QUOTE (metamars+Jan 8 2008, 06:06 PM)
Which is why people shouldn't say that "everything was pulverized to dust" - including Richard Gage. Between "everything was pulverized to dust" and "the building collapsed, crushing wallboard, concrete, office contents" there's more than a few shades of in between.
Both verbal and photographs don't jive with what I'd expect an unassisted collapse aftermath to look like. Of course, neither does the video, but that's another matter.
I don't know what to make of 1). The powder residue was somewhat asphyxiating, already. I've never heard anybody make such a claim re explosives, themselves, before.
2) maybe, but identifiable as such, within the chemical soup that resulted? Furthermore, if you don't look for a particular substance, are you going to find it?
3) well, then we can probably discount explosives that people can detect with their noses!
I previously posted a pressure vs. time graph from an Australian military web site. While the graph was heuristic - the unidentified thermobaric was had a peak pressure of exactly half the peak pressure of the comparison unidentified high explosive - one can at least tentatively conclude that at least some real thermobarics will get you peak pressures of 2,000 psi. For a wave hitting a floor panel, some reflection off a steel pan might get you 4,000 psi, which I expect would pulverize 3,000 psi quite readily.
Furthermore, these are more diffuse than either high explosives or, I presume, the maximal impact area that all the columns could impact during a collapse.
Just speculating, but I believe the diffuseness combined with the longer duration allow more pressure waves to enter any give physical object from more directions, thus creating a 'crazy quilt' or 'choppy sea' of internal pressure waves. The net effect might be more pulverization, since, e.g., reinforcing peaks would only rupture the object in random locations, but only after the body had become 'loaded' with sufficient pressure waves to continue the rupturing process as subsequent wave peaks coincided.
There has been some discussion of explosives and thermobarics on the physorg threads. However, I don't recall anything quantitative that would relate thermobarics to pulverization granularity.
OR you will find a thousand natural substances that mimic the substance your looking for.
Take the thermite evidence as a clue of that, most explosives use common chemical compounds in simple unstable chemical formulas. IT is often difficult to tell them from naturally occurring compound in such situations.
OR you will find a thousand natural substances that mimic the substance your looking for.
Take the thermite evidence as a clue of that, most explosives use common chemical compounds in simple unstable chemical formulas. IT is often difficult to tell them from naturally occurring compound in such situations.
3) well, then we can probably discount explosives that people can detect with their
noses!
I agree the smell of cordite comes from sulfur-gun cotton it is pretty well evident that was present, a rotten egg like smell often associated with bad car batteries, lead acid batteries.
Why would you need man made explosives when natural explosives would have been in the buildings from the chemical reactions in the fires?
http://www.firetactics.com/
Why would you need man made explosives when natural explosives would have been in the buildings from the chemical reactions in the fires?
http://www.firetactics.com/
Smoke Explosion - 'Smoke Burns'
"A smoke explosion happens when a large buildup of smoke becomes very hot inside a room, and the whole cloud ignites all at one time," said the County Fire Marshal. "A flashover is pretty much the same thing without smoke."
PS, a smoke explosion can create a burning metals fire like the one Max P. describes.
It is simple it can create small particles of metal iron oxide or lead oxide, that start aluminum to oxidizing.
once you get the aluminum to oxidizing it will burn.
That is what I did in the first experiment that I told Dr. Steven E Jones about.
Captured smoke and blew it up and caused a thermite like reaction in metal, just could not find the ignition source for the smoke.
Smoke explosions are also highly unpredictable, and that is also what destroys the floor pans and causes their ignition, in the live conduits.
NIST did not do this type of testing, Dr. Jones did not do this type of testing I did, It could even have been what happened at World Trade Center 7, but who cares at this point what the truth actually might be?
Hehehe.
Hi Max Photon.
How about you first give us the detailed reasoning as to why your supposedly 'collapse insurance' EFFECTIVE thermite 'charges' did NOT ENSURE assisted-demolition in the same order of plane-impact ignition of your thermite charges?
After that, we'll get to your thoughts on the implications of the LOCKERBY 'large crater' for your 'incendiary-assisted' speculations in general and your 9/11 speculations in particular.
Thanks. Cheers all!
RC.
.
Can someone here kindly tell me where RealityCheck is coming from?
Thanks.
Max
NIST did not do this type of testing, Dr. Jones did not do this type of testing I did, It could even have been what happened at World Trade Center 7, but who cares at this point what the truth actually might be?
Family members of the murdered? Patriotic Americans? Those two groups of people readily spring to mind.
Both verbal and photographs don't jive with what I'd expect an unassisted collapse aftermath to look like. Of course, neither does the video, but that's another matter.
I don't know what to make of 1). The powder residue was somewhat asphyxiating, already. I've never heard anybody make such a claim re explosives, themselves, before.
2) maybe, but identifiable as such, within the chemical soup that resulted? Furthermore, if you don't look for a particular substance, are you going to find it?
3) well, then we can probably discount explosives that people can detect with their noses!
I previously posted a pressure vs. time graph from an Australian military web site. While the graph was heuristic - the unidentified thermobaric was had a peak pressure of exactly half the peak pressure of the comparison unidentified high explosive - one can at least tentatively conclude that at least some real thermobarics will get you peak pressures of 2,000 psi. For a wave hitting a floor panel, some reflection off a steel pan might get you 4,000 psi, which I expect would pulverize 3,000 psi quite readily.
Furthermore, these are more diffuse than either high explosives or, I presume, the maximal impact area that all the columns could impact during a collapse.
Just speculating, but I believe the diffuseness combined with the longer duration allow more pressure waves to enter any give physical object from more directions, thus creating a 'crazy quilt' or 'choppy sea' of internal pressure waves. The net effect might be more pulverization, since, e.g., reinforcing peaks would only rupture the object in random locations, but only after the body had become 'loaded' with sufficient pressure waves to continue the rupturing process as subsequent wave peaks coincided.
There has been some discussion of explosives and thermobarics on the physorg threads. However, I don't recall anything quantitative that would relate thermobarics to pulverization granularity.
QUOTE
2) maybe, but identifiable as such, within the chemical soup that resulted? Furthermore, if you don't look for a particular substance, are you going to find it?
OR you will find a thousand natural substances that mimic the substance your looking for.
Take the thermite evidence as a clue of that, most explosives use common chemical compounds in simple unstable chemical formulas. IT is often difficult to tell them from naturally occurring compound in such situations.
QUOTE (->
| QUOTE |
| 2) maybe, but identifiable as such, within the chemical soup that resulted? Furthermore, if you don't look for a particular substance, are you going to find it? |
OR you will find a thousand natural substances that mimic the substance your looking for.
Take the thermite evidence as a clue of that, most explosives use common chemical compounds in simple unstable chemical formulas. IT is often difficult to tell them from naturally occurring compound in such situations.
3) well, then we can probably discount explosives that people can detect with their
noses!
I agree the smell of cordite comes from sulfur-gun cotton it is pretty well evident that was present, a rotten egg like smell often associated with bad car batteries, lead acid batteries.
QUOTE
I previously posted a pressure vs. time graph from an Australian military web site. While the graph was heuristic - the unidentified thermobaric was had a peak pressure of exactly half the peak pressure of the comparison unidentified high explosive - one can at least tentatively conclude that at least some real thermobarics will get you peak pressures of 2,000 psi. For a wave hitting a floor panel, some reflection off a steel pan might get you 4,000 psi, which I expect would pulverize 3,000 psi quite readily.
Why would you need man made explosives when natural explosives would have been in the buildings from the chemical reactions in the fires?
http://www.firetactics.com/
QUOTE (->
| QUOTE |
| I previously posted a pressure vs. time graph from an Australian military web site. While the graph was heuristic - the unidentified thermobaric was had a peak pressure of exactly half the peak pressure of the comparison unidentified high explosive - one can at least tentatively conclude that at least some real thermobarics will get you peak pressures of 2,000 psi. For a wave hitting a floor panel, some reflection off a steel pan might get you 4,000 psi, which I expect would pulverize 3,000 psi quite readily. |
Why would you need man made explosives when natural explosives would have been in the buildings from the chemical reactions in the fires?
http://www.firetactics.com/
Smoke Explosion - 'Smoke Burns'
"A smoke explosion happens when a large buildup of smoke becomes very hot inside a room, and the whole cloud ignites all at one time," said the County Fire Marshal. "A flashover is pretty much the same thing without smoke."
PS, a smoke explosion can create a burning metals fire like the one Max P. describes.
It is simple it can create small particles of metal iron oxide or lead oxide, that start aluminum to oxidizing.
once you get the aluminum to oxidizing it will burn.
That is what I did in the first experiment that I told Dr. Steven E Jones about.
Captured smoke and blew it up and caused a thermite like reaction in metal, just could not find the ignition source for the smoke.
Smoke explosions are also highly unpredictable, and that is also what destroys the floor pans and causes their ignition, in the live conduits.
NIST did not do this type of testing, Dr. Jones did not do this type of testing I did, It could even have been what happened at World Trade Center 7, but who cares at this point what the truth actually might be?
QUOTE (Max Photon+Jan 8 2008, 01:42 PM)
Arthur,
I asked what your second best guess was for the white flashes.
Shall I take it you are busy busting out the video into individual frames so you can map the flashes on a splice map?
Or are you contacting buddies at NIST to get the video of the entire 7 minutes so you can show that pesky Max Photon that there is no way - not even a 1:100,000,000,000,000,000,000,000,000 chance - that those white flashes are related to some idiotic ignition mechanism?
Max White Flash Photon
RealtyChick, Grouchy:
You guys can get in on it too if you want.
What is your best explanation for the white flashes, after "falling debris"?
* * *
Hehehe.
Hi Max Photon.
How about you first give us the detailed reasoning as to why your supposedly 'collapse insurance' EFFECTIVE thermite 'charges' did NOT ENSURE assisted-demolition in the same order of plane-impact ignition of your thermite charges?
After that, we'll get to your thoughts on the implications of the LOCKERBY 'large crater' for your 'incendiary-assisted' speculations in general and your 9/11 speculations in particular.
Thanks. Cheers all!
RC.
.
I asked what your second best guess was for the white flashes.
Shall I take it you are busy busting out the video into individual frames so you can map the flashes on a splice map?
Or are you contacting buddies at NIST to get the video of the entire 7 minutes so you can show that pesky Max Photon that there is no way - not even a 1:100,000,000,000,000,000,000,000,000 chance - that those white flashes are related to some idiotic ignition mechanism?
Max White Flash Photon
RealtyChick, Grouchy:
You guys can get in on it too if you want.
What is your best explanation for the white flashes, after "falling debris"?
* * *
Hehehe.
Hi Max Photon.
How about you first give us the detailed reasoning as to why your supposedly 'collapse insurance' EFFECTIVE thermite 'charges' did NOT ENSURE assisted-demolition in the same order of plane-impact ignition of your thermite charges?
After that, we'll get to your thoughts on the implications of the LOCKERBY 'large crater' for your 'incendiary-assisted' speculations in general and your 9/11 speculations in particular.
Thanks. Cheers all!
RC.
.
QUOTE (metamars+Jan 8 2008, 10:29 AM)
Not very impressive, especially when you consider their importance to the collapse scenario they're pushing.
Au contraire. For a first time effort, it was enough to satisfy the experts.
Au contraire. For a first time effort, it was enough to satisfy the experts.
QUOTE (RealityCheck+Jan 8 2008, 09:54 PM)
Hehehe.
Hi Max Photon.
How about you first give us the detailed reasoning as to why your supposedly 'collapse insurance' EFFECTIVE thermite 'charges' did NOT ENSURE assisted-demolition in the same order of plane-impact ignition of your thermite charges?
After that, we'll get to your thoughts on the implications of the LOCKERBY 'large crater' for your 'incendiary-assisted' speculations in general and your 9/11 speculations in particular.
Thanks. Cheers all!
RC.
.
Can someone here kindly tell me where RealityCheck is coming from?
Thanks.
Max
QUOTE (metamars+Jan 8 2008, 11:06 AM)
Both verbal and photographs don't jive with what I'd expect an unassisted collapse aftermath to look like.
Of course, neither does the video, but that's another matter.
How would you know? It looks rather similar to the remains of a large avalanche, filled with ice blocks, shattered trees and even boulders.
Looks like a vertical avalanche to me. Similar to videos of flowing snow avalanches, sand slides, or other fluidized solids.
Of course, neither does the video, but that's another matter.
How would you know? It looks rather similar to the remains of a large avalanche, filled with ice blocks, shattered trees and even boulders.
Looks like a vertical avalanche to me. Similar to videos of flowing snow avalanches, sand slides, or other fluidized solids.
QUOTE (einsteen+Jan 8 2008, 09:33 AM)
http://www.photolibrary.fema.gov/photolibr...pher=&SEndDate=
Thanks again.
Look at phot #5646 on page 18. See anything which looks like a east wall section fell over onto WTC 5?
Thanks again.
Look at phot #5646 on page 18. See anything which looks like a east wall section fell over onto WTC 5?
David,
I think the vertical avalanche metaphor is pretty impressive.
There are two videos in particular - (I can't seem to find them) - that when viewed by sliding the video viewer back and forth - one can really see how well that description fits.
Vertical avalanche is exactly the description I was looking for when I last viewed those videos.
At the time I was impressed with Forbes' "pillars of sand" analogy, but that implies more of an all-at-once slump. (But the analogy does at least grope at some of the features of the vertical avalanche.)
Very good!
Max
I think the vertical avalanche metaphor is pretty impressive.
There are two videos in particular - (I can't seem to find them) - that when viewed by sliding the video viewer back and forth - one can really see how well that description fits.
Vertical avalanche is exactly the description I was looking for when I last viewed those videos.
At the time I was impressed with Forbes' "pillars of sand" analogy, but that implies more of an all-at-once slump. (But the analogy does at least grope at some of the features of the vertical avalanche.)
Very good!
Max
QUOTE (Max Photon+Jan 8 2008, 05:52 PM)
I think the vertical avalanche metaphor is pretty impressive.
Thank you. It is supposed to be a bit more than just a metaphor. Of course, if only snow can avalanche, then it is but metaphor. But as soon as one allows other fluidized solids to 'avalanche', as in the following definition
An avalanche is a massive slide of snow, ice, rock or debris down a mountainside.
then it seems closer.
Edited to add:
A landslide is a type of avalanche consisting of materials such as rock, slag or coal. Torrential rains and storms can cause a massive flow of mud, called a mudslide.
Slides of volcanic ash, with mud, water and rock, are often called lahars.
All the above are suggestive as well...
Thank you. It is supposed to be a bit more than just a metaphor. Of course, if only snow can avalanche, then it is but metaphor. But as soon as one allows other fluidized solids to 'avalanche', as in the following definition
An avalanche is a massive slide of snow, ice, rock or debris down a mountainside.
then it seems closer.
Edited to add:
A landslide is a type of avalanche consisting of materials such as rock, slag or coal. Torrential rains and storms can cause a massive flow of mud, called a mudslide.
Slides of volcanic ash, with mud, water and rock, are often called lahars.
All the above are suggestive as well...
Quite a good fit to the C447 data is given by the resistive force function
k0 + k1*Z + k2*(Z-Z0)*S*S
where Z is the normalized location of the crushing front, stating at Z0 and proceeding towards one, S is the normalized speed (S=1 is about 67 m/s), and the parameters are now explained:
a constant resistive force of k0 = 0.06 (compared to g = 1);
a building structural resistance of k1 = 0.03 (compared to k1 = 1 for the undamaged tower);
a crushing and re-crushing parameter of k2 = 8.15 (vertical avalanche component).
This gives a standard deviation from the data of a mere 0.107 meters, not at all shabby for a drop of 40.4 meters. (which occurred in 3.7 seconds at which time the crushing front was advancing at 24.3 m/s)
k0 + k1*Z + k2*(Z-Z0)*S*S
where Z is the normalized location of the crushing front, stating at Z0 and proceeding towards one, S is the normalized speed (S=1 is about 67 m/s), and the parameters are now explained:
a constant resistive force of k0 = 0.06 (compared to g = 1);
a building structural resistance of k1 = 0.03 (compared to k1 = 1 for the undamaged tower);
a crushing and re-crushing parameter of k2 = 8.15 (vertical avalanche component).
