QUOTE (zoktoberfest+Sep 23 2007, 12:53 PM)
... the work environment of an elevator maintenance man. ...
My understanding is that elevator maintenance is done by some other group, Alan doing what might me termed general maintenance.
Alan lives and works in Houston, I believe.
I, having spent my life in ivory towers, greatly appreciate his knowledge of tall building construction and maintenance.
My understanding is that elevator maintenance is done by some other group, Alan doing what might me termed general maintenance.
Alan lives and works in Houston, I believe.
I, having spent my life in ivory towers, greatly appreciate his knowledge of tall building construction and maintenance.
An additional distinction about what I refer to as automated methods. Subpixel extraction is deriving a pixel displacement directly from image data; that's what I was talking about above. There is also code to produce csv from hand-produced points, which is just perfect transcription of subjective data. Usually I'm talking about the first when referring to automation.
QUOTE (OneWhiteEye+Sep 23 2007, 01:17 PM)
3) All error will be left in the data. I just think it needs a reasonable accounting. Depending on justification, I can see the error exceeding the magnitude of the signal. In order to have this confidence, the sources of error, the characteristics in this context, the estimated magnitude, all should be known as well as possible so as to be able to recognize the signal that is most surely there. If I can see it with my eye, I can quantify it - provided I choose the right method. Then I can say that the numbers are data; noisy, yes, but data all the same.
I think I understand the techniques for obtaining data under conditions of very poor S/N ratios. To do so means having lots of data in comparison to a slowly changing signal, the situation here.
I agree that having some understanding of the noise processes is important, but we do here, provided the camera is steady or there is another way to take out the effects of camera bobbles. Leaving that aside, it seems that the noise is thermal. Good, for that means a suitable approximation is simply Gaussian noise with zero mean and not much variance. (I emphasize that Gaussian is an approximation to the way turbulent winds actually work, but surely adequate for the current task.
Since there is no particular hurry, and since I agree that automated techniques can disguise problems, it certainly seems best to first work with pixel-by-pixel data. That may suffice. If so fine. If not we can later work out sub-pixel techniques. For those, having the pixel-by-pixel data in hand helps assure that nothing gang agley.
I think I understand the techniques for obtaining data under conditions of very poor S/N ratios. To do so means having lots of data in comparison to a slowly changing signal, the situation here.
I agree that having some understanding of the noise processes is important, but we do here, provided the camera is steady or there is another way to take out the effects of camera bobbles. Leaving that aside, it seems that the noise is thermal. Good, for that means a suitable approximation is simply Gaussian noise with zero mean and not much variance. (I emphasize that Gaussian is an approximation to the way turbulent winds actually work, but surely adequate for the current task.
Since there is no particular hurry, and since I agree that automated techniques can disguise problems, it certainly seems best to first work with pixel-by-pixel data. That may suffice. If so fine. If not we can later work out sub-pixel techniques. For those, having the pixel-by-pixel data in hand helps assure that nothing gang agley.
QUOTE
...for the very slow subsidence that Frank Greening and Carter Elliot (and now I) suspect was occurring well before anything sensible to the eye occurred.
From looking at the one video (endlessly, back and forth, small and large, here and there... down and to the left, down and to the left, down and to the left...) I'm pretty sure there is slow motion preceding the obvious drop. It remains to quantify the early fine motion but, to a limited degree of accuracy, the first few meters of motion have been quantified and appear indeed to be slow.
With that result, I must point out employing the potentially useful simplification of an unimpeded free-fall descent of the top block a distance of one or more initial floors does in fact deviate significantly from what is observed. The slow initial descent means that a substantial amount of potential energy from the initial lost height was expended through work done (deformation, breakage, whatever) and was not available as kinetic energy at the corresponding time/position as such a simplification would imply.
The work done could, of course, be distributed across many floors, reducing the energy necessary to complete their destruction (disassembly?) at a subsequent time.
QUOTE (zoktoberfest+Sep 23 2007, 12:53 PM)
I was expecting it to be administrative.
Instead, a ringer and a vigilante were brought forth, from within.
Here is how the moderator works, based solely on my experience.
Every post comes equipped with a report this post button. Offensive and off-topic posts are reported by (some of) those reading the post.
Insults will eventually cause one to be banned, after enough demerits.
Off-topic posts are often just deleted, but if the moderator doesn't like the post enough, it'll cause a demerit.
Terms such as ringer and vigilante might be offensive to some reader. I recommend avoiding such, even when you haven't specifically named which poster fits what description.
Just stick to sci-tech and the history, post-aircraft impact. Then you'll not even get one demerit here.
Instead, a ringer and a vigilante were brought forth, from within.
Here is how the moderator works, based solely on my experience.
Every post comes equipped with a report this post button. Offensive and off-topic posts are reported by (some of) those reading the post.
Insults will eventually cause one to be banned, after enough demerits.
Off-topic posts are often just deleted, but if the moderator doesn't like the post enough, it'll cause a demerit.
Terms such as ringer and vigilante might be offensive to some reader. I recommend avoiding such, even when you haven't specifically named which poster fits what description.
Just stick to sci-tech and the history, post-aircraft impact. Then you'll not even get one demerit here.
QUOTE (OneWhiteEye+Sep 23 2007, 01:57 PM)
With that result, I must point out employing the potentially useful simplification of an unimpeded free-fall descent of the top block a distance of one or more initial floors does in fact deviate significantly from what is observed. The slow initial descent means that a substantial amount of potential energy from the initial lost height was expended through work done (deformation, breakage, whatever) and was not available as kinetic energy at the corresponding time/position as such a simplification would imply.
Right and that I will not do. That technique works fine once collapse is visibly started, although the Bazant & Verdure crush-down equation even then appears to be preferable is studying the first 0.6 seconds of the drop.
I have considered the question of the equation of motion to use for the slow beginning. So far I see no reason not to continue using the B & V crush-down equation, even though it is not entirely correct regarding the mass accumulation in a so-called crushed block.
Right and that I will not do. That technique works fine once collapse is visibly started, although the Bazant & Verdure crush-down equation even then appears to be preferable is studying the first 0.6 seconds of the drop.
I have considered the question of the equation of motion to use for the slow beginning. So far I see no reason not to continue using the B & V crush-down equation, even though it is not entirely correct regarding the mass accumulation in a so-called crushed block.
QUOTE (David B. Benson+Sep 23 2007, 08:48 PM)
I think I understand the techniques for obtaining data under conditions of very poor S/N ratios. To do so means having lots of data in comparison to a slowly changing signal, the situation here.
I agree that having some understanding of the noise processes is important, but we do here, provided the camera is steady or there is another way to take out the effects of camera bobbles. Leaving that aside, it seems that the noise is thermal. Good, for that means a suitable approximation is simply Gaussian noise with zero mean and not much variance. (I emphasize that Gaussian is an approximation to the way turbulent winds actually work, but surely adequate for the current task.
Since there is no particular hurry, and since I agree that automated techniques can disguise problems, it certainly seems best to first work with pixel-by-pixel data. That may suffice. If so fine. If not we can later work out sub-pixel techniques. For those, having the pixel-by-pixel data in hand helps assure that nothing gang agley.
I have every confidence that your methods will derive meaningful position data from noisy raw data, given sufficient volume and redundancy. The volume aspect may be a problem, but I'll work on that.
I could ship you mountains of data, today, that show a marked difference in characteristics between the first moments of motion and the moments prior, and as well exhibit largely monotonic trends in the direction in which detectable motion is subsequently (and smoothly) observed. Problem is, they can't be scaled to pixels, let alone meters.
These are not per se noise or systematic error issues, true. But the magnitude and slew rate of such is can be right around that of the signal I'm looking for at the time. With the shortage of suitable features and only so many possibilities of measuring them, it may not be possible to get enough views of the underlying motion to apply statistical or classification methods to eliminate error of the order of the signal. There may only ever be a handful (at most) of such datasets derived for the antenna, and maybe only from the DVD form of this one clip. If so, all could be subject to hidden systematic bias, as in a gush of hot air that did not occur in the baseline.
If analysis alone could do it, I could give you sets measured in pixels with the understanding that they are each accurate but to unknown individual scale factors. Knowing this is near-infinitesimal motion of a reliably rigid body, could you derive the true pixel displacement? If you can, maybe I should post the mountains of data!
When I have subpixel data that roughly matches what I see and matches the boundary condition of ending where the next method begins, I will definitely put it up, no matter how noisy.
