as MT's "1° tilt angle", taken from only one location, merely represents a MINIMUM tilt angle.

The RED "line parallel to the antenna", drawn beside the NW corner of the building shows that the tilt angle of the upper block is approximately equal to the angle of the antenna. (As best can be determined by few portions of edge visible thru the smoke.) Thereby suggesting little angular tilt between upper block and antenna (in this plane).

Where are femr's & MT's graphs of the tilt angle vs. time?
How about drop distance (in feet, not pixels) vs. time.
How about a statement of the frame in which you think that the drop transitions from rotation to pure descent.

 

[tfk]

I've just given my opinion on those items to Myriad.

Typical...

And your statements regarding each item's pertinence to collapse initiation is where?

 

[femr2]

Here is an image taken from NCSTAR1-5A

...and completely irrelevant to the context of discussion, and a particularly poor choice of video.

represents a MINIMUM tilt angle

Did you not understand the alternate method I presented a few posts previous ?

The method almost completely negates any requirement for perspective correction, by utilising a relative vertical displacement.

Where are femr's & MT's graphs of the tilt angle vs. time?

I haven't produced one. There are several in the link in MT's OP. Have you not even bothered to look ?

How about drop distance (in feet, not pixels) vs. time.

MT posted one in post #268:

...and one from me in post #360...

Upper curve - NW Corner vertical displacement(ft)/time(s)

How about a statement of the frame in which you think that the drop transitions from rotation to pure descent.

Inept question.

 

[tfk]

...and completely irrelevant to the context of discussion, and a particularly poor choice of video.

Your typical dodge…

It's an exactly pertinent photo, for the specific reason that it shows the tower from an alternate angle from the ones above. EXACTLY the info that I've been asking for, and you guys have been avoiding.

Did you not understand the alternate method I presented a few posts previous ?

The method almost completely negates any requirement for perspective correction, by utilising a relative vertical displacement.

Any and all discussions with you ceased being an open exchange of information a long, long time ago. And turned into a "why doesn't everybody try to guess what I'm saying, and I'll tell y'all how stupid you are" pissing contest. In other words, a giant waste of time.

So I just skip over most of what you say these days.

But I did read that section. LoL. It's just the latest in a long line of incompetent hand-waving.

It doesn't negate the need for an oblique angle in the slightest.
It substitutes a new set of unsupported assumptions for the old set of unsupported assumptions.

So, you excerpt a tiny bit of the video …
… use a non-fixed element (the fire) as your marker …
… in a situation with hurricane force winds …
… stop the video where it suits you (rather than letting it run the length needed to reveal the collapse properties of interest) …
… do no math …
… and state no conclusions.

And, for the record, no, "Now, who thinks that the fire near the SW corner descents about 29 feet before the release of the NW corner ?" is not a conclusion.

It's one of your typical "no claimer" questions.

I haven't produced one. There are several in the link in MT's OP. Have you not even bothered to look ?

Nope.

In spite of the fact that it's been pointed out to you 100 times, you still don't get it.

It is YOUR job to present YOUR case. You haven't presented squat.

You've made no arguments.
You post a bunch of links to dummies bloviating on blogs.
Those ain't arguments.

MT posted one in post #268:
http://img101.imageshack.us/img101/4753/image00029.png
...and one from me in post #360...
http://femr2.ucoz.com/_ph/6/378476413.png
Upper curve - NW Corner vertical displacement(ft)/time(s)

Right.

Apparently you don't read for comprehension.

The NIST photo that I posted says explicitly "~2 seconds after collapse initiation".
The curves you cite stop around 1 second after collapse initiation, and lack the info I was looking for.

How about a statement of the frame in which you think that the drop transitions from rotation to pure descent.

Inept question.

Nope.
Exactly pertinent question.
Inept answer, tho.
The typical inept response that you give when you can't, or don't wish to, address any particular question.
___

As others have stated, the question here is what did NIST really mean by their statements.

Others have very reasonably suggested that NIST meant "the upper block pivoted (some unspecified amount) before it fell straight down, and it pivoted at least 8° before it disappeared from view."

Your interpretation is "the upper block pivoted as a unit, and it tilted at least 8° before it fell straight down."

I'm persuaded by the comments of Dr. Terese McAllister, quoted earlier. ("… 8° before it disappeared from view…")

As in ALL cases, the one true arbiter of what any person means when they say something is the person making the statement.

Here's Dr. McAllister's web page & contact info. Why don't you give her a call & ask her.

She seems like a very accomplished, very pleasant person. Try not to call her "a fraud & a shill", OK?

tk

PS. STILL waiting for your (& MT's) statement as to how 4 out of those first 5 elements (I'll agree to Inward bowing) relate to "collapse initiation".

 

[femr2]

BasqueArch,

No apology from you for this ridiculous post yet I see.

Therefore I'll highlight the extent of the nonsense within it...

Two Deceptions-
femr2’s edited video of the west wall nearly perpendicular to the fall south.

Deception 1) At the start of femr2’s edited about half second clip

The animated GIF you reference is 1.67s in length, not 0.5s...