This gives a standard deviation from the data of a mere 0.107 meters, not at all shabby for a drop of 40.4 meters. (which occurred in 3.7 seconds at which time the crushing front was advancing at 24.3 m/s)
Oops. The terminal speed for a pure vertical avalanche, neglecting both air resistance and stretch change is
1/sqrt(rk)
where r is the average lineal (vertical) density and k is the constant of the vertical avalanche resistive force.
Checking this against the run I reported in the previous post, all this implies a terminal speed of only about 25--26 m/s, which should come as a surprise to many...
1/sqrt(rk)
where r is the average lineal (vertical) density and k is the constant of the vertical avalanche resistive force.
Checking this against the run I reported in the previous post, all this implies a terminal speed of only about 25--26 m/s, which should come as a surprise to many...
QUOTE (Chainsaw,+Jan 8 2008, 07:05 PM)
NIST did not do this type of testing, Dr. Jones did not do this type of testing I did, It could even have been what happened at World Trade Center 7, but who cares at this point what the truth actually might be?
Family members of the murdered? Patriotic Americans? Those two groups of people readily spring to mind.
QUOTE (David B. Benson+Jan 8 2008, 10:07 PM)
Au contraire. For a first time effort,
First time effort? Don't you mean first and last effort?
it was enough to satisfy the experts.
Such as Quintiere? I wonder what he believes about the pull-in forces.
Of course, you're not conflating opinions of the civil engineering community on the NIST report, as a whole, with the specific issue of the validity of their ad hoc pullin force, are you?
I am aware that JayUtah of apollohoax finds nothing mysterious about it. So that's 1.
Frankly, though, I'm inclined to dismiss the opinions of a "debunker" for the same reason that a skeptic is inclined to dismiss the opinions of a CT'er. I'd be much more interested in the opinion of a structural/civil engineer who spends no time on forums such as these, but who, nevertheless, had a background in FEA's and had studied the NIST report closely.
(Nothing personal intended. If there weren't serious debunkers, such as yourself, we'd have little to debate.)
First time effort? Don't you mean first and last effort?
QUOTE
it was enough to satisfy the experts.
Such as Quintiere? I wonder what he believes about the pull-in forces.
Of course, you're not conflating opinions of the civil engineering community on the NIST report, as a whole, with the specific issue of the validity of their ad hoc pullin force, are you?
I am aware that JayUtah of apollohoax finds nothing mysterious about it. So that's 1.
Frankly, though, I'm inclined to dismiss the opinions of a "debunker" for the same reason that a skeptic is inclined to dismiss the opinions of a CT'er. I'd be much more interested in the opinion of a structural/civil engineer who spends no time on forums such as these, but who, nevertheless, had a background in FEA's and had studied the NIST report closely.
(Nothing personal intended. If there weren't serious debunkers, such as yourself, we'd have little to debate.)
QUOTE (metamars+Jan 8 2008, 07:46 PM)
First time effort? Don't you mean first and last effort?
I'd be much more interested in the opinion of a structural/civil engineer who spends no time on forums such as these, but who, nevertheless, had a background in FEA's and had studied the NIST report closely.
By first time effort I was referring to the entire attempt to understand two major progressive collapses. While this might be the last time for NIST, it certainly is not for the structural engineering community as a whole, with the new(er) FEMA guidelines and various government agency requirements.
Then you should read the public comments which were made on the various drafts of the report.
I'd be much more interested in the opinion of a structural/civil engineer who spends no time on forums such as these, but who, nevertheless, had a background in FEA's and had studied the NIST report closely.
By first time effort I was referring to the entire attempt to understand two major progressive collapses. While this might be the last time for NIST, it certainly is not for the structural engineering community as a whole, with the new(er) FEMA guidelines and various government agency requirements.
Then you should read the public comments which were made on the various drafts of the report.
QUOTE (metamars+Jan 8 2008, 09:46 PM)
Of course, you're not conflating opinions of the civil engineering community on the NIST report, as a whole, with the specific issue of the validity of their ad hoc pullin force, are you?
The bowing in of the walls was an OBSERVED phenomena.
NIST ensured that their models corresponded to OBSERVED phenomena.
Clearly the ONLY way the perimeter walls could BOW INWARD over that span would be for them not to be laterally supported by the floor trusses.
If the trusses remain on their seats then the only way for the walls to bow is for the trusses to either SAG or come off their seats.
However, the conditions were not sufficient, in most cases, for the trusses to come off there seats, but the multifloor fires created conditions that WERE sufficient for trusses to sag.
We DO know that even the 35' trusses will sag when heated and modeling shows that the 60' trusses will sag even more.
Modeling shows that when the trusses are in a catenary shape they WILL provide a pull in force.
NIST modeled the pull in force that it would take to come in with a good approximation of the observations and the result was a MODEST pull in force of ~ 5 kip on the long truss sides of the towers.
Arthur
The bowing in of the walls was an OBSERVED phenomena.
NIST ensured that their models corresponded to OBSERVED phenomena.
Clearly the ONLY way the perimeter walls could BOW INWARD over that span would be for them not to be laterally supported by the floor trusses.
If the trusses remain on their seats then the only way for the walls to bow is for the trusses to either SAG or come off their seats.
However, the conditions were not sufficient, in most cases, for the trusses to come off there seats, but the multifloor fires created conditions that WERE sufficient for trusses to sag.
We DO know that even the 35' trusses will sag when heated and modeling shows that the 60' trusses will sag even more.
Modeling shows that when the trusses are in a catenary shape they WILL provide a pull in force.
NIST modeled the pull in force that it would take to come in with a good approximation of the observations and the result was a MODEST pull in force of ~ 5 kip on the long truss sides of the towers.
Arthur
David,
Perhaps the second harmonic of a vertical avalanche can explain the "squibs".
I believe the current non-CD explanation of the "squibs" is some version of a piston effect, or over-pressures, or what have you.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
(By the way, when I used the phrase "vertical avalanche metaphor," I in no way meant that to be diminutive. I was using the term as sort of as a "model - concept - yeah, it's kinda like that - homologous dynamic-y kind of thing". You know - technical talk. But I get it that it's deeper than that. The collapse was an avalanche!)
I have been to Upper Yosemite Falls when the falls have been cranking. The dynamics of the falling water - which is absolutely fascinating - would seem to be a form of vertical avalanche.
When you watch a unit of water go over the upper edge, what is striking is that as the water breaks apart, it does not seem to fall together like a bunch of Newton's apples, their relative positions somewhat fixed. Instead the water self-organizes into wavefronts that are like fingers reaching downward, each with ever-new fingers piercing through - a "cascade of reaching ahead" so to speak. I have seen different materials - at many scale levels - approximate fine powder in free-fall - and behave similarly to the waterfall.
It absolutely mesmerizing. I believe that there are water fountain ornaments that have a sheet of water flowing over a vertical or near vertical surface, and complex waves cascade through the flowing water.
So David, perhaps as the WTC avalanche advanced, it was not a one-floor-at-a-time front.
Perhaps "fingers of avalanche" raced well ahead of the external perceived collapse front. Just because rows of debris were sequentially ejected from windows - you know, what everyone would call the collapse front - does not preclude that inside the towers, out of view, fingers of collapse - fingers of avalanche - were reaching many floors below the apparent collapse front, and that the "squibs" are evidence of just that advanced internal damage.
Max Apres Photon
Perhaps the second harmonic of a vertical avalanche can explain the "squibs".
I believe the current non-CD explanation of the "squibs" is some version of a piston effect, or over-pressures, or what have you.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
(By the way, when I used the phrase "vertical avalanche metaphor," I in no way meant that to be diminutive. I was using the term as sort of as a "model - concept - yeah, it's kinda like that - homologous dynamic-y kind of thing". You know - technical talk. But I get it that it's deeper than that. The collapse was an avalanche!)
I have been to Upper Yosemite Falls when the falls have been cranking. The dynamics of the falling water - which is absolutely fascinating - would seem to be a form of vertical avalanche.
When you watch a unit of water go over the upper edge, what is striking is that as the water breaks apart, it does not seem to fall together like a bunch of Newton's apples, their relative positions somewhat fixed. Instead the water self-organizes into wavefronts that are like fingers reaching downward, each with ever-new fingers piercing through - a "cascade of reaching ahead" so to speak. I have seen different materials - at many scale levels - approximate fine powder in free-fall - and behave similarly to the waterfall.
It absolutely mesmerizing. I believe that there are water fountain ornaments that have a sheet of water flowing over a vertical or near vertical surface, and complex waves cascade through the flowing water.
So David, perhaps as the WTC avalanche advanced, it was not a one-floor-at-a-time front.
Perhaps "fingers of avalanche" raced well ahead of the external perceived collapse front. Just because rows of debris were sequentially ejected from windows - you know, what everyone would call the collapse front - does not preclude that inside the towers, out of view, fingers of collapse - fingers of avalanche - were reaching many floors below the apparent collapse front, and that the "squibs" are evidence of just that advanced internal damage.
Max Apres Photon
QUOTE (adoucette+Jan 9 2008, 03:09 AM)
The bowing in of the walls was an OBSERVED phenomena.
NIST ensured that their models corresponded to OBSERVED phenomena.
Clearly the ONLY way the perimeter walls could BOW INWARD over that span would be for them not to be laterally supported by the floor trusses.
If the trusses remain on their seats then the only way for the walls to bow is for the trusses to either SAG or come off their seats.
However, the conditions were not sufficient, in most cases, for the trusses to come off there seats, but the multifloor fires created conditions that WERE sufficient for trusses to sag.
We DO know that even the 35' trusses will sag when heated and modeling shows that the 60' trusses will sag even more.
Modeling shows that when the trusses are in a catenary shape they WILL provide a pull in force.
NIST modeled the pull in force that it would take to come in with a good approximation of the observations and the result was a MODEST pull in force of ~ 5 kip on the long truss sides of the towers.
Arthur
I'm not impressed. Certainly, this would make a good research project for, say, a Ph.D. thesis. Model the floor panels in sufficient detail, 'borrow' NIST's fire models, and see if you get a pullin force.
I find it hard to believe that this would be much harder than modeling a plane impact. And it sounds potentially more useful.
NIST ensured that their models corresponded to OBSERVED phenomena.
Clearly the ONLY way the perimeter walls could BOW INWARD over that span would be for them not to be laterally supported by the floor trusses.
If the trusses remain on their seats then the only way for the walls to bow is for the trusses to either SAG or come off their seats.
However, the conditions were not sufficient, in most cases, for the trusses to come off there seats, but the multifloor fires created conditions that WERE sufficient for trusses to sag.
We DO know that even the 35' trusses will sag when heated and modeling shows that the 60' trusses will sag even more.
Modeling shows that when the trusses are in a catenary shape they WILL provide a pull in force.
NIST modeled the pull in force that it would take to come in with a good approximation of the observations and the result was a MODEST pull in force of ~ 5 kip on the long truss sides of the towers.
Arthur
I'm not impressed. Certainly, this would make a good research project for, say, a Ph.D. thesis. Model the floor panels in sufficient detail, 'borrow' NIST's fire models, and see if you get a pullin force.
I find it hard to believe that this would be much harder than modeling a plane impact. And it sounds potentially more useful.
Details of Red/Gray Chips
Professor Jones has posted the following:
Size is typically about 1mm by 1mm, of that order. Largest red chip is about 3 mm long and 2 mm at the widest point. Thickness is shown on the video clip, note the 20 micron scale at the bottom. Red side about 40 microns thick, gray slab about 25 microns thick.
Total thickness is thus about 0.003", 3 mils.
I've been told that mils is thousandths of an inch.
He also previously mentioned that he didn't think the gray side was plastic.
Professor Jones has posted the following:
QUOTE
Size is typically about 1mm by 1mm, of that order. Largest red chip is about 3 mm long and 2 mm at the widest point. Thickness is shown on the video clip, note the 20 micron scale at the bottom. Red side about 40 microns thick, gray slab about 25 microns thick.
Total thickness is thus about 0.003", 3 mils.
I've been told that mils is thousandths of an inch.
He also previously mentioned that he didn't think the gray side was plastic.
QUOTE (metamars+Jan 9 2008, 04:22 AM)
Details of Red/Gray Chips
Professor Jones has posted the following:
I've been told that mils is thousandths of an inch.
He also previously mentioned that he didn't think the gray side was plastic.
studio cassette tapes are 25-35 microns
compact audio cassette tapes 16 microns
( http://en.wikipedia.org/wiki/Audio_tape_length_and_thickness )
Somebody else can look up eggshells.
Professor Jones has posted the following:
I've been told that mils is thousandths of an inch.
He also previously mentioned that he didn't think the gray side was plastic.
studio cassette tapes are 25-35 microns
compact audio cassette tapes 16 microns
( http://en.wikipedia.org/wiki/Audio_tape_length_and_thickness )
Somebody else can look up eggshells.
QUOTE (David B. Benson+Jan 9 2008, 02:55 AM)
Then you should read the public comments which were made on the various drafts of the report.
Do you recall any of the comments regarding the ad hoc pullin force? Comments such as "Jolly good show, lads! I use ad hoc pullin and pushout forces in my own work. I was afraid that I was the only one." might enlighten us.
Do you recall any of the comments regarding the ad hoc pullin force? Comments such as "Jolly good show, lads! I use ad hoc pullin and pushout forces in my own work. I was afraid that I was the only one." might enlighten us.
QUOTE (metamars+Jan 8 2008, 11:10 PM)
I'm not impressed. Certainly, this would make a good research project for, say, a Ph.D. thesis. Model the floor panels in sufficient detail, 'borrow' NIST's fire models, and see if you get a pullin force.
I find it hard to believe that this would be much harder than modeling a plane impact. And it sounds potentially more useful.
Who cares what impresses YOU?
You have already shown so little common sense over the course of these debates.
But maybe if you applied a little COMMON SENSE it would help you to realize that SAGGING of 60' lightweight concrete floor trusses in a multistory fire, particularly when some to much of their insulation has been scoured off, is to be EXPECTED.
The bowing in of the columns can't happen if the floors are providing lateral support, but testing shows that in most cases they would sag rather than disconnect.
So when the bowing of the perimeter columns IS observed in the real towers then it clearly makes sense to include the sagging of the trusses and bowing in of the perimeter columns in the models.
Arthur
I find it hard to believe that this would be much harder than modeling a plane impact. And it sounds potentially more useful.
Who cares what impresses YOU?
You have already shown so little common sense over the course of these debates.
But maybe if you applied a little COMMON SENSE it would help you to realize that SAGGING of 60' lightweight concrete floor trusses in a multistory fire, particularly when some to much of their insulation has been scoured off, is to be EXPECTED.
The bowing in of the columns can't happen if the floors are providing lateral support, but testing shows that in most cases they would sag rather than disconnect.
So when the bowing of the perimeter columns IS observed in the real towers then it clearly makes sense to include the sagging of the trusses and bowing in of the perimeter columns in the models.
Arthur
QUOTE (Max Photon+Jan 9 2008, 03:27 AM)
I believe the current non-CD explanation of the "squibs" is some version of a piston effect, or over-pressures, or what have you.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
I don't think the squibs are explained. There is an attempt to explain them with air. From recent video observation I'm absolutely convinced that this model doesn't hold. Max, the collapse itself is very interesting.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
I don't think the squibs are explained. There is an attempt to explain them with air. From recent video observation I'm absolutely convinced that this model doesn't hold. Max, the collapse itself is very interesting.
QUOTE (einsteen+Jan 8 2008, 10:26 AM)
OneWhiteEye, Neu, David,
FYI, I found out how to synchronize two videos now in one screen using avisynth. This is very interesting. Both videos ( I tested) have the same framerate and the unique patterns of the debris make it possible to synch precisely with an error of 1/29.97 seconds. If the framerate differs then it is of course also possible but the error will be bigger. I'm sure there are a lot of programs out that can do that already, but I like free/clean/tiny softsware tools.
You are ever-creative with the video. Avisynth is a serious tool by any standard.
Looking forward to that, should be fun.
FYI, I found out how to synchronize two videos now in one screen using avisynth. This is very interesting. Both videos ( I tested) have the same framerate and the unique patterns of the debris make it possible to synch precisely with an error of 1/29.97 seconds. If the framerate differs then it is of course also possible but the error will be bigger. I'm sure there are a lot of programs out that can do that already, but I like free/clean/tiny softsware tools.
You are ever-creative with the video. Avisynth is a serious tool by any standard.
QUOTE
I'll soon post a small debunking challenge if I don't debunk it myself......