I agree that having some understanding of the noise processes is important, but we do here, provided the camera is steady or there is another way to take out the effects of camera bobbles. Leaving that aside, it seems that the noise is thermal. Good, for that means a suitable approximation is simply Gaussian noise with zero mean and not much variance. (I emphasize that Gaussian is an approximation to the way turbulent winds actually work, but surely adequate for the current task.
Since there is no particular hurry, and since I agree that automated techniques can disguise problems, it certainly seems best to first work with pixel-by-pixel data. That may suffice. If so fine. If not we can later work out sub-pixel techniques. For those, having the pixel-by-pixel data in hand helps assure that nothing gang agley.
I have every confidence that your methods will derive meaningful position data from noisy raw data, given sufficient volume and redundancy. The volume aspect may be a problem, but I'll work on that.
I could ship you mountains of data, today, that show a marked difference in characteristics between the first moments of motion and the moments prior, and as well exhibit largely monotonic trends in the direction in which detectable motion is subsequently (and smoothly) observed. Problem is, they can't be scaled to pixels, let alone meters.
These are not per se noise or systematic error issues, true. But the magnitude and slew rate of such is can be right around that of the signal I'm looking for at the time. With the shortage of suitable features and only so many possibilities of measuring them, it may not be possible to get enough views of the underlying motion to apply statistical or classification methods to eliminate error of the order of the signal. There may only ever be a handful (at most) of such datasets derived for the antenna, and maybe only from the DVD form of this one clip. If so, all could be subject to hidden systematic bias, as in a gush of hot air that did not occur in the baseline.
If analysis alone could do it, I could give you sets measured in pixels with the understanding that they are each accurate but to unknown individual scale factors. Knowing this is near-infinitesimal motion of a reliably rigid body, could you derive the true pixel displacement? If you can, maybe I should post the mountains of data!
When I have subpixel data that roughly matches what I see and matches the boundary condition of ending where the next method begins, I will definitely put it up, no matter how noisy.
QUOTE (OneWhiteEye+Sep 23 2007, 02:43 PM)
Problem is, they can't be scaled to pixels, let alone meters.
With the shortage of suitable features and only so many possibilities of measuring them, it may not be possible to get enough views of the underlying motion to apply statistical or classification methods to eliminate error of the order of the signal.
If so, all could be subject to hidden systematic bias, as in a gush of hot air that did not occur in the baseline.
If analysis alone could do it, I could give you sets measured in pixels with the understanding that they are each accurate but to unknown individual scale factors. Knowing this is near-infinitesimal motion of a reliably rigid body, could you derive the true pixel displacement?
Then lets leave such data until and if a time arrives that we absolutely must use it.
Feature recognition is certainly an important aspect of using the data. However, you already have more than enough features if you can extract the data at the full rate of nearly 30 frames per second.
Yes, but the gushes of how air are unlikely to be affecting both corners and the antenna tower in the same way at the same time. I don't (yet) view it as a problem.
Actually, the body is not quite rigid. While the corners can probably be adequately viewed as such, the antenna tower surely has a fairly short fundamental period. That isn't a problem, just makes the analysis a bit tricky. However, I fail to understand what unknown individual scale factors is referring to. Please elucidate (especially before sending massive mounds of data.)
With the shortage of suitable features and only so many possibilities of measuring them, it may not be possible to get enough views of the underlying motion to apply statistical or classification methods to eliminate error of the order of the signal.
If so, all could be subject to hidden systematic bias, as in a gush of hot air that did not occur in the baseline.
If analysis alone could do it, I could give you sets measured in pixels with the understanding that they are each accurate but to unknown individual scale factors. Knowing this is near-infinitesimal motion of a reliably rigid body, could you derive the true pixel displacement?
Then lets leave such data until and if a time arrives that we absolutely must use it.
Feature recognition is certainly an important aspect of using the data. However, you already have more than enough features if you can extract the data at the full rate of nearly 30 frames per second.
Yes, but the gushes of how air are unlikely to be affecting both corners and the antenna tower in the same way at the same time. I don't (yet) view it as a problem.
Actually, the body is not quite rigid. While the corners can probably be adequately viewed as such, the antenna tower surely has a fairly short fundamental period. That isn't a problem, just makes the analysis a bit tricky. However, I fail to understand what unknown individual scale factors is referring to. Please elucidate (especially before sending massive mounds of data.)
QUOTE (David B. Benson+Sep 23 2007, 10:19 PM)
Then lets leave such data until and if a time arrives that we absolutely must use it.
Feature recognition is certainly an important aspect of using the data. However, you already have more than enough features if you can extract the data at the full rate of nearly 30 frames per second.
Yes, but the gushes of how air are unlikely to be affecting both corners and the antenna tower in the same way at the same time. I don't (yet) view it as a problem.
Actually, the body is not quite rigid. While the corners can probably be adequately viewed as such, the antenna tower surely has a fairly short fundamental period. That isn't a problem, just makes the analysis a bit tricky. However, I fail to understand what unknown individual scale factors is referring to. Please elucidate (especially before sending massive mounds of data.)
All of my babble to which you refer is concerned with subpixel data, so let me clarify details.
The data I posted recently for the antenna, washer and corners is hand-derived and is not in question at all, in my mind. It is what it is and I reserve the right to go back and review the work and correct a placement here and there. It's subjective but essentially accurate to about a pixel. It's just a pain in the arse, takes some time, and leads to eyestrain and fatigue which does influence the quality of the measurement.
At that scope, nothing except camera motion and block compression artifact would be a problem. Already ruled out for this video. So that data's OK as it is and ready to plug into your process.
But subpixel is a different thing. Thus far, the only candidate in this video for subpixel extraction is the antenna. I'd hoped the washer would be another but I have less confidence in that now. The corners and other features like floor lines might be amenable to 1D methods HOWEVER I'd want to succeed with the obviously easier target of the antenna first, before proceeding to more difficult quarry. (Incidentally, the floor lines can be done manually anyway - that's what was driving me nuts, moving my alignment line away and back to the floorline repeatedly to ensure proper placement but having to wait until the afterimage of my line faded sufficiently to see the floor line at all!)
So, the rigid body I mentioned was actually a portion of the antenna of a size roughly the width of the antenna. Probably doesn't have vibrational modes over that distance, eh? And we're talking about a thermal affecting an area of only that size.
By 'unknown individual scale factors' I mean I have a lot of curves that my gut tells me are accurate to within a scale factor but the factor is unique to each measurement. The reasoning is rigorous yet fairly simple; I'll just say that the nature of the measurement is that it can be and is diluted by the environment around the feature. If you do center of mass calculation on someone transferring a ball from one hand to the other, you will have an accurate account of the qualitative motion of the arms and ball, but the scale for actual displacement will be off because the ball's mass is small compared to the body.
Feature recognition is certainly an important aspect of using the data. However, you already have more than enough features if you can extract the data at the full rate of nearly 30 frames per second.
Yes, but the gushes of how air are unlikely to be affecting both corners and the antenna tower in the same way at the same time. I don't (yet) view it as a problem.
Actually, the body is not quite rigid. While the corners can probably be adequately viewed as such, the antenna tower surely has a fairly short fundamental period. That isn't a problem, just makes the analysis a bit tricky. However, I fail to understand what unknown individual scale factors is referring to. Please elucidate (especially before sending massive mounds of data.)
All of my babble to which you refer is concerned with subpixel data, so let me clarify details.
The data I posted recently for the antenna, washer and corners is hand-derived and is not in question at all, in my mind. It is what it is and I reserve the right to go back and review the work and correct a placement here and there. It's subjective but essentially accurate to about a pixel. It's just a pain in the arse, takes some time, and leads to eyestrain and fatigue which does influence the quality of the measurement.
At that scope, nothing except camera motion and block compression artifact would be a problem. Already ruled out for this video. So that data's OK as it is and ready to plug into your process.
But subpixel is a different thing. Thus far, the only candidate in this video for subpixel extraction is the antenna. I'd hoped the washer would be another but I have less confidence in that now. The corners and other features like floor lines might be amenable to 1D methods HOWEVER I'd want to succeed with the obviously easier target of the antenna first, before proceeding to more difficult quarry. (Incidentally, the floor lines can be done manually anyway - that's what was driving me nuts, moving my alignment line away and back to the floorline repeatedly to ensure proper placement but having to wait until the afterimage of my line faded sufficiently to see the floor line at all!)
So, the rigid body I mentioned was actually a portion of the antenna of a size roughly the width of the antenna. Probably doesn't have vibrational modes over that distance, eh? And we're talking about a thermal affecting an area of only that size.