It contains 50 frames played back at 30*1000/1001fps.

Perhaps, whilst making an accusation of deception, you just made a simple typo or something...

, the top appears to stop rotating at ¼ second and then falling vertically for the other ¼ second.

Nope, you split a 1.67s clip into two 0.25s halves.

Not only that, but you are suggesting that the upper block stops rotating for some reason.

Wow.

Take a piece of paper and mark the following:

In a thread which makes extensive use of high-precision tracing techniques, you're going to use a piece of paper held against your monitor ? Incredibly primitive, but I'd have no problem with it IF the camera was static. It's clearly not a static camera, and clearly undergoes motion in multiple axes, including rotation.

a) The drop of the NW corner at upper left of west façade (window wash platform) about 5/16” on my 19” monitor.
b) The drop of the floor at the smoke/flame line, lower left corner of west wall, about 3/16”
c) The drop of the flame up at right side of west wall, about 6/16” indicating a tilt in the south direction including deception 2)

The net drop of the NW corner, a) minus b) is actually 2/16” not the 5/16” illusion of the edit, a 40% distortion.

Your ridiculous accusation is based upon you utterly failing to recognise the clear implications of camera movement.

Also, at what point have I posted any measurement data about that clip ? Well ? I stated the vertical descent of the NW corner begins about half-way through the clip (that's the actual 1.76s long clip yeah).

You make an erronious measurement of your own invention, then when you arrive at your result you don't even realise how utterly bizarre it is. Did you bother to think about what manipulation of the video would be required to result in your accusation being correct, had your result not been due to your mistake ?

It's not looking good, is it...

Deception 2) Place your pointer at the bottom left corner of the NE wall at the start of the video and note the shift of this point to the right at the end of the clip, reducing the apparent tilt of the rotation.

So let me get this straight, you notice the movement which indicates camera motion, and should immediately result in you realising how foolish your measurement and accusation above are, and yet the end result is another accusation of deception ? Mind boggling.

Surely you're done by now...

Could these two effects have been in the original video.

Everything above aside, there is a great way to find out, isn't there. Look at another copy of the source video. As I stated in the original post in which the image was contained, the video was from the NIST Cumulus Database.

No, from femr2’s own other video where this clip is edited from, we don’t see the two deceptions above. Throughout the edited portion, the original video actually shows a tilt to the right of vertical. The deceptions were intentional.

Compare Femr2’s original video (at 1:15)
http://www.youtube.com/watch?v=wjnJ7CPIoFA

Oh. My. Many Gods.

Okay, let's compare a frame at 1:15 in the video you link above to the same relative time in the GIF you've been, er, analysing...

(http://www.youtube.com/watch?v=wjnJ7CPIoFA @ 1:15)

(Uncropped frame 43 from the GIF)

Uncropped original video:
http://www.youtube.com/watch?v=1Q-ffzFjMKQ

NIST Cumulus Database Filename reference:
.\NIST Cumulus Video\CNN Aircheck Eric Levin\CNN Aircheck Eric Letvin Cli24.avi


I am utterly at a loss to imagine how you can possibly think these two images are from the same video.

Could it be a simple mistake ? Well, no, you state the time in the YT video you reference...1:15...so it's not just a video link error.

Combine the vertical fall distortion and the righting of the tilt angle and you get -

Angry.

Perhaps you should refrain from attempting any form of video analysis in the future.

Perhaps it would have been a good idea for you to ask me about the source video before making ridiculous unfounded accusations.

Perhaps you should realise I have no reason to deceive, and nothing to gain if I were to do so.

I've lost track of the number of times I've been accused here on JREF of lying, deception, distortion, ...the list goes on.

None of which have been valid accusations.

It's a disgrace.

 

[femr2]

Your typical dodge…

It's an exactly pertinent photo, for the specific reason that it shows the tower from an alternate angle from the ones above. EXACTLY the info that I've been asking for, and you guys have been avoiding.

Nonsense. The video is too poor in quality to accurately determine the release points, and you're not even using a frame of the thing itself, but a rescaled copy from the NIST report.

You haven't bothered to read the information in MT's OP links, and you haven't bothered to even read the content on this thread either, where the steps that were performed to minimise perspective implications were presented.

You hang from my coat-tail demanding attention, can't be bothered to find resources for yourself, and then accuse of avoidance when your whiney pointless whims are not serviced ?

I just skip over most of what you say these days.

But I did read that section. LoL. It's just the latest in a long line of incompetent hand-waving.

It doesn't negate the need for an oblique angle in the slightest.
It substitutes a new set of unsupported assumptions for the old set of unsupported assumptions.

It's incredibly simple tom. I'll be posting a slightly more detailed calc utilising the method soon, so you can put the blinkers on and ignore the obvious for a little longer.

Exactly pertinent question.

Nope. Dumb. Inept question.
Which video ?
Why attempt to create the trap of stating a singluar frame, which you'll then whine about ?
Pure descent ? You one of those folks who think rotation stopped suddenly ?

As others have stated, the question here is what did NIST really mean by their statements.