Looking forward to that, should be fun.
QUOTE (adoucette+Jan 9 2008, 05:58 AM)
Who cares what impresses YOU?
You have already shown so little common sense over the course of these debates.
P-f-f-f-f-t
And who cares what fudge-factor impresses YOU? Especially if it's integral to a $20 million dollar research project, but it's ad hoc nature raises questions about not only it's validity, but the validity of the NIST report, in general?
But maybe if you applied a little COMMON SENSE it would help you to realize that SAGGING of 60' lightweight concrete floor trusses in a multistory fire, particularly when some to much of their insulation has been scoured off, is to be EXPECTED.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
The bowing in of the columns can't happen if the floors are providing lateral support, but testing shows that in most cases they would sag rather than disconnect.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
So when the bowing of the perimeter columns IS observed in the real towers then it clearly makes sense to include the sagging of the trusses and bowing in of the perimeter columns in the models.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
As should be obvious, some folks like to swallow anything they're presented, as long as it fits into their pre-conceived notions, and don't care whether it can be validated, or not.
People will often annoy me with such elementary questions as:
[plug in nasal, whiney voice here]
"Max, how in God's creation could military deception and demolition planners hide controlled-demolition in plain view?
People annoy me too, with their silly ideas, especially when they have no clue how impossible it would be to install demo-charges without anybody knowing it.
Ok, start with something real simple. How did the thermite get TO the building? A truck, unloaded at the loading dock? Who took delivery and how could they distribute it to the floors without anybody seeing? Don't say 'during a powerdown', because the elevators would be out of service. That pretty much leaves thermite fairies humping it up the stairs. THAT'S alot of fairies!
Prolly took that many construction fairies too, to set the charges, busting out walls, chipping concrete, etc... without a soul noticing it.
I've got plenty more problems you/they would have to overcome, but let's let you tackle the easy ones first.
You have already shown so little common sense over the course of these debates.
P-f-f-f-f-t
And who cares what fudge-factor impresses YOU? Especially if it's integral to a $20 million dollar research project, but it's ad hoc nature raises questions about not only it's validity, but the validity of the NIST report, in general?
QUOTE
But maybe if you applied a little COMMON SENSE it would help you to realize that SAGGING of 60' lightweight concrete floor trusses in a multistory fire, particularly when some to much of their insulation has been scoured off, is to be EXPECTED.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
QUOTE (->
| QUOTE |
But maybe if you applied a little COMMON SENSE it would help you to realize that SAGGING of 60' lightweight concrete floor trusses in a multistory fire, particularly when some to much of their insulation has been scoured off, is to be EXPECTED. |
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
The bowing in of the columns can't happen if the floors are providing lateral support, but testing shows that in most cases they would sag rather than disconnect.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
QUOTE
So when the bowing of the perimeter columns IS observed in the real towers then it clearly makes sense to include the sagging of the trusses and bowing in of the perimeter columns in the models.
Irrelevant, the question has to do with properly quantifying the magnitude (and direction, actually) of the horizontal force associated with a sagging floor truss.
As should be obvious, some folks like to swallow anything they're presented, as long as it fits into their pre-conceived notions, and don't care whether it can be validated, or not.
Arthur, David, anyone,
I can't remember...does NIST discuss the cooling of sagging trusses?
As trusses first heat, they lengthen, not sag, and push perimeter columns outward.
As trusses heat more, they soften, sag, and exert a catenary pull (inward).
If trusses cool and shorten while in the sagging position, tensile action will add to the inward pull.
Does NIST discuss the extra pull-in force of cooling / shortening trusses?
(I'm finding my memory of the NIST Reports diffusing a bit, between the passage of time and the din of JREF. By the way, David, I see where I was off it bit. It's the cores that were aluminum.
)
Mix
I can't remember...does NIST discuss the cooling of sagging trusses?
As trusses first heat, they lengthen, not sag, and push perimeter columns outward.
As trusses heat more, they soften, sag, and exert a catenary pull (inward).
If trusses cool and shorten while in the sagging position, tensile action will add to the inward pull.
Does NIST discuss the extra pull-in force of cooling / shortening trusses?
(I'm finding my memory of the NIST Reports diffusing a bit, between the passage of time and the din of JREF. By the way, David, I see where I was off it bit. It's the cores that were aluminum.
)Mix
QUOTE (Max Photon+Jan 9 2008, 08:22 AM)
I can't remember...does NIST discuss the cooling of sagging trusses?
As trusses first heat, they lengthen, not sag, and push perimeter columns outward.
As trusses heat more, they soften, sag, and exert a catenary pull (inward).
If trusses cool and shorten while in the sagging position, tensile action will add to the inward pull.
Does NIST discuss the extra pull-in force of cooling / shortening trusses?
AFAIK, NIST does not discuss this behavior.
If you look at the graphs (such as fig 5-8 in 1-6C) the horizontal forces are simply measured by temp.
This shows essentially more pull in forces based on the increasing temp of the truss, until failure or truss walks off of seat.
To model a cooling impact one would have to see a graph that shows a peak truss temp reached and then a new graph of the force as the temp decreased.
Arthur
As trusses first heat, they lengthen, not sag, and push perimeter columns outward.
As trusses heat more, they soften, sag, and exert a catenary pull (inward).
If trusses cool and shorten while in the sagging position, tensile action will add to the inward pull.
Does NIST discuss the extra pull-in force of cooling / shortening trusses?
AFAIK, NIST does not discuss this behavior.
If you look at the graphs (such as fig 5-8 in 1-6C) the horizontal forces are simply measured by temp.
This shows essentially more pull in forces based on the increasing temp of the truss, until failure or truss walks off of seat.
To model a cooling impact one would have to see a graph that shows a peak truss temp reached and then a new graph of the force as the temp decreased.
Arthur
A typical WTC core column (1003) showing cross sections of all 42 elements from top to bottom, courtesy someone over at jref.
(click for larger view)
(click for larger view)
QUOTE (einsteen+Jan 9 2008, 07:07 AM)
I don't think the squibs are explained. There is an attempt to explain them with air. From recent video observation I'm absolutely convinced that this model doesn't hold. Max, the collapse itself is very interesting.
Since the interior funnel effect is racing ahead of the exterior collapse front generating heat and pressure waves I believe explosive gasses trapped in the buildings do to the redesign of said buildings to prevent chimney effects would be an excellent cause of the So called low explosive squibs.
They are definitely not a high explosive phenomena, they look like gun powder explosions more than anything else that would seem to confirm explosive gasses like carbon monoxide with carbon as the primary source.
Since the interior funnel effect is racing ahead of the exterior collapse front generating heat and pressure waves I believe explosive gasses trapped in the buildings do to the redesign of said buildings to prevent chimney effects would be an excellent cause of the So called low explosive squibs.
They are definitely not a high explosive phenomena, they look like gun powder explosions more than anything else that would seem to confirm explosive gasses like carbon monoxide with carbon as the primary source.
QUOTE (metamars+Jan 9 2008, 04:35 AM)
studio cassette tapes are 25-35 microns
compact audio cassette tapes 16 microns
( http://en.wikipedia.org/wiki/Audio_tape_length_and_thickness )
Somebody else can look up eggshells.
How about the oxide paints used on the aircrafts?
Aluminum White, and iron oxide red and yellow?
There are so many potential sources that this is now ridiculous.
compact audio cassette tapes 16 microns
( http://en.wikipedia.org/wiki/Audio_tape_length_and_thickness )
Somebody else can look up eggshells.
How about the oxide paints used on the aircrafts?
Aluminum White, and iron oxide red and yellow?
There are so many potential sources that this is now ridiculous.
David, NEU-FONZE, OneWhiteEye, Max-Mihop, CC and of course the rest,
I had plans to work out the following very precisely, but maybe I can better post this
now because if it is old (already 'debunked') info then I know that I have
to stop and can spend my time better.
The south tower's top section topples as we all know. It seems that some
rows of squibs (I know it is not the best word) or puffs appear when
the top block starts toppling. I've currently only synchronized two videos,
one with the camera perpendicular to the wall, in this direction the block
topples (it topples mainly in that direction and a little bit to the left).
The other video is from front/right, about 45 degrees very far away.
Let's go back to these videos (it's not needed to download them but they are here for reference)
http://rapidshare.com/files/80160735/911.w...headon.avi.html
http://rapidshare.com/files/82166625/south...lapse.mpeg.html
We've seen before that when we take into account the distance that the rumbling
sound already starts before a part of the top section hits the next floor.
But audio could be faked very easily, something that we've seen in the past. On the
other hand it could also be that the sound of the first video is genuine but shifted
in order to correct for the time delay. Personally I don't believe this because I've
seen more videos that show this. But let's skip the audio and concentrate on the
visual evidence.
The first video (and also the 2nd) show that there appears some rows of what is often
called squibs. See the following animated gif:
http://i17.tinypic.com/8ekther.gif
If we synchronize both videos and extract some frames we get
http://i10.tinypic.com/6sum8a9.jpg
http://i3.tinypic.com/6y1bwcp.jpg
http://i9.tinypic.com/71dr2vn.jpg
http://i6.tinypic.com/6yjwc2q.jpg
The red line in the picture is the low part of the impact zone and the yellow lines
are the locations where the squibs seem to originate. If we take the average of these four images we get the following
http://i18.tinypic.com/86ocrqa.jpg
This easily shows that the average distance between the rows of squibs doesn't fit
the height of a story. Although there is an error margin in the measurements it is
absolutely clear that we see distinct rows, especially when you look at the videos
in detail. The 2nd row clearly originates from the mechanical floors. The colour is
also different than the colour of the smoke at top, I don't know what that means but that's just an observation.
Since for the first video a width of 108 pixels is 64 meter the distance between the
yellow lines is resp 14 and 20 pixels, i.e. 8.3 meter and 11.9 meter
The distance of a story is known and that is roughly 3.78 meter. This means that it
cannot be made plausible that the squibs are caused by the air pressed out, because
1) it doesn't fit with the distance between the floors
2) the top section topples, which means that the lowest floor of that section and
the next one of the intact building cannot enclose the air. The effect could play a role when enough floors are pancaked.
3) the velocity is relatively low in the beginning
4) if the top section breaks the concrete of the intact floors and the effect is due to the ejection of dust caused by these collisions then the distance should also be the same as in 1)
In the first video we also observe something else that is important, the following
animated gif has been made for that
http://i6.tinypic.com/853hms5.gif
The left wall of the south tower (seen from video) is the right part of the animation. That object is more than 5 meter because it is about 10 pixels and therefore no human being.
The average image trick cannot be used here and I placed roughly white spots on the estimated centre of mass of the object, and did an image calculation with
paint shop pro that takes the lightest of two pictures and then for a couple of extracted frames, this will give the following single picture with the trajectory of the object (this is O.W.E. stuff of course) :
http://i3.tinypic.com/8eh9w2h.png
Here a parabole should be added into. In the video it almost looks like it is ejected from mid-air which is an optical illusion because of the dark smoke and debris around it. Therefore we have to assume it comes from the building. I did a rough calculation and it looks like the horizontal ejection speed is about 13 m/s
while there is barely motion. Could a wedge effect account for this ?
I had plans to work out the following very precisely, but maybe I can better post this
now because if it is old (already 'debunked') info then I know that I have
to stop and can spend my time better.
The south tower's top section topples as we all know. It seems that some
rows of squibs (I know it is not the best word) or puffs appear when
the top block starts toppling. I've currently only synchronized two videos,
one with the camera perpendicular to the wall, in this direction the block
topples (it topples mainly in that direction and a little bit to the left).
The other video is from front/right, about 45 degrees very far away.
Let's go back to these videos (it's not needed to download them but they are here for reference)
http://rapidshare.com/files/80160735/911.w...headon.avi.html
http://rapidshare.com/files/82166625/south...lapse.mpeg.html
We've seen before that when we take into account the distance that the rumbling
sound already starts before a part of the top section hits the next floor.
But audio could be faked very easily, something that we've seen in the past. On the
other hand it could also be that the sound of the first video is genuine but shifted
in order to correct for the time delay. Personally I don't believe this because I've
seen more videos that show this. But let's skip the audio and concentrate on the
visual evidence.
The first video (and also the 2nd) show that there appears some rows of what is often
called squibs. See the following animated gif:
http://i17.tinypic.com/8ekther.gif
If we synchronize both videos and extract some frames we get
http://i10.tinypic.com/6sum8a9.jpg
http://i3.tinypic.com/6y1bwcp.jpg
http://i9.tinypic.com/71dr2vn.jpg
http://i6.tinypic.com/6yjwc2q.jpg
The red line in the picture is the low part of the impact zone and the yellow lines
are the locations where the squibs seem to originate. If we take the average of these four images we get the following
http://i18.tinypic.com/86ocrqa.jpg
This easily shows that the average distance between the rows of squibs doesn't fit
the height of a story. Although there is an error margin in the measurements it is
absolutely clear that we see distinct rows, especially when you look at the videos
in detail. The 2nd row clearly originates from the mechanical floors. The colour is
also different than the colour of the smoke at top, I don't know what that means but that's just an observation.
Since for the first video a width of 108 pixels is 64 meter the distance between the
yellow lines is resp 14 and 20 pixels, i.e. 8.3 meter and 11.9 meter
The distance of a story is known and that is roughly 3.78 meter. This means that it
cannot be made plausible that the squibs are caused by the air pressed out, because
1) it doesn't fit with the distance between the floors
2) the top section topples, which means that the lowest floor of that section and
the next one of the intact building cannot enclose the air. The effect could play a role when enough floors are pancaked.
3) the velocity is relatively low in the beginning
4) if the top section breaks the concrete of the intact floors and the effect is due to the ejection of dust caused by these collisions then the distance should also be the same as in 1)
In the first video we also observe something else that is important, the following
animated gif has been made for that
http://i6.tinypic.com/853hms5.gif
The left wall of the south tower (seen from video) is the right part of the animation. That object is more than 5 meter because it is about 10 pixels and therefore no human being.
The average image trick cannot be used here and I placed roughly white spots on the estimated centre of mass of the object, and did an image calculation with
paint shop pro that takes the lightest of two pictures and then for a couple of extracted frames, this will give the following single picture with the trajectory of the object (this is O.W.E. stuff of course) :
http://i3.tinypic.com/8eh9w2h.png
Here a parabole should be added into. In the video it almost looks like it is ejected from mid-air which is an optical illusion because of the dark smoke and debris around it. Therefore we have to assume it comes from the building. I did a rough calculation and it looks like the horizontal ejection speed is about 13 m/s
while there is barely motion. Could a wedge effect account for this ?
Video analysis of WTC collapse using Physics Toolkit
Video demonstration of using Physics Toolkit to calculate "horizontal velocity" of some WTC ejecta (actually, it's a lower bound, since we're not guaranteed that the ejecta is moving in a perpendicular plane to the observer). He shows this speed is over 70 mph.
I'm not sure he's correctly compensated for the buildings he's using as a reference (one of the towers, and WTC 7) deviating from perpendicular to him.
http://www.youtube.com/watch?v=Ah2hTMOlD5s
More such video measurements at the bottom section, "My Own Two Cents Worth: Applying Basic Physics to the Evidence" at
http://www.911speakout.org/
Video demonstration of using Physics Toolkit to calculate "horizontal velocity" of some WTC ejecta (actually, it's a lower bound, since we're not guaranteed that the ejecta is moving in a perpendicular plane to the observer). He shows this speed is over 70 mph.
I'm not sure he's correctly compensated for the buildings he's using as a reference (one of the towers, and WTC 7) deviating from perpendicular to him.
http://www.youtube.com/watch?v=Ah2hTMOlD5s
More such video measurements at the bottom section, "My Own Two Cents Worth: Applying Basic Physics to the Evidence" at
http://www.911speakout.org/
Einsteen, the "squibs" are the result of the floors within the structure falling atop one another INSIDE the frame of the building. The air from each floor is being forced out the windows along with some debris. It isnt an explosion. it is air being forced out the sides of the building as a result of debrising falling on top of it.
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
QUOTE (ASSBAG+Jan 9 2008, 07:14 PM)
Einsteen, the "squibs" are the result of the floors within the structure falling atop one another INSIDE the frame of the building. The air from each floor is being forced out the windows along with some debris. It isnt an explosion. it is air being forced out the sides of the building.
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
Hi AB,
Let's look at it from a pure pancaking point of view within the frame, a 100% perfect symmetrical funneling within the perimeter and core columns. Then my story is exactly the same.