By 'unknown individual scale factors' I mean I have a lot of curves that my gut tells me are accurate to within a scale factor but the factor is unique to each measurement. The reasoning is rigorous yet fairly simple; I'll just say that the nature of the measurement is that it can be and is diluted by the environment around the feature. If you do center of mass calculation on someone transferring a ball from one hand to the other, you will have an accurate account of the qualitative motion of the arms and ball, but the scale for actual displacement will be off because the ball's mass is small compared to the body.
QUOTE (OneWhiteEye+Sep 23 2007, 04:01 PM)
At that scope, nothing except camera motion and block compression artifact would be a problem. Already ruled out for this video. So that data's OK as it is and ready to plug into your process.
Thus far, the only candidate in this video for subpixel extraction is the antenna.
Probably doesn't have vibrational modes over that distance, eh?
And we're talking about a thermal affecting an area of only that size.
By 'unknown individual scale factors' I mean I have a lot of curves that my gut tells me are accurate to within a scale factor but the factor is unique to each measurement.
And I will! The only problem with it that I see is that you started at frame 800. Eventually I would like to have data which starts immediately after the last camera bobble.
For what I have in mind that would be a problem. I would very much like to have the corners as well.
Not enough to matter.
The thermal effects are an important reason for wanting more than just one feature.
However, once a baseline, using pixel-by-pixel data is established, I can make good use of measurements with unknown scale factors. There are several ways, but I suspect the only one of import here is to extend the very slow drop back in time as far as may be.
We know that the tower's resistance was precisely 1 g before it began to fail. So the resistive force once it does begin to fail is very slightly less than 1 g. The only thing having scale factors does is allow us to determine that value, which is not of such great interest. Determining precisely when vertical motion becomes detectable, using the most precise analysis, is of considerable interest. The goal is to see if this motion is detectable long before frame 800.
I think we are making progress.
Thus far, the only candidate in this video for subpixel extraction is the antenna.
Probably doesn't have vibrational modes over that distance, eh?
And we're talking about a thermal affecting an area of only that size.
By 'unknown individual scale factors' I mean I have a lot of curves that my gut tells me are accurate to within a scale factor but the factor is unique to each measurement.
And I will!
The only problem with it that I see is that you started at frame 800. Eventually I would like to have data which starts immediately after the last camera bobble.For what I have in mind that would be a problem. I would very much like to have the corners as well.
Not enough to matter.
The thermal effects are an important reason for wanting more than just one feature.
However, once a baseline, using pixel-by-pixel data is established, I can make good use of measurements with unknown scale factors. There are several ways, but I suspect the only one of import here is to extend the very slow drop back in time as far as may be.
We know that the tower's resistance was precisely 1 g before it began to fail. So the resistive force once it does begin to fail is very slightly less than 1 g. The only thing having scale factors does is allow us to determine that value, which is not of such great interest. Determining precisely when vertical motion becomes detectable, using the most precise analysis, is of considerable interest. The goal is to see if this motion is detectable long before frame 800.
I think we are making progress.
We are definitely making progress.
I chose Frame 800 as a standardized starting point for this video precisely because it precedes any conventionally measurable motion by a few seconds and is only seconds after the camera vibration disappears. All hand-rendered datasets, having by nature granularity greater than the motion between end of camera shake and onset of measurable collapse, will have a fixed value during that interval by definition.
Other datasets don't have that limitation. I'll be happy to provide subpixel-oriented and other types of data such as channel intensity mean and variation over the interval requested. In, fact the whole video is not a problem for many of these methods since the only manual intervention is to specify frame range and selection rectangle. The size of the resulting data file is another matter.
I'll post something illustrative of the real-world aspects of this discussion. Circumstance dictates it will likely be in several hours, but please hold that thought.
I chose Frame 800 as a standardized starting point for this video precisely because it precedes any conventionally measurable motion by a few seconds and is only seconds after the camera vibration disappears. All hand-rendered datasets, having by nature granularity greater than the motion between end of camera shake and onset of measurable collapse, will have a fixed value during that interval by definition.
Other datasets don't have that limitation. I'll be happy to provide subpixel-oriented and other types of data such as channel intensity mean and variation over the interval requested. In, fact the whole video is not a problem for many of these methods since the only manual intervention is to specify frame range and selection rectangle. The size of the resulting data file is another matter.
I'll post something illustrative of the real-world aspects of this discussion. Circumstance dictates it will likely be in several hours, but please hold that thought.
QUOTE (zoktoberfest+Sep 23 2007, 01:53 PM)
Alan was formidable, setting me straight about the responsibilities, capabilities, schedules, routines, and observational awareness required in the work environment of an elevator maintenance man. It was most impressive, and I had no idea how comprehensive. I apologize for my underestimation.
I remember Alan from the BP thread. He contributed, greatly, to our understanding of how tall buildings work.
1. I'm not an elevator maintenance man and never was. I was an elevator construction mechanic, building them as the building was being erected. I am a building mainenance man. And no, I didn't work at the WTC, but I'm fairly certain they have a computer program similiar (if not even the same one) to the buildings I have worked on, that kicks out PM's to be done. It's not a mystery or anything... we operate and maintain the same ol' things that each and every building has. I'm thinking that gives me more insight than YOU have on what could or couldn't be pulled off. In other words, YOU weren't there at WTC either, but which one of us has a better idea of how it was operated?
2. What is the BP thread? I've been on this site only, but this is the third thread that I know of. If "BP" is somewhere else, then you have mistaken me for somebody else.
I remember Alan from the BP thread. He contributed, greatly, to our understanding of how tall buildings work.
1. I'm not an elevator maintenance man and never was. I was an elevator construction mechanic, building them as the building was being erected. I am a building mainenance man. And no, I didn't work at the WTC, but I'm fairly certain they have a computer program similiar (if not even the same one) to the buildings I have worked on, that kicks out PM's to be done. It's not a mystery or anything... we operate and maintain the same ol' things that each and every building has. I'm thinking that gives me more insight than YOU have on what could or couldn't be pulled off. In other words, YOU weren't there at WTC either, but which one of us has a better idea of how it was operated?
2. What is the BP thread? I've been on this site only, but this is the third thread that I know of. If "BP" is somewhere else, then you have mistaken me for somebody else.
"1. I'm not an elevator maintenance man and never was. I was an elevator construction mechanic, building them as the building was being erected. I am a building mainenance man. And no, I didn't work at the WTC, but I'm fairly certain they have a computer program similiar (if not even the same one) to the buildings I have worked on, that kicks out PM's to be done. It's not a mystery or anything... we operate and maintain the same ol' things that each and every building has. I'm thinking that gives me more insight than YOU have on what could or couldn't be pulled off. In other words, YOU weren't there at WTC either, but which one of us has a better idea of how it was operated?"
"2. What is the BP thread? I've been on this site only, but this is the third thread that I know of. If "BP" is somewhere else, then you have mistaken me for somebody else."
OK, elevator construction mechanic it is.
Of course, your status trumps mine, and most everyone else's.
You and I weren't there, we can now agree on that, but Scott Forbes was. That was really the whole point of the post.
http://killtown.blogspot.com/2005/12/scott...-interview.html
"2. What is the BP thread? I've been on this site only, but this is the third thread that I know of. If "BP" is somewhere else, then you have mistaken me for somebody else."
OK, elevator construction mechanic it is.
Of course, your status trumps mine, and most everyone else's.
You and I weren't there, we can now agree on that, but Scott Forbes was. That was really the whole point of the post.
http://killtown.blogspot.com/2005/12/scott...-interview.html
There is nothing unusual about the juxtaposition of a power maintenance activity and 9/11 other than our natural tendency to fit a pattern to a collection of events --- even if totally unrelated. While a large building shutdown may be unusual, smaller complexes are regularly shutdown. If you need to do transformer maintenance or play with the main feeds there really is little alternative unless the electrical systems were designed for multiple services.
No evidence of a connection between these events is presented; all we have is lurid speculation.
No evidence of a connection between these events is presented; all we have is lurid speculation.
QUOTE (zoktoberfest+Sep 23 2007, 10:22 PM)
Of course, your status trumps mine, and most everyone else's.
You and I weren't there, we can now agree on that, but Scott Forbes was. That was really the whole point of the post.
http://killtown.blogspot.com/2005/12/scott...-interview.html
Except Scott Forbes provides NO EVIDENCE of ANYTHING SINISTER.
NOTHING.
Do you realize how ridiculous this is?
The tower undergoes maintenance that is WELL PUBLICIZED (see Scott's interview) and the building is NOT CLEARED and the time frame is MINOR and yet you think this is EVIDENCE of a conspiracy to bring down the tower by CD????