Nope. The question is at what angle did the transition from rotation about the north face to rotation and vertical drop ensue, indicating the point in time at which column instability progression was done and dusted.

Have a nice day.

 

[tfk]

femr,

So, what do you claim are pertinent to the collapse initiation of:


1. Ejection from 75th Fl, E Side During AA11 Impact
2. Damage to Basement and Lobby
3. Fire, Smoke Ejections as WTC2 is Struck
4. Strong Fire Ejections As WTC2 Collapses

I must have missed it.

LoL.

Nonsense. The video is too poor in quality to accurately determine the release points, and you're not even using a frame of the thing itself, but a rescaled copy from the NIST report.

Not particularly quick on the uptake for someone who has wasted an absurd amount of time on all of this…

You don't need to determine the release points from this video.
You get that info from the other videos.
You just need to sync this video to the others by some obvious event.

Gee, do you think that you might be able to come up with some distinguishing event in the video to allow you to sync it with the others???

You haven't bothered to read the information in MT's OP links,

Nope, I haven't.
All his previous stuff has been trash.
The first 5 elements of his list all turned out to be trash.
I have every expectation that the rest is trash as well.
When I invited both him and you to make your cases for the relevance of each element, you both refused.

When you refuse to make your own cases, why should I waste time on his, and your, trash?

and you haven't bothered to even read the content on this thread either, where the steps that were performed to minimise perspective implications were presented.

You're illiterate.

I told you that I did read your nonsense.

No steps "were performed" (past tense) to minimize perspective implications.

You laid out the steps you PLAN to perform (future tense).
Which will no doubt fail as well.

JMO, of course. You might fool everyone & do something right for once...

You hang from my coat-tail demanding attention, can't be bothered to find resources for yourself, and then accuse of avoidance when your whiney pointless whims are not serviced ?

"… hang from [your] coat-tail demanding attention …"

LMAO…

People don't have to "demand attention" from you. The electrons have barely settled down from anyone's posts, and you're madly typing away. From all observations, 24/7.

You have one, and only one, arrow in your quiver: "the last word".

You sit at your computer, relentlessly & immediately spitting out replies, in the blind folly that "the last response" is somehow equivalent to "the best response".

Get a frakkin life...

It's incredibly simple tom. I'll be posting a slightly more detailed calc utilising the method soon, so you can put the blinkers on and ignore the obvious for a little longer.

Yup, it is incredibly simple. Try a little math sometime.

And you've blown it already.
[psssst, the movement NEAR the south wall is not the same as the movement you get AT the south wall. Just thought you might want to know…]

Pure descent ? You one of those folks who think rotation stopped suddenly ?

Nope.

As in ALL cases, the one true arbiter of what any person means when they say something is the person making the statement.

Nope.

Yup.

 

[Major_Tom]

TFK post 389: "Where are femr's & MT's graphs of the tilt angle vs. time?
How about drop distance (in feet, not pixels) vs. time.
How about a statement of the frame in which you think that the drop transitions from rotation to pure descent. "

Tom, how many times have I mentioned frame 224 and the failure of the NW corner?? The last columns to fail are along the NW corner, around Sauret frame 224. I have been posting the same graph and explanation for a few months now.

Do you recall the expression "release point"? How about velocity take off point? Do I need to repeat it all again just because you cannot read?


That 4.4 degree explanation you gave....I'm speechless. I swear, you really don't know how many mistakes you make, do you? I would be totally ashamed to post that picture.

Tom, can you see the north wall in that picture? Have you wondered why not? Where is your mind when you dream that stuff up?

>>>>>>>>>>>>>>>>>>>>>>>>>.
>>>>>>>>>>>>>>>>>>>>>>>>>>

We have established one thing for certain: Nobody posting has a clue about how to find the angle tilt angle over which the columns originally failed. I am not judging you since it is not easy. I do judge the posters that act like they are know-it-alls while they remain ignorant of the basic mistakes they are making.


More importantly, you now realize that there is nowhere in the NIST report you can go for a clear explanation of the WTC1 collapse initiation motion.

It is a bit embarrassing to watch some posters continue to defend the NIST concerning their description of an 8 degree tilt. If the NIST was clear, would you need such tortured explanations?


>>>>>>>>>>>>>>>>>

Tilt angles vs time, Tom? You didn't notice these????

SAURET VIEWPOINT:

Earliest detectable movement leading up to collapse initiation

The earliest detectable movement is traced back to 9.5 seconds before the visible collapse initiation here:

Upper West Wall Pulls Inward 9.5s before Collapse
Antenna Base Shifts Eastward 9.5s before Collapse


VERTICAL DIFFERENCES BETWEEN 4 POINTS: MEASURING ANTENNA TILT, NORTH WALL TILT AND ROOF DEFORMITY

The motion of 4 points (2 on antenna, 1 on NW corner and 1 0n the 98th floor) is recorded and compared to the expected motion of a rigid body rotating about an axis through the north wall, 98th floor. The points a, b r and 98 are located at the elevations shown:

'

a: antenna black to white transition (pink) called ant or a
b: lower antenna ball (blue) called ball or b
r: roof NW corner (yellow) called roof or r
98: 98th fl (red) called 98.