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
Hi AB,
Let's look at it from a pure pancaking point of view within the frame, a 100% perfect symmetrical funneling within the perimeter and core columns. Then my story is exactly the same.
QUOTE (einsteen+Jan 9 2008, 02:18 PM)
Hi AB,
Let's look at it from a pure pancaking point of view within the frame, a 100% perfect symmetrical funneling within the perimeter and core columns. Then my story is exactly the same.
The strength of the glass to contain the debris falling from above compared to the outer structure is negligible. Since the building is essentially falling from within, the debris is building up inside the structure which is building up the pressure. Some of that pressure is released on floors below because the debris INSIDE the building has collapsed before the external walls have collapsed. The external walls are holding the debris inside until the strength of those walls is overcome by the force of the debris pushing on them.
Thus, the windows are popping out before the walls since they are weaker. There is no third party influence to the windows being blown out. It is all self contained.
Let's look at it from a pure pancaking point of view within the frame, a 100% perfect symmetrical funneling within the perimeter and core columns. Then my story is exactly the same.
The strength of the glass to contain the debris falling from above compared to the outer structure is negligible. Since the building is essentially falling from within, the debris is building up inside the structure which is building up the pressure. Some of that pressure is released on floors below because the debris INSIDE the building has collapsed before the external walls have collapsed. The external walls are holding the debris inside until the strength of those walls is overcome by the force of the debris pushing on them.
Thus, the windows are popping out before the walls since they are weaker. There is no third party influence to the windows being blown out. It is all self contained.
QUOTE (Max Photon+Jan 8 2008, 08:27 PM)
Perhaps the second harmonic of a vertical avalanche can explain the "squibs".
I believe the current non-CD explanation of the "squibs" is some version of a piston effect, or over-pressures, or what have you.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
"cascade of reaching ahead"
... as the WTC avalanche advanced, it was not a one-floor-at-a-time front.
Alas no. Fluids do not have, strictly speaking, harmonics.
Yes. See einsteen's animated gifs a few post back. A substantial portion of the core was voids. Overpressure makes its way down to the floors below the collapse front and blows out the windows. Just 7% overpressure suffices (and this happens to be approximately the same as the percentage of each floor which was void. Just coincidence.)
Not likely. Overpressure certainly occurred, there are even witness reports about it. The ones occurring 'far in advance' were most likely on floors with blown open elevator doors and already cracked or broken windows, both effects from the aircraft impact and the resulting fireballs.
That is a good turn of phrase. However, in the towers the reaching ahead was limited by the floor below. For a flowing snow avalanche there are no such obvious fingers, rather snow that was stationary becomes mobilized, extended the front of the avalanche. This would be more like what occurred in the towers.
That is correct, even for WTC 1 after about 1 second of collapse. THe reason, in both towers, is the tilting meant that after a short time several floors were in various stages of being crushed at the same time.
P.S. Your description of the waterfall was very good! I've seen similar effects on many waterfalls, including Yosemite Falls. I might try to describe these as vertical eddies. This is turbulence under the strong influence of gravity.
I believe the current non-CD explanation of the "squibs" is some version of a piston effect, or over-pressures, or what have you.
I propose that another explanation for the squibs might be that "fingers" of the avalanche raced ahead of the externally-perceived collapse front, and that the "squibs" - especially those far ahead of the collapse front - are from over-pressures and "blast damage" from these destructive vanguard fingers of collapse.
"cascade of reaching ahead"
... as the WTC avalanche advanced, it was not a one-floor-at-a-time front.
Alas no. Fluids do not have, strictly speaking, harmonics.
Yes. See einsteen's animated gifs a few post back. A substantial portion of the core was voids. Overpressure makes its way down to the floors below the collapse front and blows out the windows. Just 7% overpressure suffices (and this happens to be approximately the same as the percentage of each floor which was void. Just coincidence.)
Not likely. Overpressure certainly occurred, there are even witness reports about it. The ones occurring 'far in advance' were most likely on floors with blown open elevator doors and already cracked or broken windows, both effects from the aircraft impact and the resulting fireballs.
That is a good turn of phrase. However, in the towers the reaching ahead was limited by the floor below. For a flowing snow avalanche there are no such obvious fingers, rather snow that was stationary becomes mobilized, extended the front of the avalanche. This would be more like what occurred in the towers.
That is correct, even for WTC 1 after about 1 second of collapse. THe reason, in both towers, is the tilting meant that after a short time several floors were in various stages of being crushed at the same time.
P.S. Your description of the waterfall was very good! I've seen similar effects on many waterfalls, including Yosemite Falls. I might try to describe these as vertical eddies. This is turbulence under the strong influence of gravity.
QUOTE (einsteen+Jan 9 2008, 11:43 AM)
... if it is old ...
The south tower's top section topples as we all know. It seems that some
rows of squibs (I know it is not the best word) or puffs appear when
the top block starts toppling.
... That object is more than 5 meter because it is about 10 pixels and therefore no human being.
Here a parabole[sic] should be added into. In the video it almost looks like it is ejected from mid-air which is an optical illusion because of the dark smoke and debris around it. Therefore we have to assume it comes from the building. I did a rough calculation and it looks like the horizontal ejection speed is about 13 m/s
while there is barely motion. Could a wedge effect account for this ?
I have never seen this before. Thank you for your effort.
Yes, this is air being forced down the voids in the core (or around the ends of paritially detached floors). This causes overpressure sufficient to break the windows. (Do recall that not all floors were the same height. In particular floors 74, 75, 76 and 78 were 14 feet high.)
Can you tell how thick it is?
Yes. For WTC 2 about 2--3 floors all collapsed at about the same instant. Recall how massive the upper portion was.
The south tower's top section topples as we all know. It seems that some
rows of squibs (I know it is not the best word) or puffs appear when
the top block starts toppling.
... That object is more than 5 meter because it is about 10 pixels and therefore no human being.
Here a parabole[sic] should be added into. In the video it almost looks like it is ejected from mid-air which is an optical illusion because of the dark smoke and debris around it. Therefore we have to assume it comes from the building. I did a rough calculation and it looks like the horizontal ejection speed is about 13 m/s
while there is barely motion. Could a wedge effect account for this ?
I have never seen this before. Thank you for your effort.
Yes, this is air being forced down the voids in the core (or around the ends of paritially detached floors). This causes overpressure sufficient to break the windows. (Do recall that not all floors were the same height. In particular floors 74, 75, 76 and 78 were 14 feet high.)
Can you tell how thick it is?
Yes. For WTC 2 about 2--3 floors all collapsed at about the same instant. Recall how massive the upper portion was.
QUOTE (David B. Benson+Jan 9 2008, 09:54 PM)
Alas no. Fluids do not have, strictly speaking, harmonics.
Yes. See einsteen's animated gifs a few post back. A substantial portion of the core was voids. Overpressure makes its way down to the floors below the collapse front and blows out the windows. Just 7% overpressure suffices (and this happens to be approximately the same as the percentage of each floor which was void. Just coincidence.)
Not likely. Overpressure certainly occurred, there are even witness reports about it. The ones occurring 'far in advance' were most likely on floors with blown open elevator doors and already cracked or broken windows, both effects from the aircraft impact and the resulting fireballs.
That is a good turn of phrase. However, in the towers the reaching ahead was limited by the floor below. For a flowing snow avalanche there are no such obvious fingers, rather snow that was stationary becomes mobilized, extended the front of the avalanche. This would be more like what occurred in the towers.
That is correct, even for WTC 1 after about 1 second of collapse. THe reason, in both towers, is the tilting meant that after a short time several floors were in various stages of being crushed at the same time.
P.S. Your description of the waterfall was very good! I've seen similar effects on many waterfalls, including Yosemite Falls. I might try to describe these as vertical eddies. This is turbulence under the strong influence of gravity.
David,
Just so I'm clear, do you imagine an internal collapse front or avalanche front (hidden from view by the perimeter) as being roughly a horizontal plane moving downward, or do you imagine a more complex internal cascade of sections - some extending ahead of others at various times? (The more complex version is what I meant by second harmonic of the avalanche.)
As to the waterfall dynamics, those are neat aren't they?
Your term "vertical eddies" is perfect. Indeed, those forms - those turbulent forms - those dissipative structures - spontaneously emerge, and function to allow for greater through-put than if the water all fell like a bunch of Newton's apples.
All of this reminds me of my artistic days at JREF...
Viscous Thinking
(A poem by Max Photon)
Big idiots have little idiots,
That feed on their lucidity.
Little idiots have smaller idiots,
And so on to stupidity.
Maxspear
Yes. See einsteen's animated gifs a few post back. A substantial portion of the core was voids. Overpressure makes its way down to the floors below the collapse front and blows out the windows. Just 7% overpressure suffices (and this happens to be approximately the same as the percentage of each floor which was void. Just coincidence.)
Not likely. Overpressure certainly occurred, there are even witness reports about it. The ones occurring 'far in advance' were most likely on floors with blown open elevator doors and already cracked or broken windows, both effects from the aircraft impact and the resulting fireballs.
That is a good turn of phrase. However, in the towers the reaching ahead was limited by the floor below. For a flowing snow avalanche there are no such obvious fingers, rather snow that was stationary becomes mobilized, extended the front of the avalanche. This would be more like what occurred in the towers.
That is correct, even for WTC 1 after about 1 second of collapse. THe reason, in both towers, is the tilting meant that after a short time several floors were in various stages of being crushed at the same time.
P.S. Your description of the waterfall was very good! I've seen similar effects on many waterfalls, including Yosemite Falls. I might try to describe these as vertical eddies. This is turbulence under the strong influence of gravity.
David,
Just so I'm clear, do you imagine an internal collapse front or avalanche front (hidden from view by the perimeter) as being roughly a horizontal plane moving downward, or do you imagine a more complex internal cascade of sections - some extending ahead of others at various times? (The more complex version is what I meant by second harmonic of the avalanche.)
As to the waterfall dynamics, those are neat aren't they?
Your term "vertical eddies" is perfect. Indeed, those forms - those turbulent forms - those dissipative structures - spontaneously emerge, and function to allow for greater through-put than if the water all fell like a bunch of Newton's apples.
All of this reminds me of my artistic days at JREF...
Viscous Thinking
(A poem by Max Photon)
Big idiots have little idiots,
That feed on their lucidity.
Little idiots have smaller idiots,
And so on to stupidity.
Maxspear
Gentle readers,
People will often annoy me with such elementary questions as:
[plug in nasal, whiney voice here]
"Max, how in God's creation could military deception and demolition planners hide controlled-demolition in plain view? How did they cloak the demolitions, for heaven's sake?" Wouldn't experts see right through the deception? Wouldn't whistle-blowers, you know...blow?"
Here's how.
Max
People will often annoy me with such elementary questions as:
[plug in nasal, whiney voice here]
"Max, how in God's creation could military deception and demolition planners hide controlled-demolition in plain view? How did they cloak the demolitions, for heaven's sake?" Wouldn't experts see right through the deception? Wouldn't whistle-blowers, you know...blow?"
Here's how.
Max
QUOTE (Max Photon+Jan 9 2008, 03:26 PM)
... do you imagine an internal collapse front or avalanche front (hidden from view by the perimeter) as being roughly a horizontal plane moving downward,
or do you imagine a more complex internal cascade of sections - some extending ahead of others at various times?
===================
Viscous Thinking
(A poem by Max Photon)
Big idiots have little idiots,
That feed on their lucidity.
Little idiots have smaller idiots,
And so on to stupidity.
Roughly horizontal, yes. The tilt implies it extends over several floors at once.
No evidence for this. Nor is this the way that fluidized solids, such as snow, behave.
===================
I'd like to share this on other fora, if I may?
or do you imagine a more complex internal cascade of sections - some extending ahead of others at various times?
===================
Viscous Thinking
(A poem by Max Photon)
Big idiots have little idiots,
That feed on their lucidity.
Little idiots have smaller idiots,
And so on to stupidity.
Roughly horizontal, yes. The tilt implies it extends over several floors at once.
No evidence for this. Nor is this the way that fluidized solids, such as snow, behave.
===================
I'd like to share this on other fora, if I may?
Feel free.
QUOTE (Max Photon+Jan 9 2008, 04:02 PM)
Feel free.
Thanks.
Thanks.
QUOTE (metamars+Jan 9 2008, 12:51 AM)
Especially if it's integral to a $20 million dollar research project, ...
... but the validity of the NIST report, in general?
.. the horizontal force associated with a sagging floor truss.
It's not.
Nonsense.
Not a sagging floor truss. That is easy to work out. The difficulty lies in determining the pull-in force associated with a partially disconnected whole floor of trusses, some of which are sagging.
... but the validity of the NIST report, in general?
.. the horizontal force associated with a sagging floor truss.
It's not.
Nonsense.
Not a sagging floor truss. That is easy to work out. The difficulty lies in determining the pull-in force associated with a partially disconnected whole floor of trusses, some of which are sagging.
AB:
I thought the collapse of WTC 2 was initiated by the bowing of the east EXTERIOR wall. Why would the inside of a tower fall faster than the outside when the outside failed first?
I thought the collapse of WTC 2 was initiated by the bowing of the east EXTERIOR wall. Why would the inside of a tower fall faster than the outside when the outside failed first?
NEU-FONZE --- What is your reaction to an E1 in excess of 53 gigajoules per story?
QUOTE (Max Photon+Jan 9 2008, 04:40 PM)
People will often annoy me with such elementary questions as:
[plug in nasal, whiney voice here]
"Max, how in God's creation could military deception and demolition planners hide controlled-demolition in plain view?
People annoy me too, with their silly ideas, especially when they have no clue how impossible it would be to install demo-charges without anybody knowing it.
Ok, start with something real simple. How did the thermite get TO the building? A truck, unloaded at the loading dock? Who took delivery and how could they distribute it to the floors without anybody seeing? Don't say 'during a powerdown', because the elevators would be out of service. That pretty much leaves thermite fairies humping it up the stairs. THAT'S alot of fairies!
Prolly took that many construction fairies too, to set the charges, busting out walls, chipping concrete, etc... without a soul noticing it.
I've got plenty more problems you/they would have to overcome, but let's let you tackle the easy ones first.
QUOTE (einsteen+Jan 9 2008, 06:43 PM)
David, NEU-FONZE, OneWhiteEye, Max-Mihop, CC and of course the rest...
Excellent work. I'd have to spend more time with it to say anything of substance. About the only thing that jumps out at me is the 11.9 meter figure is quite close to 3 floors height. A floor or two worth of debris could explain some deviation from uniformity. If uniformity is expected.
The expulsions are an intriguing topic; not all instances equally so. I've haven't examined the issue in any depth so my opinions would be ill-formed at this time.
Excellent work. I'd have to spend more time with it to say anything of substance. About the only thing that jumps out at me is the 11.9 meter figure is quite close to 3 floors height. A floor or two worth of debris could explain some deviation from uniformity. If uniformity is expected.
The expulsions are an intriguing topic; not all instances equally so. I've haven't examined the issue in any depth so my opinions would be ill-formed at this time.
QUOTE (David B. Benson+Jan 10 2008, 12:31 AM)
It's not.
Nonsense.
Not a sagging floor truss. That is easy to work out. The difficulty lies in determining the pull-in force associated with a partially disconnected whole floor of trusses, some of which are sagging.
Why is it nonsense? If a Ph.D. candidate comes along in 5 or 50 years, models floor trusses to an uber degree of accuracy, but can in no way generate pullin in forces claimed by NIST, why should we trust anything else that NIST has done?
Correct me if I'm wrong, but the only thing close to a verification of any aspect of the NIST report was the Purdue study. Which, as we know, had significant differences with it.
Nonsense.
Not a sagging floor truss. That is easy to work out. The difficulty lies in determining the pull-in force associated with a partially disconnected whole floor of trusses, some of which are sagging.
Why is it nonsense? If a Ph.D. candidate comes along in 5 or 50 years, models floor trusses to an uber degree of accuracy, but can in no way generate pullin in forces claimed by NIST, why should we trust anything else that NIST has done?
Correct me if I'm wrong, but the only thing close to a verification of any aspect of the NIST report was the Purdue study. Which, as we know, had significant differences with it.