Priceless.
Maybe you should stick to posting this stuff in the COMIC RELIEF thread.
Arthur
You and I weren't there, we can now agree on that, but Scott Forbes was. That was really the whole point of the post.
http://killtown.blogspot.com/2005/12/scott...-interview.html
Except Scott Forbes provides NO EVIDENCE of ANYTHING SINISTER.
NOTHING.
Do you realize how ridiculous this is?
The tower undergoes maintenance that is WELL PUBLICIZED (see Scott's interview) and the building is NOT CLEARED and the time frame is MINOR and yet you think this is EVIDENCE of a conspiracy to bring down the tower by CD????
Priceless.
Maybe you should stick to posting this stuff in the COMIC RELIEF thread.
Arthur
QUOTE (OneWhiteEye+Sep 23 2007, 08:17 PM)
because it's composed solely of raw footage (yay!) without action soundtrack and droning imbecilic narrative.
LOL, that makes me smile on this early morning
LOL, that makes me smile on this early morning
[removed]
beijingyank
Yeah, we're all pulling for you BJ. You're such a classy guy.
The reason you hear nothing about the engine is it has the proper serial number for the aircraft it came from, you know, the one we all saw hit the building???
Grumpy
QUOTE
That is what you and the rest of your baby killing cabal root for: "stupidity."
Yeah, we're all pulling for you BJ. You're such a classy guy.
The reason you hear nothing about the engine is it has the proper serial number for the aircraft it came from, you know, the one we all saw hit the building???
Grumpy
QUOTE (Grumpy+Sep 24 2007, 11:24 AM)
beijingyank
Yeah, we're all pulling for you BJ. You're such a classy guy.
The reason you hear nothing about the engine is it has the proper serial number for the aircraft it came from, you know, the one we all saw hit the building???
Grumpy
Grumpster, Let's think about putting a rocket on your wheelchair, because you are slow.
The oct says 767's hit the towers. This engine on the street does not come off a 767.
Tell me ironsides, how did it get there?
Yeah, we're all pulling for you BJ. You're such a classy guy.
The reason you hear nothing about the engine is it has the proper serial number for the aircraft it came from, you know, the one we all saw hit the building???
Grumpy
Grumpster, Let's think about putting a rocket on your wheelchair, because you are slow.
The oct says 767's hit the towers. This engine on the street does not come off a 767.
Tell me ironsides, how did it get there?
QUOTE (beijingyank+Sep 24 2007, 11:32 AM)
Grumpster, Let's think about putting a rocket on your wheelchair, because you are slow.
The oct says 767's hit the towers. This engine on the street does not come off a 767.
Tell me ironsides, how did it get there?
Hey Longstreet, go to a Pratt and Whitney service center and ask them if you can feel a JT9D diffuser section and you will find that it feels just like the one that was found at Church and Murry.
The oct says 767's hit the towers. This engine on the street does not come off a 767.
Tell me ironsides, how did it get there?
Hey Longstreet, go to a Pratt and Whitney service center and ask them if you can feel a JT9D diffuser section and you will find that it feels just like the one that was found at Church and Murry.
QUOTE (beijingyank+Sep 24 2007, 07:09 AM)
Aircraft mechanics I know, have identified it as a CFM56 engine.
So lets see.
YOU claim to have access to PROOF that the OCT is a LIE
BUT
Instead of doing ANYTHING to PROVE that that engine does not come from a 767 ALL YOU DO IS POST your unsubstantiated claims on this forum?
Typical.
Might work on the LC forum but here its just a waste of everyone's time.
Here's a suggestion:
There are three SIMPLE steps that one would have to do to start to make their case that this is not a JT9D.
Draw a circle around a particular part of the picture that PROVES that it CAN'T be a JT9D.
Show LINK to picture of a CFM56 with same UNIQUE part.
Show LINK to picture of a JT9D without that UNIQUE part.
Arthur
So lets see.
YOU claim to have access to PROOF that the OCT is a LIE
BUT
Instead of doing ANYTHING to PROVE that that engine does not come from a 767 ALL YOU DO IS POST your unsubstantiated claims on this forum?
Typical.
Might work on the LC forum but here its just a waste of everyone's time.
Here's a suggestion:
There are three SIMPLE steps that one would have to do to start to make their case that this is not a JT9D.
Draw a circle around a particular part of the picture that PROVES that it CAN'T be a JT9D.
Show LINK to picture of a CFM56 with same UNIQUE part.
Show LINK to picture of a JT9D without that UNIQUE part.
Arthur
It turned out to be more than a few hours but here goes. Below is a series of pictures which are blowups of a slice of the antenna obtained from the very top of the video frame. The pictures are frames 800, 830, 860, 890, 920 and 950, spaced one second apart.
Frame 800
Frame 830
Frame 860
Frame 890
[gotta break the post up, infernal message board]
Frame 800
Frame 830
Frame 860
Frame 890
[gotta break the post up, infernal message board]
[continued]
Frame 920
Frame 950
Please note that the vertical bands move to the left over the course of time. Between frames 800 and 830, it seems they've moved a little bit, but how much? Between the next two frames it moves further, still not yet a pixel, still can't judge how much. Then there's not much change going to the next frame, possibly no horizontal motion at all. At frame 920, it looks like the antenna has moved over about a pixel and, by the end at frame 950, it has moved roughly another pixel.
If you chose carefully, the best you can do manually is to pick out those frames where it seems to have moved over a pixel. I didn't do that here, I just captured images on the second. In the first four seconds, though, the image looks almost identical but shifted a pixel to the left so we can say with confidence the antenna moved by roughly that amount.
Turning to an automated method, 2-D luminosity center, we first have to ask what is appropriate to expect of the method if it were run on this same rectangle. First, the top and bottom do not have high contrast boundaries, so the vertical component cannot be resolved. Why do 2-D then? Because it's easier for me at this stage, given the code I have, and it reduces to an aggregate 1-D analysis in each dimension, anyway, so it's perfectly good for horizontal. Second, the dark boundary extends only two pixels to the left so the method can capture at most one pixel of lateral motion, while still leaving a pixel boundary.
Now here's the result of running the extraction on the rectangle of interest, which has actually been chosen just for this purpose as good starting alignment for frame 800. The graph is horizontal pixel location by frame number for frames 500-1000.
Horizontal Displacement - subpixel accuracy
(Here I've included the entire camera shake and a couple of seconds before, David B. Benson)
Bearing in mind that the selection is ideally aligned for frame 800 and is only valid for a pixel's movement (forward in time to about frame 920 and backward to ?), we see that the method gives a difference of 0.81 pixels between those frames. That's pretty close to 1, is it close enough?
Well, yes, actually it is. When I go back and look at the image more closely, it does NOT look like the antenna has moved quite a pixel yet - the leftmost gray line is not quite as light in frame 920 as 800. It seems that the automated method is more accurate than my eyes, and indeed I believe it's so for this case. What's more, it gives a nice hi-res curve for all the motion between 0 and 1 pixel movement, something I couldn't hope to do manually.
There are still reasons why it's not perfectly accurate but it's WAY better than eyes. The camera shake is visible as high frequency oscillation; the magnitude is way off because the real amplitude is much greater than a pixel. Then the lower frequency swings which follow are due to smoke. The dark background at the edges is smoke and, during the seconds prior to frame 800, some very light smoke is passing behind, leaving the measurement contaminated but not necessarily invalid.
Conclusion: data for frames 800-920 is very close to the real (projected) horizontal displacement. Move the selection rectangle over to the left one pixel and run frames 900-960 and that will be similarly accurate for the next pixel of travel; piecewise datasets in this fashion can correlated to provide contiguous data for a stretch.
If, on the other hand, the selection rectangle is changed in any other way (bigger, smaller, translated more), the result is inaccurate and understandably so. I know, I've worked through them.
Too bad there's no such feature configuration on the antenna that works so well with vertical displacement. It is useful to check the vertical result from the above run. Here it is (graph has not been inverted - up is down):
Vertical Displacement - subpixel accuracy
The places where you'd expect to see deflection: during the camera shake, smoke distortion right afterward, and the point where the collapse has progressed such that the part of the antenna framed by the selection is changed. Sure enough, that's what you see - the period covered by the images above is rock steady except for the tail-off of smoke around frame 800. Excellent confirmation.
Frame 920
Frame 950
Please note that the vertical bands move to the left over the course of time. Between frames 800 and 830, it seems they've moved a little bit, but how much? Between the next two frames it moves further, still not yet a pixel, still can't judge how much. Then there's not much change going to the next frame, possibly no horizontal motion at all. At frame 920, it looks like the antenna has moved over about a pixel and, by the end at frame 950, it has moved roughly another pixel.