The 4th point along the 98th floor NW corner doesn't move until the NW corner fails. The upper portion rotates around it. It serves as the rotation axis for the rigid model.

The Rigid Model: Fixed relations between southward tilt and perceived downward displacement of points a, b and r.

Here is a computer model of WTC1 undergoing rigid rotation about an axis through the north wall, floor 98 as seen from the SE:
http://img214.imageshack.us/img214/1364/tiltvsvismeasurement.gif

An observer from the north looking up at the building like the Sauret viewpoint should see fixed points on NW corner and the antenna move downward together as the bulding tilts, just at different rates of descent..

Geometric, trigonometric relations of the Sauret viewpoint here:
http://img404.imageshack.us/img404/4391/sauretrelations.gif

If the whole upper portion, antenna and perimeter, rotates together as a rigid body about an axis through the north wall, floor 98 through 360 degrees, the 3 points will follow the fixed trajectories shown here

We are only interested in the region from 0 to 3 degrees, so the domain is stretched to show a small slice of the graph over the first few degrees.

The track of any point fixed to a rigid rotating body will naturally take the form of a sinusoidal wave because any fixed point on the rigid body will be seen to follow a sine wave trajectory as the object is rotated through a complete 360 degree cycle when observed from a viewpoint perpendicular to the axis of rotation. If looked at from a viewpoint parallel to the axis of rotation, a viewer will see any point fixed to the body will take a circular trajectory with a radius equal to the distance the point lies from the rotation axis. But since the Sauret viewpoint is perpendicular to the rigid model axis of rotation, each fixed point travelling along a circular trajectory will appear as taking a sinusoidal trajectory centered around the rotation axis as shown.

During the first 3 degrees of tilt, the fixed linear relation between tilt angle and the perceived drop of points a, b and r are
http://img163.imageshack.us/img163/9084/image00011.png

(Better quality images of relations between points for different angles of rigid rotation for the Sauret viewpoint can be downloaded here:
http://www.megaupload.com/?d=XUIRKRYK)

This gives drop vs southward tilt relations for the antenna and NW corner for a rigid model rotating along a north face, fl 98 hinge as this:
http://img34.imageshack.us/img34/8679/descenttiltratio.png

These near linear relations between observed drop and angular orientation over the first 3 degrees allow us to translate drop data into rotational data between any 2 points as long as the structure interconnecting the 2 points remains rigid.

Also, since each point a, b, and r experiences a linear drop as theta changes from 0 to 3 degrees, we know that the position of each point can be written in the form

where all c values are constants. These expressions can also be written in differential form to show how each measured distance a-b, b-r and r-98 on a rigid rotating body must change relative to the other two distances in each moment of time.

Using these relations, we can see whether the upper portion tilted as a rigid block simply by visually inspecting the actual values of the quantities a-b, b-r and r-98 and the shapes of the resulting graphs.

According to the differential relations between a-b, b-r and r-98, the slopes of each of the 3 graphs should have identical shapes, differing only by a constant of proportionality.




Measuring north perimeter tilt using the quantity r-98: (distance from yellow line to the 98th floor): We know the NW edge of WTC1 between the 98th fl and the NW corner roof line remained rigid until the north perimeter gave along the 98th fl because we can see the whole corner to the roofline. Therefore we can use the change in r-98 to estimate how much the north perimeter had tilted for any given NW roof line drop distance. The NW corner fails along floor 98 around Sauret frame 224, so we can use the measured value of r-98 before frame 224 to calculate the tilt of the north wallt. The r-98 drop data is mapped on the right:

http://img20.imageshack.us/img20/856/calmesnface.png

The fixed relation between r drop and southward tilt of the north perimeter is on the left. We can use the graph on the left to estimate the actual tilt angle of the north perimeter for any frame before the point at which the NW corner fails along the 98th floor The higher resolution data linked below shows us the NW corner gave around frame 224.
http://img101.imageshack.us/img101/4753/image00029.png

We can see that up to frame 224 the north face had only tilted about 0.4 degrees to the south.

Verification of north perimeter tilt angle: Comparison of NW corner movement with a rigid model rotating 1 degree:

The actual movement of the NW corner compared to a rigid model undergoing a tilt of 1 degree here:
http://img246.imageshack.us/img246/9973/1degtilt.gif

We can verify that a north face rotation of 1 degree should produce measurable downward displacement by tracking a model undergoing rigid rotation of 1 degree to frame 224 here:
http://img705.imageshack.us/img705/8757/measure.gif

If the north wall actually rotated 1 degree before failing we would have detected it. The overlay shows the northwst corner faild failed well within a 1 degree tilt confirming the results of the data.