QUOTE (metamars+Jan 9 2008, 06:57 PM)
Video analysis of WTC collapse using Physics Toolkit
Video demonstration of using Physics Toolkit to calculate "horizontal velocity" of some WTC ejecta (actually, it's a lower bound, since we're not guaranteed that the ejecta is moving in a perpendicular plane to the observer). He shows this speed is over 70 mph.
I'm not sure he's correctly compensated for the buildings he's using as a reference (one of the towers, and WTC 7) deviating from perpendicular to him.
http://www.youtube.com/watch?v=Ah2hTMOlD5s
More such video measurements at the bottom section, "My Own Two Cents Worth: Applying Basic Physics to the Evidence" at
http://www.911speakout.org/
The Physics Toolkit looks nice (470MB though, and "can't handle too many points").
I watched the WTC7 analysis; he gets 9.186 m/s^2.
edit: never mind the original edit
Video demonstration of using Physics Toolkit to calculate "horizontal velocity" of some WTC ejecta (actually, it's a lower bound, since we're not guaranteed that the ejecta is moving in a perpendicular plane to the observer). He shows this speed is over 70 mph.
I'm not sure he's correctly compensated for the buildings he's using as a reference (one of the towers, and WTC 7) deviating from perpendicular to him.
http://www.youtube.com/watch?v=Ah2hTMOlD5s
More such video measurements at the bottom section, "My Own Two Cents Worth: Applying Basic Physics to the Evidence" at
http://www.911speakout.org/
The Physics Toolkit looks nice (470MB though, and "can't handle too many points").
I watched the WTC7 analysis; he gets 9.186 m/s^2.
edit: never mind the original edit
QUOTE (ASSBAG+Jan 9 2008, 07:14 PM)
Einsteen, the "squibs" are the result of the floors within the structure falling atop one another INSIDE the frame of the building. The air from each floor is being forced out the windows along with some debris. It isnt an explosion. it is air being forced out the sides of the building as a result of debrising falling on top of it.
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
Welcome, ASSBAG. Are you my mother-in-law?
I admire your certainty and confidence.
What makes these people think that the exterior of the building had to have fallen at the same time and rate as the interior of the building...
Welcome, ASSBAG. Are you my mother-in-law?
I admire your certainty and confidence.
QUOTE (David B. Benson+Jan 9 2008, 02:24 AM)
Checking this against the run I reported in the previous post, all this implies a terminal speed of only about 25--26 m/s, which should come as a surprise to many...
Believe it or not, I'd been thinking on asking about terminal velocity. I wish I had time to discuss this in more detail, without the low-bandwidth communication.
Believe it or not, I'd been thinking on asking about terminal velocity. I wish I had time to discuss this in more detail, without the low-bandwidth communication.
DBB:
53 GJ per story?
Is that for the collapse of the pyramids?
53 GJ per story?
Is that for the collapse of the pyramids?
DBB see Nile
QUOTE (NEU-FONZE+Jan 10 2008, 12:53 AM)
AB:
I thought the collapse of WTC 2 was initiated by the bowing of the east EXTERIOR wall. Why would the inside of a tower fall faster than the outside when the outside failed first?
Neu-Fonze,
I think DBB's notion - (he can correct me if I'm wrong) - is that when the east face of WTC2 bows inward and fails, the upper block essentially falls inside the chute of the perimeter of the lower block.
Note that the upper perimeter panels of the lower block peel outward in relatively slow motion, pushed outward to start by the avalanche within, but then becoming gravity driven. (It takes them some time to fall outward from their upright position.)
So despite the fact that the perimeter fails first, an avalanche travels down the chute of the perimeter faster than the perimeter peels outward.
If this is the case, then the location in time of the dreadlocks of panels - the banana peel plumes - would not be representative of the avalanche hidden within.
(This is why I asked if the lowest "squibs", seen waaayyyy below the collapse front, might be from the most advanced fronts of the interior avalanche. I also asked David if the internal avalanche front was basically a horizontal plane, or if it was significantly asymmetric.)
Max
ETA: Now as to what Arthur thinks, get in line. I asked him a question first.
ETA2: Sorry, get in queue.
I thought the collapse of WTC 2 was initiated by the bowing of the east EXTERIOR wall. Why would the inside of a tower fall faster than the outside when the outside failed first?
Neu-Fonze,
I think DBB's notion - (he can correct me if I'm wrong) - is that when the east face of WTC2 bows inward and fails, the upper block essentially falls inside the chute of the perimeter of the lower block.
Note that the upper perimeter panels of the lower block peel outward in relatively slow motion, pushed outward to start by the avalanche within, but then becoming gravity driven. (It takes them some time to fall outward from their upright position.)
So despite the fact that the perimeter fails first, an avalanche travels down the chute of the perimeter faster than the perimeter peels outward.
If this is the case, then the location in time of the dreadlocks of panels - the banana peel plumes - would not be representative of the avalanche hidden within.
(This is why I asked if the lowest "squibs", seen waaayyyy below the collapse front, might be from the most advanced fronts of the interior avalanche. I also asked David if the internal avalanche front was basically a horizontal plane, or if it was significantly asymmetric.)
Max
ETA: Now as to what Arthur thinks, get in line. I asked him a question first.
ETA2: Sorry, get in queue.
QUOTE (Max Photon+Jan 7 2008, 04:10 PM)
Arthur,
Earlier I presented the following:
WTC Stabilized Thermite Video (17 second)
(Click the video viewer's lower right icon to watch the video in Full-Screen mode.)
(Note that this video is made up of two spliced segments.)
If one downloads this video from the internet, and uses video-processing software to watch the video frame-by-frame, one can see that in the first 1/2 second, there is a series of quick flashes at the tops and bottoms of spandrels.
Looking frame-by-frame, one also sees a series of fleeting white flashes traveling from the upper right to the lower left at a diagonal consistent with the diagonal of the offset panel splices.
The flashes - when viewed frame-by-frame - appear to be traveling along a wire-of-sorts. And it appears that the flashes intersect column splices and spandrel splices.
Note that the flashes are only visible where the cladding is missing, suggesting that the "wire" the flashes are traveling along was between the cladding and the steel, and has been exposed when over-pressures removed the cladding.
Note that after a sequence of flashes goes by, a white smoke tail appears, as if the "wire" burned, or as if discrete things burned sequentially along the flash's trajectory. (These are NIST's "coordinated smoke puffs reminiscent of old fashioned steam driven pipe organs", described in NCSTAR 1-5A/9/C.)
Note, just to the left of the metal flow, a white glow - much like a mini-supernova - that appears, correlated with the flash sequences.
Now Arthur, your first best guess was that the white flashes are falling debris.
What's your second best guess?
Max
Earlier I presented the following:
WTC Stabilized Thermite Video (17 second)
(Click the video viewer's lower right icon to watch the video in Full-Screen mode.)
(Note that this video is made up of two spliced segments.)
If one downloads this video from the internet, and uses video-processing software to watch the video frame-by-frame, one can see that in the first 1/2 second, there is a series of quick flashes at the tops and bottoms of spandrels.
Looking frame-by-frame, one also sees a series of fleeting white flashes traveling from the upper right to the lower left at a diagonal consistent with the diagonal of the offset panel splices.
The flashes - when viewed frame-by-frame - appear to be traveling along a wire-of-sorts. And it appears that the flashes intersect column splices and spandrel splices.
Note that the flashes are only visible where the cladding is missing, suggesting that the "wire" the flashes are traveling along was between the cladding and the steel, and has been exposed when over-pressures removed the cladding.
Note that after a sequence of flashes goes by, a white smoke tail appears, as if the "wire" burned, or as if discrete things burned sequentially along the flash's trajectory. (These are NIST's "coordinated smoke puffs reminiscent of old fashioned steam driven pipe organs", described in NCSTAR 1-5A/9/C.)
Note, just to the left of the metal flow, a white glow - much like a mini-supernova - that appears, correlated with the flash sequences.
Now Arthur, your first best guess was that the white flashes are falling debris.
What's your second best guess?
Max
I did it a little bit more precisely and the object is ejected with about
13.6 m/s and comes from the building 10 pixels below the red line, that means
64 meter * 10/108 and that is about 5.9 meter under the red line.
If the top section falls with g (not 3g/4) then the speed it has reached could
theoretically be 10.8 m/s, but if we shift the video bak in time it seems that
it is ejected at the moment that we have this situation
http://i16.tinypic.com/8faea0j.jpg
what speed would that be ?
Theoretically it could be this effect, but that is very hypothetical
http://i3.tinypic.com/89luv89.gif
13.6 m/s and comes from the building 10 pixels below the red line, that means
64 meter * 10/108 and that is about 5.9 meter under the red line.
If the top section falls with g (not 3g/4) then the speed it has reached could
theoretically be 10.8 m/s, but if we shift the video bak in time it seems that
it is ejected at the moment that we have this situation
http://i16.tinypic.com/8faea0j.jpg
what speed would that be ?
Theoretically it could be this effect, but that is very hypothetical
http://i3.tinypic.com/89luv89.gif
QUOTE (metamars+Jan 10 2008, 03:04 AM)
Why is it nonsense? If a Ph.D. candidate comes along in 5 or 50 years, models floor trusses to an uber degree of accuracy, but can in no way generate pullin in forces claimed by NIST, why should we trust anything else that NIST has done?
Correct me if I'm wrong, but the only thing close to a verification of any aspect of the NIST report was the Purdue study. Which, as we know, had significant differences with it.
That's a big if.
Why not read the NIST report and see what they DID do?
Try NIST NCSTAR 1-6C Chap 5 Full Floor Sub-System and 1-6D Sec 2.5 Fire Damage.
Or why not consider that since the NIST report is a PUBLISHED SCIENTIFIC document that UNTIL someone disputes its findings on the Pull In force generated by the sagging Trusses and publishes a scientific report that backs up their assertions, that there is no valid reason not to "trust" it.
I know you stated before that you don't trust NIST.
You just never explained the BASIS for this lack of trust.
Do YOU think that NIST is IN ON IT???
Oh, and the Purdue study was NOT significantly different than the NIST study.
It was a FAR SIMPLER simulation than NIST performed, using far few elements, with the MAIN modeling difference being that the Purdue study left out all interior furnishings/walls. As such it showed GREATER DAMAGE to the core than the NIST model. Of course, since the interior furnishings were left out this would be EXPECTED.
Arthur
Correct me if I'm wrong, but the only thing close to a verification of any aspect of the NIST report was the Purdue study. Which, as we know, had significant differences with it.
That's a big if.
Why not read the NIST report and see what they DID do?
Try NIST NCSTAR 1-6C Chap 5 Full Floor Sub-System and 1-6D Sec 2.5 Fire Damage.
Or why not consider that since the NIST report is a PUBLISHED SCIENTIFIC document that UNTIL someone disputes its findings on the Pull In force generated by the sagging Trusses and publishes a scientific report that backs up their assertions, that there is no valid reason not to "trust" it.
I know you stated before that you don't trust NIST.
You just never explained the BASIS for this lack of trust.
Do YOU think that NIST is IN ON IT???
Oh, and the Purdue study was NOT significantly different than the NIST study.
It was a FAR SIMPLER simulation than NIST performed, using far few elements, with the MAIN modeling difference being that the Purdue study left out all interior furnishings/walls. As such it showed GREATER DAMAGE to the core than the NIST model. Of course, since the interior furnishings were left out this would be EXPECTED.
Arthur
QUOTE (Max Photon+Jan 10 2008, 09:03 AM)
Arthur,
Here is another good video.
South Tower Molten Metal (stabilized) > (1:10 minutes)
Max
Yeah,
What seems pretty obvious when viewing that (and the other video) is that the material coming out of the towers seems unlikely to be Aluminum and certainly not Iron.
Notice it bouncing off the Aluminum cladding and doing zip damage to it.
As for the white flashes, clearly its just debris falling from the towers, no wires or indeed, anything strange about the debris is visible.
Remember extraordinary claims require extraordinary proof.
Arthur
Here is another good video.
South Tower Molten Metal (stabilized) > (1:10 minutes)
Max
Yeah,
What seems pretty obvious when viewing that (and the other video) is that the material coming out of the towers seems unlikely to be Aluminum and certainly not Iron.
Notice it bouncing off the Aluminum cladding and doing zip damage to it.
As for the white flashes, clearly its just debris falling from the towers, no wires or indeed, anything strange about the debris is visible.
Remember extraordinary claims require extraordinary proof.
Arthur
QUOTE (adoucette+Jan 10 2008, 02:20 PM)
That's a big if.
Why not read the NIST report and see what they DID do?
Try NIST NCSTAR 1-6C Chap 5 Full Floor Sub-System and 1-6D Sec 2.5 Fire Damage.
Or why not consider that since the NIST report is a PUBLISHED SCIENTIFIC document that UNTIL someone disputes its findings on the Pull In force generated by the sagging Trusses and publishes a scientific report that backs up their assertions, that there is no valid reason not to "trust" it.
I know you stated before that you don't trust NIST.
You just never explained the BASIS for this lack of trust.
Do YOU think that NIST is IN ON IT???
Oh, and the Purdue study was NOT significantly different than the NIST study.
It was a FAR SIMPLER simulation than NIST performed, using far few elements, with the MAIN modeling difference being that the Purdue study left out all interior furnishings/walls. As such it showed GREATER DAMAGE to the core than the NIST model. Of course, since the interior furnishings were left out this would be EXPECTED.
Arthur
Arthur,
I'd make one little change - it's nothing really:
"...the NIST report is a PUBLISHED POLITICAL-SCIENTIFIC document..."
...oh, and one more!
"...hence there is a valid reason not to "trust" it."
Why?
Because political science is the science of lying.
Governments lie.
Repeat:
Repeat:
GOVERNMENTS LIE
The NIST Report - while a-heepin' with scientists and engineers - halos orthogonal - was produced in a certain embedding space, and that embedding space was political.
Personally, I think it is absurd not to view the collapse of the towers from two parallel lines of research: that it was an inside job, and that it was an outside job.
I would think that any real political-science minded person would do just that.
That said, I think the NIST Reports tell the truth!
In fact - and I hope you appreciate this fact - I am - I believe - THE ONLY TRUTHER - LIKE - IN THE WHOLE UNIVERSE - who argues - even with other truthers - hell, especially with other truthers - to the death! - that the NIST Reports tell the truth. In fact, I think I am slowly, single-handedly weening those truth-seeking-commie-bastards off of the explosives/molten steel/cutting/NIST is lying nonsense.
No, the NIST Reports do not lie. The reporting is honest. The science part, tres macho (although, it sure would have been easier to just look inside the box columns...but hey, I'm no expert).
The NIST Reports do not lie. NIST just doesn't come to the right conclusion. NIST is correct that if found no evidence of controlled demolition due to explosives prior to September 11. But NIST failed to say that it found evidence of controlled demolition by heat-weakening due to thermite planted prior to September 11.
Political science is often just science with a curly-cue at the end - a little twist.
The little twist is that someone hid fire in fire.
The 10 minute metal fire is the little white lie.
Maxiavelli
Why not read the NIST report and see what they DID do?
Try NIST NCSTAR 1-6C Chap 5 Full Floor Sub-System and 1-6D Sec 2.5 Fire Damage.
Or why not consider that since the NIST report is a PUBLISHED SCIENTIFIC document that UNTIL someone disputes its findings on the Pull In force generated by the sagging Trusses and publishes a scientific report that backs up their assertions, that there is no valid reason not to "trust" it.
I know you stated before that you don't trust NIST.
You just never explained the BASIS for this lack of trust.
Do YOU think that NIST is IN ON IT???
Oh, and the Purdue study was NOT significantly different than the NIST study.
It was a FAR SIMPLER simulation than NIST performed, using far few elements, with the MAIN modeling difference being that the Purdue study left out all interior furnishings/walls. As such it showed GREATER DAMAGE to the core than the NIST model. Of course, since the interior furnishings were left out this would be EXPECTED.
Arthur
Arthur,
I'd make one little change - it's nothing really:
"...the NIST report is a PUBLISHED POLITICAL-SCIENTIFIC document..."
...oh, and one more!
"...hence there is a valid reason not to "trust" it."
Why?
Because political science is the science of lying.
Governments lie.
Repeat:
Repeat:
GOVERNMENTS LIE
The NIST Report - while a-heepin' with scientists and engineers - halos orthogonal - was produced in a certain embedding space, and that embedding space was political.
Personally, I think it is absurd not to view the collapse of the towers from two parallel lines of research: that it was an inside job, and that it was an outside job.
I would think that any real political-science minded person would do just that.