If you chose carefully, the best you can do manually is to pick out those frames where it seems to have moved over a pixel. I didn't do that here, I just captured images on the second. In the first four seconds, though, the image looks almost identical but shifted a pixel to the left so we can say with confidence the antenna moved by roughly that amount.
Turning to an automated method, 2-D luminosity center, we first have to ask what is appropriate to expect of the method if it were run on this same rectangle. First, the top and bottom do not have high contrast boundaries, so the vertical component cannot be resolved. Why do 2-D then? Because it's easier for me at this stage, given the code I have, and it reduces to an aggregate 1-D analysis in each dimension, anyway, so it's perfectly good for horizontal. Second, the dark boundary extends only two pixels to the left so the method can capture at most one pixel of lateral motion, while still leaving a pixel boundary.
Now here's the result of running the extraction on the rectangle of interest, which has actually been chosen just for this purpose as good starting alignment for frame 800. The graph is horizontal pixel location by frame number for frames 500-1000.
Horizontal Displacement - subpixel accuracy
(Here I've included the entire camera shake and a couple of seconds before, David B. Benson)
Bearing in mind that the selection is ideally aligned for frame 800 and is only valid for a pixel's movement (forward in time to about frame 920 and backward to ?), we see that the method gives a difference of 0.81 pixels between those frames. That's pretty close to 1, is it close enough?
Well, yes, actually it is. When I go back and look at the image more closely, it does NOT look like the antenna has moved quite a pixel yet - the leftmost gray line is not quite as light in frame 920 as 800. It seems that the automated method is more accurate than my eyes, and indeed I believe it's so for this case. What's more, it gives a nice hi-res curve for all the motion between 0 and 1 pixel movement, something I couldn't hope to do manually.
There are still reasons why it's not perfectly accurate but it's WAY better than eyes. The camera shake is visible as high frequency oscillation; the magnitude is way off because the real amplitude is much greater than a pixel. Then the lower frequency swings which follow are due to smoke. The dark background at the edges is smoke and, during the seconds prior to frame 800, some very light smoke is passing behind, leaving the measurement contaminated but not necessarily invalid.
Conclusion: data for frames 800-920 is very close to the real (projected) horizontal displacement. Move the selection rectangle over to the left one pixel and run frames 900-960 and that will be similarly accurate for the next pixel of travel; piecewise datasets in this fashion can correlated to provide contiguous data for a stretch.
If, on the other hand, the selection rectangle is changed in any other way (bigger, smaller, translated more), the result is inaccurate and understandably so. I know, I've worked through them.
Too bad there's no such feature configuration on the antenna that works so well with vertical displacement. It is useful to check the vertical result from the above run. Here it is (graph has not been inverted - up is down):
Vertical Displacement - subpixel accuracy
The places where you'd expect to see deflection: during the camera shake, smoke distortion right afterward, and the point where the collapse has progressed such that the part of the antenna framed by the selection is changed. Sure enough, that's what you see - the period covered by the images above is rock steady except for the tail-off of smoke around frame 800. Excellent confirmation.
QUOTE (OneWhiteEye+Sep 24 2007, 01:31 PM)
Vertical Displacement - subpixel accuracy
These posts are certainly aiding me in understanding the difficulties involved in precise data capture!
It seems that the camera jiggling is at a sufficiently high frequency that it won't be a problem. The lower frequency 'smoke' might be. Of greatest concern, just now, is whether the camera is aligned the same way before the jiggle as after. Thoughts?
Any thoughts about the high frequency components from frame 950 to the end? (Vertical Displacement)
Ideally, I would like three vertical displacements (but I'll take what I can get), one as far east as may be, one centered (the antenna tower will do), and one as far west as may be. The goal is to help eliminate noise from smoke and other thermal effects by having widely spaced measuring points...
These posts are certainly aiding me in understanding the difficulties involved in precise data capture!
It seems that the camera jiggling is at a sufficiently high frequency that it won't be a problem. The lower frequency 'smoke' might be. Of greatest concern, just now, is whether the camera is aligned the same way before the jiggle as after. Thoughts?
Any thoughts about the high frequency components from frame 950 to the end? (Vertical Displacement)
Ideally, I would like three vertical displacements (but I'll take what I can get), one as far east as may be, one centered (the antenna tower will do), and one as far west as may be. The goal is to help eliminate noise from smoke and other thermal effects by having widely spaced measuring points...
QUOTE (David B. Benson+Sep 24 2007, 08:49 PM)
These posts are certainly aiding me in understanding the difficulties involved in precise data capture!
It seems that the camera jiggling is at a sufficiently high frequency that it won't be a problem. The lower frequency 'smoke' might be. Of greatest concern, just now, is whether the camera is aligned the same way before the jiggle as after. Thoughts?
Any thoughts about the high frequency components from frame 950 to the end? (Vertical Displacement)
Ideally, I would like three vertical displacements (but I'll take what I can get), one as far east as may be, one centered (the antenna tower will do), and one as far west as may be. The goal is to help eliminate noise from smoke and other thermal effects by having widely spaced measuring points...
Alignment before and after camera jiggle: I've not formally studied that question but 1) it should be possible to determine with great precision, 2) I seem to remember einsteen saying it returned almost to the same orientation, and 3) where I have extracted data that spans the range, I do consistently see offsets before and after; I could only guess at the magnitude right now but it's small.
The high frequency components at the end: this is where the antenna is dropping rapidly past the selection rectangle, exposing a radical variety of features and shapes in that 'window' on the way down. The antenna is only uniform along the long axis for a short distance above the selection rectange, and even then not precisely uniform. You see how a lot of piecewise measurements come in to play? This makes presentation of a single, coherent dataset difficult.
1-D analysis is way more fragmented than this.
Multiple points: I'm working on it. This is a learning experience and I'm getting a little better at it as time goes along. I have high hopes. Time.
It seems that the camera jiggling is at a sufficiently high frequency that it won't be a problem. The lower frequency 'smoke' might be. Of greatest concern, just now, is whether the camera is aligned the same way before the jiggle as after. Thoughts?
Any thoughts about the high frequency components from frame 950 to the end? (Vertical Displacement)
Ideally, I would like three vertical displacements (but I'll take what I can get), one as far east as may be, one centered (the antenna tower will do), and one as far west as may be. The goal is to help eliminate noise from smoke and other thermal effects by having widely spaced measuring points...
Alignment before and after camera jiggle: I've not formally studied that question but 1) it should be possible to determine with great precision, 2) I seem to remember einsteen saying it returned almost to the same orientation, and 3) where I have extracted data that spans the range, I do consistently see offsets before and after; I could only guess at the magnitude right now but it's small.
The high frequency components at the end: this is where the antenna is dropping rapidly past the selection rectangle, exposing a radical variety of features and shapes in that 'window' on the way down. The antenna is only uniform along the long axis for a short distance above the selection rectange, and even then not precisely uniform. You see how a lot of piecewise measurements come in to play? This makes presentation of a single, coherent dataset difficult.
1-D analysis is way more fragmented than this.
Multiple points: I'm working on it. This is a learning experience and I'm getting a little better at it as time goes along. I have high hopes. Time.
QUOTE (OneWhiteEye+Sep 24 2007, 02:09 PM)
You see how a lot of piecewise measurements come in to play?
Time.
I'm beginning to and I am impressed.
That we have.
Time.
I'm beginning to and I am impressed.
That we have.
I remember that after the shaking it became shifted a few pixels. When I first saw the video I did it very primitively and at that time I came to a much too large E1 value and already noticed the shift.
David, did you notice that the crushing force E1/h is lower than the static force in the building. This again indicates how important a realistic complex model is, however it will be a complex one. For me certainly to complex
David, did you notice that the crushing force E1/h is lower than the static force in the building. This again indicates how important a realistic complex model is, however it will be a complex one. For me certainly to complex
One final point about the difference between manual and automated extraction. The above only required settiing a selection rectangle and frame range, then (BAM!) there's a CSV file a few seconds later. Figuring out what rectangle and making pretty graphs take the lion's share of time, which is only a few minutes. That's why there are 500 frames of data.
The manual method, used to generate previous data which included the washer and corners, takes about 15-20 minutes per frame. This method is not capable of giving accuracy better than about a pixel. Other than the collapse, the only thing that causes multi-pixel deflection is the camera shake. As I mentioned, to do the manual process prior to frame 800 is to have constant values until reaching far enough back to see camera vibration.