Measuring antenna south tilt using the quantity a-b: (distance from pink to blue line): We know the antenna remains rigid between a and b because we can see it. It is just a big stick moving downward nd tilting away from the camera. The change of the distance a-b is directly proportional to the change of the the south tilt of the antenna over the first 3 degrees. In the graphs below, on the right side we can see the measured a-b as the blue line. We can use the fixed linear relation between a-b and south tilt angle on the left to estimate the actual south tilt in any frame. We can see that in frame 224 the south tilt of the antenna is about 0.6 to 0.7 degrees.
http://img46.imageshack.us/img46/5084/image00000x.png

Measurement of the distance (a-b) compared with measurement of the distance (b-r), multiple points, 2 sets of measurements
http://img541.imageshack.us/img541/7176/calmesant.png
http://img213.imageshack.us/img213/8965/image00001.png


Features:
a) We already know from the antenna drop and velocity graph that the antenna sagged downward from frame 155 to 215, at which time it started to fall at a significant fraction of g. The graphs tell us that the estimated south tilt in frame 215 is about 1 degree.


Measuring roof-line deformation using quantity b-r: (distance from blue to yellow lines): The measured data for b-r shows there must have been significant deformation between the points b and r. Measurements for b-r are mapped as the pink line in the graph on the right
http://img46.imageshack.us/img46/5084/image00000x.png

If we assume the building remained rigid between points b and r and try to estimate rotation in frame 224 using the fixed b-r to angle relations in the graph on the right, we would place the tilt at about 1 degree.

Using a-b tells us the antenna rotated about 0.6 degrees to the south in frame 224. Using r-98 tells us the north face rotated about 0.4 degrees to the south in frame 224.

Using b-r as if the structure is rigid tells us the upper portion rotated about 1 degree by frame 224, which cannot be true considering the actual rotations of the antenna and the north face. Treating points b and r as fixed (rigid) relative to each other gives us a tilt angle which is too large.

Since we know points a and b remained fixed relative to each other through the antenna, and points r and 98 remained fixed relative to each other through the north wall over the frames of interest, this means point b must have sank too much relative to point r to be considered to maintain a rigid relation.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Large antenna drop for multiple points:

Over 200 frames
http://img52.imageshack.us/img52/1452/dropvstilt00007.png

Same with frames stretched
http://img267.imageshack.us/img267/3524/dropvstilt00006.png

Same over 700 frames
http://img62.imageshack.us/img62/2940/dropvstilt00008.png


East tilt large antenna, measured by tracking the horizontal difference between 2 points on the antenna.
http://img210.imageshack.us/img210/8246/easttilt.png

Features of the graph:
a) The earliest eastward tilt drift is detectable in frame -100 (or frame 70??)
b) The tilt measures about 0.3 degrees in frame 220
c) By frame 320 the tilt has not yet reached one degree


Evolution of east tilting of large antenna visualized (angle exaggerated)
http://img221.imageshack.us/img221/328/easttilt.gif

Features of the east tilting of large antenna :
a) The data of the east tilt shows a gradual drift leaning of the antenna eastward, beginning more than 4 seconds before the first visible movement. Downward movement of the antenna begins in frame 155 and falling begins in frame 215. Notice how drift leaning to the east is detectable as early as frame -200.
b) The whole antenna is drifting eastward while it leans.

The same highlighting initiation frames only
http://img691.imageshack.us/img691/2889/easttiltsiminit.gif
...................................

South tilt large antenna, measured by tracking the vertical difference and convergence of 2 points on the antenna.
http://img517.imageshack.us/img517/2149/nstilt.png

Features of the south tilt graph:
a) A south lean is first detected near frame 175
b) The antenna is leaning about 0.3 degrees to the south in frame 220 (it is later shown that the antenna starts to fall downward at a significant fraction of g in frame 220
c) The tilt reaches one degree in frame 295
d) By frame 320 the tilt has reached 2 degrees

For comparison, movement of stationary object in foreground
http://img440.imageshack.us/img440/2797/easttiltmetal.png
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Large antenna drop compared to east antenna drop
http://img704.imageshack.us/img704/7726/twoantennas.png


NW corner drop

Multiple measurements of NW corner drop
http://img232.imageshack.us/img232/6412/dropvstilt00005.png

Features:
a) The graphs clearly show there is no downward movement until frame 220

Comparison of north (Sauret) with NE (NBC) viewpoints: Large antenna angle
http://img694.imageshack.us/img694/6851/neview.png

Features of the comparison:
a)

Large antenna drop compared to NW corner drop, Sauret viewpoint
http://img101.imageshack.us/img101/4753/image00029.png
The graph shows the drop data of the antenna compared to the NW corner. The measured downward velocities of both points are also shown.

Features:
a) Once again we see no movement of the NW corner until frame 220. Velocity measurements confirm this. The antenna moves downward as early as frame 155. The velocity graph of the antenna also seems to show a slow downward movement from frame 155 to frame 215, after which the antenna starts to fall at a significant fraction of g along with the NW corner.
b) Release points:

NE corner drop

http://img186.imageshack.us/img186/6988/nedropraw.png

http://img683.imageshack.us/img683/7884/necornerdata.png

NE corner, NW corner and large antenna drops compared
http://img522.imageshack.us/img522/3816/nedrop30.png
http://img6.imageshack.us/img6/4128/nedrop3.png

NW corner drop velocity reductions
http://femr2.ucoz.com/photo/6-0-372-3
red is drop in ft
orange is velocity

Features:
a)

NW corner drop vs velocity
http://img194.imageshack.us/img194/9369/image00007.png
http://img14.imageshack.us/img14/5808/image00010.png



..........................................