That said, I think the NIST Reports tell the truth!
In fact - and I hope you appreciate this fact - I am - I believe - THE ONLY TRUTHER - LIKE - IN THE WHOLE UNIVERSE - who argues - even with other truthers - hell, especially with other truthers - to the death! - that the NIST Reports tell the truth. In fact, I think I am slowly, single-handedly weening those truth-seeking-commie-bastards off of the explosives/molten steel/cutting/NIST is lying nonsense.
No, the NIST Reports do not lie. The reporting is honest. The science part, tres macho (although, it sure would have been easier to just look inside the box columns...but hey, I'm no expert).
The NIST Reports do not lie. NIST just doesn't come to the right conclusion. NIST is correct that if found no evidence of controlled demolition due to explosives prior to September 11. But NIST failed to say that it found evidence of controlled demolition by heat-weakening due to thermite planted prior to September 11.
Political science is often just science with a curly-cue at the end - a little twist.
The little twist is that someone hid fire in fire.
The 10 minute metal fire is the little white lie.
Maxiavelli
QUOTE (adoucette+Jan 10 2008, 02:38 PM)
Yeah,
What seems pretty obvious when viewing that (and the other video) is that the material coming out of the towers seems unlikely to be Aluminum and certainly not Iron.
Notice it bouncing off the Aluminum cladding and doing zip damage to it.
As for the white flashes, clearly its just debris falling from the towers, no wires or indeed, anything strange about the debris is visible.
Remember extraordinary claims require extraordinary proof.
Arthur
Arthur,
I am intrigued you are willing to be at odds with NIST on the molten metal flows.
NIST says it is probably aluminum.
What do you think it is? Lead from UPS batteries?
Max
What seems pretty obvious when viewing that (and the other video) is that the material coming out of the towers seems unlikely to be Aluminum and certainly not Iron.
Notice it bouncing off the Aluminum cladding and doing zip damage to it.
As for the white flashes, clearly its just debris falling from the towers, no wires or indeed, anything strange about the debris is visible.
Remember extraordinary claims require extraordinary proof.
Arthur
Arthur,
I am intrigued you are willing to be at odds with NIST on the molten metal flows.
NIST says it is probably aluminum.
What do you think it is? Lead from UPS batteries?
Max
QUOTE (Max Photon+Jan 10 2008, 10:19 AM)
Arthur,
I am intrigued you are willing to be at odds with NIST on the molten metal flows.
NIST says it is probably aluminum.
What do you think it is? Lead from UPS batteries?
Max
Because I don't think NIST was aware of the huge bank of batteries above this floor.
I think that if one sees this, in the context of when NIST was doing the study, then molten Aluminum with other material mixed in, seems a reasonable assumption, given time and temps and the amount of aircraft debris in that area.
I don't think that NIST thought it was important though, as the temps for melting aluminum were not unexpected in that corner.
But, if they knew there was a massive amount of lead/acid batteries on the floor above would they come to the same assumption?
What I SUSPECT is that the melting point of lead is low enough to have melted and fallen and appeared like the material in the video and also not have harmed the aluminum cladding.
I SUSPECT, that falling molten aluminum, in the quantities seen in the videos, would have a similar look but would have had a more noticable effect on the cladding.
Arthur
I am intrigued you are willing to be at odds with NIST on the molten metal flows.
NIST says it is probably aluminum.
What do you think it is? Lead from UPS batteries?
Max
Because I don't think NIST was aware of the huge bank of batteries above this floor.
I think that if one sees this, in the context of when NIST was doing the study, then molten Aluminum with other material mixed in, seems a reasonable assumption, given time and temps and the amount of aircraft debris in that area.
I don't think that NIST thought it was important though, as the temps for melting aluminum were not unexpected in that corner.
But, if they knew there was a massive amount of lead/acid batteries on the floor above would they come to the same assumption?
What I SUSPECT is that the melting point of lead is low enough to have melted and fallen and appeared like the material in the video and also not have harmed the aluminum cladding.
I SUSPECT, that falling molten aluminum, in the quantities seen in the videos, would have a similar look but would have had a more noticable effect on the cladding.
Arthur
QUOTE (Max Photon+Jan 10 2008, 10:14 AM)
The NIST Reports do not lie. NIST just doesn't come to the right conclusion. NIST is correct that if found no evidence of controlled demolition due to explosives prior to September 11. But NIST failed to say that it found evidence of controlled demolition by heat-weakening due to thermite planted prior to September 11.
Political science is often just science with a curly-cue at the end - a little twist.
The little twist is that someone hid fire in fire.
The 10 minute metal fire is the little white lie.
While metal fires are not expected in building fires, metal fires CAN happen in aircraft crashes.
Since WTC tower was both an aircraft crash and a building fire, the 10 min metal fire in the corner does NOT constitute evidence that NIST lied or that there was thermite in the building.
So far your only EVIDENCE is lack of evidence.
Arthur
Political science is often just science with a curly-cue at the end - a little twist.
The little twist is that someone hid fire in fire.
The 10 minute metal fire is the little white lie.
While metal fires are not expected in building fires, metal fires CAN happen in aircraft crashes.
Since WTC tower was both an aircraft crash and a building fire, the 10 min metal fire in the corner does NOT constitute evidence that NIST lied or that there was thermite in the building.
So far your only EVIDENCE is lack of evidence.
Arthur
QUOTE (adoucette+Jan 10 2008, 03:55 PM)
While metal fires are not expected in building fires, metal fires CAN happen in aircraft crashes.
Since WTC tower was both an aircraft crash and a building fire, the 10 min metal fire in the corner does NOT constitute evidence that NIST lied or that there was thermite in the building.
So far your only EVIDENCE is lack of evidence.
Arthur
Is it just me, or did anyone else find WTC2's prolonged fire in the NE corner reminiscent of an old Japanese monster movie?
Max Photon
911-Godzilla
ETA - (or in this case, EAT): Come to think of it, there were a number of bad scenes in the WTC2 production.
Since WTC tower was both an aircraft crash and a building fire, the 10 min metal fire in the corner does NOT constitute evidence that NIST lied or that there was thermite in the building.
So far your only EVIDENCE is lack of evidence.
Arthur
Is it just me, or did anyone else find WTC2's prolonged fire in the NE corner reminiscent of an old Japanese monster movie?
Max Photon
911-Godzilla
ETA - (or in this case, EAT): Come to think of it, there were a number of bad scenes in the WTC2 production.
QUOTE (Max Photon+Jan 10 2008, 06:42 AM)
I think DBB's notion - (he can correct me if I'm wrong) - is that when the east face of WTC2 bows inward and fails, the upper block essentially falls inside the chute of the perimeter of the lower block.
So despite the fact that the perimeter fails first, an avalanche travels down the chute of the perimeter faster than the perimeter peels outward.
If this is the case, then the location in time of the dreadlocks of panels - the banana peel plumes - would not be representative of the avalanche hidden within.
(This is why I asked if the lowest "squibs", seen waaayyyy below the collapse front, might be from the most advanced fronts of the interior avalanche. I also asked David if the internal avalanche front was basically a horizontal plane, or if it was significantly asymmetric.)
I have only studied WTC 1 in depth. The initial collapse (and the collapse progression) of WTC 2 was much more complex.
Possibly at the beginning. Once there is enough crushed materials to push out the exterior walls, then but might go at the same rate.
The expulsion of dirty air from the towers shows the (approximate) location of the crushing front. The air must move out of the way of the descending materials before the next floor can be impacted.
"way below" No. See the paragraph just above.
========================================
By the way, the core columns were also steel. The building cladding was aluminum.
So despite the fact that the perimeter fails first, an avalanche travels down the chute of the perimeter faster than the perimeter peels outward.
If this is the case, then the location in time of the dreadlocks of panels - the banana peel plumes - would not be representative of the avalanche hidden within.
(This is why I asked if the lowest "squibs", seen waaayyyy below the collapse front, might be from the most advanced fronts of the interior avalanche. I also asked David if the internal avalanche front was basically a horizontal plane, or if it was significantly asymmetric.)
I have only studied WTC 1 in depth. The initial collapse (and the collapse progression) of WTC 2 was much more complex.
Possibly at the beginning. Once there is enough crushed materials to push out the exterior walls, then but might go at the same rate.
The expulsion of dirty air from the towers shows the (approximate) location of the crushing front. The air must move out of the way of the descending materials before the next floor can be impacted.
"way below" No. See the paragraph just above.
========================================
By the way, the core columns were also steel. The building cladding was aluminum.
QUOTE (adoucette+Jan 10 2008, 03:48 PM)
Because I don't think NIST was aware of the huge bank of batteries above this floor.
I think that if one sees this, in the context of when NIST was doing the study, then molten Aluminum with other material mixed in, seems a reasonable assumption, given time and temps and the amount of aircraft debris in that area.
I don't think that NIST thought it was important though, as the temps for melting aluminum were not unexpected in that corner.
But, if they knew there was a massive amount of lead/acid batteries on the floor above would they come to the same assumption?
What I SUSPECT is that the melting point of lead is low enough to have melted and fallen and appeared like the material in the video and also not have harmed the aluminum cladding.
I SUSPECT, that falling molten aluminum, in the quantities seen in the videos, would have a similar look but would have had a more noticable effect on the cladding.
Arthur
Arthur,
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
M
a
x
I think that if one sees this, in the context of when NIST was doing the study, then molten Aluminum with other material mixed in, seems a reasonable assumption, given time and temps and the amount of aircraft debris in that area.
I don't think that NIST thought it was important though, as the temps for melting aluminum were not unexpected in that corner.
But, if they knew there was a massive amount of lead/acid batteries on the floor above would they come to the same assumption?
What I SUSPECT is that the melting point of lead is low enough to have melted and fallen and appeared like the material in the video and also not have harmed the aluminum cladding.
I SUSPECT, that falling molten aluminum, in the quantities seen in the videos, would have a similar look but would have had a more noticable effect on the cladding.
Arthur
Arthur,
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
M
a
x
QUOTE (David B. Benson+Jan 10 2008, 06:29 PM)
By the way, the core columns were also steel. The building cladding was aluminum.
Yes David, I was kidding about the cores being aluMINium.
Also, your point is well taken that the air must move out of the way.
Max
Yes David, I was kidding about the cores being aluMINium.
Also, your point is well taken that the air must move out of the way.
Max
QUOTE (Max Photon+Jan 10 2008, 11:43 AM)
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
Are we certain the metal flows are molten lead or aluminum?
1) Nonsense.
2) Authoritative reference? I don't believe this is so, but could be wrong.
5) Oxygen generation cylinders, carried in the aircraft, are implicated.
I am certain the 'metal' flows were not! The flows might have contained some aluminum or lead, but whatever these were, the flows were 'dirty', not pure anything.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
Are we certain the metal flows are molten lead or aluminum?
1) Nonsense.
2) Authoritative reference? I don't believe this is so, but could be wrong.
5) Oxygen generation cylinders, carried in the aircraft, are implicated.
I am certain the 'metal' flows were not! The flows might have contained some aluminum or lead, but whatever these were, the flows were 'dirty', not pure anything.
David,
I have no trouble with the compressed air notion.
However, please look at this 11 second video (which I posted before).
Note the "squib" at the lower left.
Here are two short JREF posts of mine on the clip:
That ain't no squib! That's just a wisp of aluminum-oxide
A discussion of the lower ejections from WTC2
Question: Do you think that lowest LH "squib" is from overpressure?
Max PSI
I have no trouble with the compressed air notion.
However, please look at this 11 second video (which I posted before).
Note the "squib" at the lower left.
Here are two short JREF posts of mine on the clip:
That ain't no squib! That's just a wisp of aluminum-oxide
A discussion of the lower ejections from WTC2
Question: Do you think that lowest LH "squib" is from overpressure?
Max PSI
QUOTE (Max Photon+Jan 10 2008, 12:08 PM)
However, please look at this 11 second video (which I posted before).
Question: Do you think that lowest LH "squib" is from overpressure?
I can't watch videos.
Probably I have seen clips of this before, but show me some clips. In the interim, yes.
Question: Do you think that lowest LH "squib" is from overpressure?
I can't watch videos.
Probably I have seen clips of this before, but show me some clips. In the interim, yes.
QUOTE (Max Photon+Jan 10 2008, 06:43 PM)
Arthur,
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
M
a
x
Yes but the problem is Max that at yellow the sulfur is gone leaving Fe 3O4 which will not flow when bright orange or yellow.
However inclusions and confinement can make either aluminum or lead flow at yellow.
The inclusions however have to be below the oxide layer, I would also like to point out that aluminum silicate or lead silicate can flow at those temperatures and the cement is made from aluminum silicate fly ash.
Jones is right the sulfur will make the material molten at lower temperature, look up pyrites, Iron sulfides they burn in air, however they burn to quickly and to well to be the metal flowing from the towers.
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
M
a
x
Yes but the problem is Max that at yellow the sulfur is gone leaving Fe 3O4 which will not flow when bright orange or yellow.
However inclusions and confinement can make either aluminum or lead flow at yellow.
The inclusions however have to be below the oxide layer, I would also like to point out that aluminum silicate or lead silicate can flow at those temperatures and the cement is made from aluminum silicate fly ash.
Jones is right the sulfur will make the material molten at lower temperature, look up pyrites, Iron sulfides they burn in air, however they burn to quickly and to well to be the metal flowing from the towers.
QUOTE (Max Photon+Jan 10 2008, 01:43 PM)
1) The glow is too bright for lead or aluminum.
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
No, the glow is NOT too bright for lead or aluminum if it has OTHER MATERIAL mixed into it and since the material is NOT pure, we can't make any conclusion regarding its temp from its color.
No, there is no concern about fuel load as much of the plane and interior contents were "bulldozed" into that corner.
As NIST pointed out:
As to the metal fire, there ARE metals on a plane that WILL burn (Wheels for instance) and the fire is NOT right at the bolt access holes of 301, that's just your wishful thinking at play.
We are NOT certain what the material is, but what is clear is it isn't melting (or indeed doesn't appear to even damage) the aluminum cladding and that lowers the maximum possible temp of the material to well below that of thermite.
No, we aren't certain what it was, but we can be fairly certain what it WASN'T.
Arthur
2) Lead and aluminum would have to have been heated some 500C past their melting points to account for the color. The problem is that as soon as the metal melt, it tends to flow away from the heat source, unless it is contained.
3) This is also saying the fires in the NE corner (or fires + chemical reactions) were at least 1000C (to account for the metal color), and some 50 minutes after the fires started. No concern about fuel load?
4) Jones claims that in his physical trials with thermite + S, the molten iron product flows even when as cold as orange, thereby putting molten iron in play.
5) Video of the metal flow shows bright white reaction regions - a little supernova - right next to the visible source of the molten metal.
6) Earlier, there was a 10 minute metal fire right at Column 301's bolt-access-holes. (Remember, one can see 301 fail in videos, initiating collapse.)
Are we certain the metal flows are molten lead or aluminum?
No, the glow is NOT too bright for lead or aluminum if it has OTHER MATERIAL mixed into it and since the material is NOT pure, we can't make any conclusion regarding its temp from its color.
No, there is no concern about fuel load as much of the plane and interior contents were "bulldozed" into that corner.
As NIST pointed out:
QUOTE
Photographs, and NIST simulations of the aircraft impact, show large piles of debris in the 80th and 81st floors of WTC 2 near the site where the glowing liquid eventually appeared. Much of this debris came from the aircraft itself and from the office furnishings that the aircraft pushed forward as it tunneled to this far end of the building. Large fires developed on these piles shortly after the aircraft impact and continued to burn in the area until the tower collapsed.
NIST concluded that the source of the molten material was aluminum alloys from the aircraft, since these are known to melt between 475 degrees Celsius and 640 degrees Celsius (depending on the particular alloy), well below the expected temperatures (about 1,000 degrees Celsius) in the vicinity of the fires. Aluminum is not expected to ignite at normal fire temperatures and there is no visual indication that the material flowing from the tower was burning.
Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow, much like logs burning in a fireplace. The apparent color also would have been affected by slag formation on the surface.
NIST concluded that the source of the molten material was aluminum alloys from the aircraft, since these are known to melt between 475 degrees Celsius and 640 degrees Celsius (depending on the particular alloy), well below the expected temperatures (about 1,000 degrees Celsius) in the vicinity of the fires. Aluminum is not expected to ignite at normal fire temperatures and there is no visual indication that the material flowing from the tower was burning.
Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow, much like logs burning in a fireplace. The apparent color also would have been affected by slag formation on the surface.
As to the metal fire, there ARE metals on a plane that WILL burn (Wheels for instance) and the fire is NOT right at the bolt access holes of 301, that's just your wishful thinking at play.
We are NOT certain what the material is, but what is clear is it isn't melting (or indeed doesn't appear to even damage) the aluminum cladding and that lowers the maximum possible temp of the material to well below that of thermite.
No, we aren't certain what it was, but we can be fairly certain what it WASN'T.
Arthur
QUOTE (David B. Benson+Jan 10 2008, 07:20 PM)
I can't watch videos.
Probably I have seen clips of this before, but show me some clips. In the interim, yes.
David, with all respect but you really should buy an old 2nd hand machine, install windows on it, plug it in and watch some videos, a whole new world will open for you. There is almost an unlimited world to discover.
http://www.megaupload.com/nl/?d=LRCJD5FF
Probably I have seen clips of this before, but show me some clips. In the interim, yes.
David, with all respect but you really should buy an old 2nd hand machine, install windows on it, plug it in and watch some videos, a whole new world will open for you. There is almost an unlimited world to discover.
http://www.megaupload.com/nl/?d=LRCJD5FF
QUOTE (einsteen+Jan 10 2008, 02:39 PM)
... install windows on it, ...
... a whole new world will open for you.
Never!
I prefer the old one.
... a whole new world will open for you.
Never!
I prefer the old one.
From work by shagster and Greg Ulrich we have that WTC 1 massed about 283--288 kilo-tonnes. Subtracting the non-participating perimeter walls leaves about 250 kilo-tonnes, I guestimate.
That means that the average lineal density, i.e., mass per vertical unit, was about 600 tonnes/meter.
That means that the average lineal density, i.e., mass per vertical unit, was about 600 tonnes/meter.
NEU-FONZE --- Oops! 53 megajoules per story!
That is the constant term in a good-fitting force function which also has a term representing about 3% of the tower's original (design) resistance and then also a term for the vertical avalanche component.
(In my notes I wrote down GJ when I should have written MJ. Apologies.)
Edited to add: And a decimal point error! 530 MJ per story. (A slightly better estimate is 583 MJ per story.)
That is the constant term in a good-fitting force function which also has a term representing about 3% of the tower's original (design) resistance and then also a term for the vertical avalanche component.
(In my notes I wrote down GJ when I should have written MJ. Apologies.)
Edited to add: And a decimal point error! 530 MJ per story. (A slightly better estimate is 583 MJ per story.)
DBB:
Well there is a coincidence.......
here is part of something I posted today over at JREF:
First please note that the numbers I use are just examples and need to be tweaked for the particular floor of interest since the methodology I am using implies that E1 is different for every floor which is no surprise!
Anyway here is what I wrote - the calculation of E1 comes at the very end:
Consider each WTC tower as being divided (mathematically) into upper and lower sections such that an upper mass Mu acts on a lower mass Ml and the mass of the tower Mt is thus [Mu + Ml]. In a normal, undamaged, tower the load acting on Ml is Mu .g. Then, for example, if we consider the upper mass to be say 50,000 tonnes, the downward-acting force on the top of the lower section is 50,000,000 kg x 9.8 m/s^2 ~ 500 MN. In the Twin Towers this load was shared more or less equally between the core and the perimeter columns.
Let us suppose that, under the compressive load of the upper section, the lower section of a tower acts like a giant spring and obeys Hooke’s Law. This means that the downward displacement, d, of the lower section due to the static weight of the upper section is proportional to the applied compressive force, Fu. This leads to the familiar result:
Fu = Mu. g = k.d,
where k is the stiffness, also called the spring constant, of the lower section of the tower.
Now since Young’s modulus, E, equals stress, s, divided by strain, the downward displacement of the top of the lower section of a tower due to static loading by mass Mu, is given by,
d = L. Mu .g /AE
where L is the length of the lower section and A is the effective cross sectional area of the structural steel.
Representative values of L and A would be 300 meters and 5 m^2, respectively, while E for structural steel is typically ~ 200 GPa. It follows that d is ~ 15 cm and since k is equal to Mu. g / d we have k = 3 GN/m. The elastic energy stored by this compression is (500 x 0.15) MJ or 75 MJ. Now since structural steel has an elastic strain energy capacity of 50 J/kg, the building can handle the weight of the upper section because the resulting strain energy is taken up by a large mass of steel below it. There was, in fact, at least 15,000,000 kg of structural steel available to support a 50,000,000 kg upper section, so we have 75 MJ of elastic strain energy per 15 x 10^6 kg or 5 J/kg which is well below the 50 J/kg elastic capacity of the structural steel.
Now consider what happens if there is a failure of a significant number of columns supporting a 50,000,000 kg upper section of a tower. Prior to such a failure we had a stable building in which the downward-acting force on the lower section was countered by an equal and opposite reaction force on the upper section. If the perimeter wall columns should suddenly fail at the interface between our upper and lower sections, the wall will unload (?) some or all of the reaction force so that the downward-acting force now exceeds the reaction force acting on the upper section. This creates a net accelerating force on the upper section of the tower.
Data reported in NCSTAR 1-6D show that the total perimeter column load at the 83rd floor of WTC 2 was about 250 MN. It follows that after unloading by the perimeter columns at or near this floor, the upper section will move downwards under the action of this force with an acceleration, a, given by:
a = Force /Mass ~ 250 MN/50,000,000 = 5 m/s^2 ~ ½ g
Assuming that the upper section drops one story height or 3.7 meters, the stiffness, k, of the “spring” that held up the lower section of the tower has been reduced from 3 GN/m to 68 MN/m, (250 MN/3.7 m). We also note that the work done by the upper section in collapsing one floor, Wc, is given by:
Wc = Force x Distance = 250 MN x 3.7 m = 925 MJ
Now, since the loss in potential energy is Mu. g. h, we see that the amount of kinetic energy gained by the upper section after falling 3.7 meters is:
K.E. = (Mu. g. h) - Wc = (1813 – 925) MJ = 888 MJ
It follows from the equation K.E. = ½ Mu. v^2, that the upper section would be moving with a velocity v ~ 6 m/s after this 3.7 meter drop. It is interesting to note that Wc is identical to the quantity I have previously called E1 and the calculated value of 925 MJ given above is in good agreement with the range of values previously proposed for E1.
Well there is a coincidence.......
here is part of something I posted today over at JREF:
First please note that the numbers I use are just examples and need to be tweaked for the particular floor of interest since the methodology I am using implies that E1 is different for every floor which is no surprise!
Anyway here is what I wrote - the calculation of E1 comes at the very end:
Consider each WTC tower as being divided (mathematically) into upper and lower sections such that an upper mass Mu acts on a lower mass Ml and the mass of the tower Mt is thus [Mu + Ml]. In a normal, undamaged, tower the load acting on Ml is Mu .g. Then, for example, if we consider the upper mass to be say 50,000 tonnes, the downward-acting force on the top of the lower section is 50,000,000 kg x 9.8 m/s^2 ~ 500 MN. In the Twin Towers this load was shared more or less equally between the core and the perimeter columns.
Let us suppose that, under the compressive load of the upper section, the lower section of a tower acts like a giant spring and obeys Hooke’s Law. This means that the downward displacement, d, of the lower section due to the static weight of the upper section is proportional to the applied compressive force, Fu. This leads to the familiar result:
Fu = Mu. g = k.d,
where k is the stiffness, also called the spring constant, of the lower section of the tower.
Now since Young’s modulus, E, equals stress, s, divided by strain, the downward displacement of the top of the lower section of a tower due to static loading by mass Mu, is given by,
d = L. Mu .g /AE
where L is the length of the lower section and A is the effective cross sectional area of the structural steel.
Representative values of L and A would be 300 meters and 5 m^2, respectively, while E for structural steel is typically ~ 200 GPa. It follows that d is ~ 15 cm and since k is equal to Mu. g / d we have k = 3 GN/m. The elastic energy stored by this compression is (500 x 0.15) MJ or 75 MJ. Now since structural steel has an elastic strain energy capacity of 50 J/kg, the building can handle the weight of the upper section because the resulting strain energy is taken up by a large mass of steel below it. There was, in fact, at least 15,000,000 kg of structural steel available to support a 50,000,000 kg upper section, so we have 75 MJ of elastic strain energy per 15 x 10^6 kg or 5 J/kg which is well below the 50 J/kg elastic capacity of the structural steel.
Now consider what happens if there is a failure of a significant number of columns supporting a 50,000,000 kg upper section of a tower. Prior to such a failure we had a stable building in which the downward-acting force on the lower section was countered by an equal and opposite reaction force on the upper section. If the perimeter wall columns should suddenly fail at the interface between our upper and lower sections, the wall will unload (?) some or all of the reaction force so that the downward-acting force now exceeds the reaction force acting on the upper section. This creates a net accelerating force on the upper section of the tower.
Data reported in NCSTAR 1-6D show that the total perimeter column load at the 83rd floor of WTC 2 was about 250 MN. It follows that after unloading by the perimeter columns at or near this floor, the upper section will move downwards under the action of this force with an acceleration, a, given by:
a = Force /Mass ~ 250 MN/50,000,000 = 5 m/s^2 ~ ½ g
Assuming that the upper section drops one story height or 3.7 meters, the stiffness, k, of the “spring” that held up the lower section of the tower has been reduced from 3 GN/m to 68 MN/m, (250 MN/3.7 m). We also note that the work done by the upper section in collapsing one floor, Wc, is given by:
Wc = Force x Distance = 250 MN x 3.7 m = 925 MJ
Now, since the loss in potential energy is Mu. g. h, we see that the amount of kinetic energy gained by the upper section after falling 3.7 meters is:
K.E. = (Mu. g. h) - Wc = (1813 – 925) MJ = 888 MJ
It follows from the equation K.E. = ½ Mu. v^2, that the upper section would be moving with a velocity v ~ 6 m/s after this 3.7 meter drop. It is interesting to note that Wc is identical to the quantity I have previously called E1 and the calculated value of 925 MJ given above is in good agreement with the range of values previously proposed for E1.
QUOTE (NEU-FONZE+Jan 11 2008, 01:04 AM)
here is part of something I posted today over at JREF:
That's very good. I saw it over there and I'm glad you put it here, too.
There was something else you said today over there that I would love to see you elaborate on here. Something about the questionable usefulness of videos shot from the north, because of mixed rotation and translation. This has been a concern of mine as well, and it is my intention to resolve the rotational and translational components. Until then, how fit are these for fitness tests?
PS Note the increased frequency of mention of JREF. I have two words for you - weaponized marketing.
That's very good. I saw it over there and I'm glad you put it here, too.
There was something else you said today over there that I would love to see you elaborate on here. Something about the questionable usefulness of videos shot from the north, because of mixed rotation and translation. This has been a concern of mine as well, and it is my intention to resolve the rotational and translational components. Until then, how fit are these for fitness tests?
PS Note the increased frequency of mention of JREF. I have two words for you - weaponized marketing.
Quoting a 'JERF' -
"So you need to include a dropping motion AND a rotational motion to properly analyse the first few seconds of the collapse of WTC 1. A video that shows the collapse from the north is almost useless in this regard because it obscures the tilting motion which is usually interpreted as a dropping motion."
"So you need to include a dropping motion AND a rotational motion to properly analyse the first few seconds of the collapse of WTC 1. A video that shows the collapse from the north is almost useless in this regard because it obscures the tilting motion which is usually interpreted as a dropping motion."
QUOTE (OneWhiteEye+Jan 11 2008, 01:58 AM)
PS Note the increased frequency of mention of JREF. I have two words for you - weaponized marketing.
Ha! I suppose that the weaponized marketer is none other than Max Photon!
Ha! I suppose that the weaponized marketer is none other than Max Photon!
QUOTE (Max Photon+Jan 10 2008, 06:47 PM)
Yes David, I was kidding about the cores being aluMINium.
Also, your point is well taken that the air must move out of the way.
Max
We know that story Max, but why does it start with some (almost) symmetrical rows at the sides of the building while the block topples and why doesn't it look like the first 3 sets of rows are seperated the distance of a story ? If we take a simple mathematic model than we immediately can see it doesn't fit with that model.
Also, your point is well taken that the air must move out of the way.
Max
We know that story Max, but why does it start with some (almost) symmetrical rows at the sides of the building while the block topples and why doesn't it look like the first 3 sets of rows are seperated the distance of a story ? If we take a simple mathematic model than we immediately can see it doesn't fit with that model.
OneWhiteEye:
Well you know how I feel about JREF.... but somehow I can't help but take a look just like a motorist passing the scene of a crash! It's ugly, but I am curious.....
As for the analysis of the dropping-tipping of the upper section of WTC 1, I thought you were the expert on that issue! As you know, if you can determine the viewing angles precisely the problem can be worked out properly except for the case of viewing parallel to the tipping, and some videos come pretty close to that angle of view.
It is very instructive to make a model of a WTC tower, (it can be just a block of wood with a straw sticking out of the top!), and arrange for it to be tipped by increments of a few degrees upto say 25 deg. Now view the model through a telephoto lens and observe the trompe-l'oeil of the antenna "sinking" into the roof of the tower as it is tipped.... it's very convincing!
Just like the "near free fall" debate there are too many people out there making blanket statements about the collapse of WTC 1 without providing any quantitative arguments to support their claims. So, I think it's very important to work this problem out to settle the question as to whether or not the antenna drops first!
Well you know how I feel about JREF.... but somehow I can't help but take a look just like a motorist passing the scene of a crash! It's ugly, but I am curious.....
As for the analysis of the dropping-tipping of the upper section of WTC 1, I thought you were the expert on that issue! As you know, if you can determine the viewing angles precisely the problem can be worked out properly except for the case of viewing parallel to the tipping, and some videos come pretty close to that angle of view.
It is very instructive to make a model of a WTC tower, (it can be just a block of wood with a straw sticking out of the top!), and arrange for it to be tipped by increments of a few degrees upto say 25 deg. Now view the model through a telephoto lens and observe the trompe-l'oeil of the antenna "sinking" into the roof of the tower as it is tipped.... it's very convincing!
Just like the "near free fall" debate there are too many people out there making blanket statements about the collapse of WTC 1 without providing any quantitative arguments to support their claims. So, I think it's very important to work this problem out to settle the question as to whether or not the antenna drops first!
I also still can't let it, I was recently insulted by a thruther who probably thought I was one of the bad guys.
ps. I just see that a new hi-res video of the south tower collapse (one of the best ones that I know) has been posted, link to file available!
http://www.youtube.com/watch?v=qJsq_mu9sus
ps. I just see that a new hi-res video of the south tower collapse (one of the best ones that I know) has been posted, link to file available!
http://www.youtube.com/watch?v=qJsq_mu9sus
Charles M. Beck is up to version 8 in his WTC avalanche paper. Dated 16 Nov 2007, it now is 15 pp and has 16 references.
His original paper of 13 Sep 2006 had 9 pp and 6 references.
I sent him an email alerting him to Urich paper on WTC mass and PE, as well as the Ari-Gur/Singer paper on axial column impact.
His original paper of 13 Sep 2006 had 9 pp and 6 references.
I sent him an email alerting him to Urich paper on WTC mass and PE, as well as the Ari-Gur/Singer paper on axial column impact.
QUOTE (metamars+Jan 11 2008, 03:04 AM)
Ha! I suppose that the weaponized marketer is none other than Max Photon!
Weapons of Max Destruction
Now with 50% more carnage, FREE!
Max is a registered trademark of Max Photon Worldwide Industries.
Proud sponsor of the JREF Special Olympics
Weapons of Max Destruction
Now with 50% more carnage, FREE!
Max is a registered trademark of Max Photon Worldwide Industries.
Proud sponsor of the JREF Special Olympics
NEU-FONZE --- Thanks. My figure is for WTC 1, from matching to data. To that value for 'E1' should be added about 2.5% times the mass of the falling portion of the building times g times h=3.6576, of course.
QUOTE (NEU-FONZE+Jan 11 2008, 12:47 PM)
...like a motorist passing the scene of a crash!
Yes, but then you stop, get out, administer first aid and, noting the undernourished state of some of the victims, teach them how to fish. This compels people like me to keep circling the block because I'm afraid I'll miss something.
No, but I like the way that sounds, so feel free to keep saying it.