That's why I didn't want to plot a lot of known noise at 20 minutes per frame. You can't see the high frequency content unless it's plotted at full frame rate - anything less is just aliasing.
On the other hand, the automated method above (and several others) give very accurate indication of the presence of camera vibration, if not magnitude. I think it would be more fruitful to characterize the tail-off of camera shake using these methods... well, I know it would be.
The manual method, used to generate previous data which included the washer and corners, takes about 15-20 minutes per frame. This method is not capable of giving accuracy better than about a pixel. Other than the collapse, the only thing that causes multi-pixel deflection is the camera shake. As I mentioned, to do the manual process prior to frame 800 is to have constant values until reaching far enough back to see camera vibration.
That's why I didn't want to plot a lot of known noise at 20 minutes per frame. You can't see the high frequency content unless it's plotted at full frame rate - anything less is just aliasing.
On the other hand, the automated method above (and several others) give very accurate indication of the presence of camera vibration, if not magnitude. I think it would be more fruitful to characterize the tail-off of camera shake using these methods... well, I know it would be.
QUOTE (einsteen+Sep 24 2007, 02:34 PM)
I remember that after the shaking it became shifted a few pixels.
David, did you notice that the crushing force E1/h is lower than the static force in the building.
Thanks for the heads-up.
I'm not sure I understand what you are saying. Before the aircraft impact of WTC 1 we can put into the crush-down equation a resistive force which exactly cancels the force of gravity. Eventually enough structural integrity is lost that the resistive force is slightly less. The tower begins to fail. As some components fail more of the load is transfered to other components, so they begin to fail as well. This means that the resistive force, overall, is now even smaller.
This process repeats, going faster and faster as there are fewer and fewer components capable of bearing load. Eventually the three walls buckle and progressive collapsed has commenced. After that, for a least a few seconds, treating E1 (or E1/h) as constant looks to be ok.
This means that working with this early data I'll assume a resistive force which begins at fully resisting gravity and exponentially decaying to the E1/h determined by the first few seconds of actual progressive collapse. The time constant of the exponential will be determined from the data.
Edited to add: I did not state that properly but do not have time to do more than note that it is the deficit from the original static force down to E1/h that is exponential.
If necessary, I'll explain that more fully another time...
David, did you notice that the crushing force E1/h is lower than the static force in the building.
Thanks for the heads-up.
I'm not sure I understand what you are saying. Before the aircraft impact of WTC 1 we can put into the crush-down equation a resistive force which exactly cancels the force of gravity. Eventually enough structural integrity is lost that the resistive force is slightly less. The tower begins to fail. As some components fail more of the load is transfered to other components, so they begin to fail as well. This means that the resistive force, overall, is now even smaller.
This process repeats, going faster and faster as there are fewer and fewer components capable of bearing load. Eventually the three walls buckle and progressive collapsed has commenced. After that, for a least a few seconds, treating E1 (or E1/h) as constant looks to be ok.
This means that working with this early data I'll assume a resistive force which begins at fully resisting gravity and exponentially decaying to the E1/h determined by the first few seconds of actual progressive collapse. The time constant of the exponential will be determined from the data.
Edited to add: I did not state that properly but do not have time to do more than note that it is the deficit from the original static force down to E1/h that is exponential.
If necessary, I'll explain that more fully another time...
I believe it is roughly a factor 3. Of course when there is movement then it is the value of the resistance/resistive? force over distance, but I was thinking since we know that statical force (and add a factor 2-3 for overengineering, and further I've heard that dynamic forces can reach a higher value than the maximal static force as long as it is short timed) then we can maybe conclude that a peak force is only relevant at a distance which is a fraction of h, I'm sure that prof. Bazant has these values. But I was wondering if there is difference between the homogenous force model and the peak force model, the collapse time will not really matter, that is the difference between connected free fall paraboles with a small stepfunction between them and almost-free-fall paraboles. I don't know really much about material science and stuff, but you came with the 396MJ due to a homogeneous force, would it differ much with the peak force model?
QUOTE (einsteen+Sep 24 2007, 04:13 PM)
I believe it is roughly a factor 3.
... you came with the 396MJ due to a homogeneous force, would it differ much with the peak force model?
We know that at the beginning of progressive collapse the acceleration is approximately (2/3)g. So I think a factor of 3 is wrong.
Yes it would, but the instantaneous force model does not appear to apply during progressive collapse, on both fundamental grounds and the simple fact that the crush-down equation gives a very good fit.
... you came with the 396MJ due to a homogeneous force, would it differ much with the peak force model?
We know that at the beginning of progressive collapse the acceleration is approximately (2/3)g. So I think a factor of 3 is wrong.Yes it would, but the instantaneous force model does not appear to apply during progressive collapse, on both fundamental grounds and the simple fact that the crush-down equation gives a very good fit.
I want to commend you on some very fine work, and I recognize that you've put a lot of effort into this.
It occurs to me that there might be seismic data available from the video using a similar process, if there were a sufficiently stable object in the camera's FOV.
If one assumes that a far object (preferably a point-source) is assumed stable, then and visible (sub-pixel) movement of that far object would be due to the camera-shake resulting from the seismic energy of the collapsing tower. This assumes, of course, that the camera was tripod-mounted, and that the seismic influences outweigh the aerodynamic influences.
I'm not requesting that you perform any additional work along these lines, I'm just pointing out that another dataset could be extracted using the same approach, if you were interested.
It occurs to me that there might be seismic data available from the video using a similar process, if there were a sufficiently stable object in the camera's FOV.
If one assumes that a far object (preferably a point-source) is assumed stable, then and visible (sub-pixel) movement of that far object would be due to the camera-shake resulting from the seismic energy of the collapsing tower. This assumes, of course, that the camera was tripod-mounted, and that the seismic influences outweigh the aerodynamic influences.
I'm not requesting that you perform any additional work along these lines, I'm just pointing out that another dataset could be extracted using the same approach, if you were interested.
QUOTE (wcelliott+Sep 25 2007, 01:01 AM)
I want to commend you on some very fine work, and I recognize that you've put a lot of effort into this.
It occurs to me that there might be seismic data available from the video using a similar process, if there were a sufficiently stable object in the camera's FOV.
If one assumes that a far object (preferably a point-source) is assumed stable, then and visible (sub-pixel) movement of that far object would be due to the camera-shake resulting from the seismic energy of the collapsing tower. This assumes, of course, that the camera was tripod-mounted, and that the seismic influences outweigh the aerodynamic influences.
I'm not requesting that you perform any additional work along these lines, I'm just pointing out that another dataset could be extracted using the same approach, if you were interested.
Thank you. I assume you're talking about me, haha!
Good thoughts. This video is a gem because it's on a tripod, framed well, starts well before collapse, and has a nearby building (the static object but not far away) in-focus on one side. The only drawbacks are the camera vibration - really good that it stopped when it did - and the artifacts introduced by file format conversion in the copy I have. When I have the DVD, the latter issue will undoubtedly go away. Possibly there will be more frames before and after as well. Definitely has audio, and that means distance to camera can be discovered.
There could be effects of seismic energy evident in the video. einsteen said the camera does vibrate in response to the (later) collapse so I definitely wanted to check that out at some point. I've been a bit myopic so far, only concerning myself with the first few seconds and whatever other time frames are necessary to validate that work.
Interested? Oh yes, certainly. I plan to wring every last bit of qualitative and quantitative information possible out of this video... then move on to the next one. Can't give up the rest of my life, that's why it will go slowly.
There's so much that can come from this. Compression of each of the top 20 floors in the NW corner, sub-second affine transformation matrices for the antenna, residual sway, seismic trace, etc.
Something else on the list is investigating the blur of floor lines a few seconds after my Tzero. This is one of the things that put manual floor line measurements on hold, too hard to see for a period of time. I'm entertaining the notion that this is shock propagating across the north wall...
It occurs to me that there might be seismic data available from the video using a similar process, if there were a sufficiently stable object in the camera's FOV.
If one assumes that a far object (preferably a point-source) is assumed stable, then and visible (sub-pixel) movement of that far object would be due to the camera-shake resulting from the seismic energy of the collapsing tower. This assumes, of course, that the camera was tripod-mounted, and that the seismic influences outweigh the aerodynamic influences.
I'm not requesting that you perform any additional work along these lines, I'm just pointing out that another dataset could be extracted using the same approach, if you were interested.
Thank you. I assume you're talking about me, haha!