NBC NW VIEWPOINT:

Large antenna drop compared to SW corner drop,
http://img163.imageshack.us/img163/3738/graphinitialdrop.png
We only care about the lines marked "real fire" and "real antenna".

104 fl fire drop raw
http://img442.imageshack.us/img442/6379/firex.png
http://img15.imageshack.us/img15/1323/fireyr.png

Features:
a) Downward movement of the antenna is measured before the SW corner is observed to move.


Multiple measurements of large antenna, NW corner and SW corner drops taken separately and stretched, NBC NW viewpoint, show the same downward movement of these 3 points relative to each other:

NW corner drop
http://img517.imageshack.us/img517/3391/necornersmall.png

Large antenna drop
http://img718.imageshack.us/img718/2868/antennasmall.png

SW corner drop (104th fl fire)
http://img22.imageshack.us/img22/840/firesmall.png

Static point for comparison
http://img42.imageshack.us/img42/9170/staticsmall.png

Features:
a)


Another measurement of the large antenna, SW corner fire and NW corner washer drops from the NW NBC viewpoint shows once again that the antenna was moving downward before the SW and NW corners of the building.
http://femr2.ucoz.com/_ph/6/859401119.png
(notes: Black - Antenna
Red - Washer
Purple - SW Fire

59.94 fps - Resolution Doubled. 1 pixel on the graph is 0.5 pixels on the original video.)
............................

NBC NE VIEWPOINT:

NE NBC viewpoint: Measurements of large antenna movement,

Angular movement of large antenna from NE, measured by tracking the horizontal difference between 2 points on the antenna
http://img707.imageshack.us/img707/30/nemaxsouthtilt.png


Evolution of angular movement from NE viewpoint visualized (angle exaggerated)
http://img85.imageshack.us/img85/9061/tilttimeline.gif

Features of the angular movement:
a) Between frame 165 and 217 the antenna tilted faster and reached about 0.75°. After frame 217 the tilting of the antenna stopped for the next 40 frames. During that time the antenna just shifted towards south while the north face (upper floors) apparently tilted more.
In the GIF above the x component of the movement is extremely stretched. Both axis are numbered each 10000 units. A thin blue line shows the position 10 frames ahead and a thin yellow line shows the position 10 frames before. The thin horizontal green lines show the measured antenna section. I extended the vertical lines to see at which elevation the "antenna" rotates (floor 98 is about at y=70000). It's obvious that the antenna started to descent at virtually 0° tilting. At about 0.6°tilting the north face gave way and stopped further tilting for the next 40 frames.)

 

[femr2]

I must have missed it.

No. I've not made any correlation of the features you reference to initiation.

Again, see my response to Myriad...
http://www.internationalskeptics.com/forums/showpost.php?p=6616930&postcount=382

No steps "were performed" (past tense) to minimize perspective implications.

MT has posted links to this image and associated explanations numerous times during this thread...
http://img404.imageshack.us/img404/4391/sauretrelations.gif

You laid out the steps you PLAN to perform (future tense).

Correct. Your error is that you incorrectly assumed I was referring to my recently posted additional method.

The electrons have barely settled down from anyone's posts, and you're madly typing away. From all observations, 24/7.

ROFL. About 2 posts a day. Riiight.

psssst, the movement NEAR the south wall is not the same as the movement you get AT the south wall. Just thought you might want to know…

Er, psst, tom, ...

Of course, the appropriate math can be applied to account for the actual location of the chosen feature on the West face.

 

[BasqueArch]

My bold

BasqueArch,
………….
The animated GIF you reference is 1.67s in length, not 0.5s...
[qimg]http://femr2.ucoz.com/CNN_Aircheck_Eric_Letvin_Cli24.gif[/qimg]
It contains 50 frames played back at 30*1000/1001fps.

You’re right. I didn’t have a watch with second hand, that’s why I said about half a second. I was off. I should have said short clip.
This point obscures the main claim of your post:
That this clip shows vertical motion (vertical falling), when it does not.

Note that the NW corner is visibly descending from half way through the short clip. Trace data can show more accurately the point at which vertical motion begins.
…………….
Also, at what point have I posted any measurement data about that clip ? Well ? I stated the vertical descent of the NW corner begins about half-way through the clip (that's the actual 1.76s long clip yeah).

In a thread which makes extensive use of high-precision tracing techniques, you're going to use a piece of paper held against your monitor ? Incredibly primitive, but I'd have no problem with it IF the camera was static. It's clearly not a static camera, and clearly undergoes motion in multiple axes, including rotation.

You had no objection to MT’s monkey with protractor on screen suggestion, and …

I'll probably apply some annotation and measurement (though your eyeballs are quite sufficient in this case), but, come on, suggesting that *The building section rotated about 8 degrees and then fell vertically* is simply an acute case of NISTitis.