No, but I like the way that sounds, so feel free to keep saying it.
As you know, if you can determine the viewing angles precisely the problem can be worked out properly except for the case of viewing parallel to the tipping, and some videos come pretty close to that angle of view.
Yes. The one I've been working with is such. I was in the midst of trying to obtain a rough approximation of tilt away, already awash in dubious simplifying assumptions, when I realized I was accounting for only two of three relevant angles, anyway. Interesting, but humbling, so that's one I'll come back to later. I figure video from a few more camera angles will fix the tilt angle over time fairly well (if you haven't done so already) so correction for it is at least possible.
My concern is not so much doing the correction, but rather the consequences of NOT doing it. If an analysis based on a 1-D model ignores rotation entirely, to what extent must the real world data which feeds that analysis be massaged to ensure the analysis is correct? Accurately measuring pixel displacement of a feature, even if two-dimensional, gives a measurement in the image plane. Suppose multiple views eventually provide accurate determination of antenna azimuth and zenith, and hinge location if need be, such that corrections could be applied to any given video.
I'm left with the following questions:
- Does it matter if all vertical displacement in the image plane is assumed to be drop of the rigid body?
- Wouldn't the real initial position and velocity of the body coords at the onset of true collapse be non-zero?
- How is the time for onset of true collapse determined if not directly observable in the data?
- Does it matter if the transition from deformation-only to post-buckling breakage is murky?
I'm with you on that 100%. You know, a few months ago, I was holding a pencil vertically in my hand, tipping it away, pivoting at my wrist, pivoting at my elbow.... Yes, I was observed by others. Based on the myopiad (like that, MP?) that comprises my observations thus far, I propose upgrading to a (thick but not solid) rectangular block of dense styrene with a load placed asymmetrically on the top, sufficient to cause buckling in the undamaged material. For the first couple of seconds. Or not, I don't know.
I think the key is to accurately perceive the hierarchy of simplifying assumptions:
- mixed deformation and displacement of non-rigid body
- rotation and translation of a rigid body
- translation only
- drop only
- image vertical is true vertical
and ask how successive layers affect discrimination when one tries to look closely at the initial phase, both from a model-oriented energetic view AND the use of real-world data for comparisons.
I could be behind the curve on all this.
The deltaT adjusts the collapse start by tat many seconds. The S parameter shape the stretch function.
Note that the better fitting force founction is not enough better to disconfirm the poorer hypothesis by this C447 data alone. (Results for C449 are similar.)
Yes, but then you stop, get out, administer first aid and, noting the undernourished state of some of the victims, teach them how to fish. This compels people like me to keep circling the block because I'm afraid I'll miss something.
QUOTE
As for the analysis of the dropping-tipping of the upper section of WTC 1, I thought you were the expert on that issue!
No, but I like the way that sounds, so feel free to keep saying it.
QUOTE (->
| QUOTE |
| As for the analysis of the dropping-tipping of the upper section of WTC 1, I thought you were the expert on that issue! |
No, but I like the way that sounds, so feel free to keep saying it.
As you know, if you can determine the viewing angles precisely the problem can be worked out properly except for the case of viewing parallel to the tipping, and some videos come pretty close to that angle of view.
Yes. The one I've been working with is such. I was in the midst of trying to obtain a rough approximation of tilt away, already awash in dubious simplifying assumptions, when I realized I was accounting for only two of three relevant angles, anyway. Interesting, but humbling, so that's one I'll come back to later. I figure video from a few more camera angles will fix the tilt angle over time fairly well (if you haven't done so already) so correction for it is at least possible.
My concern is not so much doing the correction, but rather the consequences of NOT doing it. If an analysis based on a 1-D model ignores rotation entirely, to what extent must the real world data which feeds that analysis be massaged to ensure the analysis is correct? Accurately measuring pixel displacement of a feature, even if two-dimensional, gives a measurement in the image plane. Suppose multiple views eventually provide accurate determination of antenna azimuth and zenith, and hinge location if need be, such that corrections could be applied to any given video.
I'm left with the following questions:
- Does it matter if all vertical displacement in the image plane is assumed to be drop of the rigid body?
- Wouldn't the real initial position and velocity of the body coords at the onset of true collapse be non-zero?
- How is the time for onset of true collapse determined if not directly observable in the data?
- Does it matter if the transition from deformation-only to post-buckling breakage is murky?
QUOTE
It is very instructive to make a model of a WTC tower, (it can be just a block of wood with a straw sticking out of the top!), and arrange for it to be tipped by increments of a few degrees upto say 25 deg. Now view the model through a telephoto lens and observe the trompe-l'oeil of the antenna "sinking" into the roof of the tower as it is tipped.... it's very convincing!
I'm with you on that 100%. You know, a few months ago, I was holding a pencil vertically in my hand, tipping it away, pivoting at my wrist, pivoting at my elbow.... Yes, I was observed by others. Based on the myopiad (like that, MP?) that comprises my observations thus far, I propose upgrading to a (thick but not solid) rectangular block of dense styrene with a load placed asymmetrically on the top, sufficient to cause buckling in the undamaged material. For the first couple of seconds. Or not, I don't know.
I think the key is to accurately perceive the hierarchy of simplifying assumptions:
- mixed deformation and displacement of non-rigid body
- rotation and translation of a rigid body
- translation only
- drop only
- image vertical is true vertical
and ask how successive layers affect discrimination when one tries to look closely at the initial phase, both from a model-oriented energetic view AND the use of real-world data for comparisons.
I could be behind the curve on all this.
For WTC 1, for most purposes the tilt is small enough (during the period of observation) that the necessary corrections will be very small. Even for WTC 2, Mr. Le worked out the tilt+rotation corrections for the BLGB paper and mentioned that those corrections hardly mattered (during the 4 seconds of measured observations).
With just the one video, using measurements on the roof line versus measurements on the antenna tower ought to be enough to determine the tilt (just to the south) as a function of time. So far I haven't had the time nor enthusiasm to work this out.
With just the one video, using measurements on the roof line versus measurements on the antenna tower ought to be enough to determine the tilt (just to the south) as a function of time. So far I haven't had the time nor enthusiasm to work this out.
The first two parameters are for constant force and a force growing linearly with the collapse front. Note that added the third term, for the vertical avalanche, produces a better fit to the data.
CODE
-------------------------------------------------------------------------------
Sef-K+Z+ZSS-F-exp-pow-stretch dB= 0.0 sd= 0.101
F0=0.0601 F1=0.0177 F2=9.7356 S0=0.5473 S1=-8.7663 S2=1.1907 deltaT=-0.0245
Sef-K+Z-F-exp-pow-stretch dB= 4.6 sd= 0.234
F0=0.0694 F1=0.0368 F1SI=0.0054 S0=0.5600 S1=-7.5038 S2=0.5156 deltaT=0.0478
Sef-K+Z+ZSS-F-exp-pow-stretch dB= 0.0 sd= 0.101
F0=0.0601 F1=0.0177 F2=9.7356 S0=0.5473 S1=-8.7663 S2=1.1907 deltaT=-0.0245
Sef-K+Z-F-exp-pow-stretch dB= 4.6 sd= 0.234
F0=0.0694 F1=0.0368 F1SI=0.0054 S0=0.5600 S1=-7.5038 S2=0.5156 deltaT=0.0478
The deltaT adjusts the collapse start by tat many seconds. The S parameter shape the stretch function.
Note that the better fitting force founction is not enough better to disconfirm the poorer hypothesis by this C447 data alone. (Results for C449 are similar.)
QUOTE (David B. Benson+Jan 11 2008, 10:11 PM)
For WTC 1, for most purposes the tilt is small enough (during the period of observation) that the necessary corrections will be very small. Even for WTC 2, Mr. Le worked out the tilt+rotation corrections for the BLGB paper and mentioned that those corrections hardly mattered (during the 4 seconds of measured observations).
What I may not be grasping here is the difference between the analysis, with corrections, already performed and your work to establish the best of form candidates for resistive force and stretch, as functions of time, position and velocity. It seems to me that the best the prior analysis could be is a simplified form soluble analytically and, whatever results obtained, could only be improved by the final results of your analysis.
There are innumerable scenarios where I would have no problem with brushing aside much larger errors of all kinds. The reason I return to this issue is because, so far, the results of your analysis have displayed certain sensitivity to the input data. In many aspects, I'd consider that good; in fact, in my naive opinion, it passes a test of credibility because of the sensitivity. But I have to wonder about the possible consequences of giving subtly twisted data to such a sensitive process.
You see, in that list of simplifications I offered above, I could add one more line at the bottom:
- There is only one feature being measured over the span of the dataset
The datasets C447, 448, and 449 do not really represent the same feature over time. Maybe that's not a problem. I'd be more convinced of that if there were no significant rank or viability change when running the columns independently or together. However, knowing what I know about the data, it would necessarily force me to diminish my confidence in your method to discriminate finely in the situation given.
Suppose a single, very accurate dataset is produced which also purports to measure the dark band location. There are at least as many points as C447-449 combined. There might be a peak magnitude of +/- 1 pixel of very gaussian noise. And suppose the result of running that data resembles at most one of the runs 447, 448, 449, or 447-449. Is the next course of action to discard C447-449, only the columns with most disagreement, merge them all, or add the new set as a roughly equal contender, choosing fitness of form by common success in all lists?
What I may not be grasping here is the difference between the analysis, with corrections, already performed and your work to establish the best of form candidates for resistive force and stretch, as functions of time, position and velocity. It seems to me that the best the prior analysis could be is a simplified form soluble analytically and, whatever results obtained, could only be improved by the final results of your analysis.
There are innumerable scenarios where I would have no problem with brushing aside much larger errors of all kinds. The reason I return to this issue is because, so far, the results of your analysis have displayed certain sensitivity to the input data. In many aspects, I'd consider that good; in fact, in my naive opinion, it passes a test of credibility because of the sensitivity. But I have to wonder about the possible consequences of giving subtly twisted data to such a sensitive process.
You see, in that list of simplifications I offered above, I could add one more line at the bottom:
- There is only one feature being measured over the span of the dataset
The datasets C447, 448, and 449 do not really represent the same feature over time. Maybe that's not a problem. I'd be more convinced of that if there were no significant rank or viability change when running the columns independently or together. However, knowing what I know about the data, it would necessarily force me to diminish my confidence in your method to discriminate finely in the situation given.
Suppose a single, very accurate dataset is produced which also purports to measure the dark band location. There are at least as many points as C447-449 combined. There might be a peak magnitude of +/- 1 pixel of very gaussian noise. And suppose the result of running that data resembles at most one of the runs 447, 448, 449, or 447-449. Is the next course of action to discard C447-449, only the columns with most disagreement, merge them all, or add the new set as a roughly equal contender, choosing fitness of form by common success in all lists?
OneWhiteEye --- Fitness of form, as I am practicing it, has to pass all tests. However, even those with odds against of up to 3:1 are kept as viable candidates. So in my just prior post, both hypotheses remain in the pool of viable candidates, the poorer one not be sufficiently disconfirmed.
If another data set measuring the dark band comes along, so long as it is not significantly different in form from the existing ones, it simply becomes another data set to test against.
What has been determined so far is that a constant stretch is at least strongly disconfirmed in favor of a monotonically strictly decreasing function.
If another data set measuring the dark band comes along, so long as it is not significantly different in form from the existing ones, it simply becomes another data set to test against.
What has been determined so far is that a constant stretch is at least strongly disconfirmed in favor of a monotonically strictly decreasing function.
I talked about rotation in one post, and dataset accuracy in another. Not mixing issues up, I consider them related. The last list item I added might be a bigger issue than all above, but I don't think so. If switching columns that ostensibly measure features adjacent to the pixel causes such different results, correcting for rotation might be pretty significant, too.
I'm pretty sure that the totality of list items is pretty significant.
I'm pretty sure that the totality of list items is pretty significant.
QUOTE (OneWhiteEye+Jan 11 2008, 05:29 PM)
... correcting for rotation might be pretty significant, too.
Going from an only mostly-correct correction for perspective to one which is correct (up to placement of camera details and height of feature above the roof line details) has made only slight changes in values and none in rankings. So I doubt that the tilt will matter much, since the details of the parameter values are of little interest.
Going from an only mostly-correct correction for perspective to one which is correct (up to placement of camera details and height of feature above the roof line details) has made only slight changes in values and none in rankings. So I doubt that the tilt will matter much, since the details of the parameter values are of little interest.
QUOTE (David B. Benson+Jan 12 2008, 12:47 AM)
Going from an only mostly-correct correction for perspective to one which is correct (up to placement of camera details and height of feature above the roof line details) has made only slight changes in values and none in rankings. So I doubt that the tilt will matter much, since the details of the parameter values are of little interest.
Ok, that makes sense. I hadn't cross-checked your results, pre- and post-optic axis correction. Like I did the earlier inter-column runs.
Your t0 is... frame 917/918, right? Without being too precise, the dark band drops about 2 pixels between frames 800 and 916, then continues smoothly into descent. The speed of the c.m. of the upper block in the downward direction is much less than the antenna, of course (but not zero).
When you choose a t0, is velocity treated as zero at t0?
Ok, that makes sense. I hadn't cross-checked your results, pre- and post-optic axis correction. Like I did the earlier inter-column runs.
Your t0 is... frame 917/918, right? Without being too precise, the dark band drops about 2 pixels between frames 800 and 916, then continues smoothly into descent. The speed of the c.m. of the upper block in the downward direction is much less than the antenna, of course (but not zero).
When you choose a t0, is velocity treated as zero at t0?
How much difference did perspective correction as a whole make?
QUOTE (OneWhiteEye+Jan 11 2008, 06:08 PM)
Your t0 is... frame 917/918, right?
When you choose a t0, is velocity treated as zero at t0?
Yes.
No. Based on earlier work, I assume that at t0 the drop which occurred up until then is the result of accelerating at about 0.05g. That gives the initial speed of about 0.4 m/s.
=====================
The optical axis correction made a few percent difference, but I didn't try to measure it.
When you choose a t0, is velocity treated as zero at t0?
Yes.
No. Based on earlier work, I assume that at t0 the drop which occurred up until then is the result of accelerating at about 0.05g. That gives the initial speed of about 0.4 m/s.
=====================
The optical axis correction made a few percent difference, but I didn't try to measure it.
QUOTE (David B. Benson+Jan 12 2008, 01:22 AM)
The optical axis correction made a few percent difference, but I didn't try to measure it.
OK, thanks. It's interesting to see how the analysis system as a whole functions. No camera angle correction at all versus final perspective correction results in... no significant rank changes?
OK, thanks. It's interesting to see how the analysis system as a whole functions. No camera angle correction at all versus final perspective correction results in... no significant rank changes?
What happens if you remove the core columns coupling the tower to the bedrock?
QUOTE (daehaus+Jan 11 2008, 11:20 PM)
What happens if you remove the core columns coupling the tower to the bedrock?
Well, as the post collapse photos show, the core columns were NOT removed, so wondering what happened if they had been is a tad silly.
Arthur
Well, as the post collapse photos show, the core columns were NOT removed, so wondering what happened if they had been is a tad silly.
Arthur
Ah, the silly assumption that I meant if hundreds of feet of the columns had been removed from the building at once.
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
QUOTE (daehaus+Jan 12 2008, 05:19 AM)
Ah, the silly assumption that I meant if hundreds of feet of the columns had been removed from the building at once.
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
NO it uses the physical evidence, at hand in the form of the videos to model what was occurring in the buildings.
Would you prefer the use of non physical imaginary exploding leprechauns?
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
NO it uses the physical evidence, at hand in the form of the videos to model what was occurring in the buildings.
Would you prefer the use of non physical imaginary exploding leprechauns?
QUOTE (daehaus+Jan 12 2008, 12:19 AM)
Ah, the silly assumption that I meant if hundreds of feet of the columns had been removed from the building at once.
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
We don't typically ignore anyone on these forums, so there is NO NEED to "get our attention"
Posting SILLYNESS to do so, is well, SILLY.
You say,
Could you back that up with a REFERENCE please?
Arthur
Either way it got your attention.
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Why?
We don't typically ignore anyone on these forums, so there is NO NEED to "get our attention"
Posting SILLYNESS to do so, is well, SILLY.
You say,
QUOTE
Everything I've read here assumes that building collapse was inevitable, and models the collapse to fit that theory.
Could you back that up with a REFERENCE please?
Arthur
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