Good thoughts. This video is a gem because it's on a tripod, framed well, starts well before collapse, and has a nearby building (the static object but not far away) in-focus on one side. The only drawbacks are the camera vibration - really good that it stopped when it did - and the artifacts introduced by file format conversion in the copy I have. When I have the DVD, the latter issue will undoubtedly go away. Possibly there will be more frames before and after as well. Definitely has audio, and that means distance to camera can be discovered.
There could be effects of seismic energy evident in the video. einsteen said the camera does vibrate in response to the (later) collapse so I definitely wanted to check that out at some point. I've been a bit myopic so far, only concerning myself with the first few seconds and whatever other time frames are necessary to validate that work.
Interested? Oh yes, certainly. I plan to wring every last bit of qualitative and quantitative information possible out of this video... then move on to the next one. Can't give up the rest of my life, that's why it will go slowly.
There's so much that can come from this. Compression of each of the top 20 floors in the NW corner, sub-second affine transformation matrices for the antenna, residual sway, seismic trace, etc.
Something else on the list is investigating the blur of floor lines a few seconds after my Tzero. This is one of the things that put manual floor line measurements on hold, too hard to see for a period of time. I'm entertaining the notion that this is shock propagating across the north wall...
QUOTE (zoktoberfest+Sep 23 2007, 08:22 PM)
You and I weren't there, we can now agree on that, but Scott Forbes was. That was really the whole point of the post.
I read his interview that you linked, and I STILL don't see the point. He saw the second plane coming in and it made him think of the powerdown?? How odd. That makes no sense at all to me. Let's see... a plane blows up and planted explosives blow up also, so one must mean the other has happened too?? What kind of twisted logic is that?
And just because he worked there as an IT tech has zero to do with knowing what all would be involved in setting up a CD. It's impossible to do without people knowing about it and even MORE IMPOSSIBLE to do from noon Sat. to 2pm Sunday.
I've explained before how building maintenance takes out (isolates) a sub-station at a time to 'routine' it annually. That is... tighten every bolt/screw/connection and clean and oil contacts, etc... but this sounded like they were pulling new conductors for an upgrade. A powerdown of half the building would involve MAIN TRANSFORMERS and you DON'T do anything with them if they're energized. The word "frying" comes to mind.
Now, was this guy the ONLY person to know about the powerdown, or just the only one that wanted publicity and tried to make something sinister about it? There must be thousands that know about it and didn't feel that way. That should give you pause, no?
I read his interview that you linked, and I STILL don't see the point. He saw the second plane coming in and it made him think of the powerdown?? How odd. That makes no sense at all to me. Let's see... a plane blows up and planted explosives blow up also, so one must mean the other has happened too?? What kind of twisted logic is that?
And just because he worked there as an IT tech has zero to do with knowing what all would be involved in setting up a CD. It's impossible to do without people knowing about it and even MORE IMPOSSIBLE to do from noon Sat. to 2pm Sunday.
I've explained before how building maintenance takes out (isolates) a sub-station at a time to 'routine' it annually. That is... tighten every bolt/screw/connection and clean and oil contacts, etc... but this sounded like they were pulling new conductors for an upgrade. A powerdown of half the building would involve MAIN TRANSFORMERS and you DON'T do anything with them if they're energized. The word "frying" comes to mind.
Now, was this guy the ONLY person to know about the powerdown, or just the only one that wanted publicity and tried to make something sinister about it? There must be thousands that know about it and didn't feel that way. That should give you pause, no?
QUOTE (NoCleverName+Sep 23 2007, 09:19 PM)
There is nothing unusual about the juxtaposition of a power maintenance activity and 9/11 other than our natural tendency to fit a pattern to a collection of events --- even if totally unrelated. While a large building shutdown may be unusual, smaller complexes are regularly shutdown. If you need to do transformer maintenance or play with the main feeds there really is little alternative unless the electrical systems were designed for multiple services.
No evidence of a connection between these events is presented; all we have is lurid speculation.
exactly ... and well-said
I kinda said the same thing replying to zoktoberfest before reading yours (the very next post too).
No evidence of a connection between these events is presented; all we have is lurid speculation.
exactly ... and well-said
I kinda said the same thing replying to zoktoberfest before reading yours (the very next post too).
The part where I stopped reading was when he'd said the one tower had a power-down, but the other one didn't.
Didn't *both* towers collapse?
Didn't *both* towers collapse?
QUOTE (Capracus+Sep 24 2007, 11:56 AM)
Hey Longstreet, go to a Pratt and Whitney service center and ask them if you can feel a JT9D diffuser section and you will find that it feels just like the one that was found at Church and Murry.
I want some numbers off that engine, or better still a play back on the indestructible black boxes that the new Hoover pixies say weren't found.
We know they are lying.
Come on physics! You guys are lagging.
Think of your legacy. Cause when the trap door begins to drop on these traitors it will be too late.
I want some numbers off that engine, or better still a play back on the indestructible black boxes that the new Hoover pixies say weren't found.
We know they are lying.
Come on physics! You guys are lagging.
Think of your legacy. Cause when the trap door begins to drop on these traitors it will be too late.
QUOTE (wcelliott+Sep 25 2007, 12:24 AM)
The part where I stopped reading was when he'd said the one tower had a power-down, but the other one didn't.
I hear ya! Another example of not thinking something through. Just throw it out there and get some publicity... and there will always be a ton of non-thinkers that will agree. It was a waste of time, but I actually wanted to read the whole interview to see what else he had twisted.
I hear ya! Another example of not thinking something through. Just throw it out there and get some publicity... and there will always be a ton of non-thinkers that will agree. It was a waste of time, but I actually wanted to read the whole interview to see what else he had twisted.
QUOTE (beijingyank+Sep 25 2007, 06:47 AM)
I want some numbers off that engine, or better still a play back on the indestructible black boxes that the new Hoover pixies say weren't found.
We know they are lying.
I know... when you can give us evidence of where the "Lost" island the real passengers and the real airplane are, then we could start trying to trace where and how they switched airplanes. The passengers and crew are really safe and sound somewhere, right? Sucks that they can't contact their family though. *shrug* Were they 'in on it', or being held on Lost Island against their will? And what secret cabal of guards keeps them there, where they can't come home either?
To believe anything you conspiracy nuts put out there, by logic gets you so far out on a limb that you'd truly need to be on LSD to agree.
We know they are lying.
I know... when you can give us evidence of where the "Lost" island the real passengers and the real airplane are, then we could start trying to trace where and how they switched airplanes. The passengers and crew are really safe and sound somewhere, right? Sucks that they can't contact their family though. *shrug* Were they 'in on it', or being held on Lost Island against their will? And what secret cabal of guards keeps them there, where they can't come home either?
To believe anything you conspiracy nuts put out there, by logic gets you so far out on a limb that you'd truly need to be on LSD to agree.
QUOTE (David B. Benson+Sep 24 2007, 04:24 PM)
We know that at the beginning of progressive collapse the acceleration is approximately (2/3)g.
Yes, poster einsteen had it right. The initial force fully resisting gravity as about 3 times E1/h.
Sometimes I don't think matters through properly before posting.
Yes, poster einsteen had it right. The initial force fully resisting gravity as about 3 times E1/h.
Sometimes I don't think matters through properly before posting.
QUOTE
Jet fuel can burn rather hotly:
That's about 1275C, peak, if I'm reading it correctly.
For a 1meter square pool of jet fuel.
I'd be interested in seeing how that figure changes when the pool increases in size. I seriously doubt that it'll have the same range, I'd expect it to get hotter, due to fire's inherently chaotic nature.
QUOTE (carterelliott+Sep 25 2007, 04:21 PM)
... I'd expect it to get hotter, due to fire's inherently chaotic nature.
the candle that burns twice as hot, burns half as long.
pretend heat is not heat, you conjurers and obfuscaters.
heat output is the same, whether over a short period or long. if the temperatures go very high, then they don't last long. if they last a long time, they don't get that hot.
hello, mcflies? PHYSICS board, here.
pretend heat is not heat, you conjurers and obfuscaters.
heat output is the same, whether over a short period or long. if the temperatures go very high, then they don't last long. if they last a long time, they don't get that hot.
hello, mcflies? PHYSICS board, here.
The strength of steel is a function of TEMPERATURE, not HEAT.
Higher temperature fires will make steel weaker than lower temperature fires that burn longer.
Buy a clue.
Higher temperature fires will make steel weaker than lower temperature fires that burn longer.
Buy a clue.
QUOTE (wcelliott+Sep 26 2007, 05:59 AM)
The strength of steel is a function of TEMPERATURE, not HEAT.