I can’t do video editing. My onscreen measurements are quite sufficient in this case to show that the vertical fall was exaggerated ,that the true tilt was hidden and that the video, whether manipulated or not, was deceptive, misleading regarding your claim that

the NW corner is visibly descending from half way through the short clip. Trace data can show more accurately the point at which vertical motion begins.

You make an erronious measurement of your own invention, then when you arrive at your result you don't even realise how utterly bizarre it is. Did you bother to think about what manipulation of the video would be required to result in your accusation being correct, had your result not been due to your mistake ?

Yes, I thought about the manipulation required.
Have you ever edited a video by zooming? Yes or no
Have you ever edited a video by stabilization (a video editing technique used to reduce blurring or shaking associated with the motion of a camera) ? Yes or no

Everything above aside, there is a great way to find out, isn't there. Look at another copy of the source video. As I stated in the original post in which the image was contained, the video was from the NIST Cumulus Database.

Perhaps it would have been a good idea for you to ask me about the source video before making ridiculous unfounded accusations.

The source video you noted was posted by femr2.
Provide a third party link to the original CNN Aircheck Eric Levin video you edited from. I can't find it.

Okay, let's compare a frame at 1:15 in the video you link above to the same relative time in the GIF you've been, er, analysing...

[qimg]http://femr2.ucoz.com/_ph/6/369802014.png[/qimg]
(http://www.youtube.com/watch?v=wjnJ7CPIoFA @ 1:15)

[qimg]http://femr2.ucoz.com/_ph/6/506718240.png[/qimg]
(Uncropped frame 43 from the GIF)

Uncropped original video:
http://www.youtube.com/watch?v=1Q-ffzFjMKQ

NIST Cumulus Database Filename reference:
.\NIST Cumulus Video\CNN Aircheck Eric Levin\CNN Aircheck Eric Letvin Cli24.avi

I am utterly at a loss to imagine how you can possibly think these two images are from the same video.

Zoom + stabilization

Do you agree that the video you originally posted whether manipulated or not, exaggerates the vertical descent of the top NW corner ? Yes or no
Do you agree that the video you originally posted whether manipulated or not, reduces the actual tilt of the upper structure? Yes or no

 

[femr2]

This point obscures the main claim of your post:
That this clip shows vertical motion (vertical falling), when it does not.

Incorrect. The clip shows a very good view from the West. Probably the closest far-westerly view available (which is why it was posted), with clear visual cues to indicate vertical motion.

Your inability to recognise and account for camera movement is no-one elses responsibility.

You had no objection to MT’s monkey with protractor on screen suggestion

I have the same objection in principle, and I clearly stated in the text you quoted...

Incredibly primitive, but I'd have no problem with it IF the camera was static.

I can’t do video editing.

This is not video editing. It's analysis.

My onscreen measurements are quite sufficient in this case to show that the vertical fall was exaggerated

No, your onscreen measurements were meaningless and your method attrocious given the clear camera movement.

the true tilt was hidden and that the video, whether manipulated or not, was deceptive, misleading

Incorrect. It is your analysis skills that are at fault.

Your decision to perform the measurements in the way you did, for the reason you did, with that footage...is the source of your error.

Your viewpoint of *deceptive and misleading* is caused by your lack of competence.

I do not see an apology from you for your ridiculous accusations of deliberate video manipulation

Yes, I thought about the manipulation required.

And yet didn't recognise the obvious camera motion.

Have you ever edited a video by zooming? Yes or no

Of course, though any suggestion that the incorrect video link you posted could be *zoomed* to result in the footage you mistook it for is ridiculous. There's not enough detail, and it's not from the same angle.

Have you ever edited a video by stabilization (a video editing technique used to reduce blurring or shaking associated with the motion of a camera) ? Yes or no

Of course, though stabilisation doesn't treat blurring, and it's irrelevant to this discussion as I have not manipulated the video. The footage is not stable either, making your question even more bizarre. What, grasp at possible de-stabilisation to make the camera wobble about ? LOL.

The source video you noted was posted by femr2.

I know, that's me What, still paranoid that I'd have manipulated it ? Ridiculous.

Provide a third party link to the original CNN Aircheck Eric Levin video you edited from. I can't find it.

I've given you the full NIST Cumulus Database filename.
Go and download it from the torrent.
And enough with the *edited from* rubbish.

Do you agree that the video you originally posted whether manipulated or not, exaggerates the vertical descent of the top NW corner ? Yes or no

No. Your inept analysis skills are your problem.

Do you agree that the video you originally posted whether manipulated or not, reduces the actual tilt of the upper structure? Yes or no

No. Your inept analysis skills are your problem.

The video is not manipulated.

Go download it.
http://911datasets.org/images/International_Center_for_911_Studies_NIST_FOIA_-_Release_14_-_NIST_Cumulus_Video_Database.torrent

Then feel free apologise for your accusations and continued handwaving.

 

[Myriad]

But the point of the *feature* is the description of fire ejections from the fire floors of WTC1 right back at WTC 2 initiation and the couple of following seconds, long before any debris slammed downward onto basement areas. Are you describing......air from WTC2 upper floors travelling, via C6, 7 & 50, 1000 feet down WTC2, bypassing any available venting, especially that around the lobby, increased pressure in the whole basement complex, which then traversed through openings in C6, 7 & 50 in WTC1...in order to push fire out up-top ? Is that what you are describing ?

Pretty much, yes. The timing of the claimed fire ejections was not clear, but I now see you're addressing the smaller fire ejections that began about a second after WTC1 collapse initiation, so you're correct, that would be before debris collapsed any basement areas.

Let's keep a few things in mind though. "Fire" is a process not a thing, and as such, has no mass. All that is needed to eject "fire" from behind an existing aperture is to eject a little bit of combustible gas (which does have some mass, but not much, as it is a gas). That doesn't take a lot of force. A mild puff of air can do it, like a breeze through a doorway.

Second, no I'm not talking about air traveling down one tower, though the basement, and up the other one. That would take too long. I'm talking about an air pressure change doing so. That would take... the distance divided by the speed of sound, which works out to -- hey, whadda ya know, about a second.

The actual routes the pressure change could have taken, I'll leave to you to work out or be incredulous of if you choose.

The first second of collapse at .66g displaced about 280,000 cubic feet of air. Let's say 90% of that flow vented immediately to the sides, 90% of the rest vented from the lobby, and 90% of that somehow diffused out before making it up the other tower. Thats still a flow rate of 280 cubic feet per second when the pressure wave reaches the fire floors. Here's a fan that can move almost 280 cubic feet of air per second. Think that thing, at full power and speed, could push some air out a few windows?

Two kickers here: first, witnesses in the path of such a pressure wave at the time of the collapse did indeed report a blast of moving air, as expected; and second, no other plausible hypothesis for the cause of the fire ejections at that time has been put forward by anyone, so there is no reason whatsoever to reject the one plausible existing hypothesis due to mere personal incredulity.

The most immediate implication is that of timing. To clarify what I mean, take the following NIST statement...

The entire section of the building above the impact zone began tilting as a rigid block (all four faces, not only the bowed and buckled south face) to the south (at least about 8º) as column instability progressed rapidly from the south wall along the adjacent east and west walls.

Regardless of whether you conclude core-led or south-perimeter-led, the process described above by NIST does not occur over an angle of at least about 8º, but over an angle of less than 1 degree. The time, described above as rapidly is indeed that, very rapid.

The NIST statement is simply unclear wording. In the context of the dynamics described in detail in the report, and other statements on the same matter in the report, it is obvious that what was meant is:

The entire section of the building above the impact zone began tilting as a rigid block (all four faces, not only the bowed and buckled south face) to the south (said tilt eventually reaching at least about 8º) as column instability progressed rapidly from the south wall along the adjacent east and west walls.

In no way do NIST's conclusions depend upon, or require, the upper block to remain attached until the tiling reached 8 degrees. Indeed, if you could show otherwise, that the upper block did tilt eight degrees before column instability progressed through the north wall, that would be a major discrepancy in NIST's findings. But of course it did not, and NIST knew it did not. Harping on some unclear wording in a parenthetical comment notwithstanding.

Once the entire upper section is descending vertically, which it is following the small amount of rotation I illustrated earlier, column instability progression is done and dusted. Rotation continues, but initiation is over.

What you want to call it when, is fine. But that has no real physical meaning.

Can vertical descent be caused by elastic buckling of support columns? Yes it can.

Can vertical descent be caused by plastic buckling of support columns? Yes it can.

Can vertical descent be caused by fracture and separation of support columns? Yes it can.

So, what physical meaning does "initiation is over" have? It does not mean all columns have fractured. It does not mean all columns have buckled. It doesn't mean descent begins only at that moment. It's just an arbitrary milestone that you have defined and given a name to. So what?

Here's a question to look into... at what point did angular acceleration of the upper block drop to zero (if it ever did)? That milestone, at least, would tell you something about when the various parts of the lower structure were able to continue to apply significant torque to the upper.

Would you agree that it is valid to say that after rotation of < 1 degree that column instability progression (in context) has completed ? I certainly would. From that point on, the upper section is *dropping* as far as I'm concerned.

Again, as I said before, I agree that you have assigned an arbitrary name to an arbitrary time at which rotation of <1 degree had occurred, and something you term "column instability progression" has completed, and descent is underway.

And as before, I ask, so what? Why would anyone expect the angle to be greater (or less) at that point? How far should you be able to rotate a chunk of a building before it breaks off? NIST agrees with you that the column failure progressed rapidly, so there is no controversy here, unless this is all about spanking the report's editors for allowing an unclear parenthetical comment through.

Is there really any need for you make make comments like this ?

Why, yes, indeed there is. You see, this forum is an entertainment medium. My prose tends to be a bit dry and dull, which is not entertaining, so I make an effort to inject some additional (usually dry, sometimes absurdist) humor at unexpected moments.

You have chosen (against considerable advice to the contrary) to use this particular entertainment medium to promote your views, so I'm afraid you will have to live with it. (At least we don't have commercial breaks to contend with here!)

Respectfully,
Myriad