Higher temperature fires will make steel weaker than lower temperature fires that burn longer.
Buy a clue.
and air doesn't conduct heat to steel very well.
it takes time for air to heat steel.
and check the heat of temperature of the core on NIST's computer generated spectral distribution graphs.
most of it is around 250C.
hang down your head, tom dooley.
Higher temperature fires will make steel weaker than lower temperature fires that burn longer.
Buy a clue.
and air doesn't conduct heat to steel very well.
it takes time for air to heat steel.
and check the heat of temperature of the core on NIST's computer generated spectral distribution graphs.
most of it is around 250C.
hang down your head, tom dooley.
One of the very first posts I made on this topic was my stating that I believed the NIST fire model underestimated the temperatures of the fire, as fire is chaotic, and most computer models assume everything is linear.
I also pointed out some 200 pages back that with structural steel, it isn't the average value of temperature that matters as much as the peak temperature, as steel's strength rapidly decreases as temperatures increase, and truss structures are like chains, only as strong as the weakest part.
This research only supports everything I've already said on the topic.
BTW, newton, I can't recall, when was the last time that *you* were right about anything?
I also pointed out some 200 pages back that with structural steel, it isn't the average value of temperature that matters as much as the peak temperature, as steel's strength rapidly decreases as temperatures increase, and truss structures are like chains, only as strong as the weakest part.
This research only supports everything I've already said on the topic.
BTW, newton, I can't recall, when was the last time that *you* were right about anything?
QUOTE (wcelliott+Sep 26 2007, 08:16 AM)
One of the very first posts I made on this topic was my stating that I believed the NIST fire model underestimated the temperatures of the fire, as fire is chaotic, and most computer models assume everything is linear.
I also pointed out some 200 pages back that with structural steel, it isn't the average value of temperature that matters as much as the peak temperature, as steel's strength rapidly decreases as temperatures increase, and truss structures are like chains, only as strong as the weakest part.
This research only supports everything I've already said on the topic.
BTW, newton, I can't recall, when was the last time that *you* were right about anything?
Of course the "weakest link" analogy would only be true for an unconnected single length of steel, not a framework of interconnected pieces.
I also pointed out some 200 pages back that with structural steel, it isn't the average value of temperature that matters as much as the peak temperature, as steel's strength rapidly decreases as temperatures increase, and truss structures are like chains, only as strong as the weakest part.
This research only supports everything I've already said on the topic.
BTW, newton, I can't recall, when was the last time that *you* were right about anything?
Of course the "weakest link" analogy would only be true for an unconnected single length of steel, not a framework of interconnected pieces.
QUOTE (frater plecticus+Sep 26 2007, 09:33 AM)
Of course the "weakest link" analogy would only be true for an unconnected single length of steel, not a framework of interconnected pieces.
Wow!
Something actually sorta sensible from frater plecticus!
Yes, but consider carefully the structure of trusses, which was the point.
By the way, given NIST's long history of building fire safety, I disagree with wcelliot's assumption that NIST's fire modeling was inadequate.
Wow!
Something actually sorta sensible from frater plecticus!Yes, but consider carefully the structure of trusses, which was the point.
By the way, given NIST's long history of building fire safety, I disagree with wcelliot's assumption that NIST's fire modeling was inadequate.
QUOTE (frater plecticus+Sep 26 2007, 10:33 AM)
Of course the "weakest link" analogy would only be true for an unconnected single length of steel, not a framework of interconnected pieces.
Say wha?? An "unconnected single length of steel" would be analogous to a single link of a chain, PERIOD. That's not a chain at all, it's what the words connote, a single link all by itself. Man, you guys twist yourself around all crazy trying to make something fit into a conspiracy.
*edited to change the bolded "link" from "piece".
Say wha?? An "unconnected single length of steel" would be analogous to a single link of a chain, PERIOD. That's not a chain at all, it's what the words connote, a single link all by itself. Man, you guys twist yourself around all crazy trying to make something fit into a conspiracy.
*edited to change the bolded "link" from "piece".
The steel in the wtc (in trusses column, beams, etc) could easily...I repeat, easily handle the fire on 9/11. Very easily.
People who are still talking about fire 2007... are just not in touch with the reality.
The fire conspiracy theory is just a one huge joke.
Most likely what Kevin Ryan said is absolutly right, that Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours.
People who are still talking about fire 2007... are just not in touch with the reality.
The fire conspiracy theory is just a one huge joke.
Most likely what Kevin Ryan said is absolutly right, that Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours.
QUOTE (Daru+Sep 27 2007, 06:47 AM)
The steel in the wtc (in trusses column, beams, etc) could easily...I repeat, easily handle the fire on 9/11. Very easily.
People who are still talking about fire 2007... are just not in touch with the reality.
The fire conspiracy theory is just a one huge joke.
Most likely what Kevin Ryan said is absolutly right, that Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours.
And yet, once again we come back to the fact that the steel truss/floor pan system used in the WTC has a notorious reputation amongst fire fighters.
Notorious as being unstable and prone to collapse in ORDINARY OFFICE FIRES.
People who are still talking about fire 2007... are just not in touch with the reality.
The fire conspiracy theory is just a one huge joke.
Most likely what Kevin Ryan said is absolutly right, that Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours.
And yet, once again we come back to the fact that the steel truss/floor pan system used in the WTC has a notorious reputation amongst fire fighters.
Notorious as being unstable and prone to collapse in ORDINARY OFFICE FIRES.
QUOTE (Daru+Sep 26 2007, 11:47 AM)
The steel in the wtc (in trusses column, beams, etc) could easily...I repeat, easily handle the fire on 9/11. Very easily.
The fire conspiracy theory is just a one huge joke.
Read NCSTAR1--5 and all the supporting sub-reports. Explain what NIST did wrong.
I don't know what a 'fire conspiracy theory' is, but I agree it is a joke. Invisible ninja fairies going around with cigarette lighters, maybe?
The fire conspiracy theory is just a one huge joke.
Read NCSTAR1--5 and all the supporting sub-reports. Explain what NIST did wrong.
I don't know what a 'fire conspiracy theory' is, but I agree it is a joke. Invisible ninja fairies going around with cigarette lighters, maybe?
QUOTE (David B. Benson+Sep 27 2007, 06:57 AM)
Read NCSTAR1--5 and all the supporting sub-reports. Explain what NIST did wrong.
I don't know what a 'fire conspiracy theory' is, but I agree it is a joke. Invisible ninja fairies going around with cigarette lighters, maybe?
I think he's referring to what he, and other conspiracy theorists refer to as "The official conspiracy theory" - in other words, the explanation being promulgated by NIST/FEMA/the US government.
I don't know what a 'fire conspiracy theory' is, but I agree it is a joke. Invisible ninja fairies going around with cigarette lighters, maybe?
I think he's referring to what he, and other conspiracy theorists refer to as "The official conspiracy theory" - in other words, the explanation being promulgated by NIST/FEMA/the US government.
QUOTE (Daru+Sep 26 2007, 12:47 PM)
Most likely what Kevin Ryan said is absolutly right, that Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours.
That would be Kevin Ryan the water tester, pouring forth (haha, a water tester pouring) about something he knows nothing about. For the hundreth time or so, UL didn't certify the steel in WTC.
That would be Kevin Ryan the water tester, pouring forth (haha, a water tester pouring) about something he knows nothing about. For the hundreth time or so, UL didn't certify the steel in WTC.
People have to keep in mind that when they designed wtc, they ofcource thought about a fire. And what did the do ? They ofcource used the best steel availible. High srength and/or Low-Alloy. Key word steel related: High srength and/or Low-Alloy.
Ofcource they dont admit what Ryan said. Of cource not...but based on my research he was most likely absolutly right !
People are talking back and forth about a fire for many years ! No one which do his own research belives the fire theory. It is the such a lame theory. Eh...it should be very easy to prove the fire theory. put a fire insteel structure add some kerosene and see what happen ! (well everybody knows what will not happen)
The fire theory is dead! Get it ? (doubt it)
Ofcource they dont admit what Ryan said. Of cource not...but based on my research he was most likely absolutly right !
People are talking back and forth about a fire for many years ! No one which do his own research belives the fire theory. It is the such a lame theory. Eh...it should be very easy to prove the fire theory. put a fire insteel structure add some kerosene and see what happen ! (well everybody knows what will not happen)
The fire theory is dead! Get it ? (doubt it)
QUOTE (Daru+Sep 26 2007, 03:34 PM)
... Eh...it should be very easy to prove the fire theory. put a fire insteel[sic] structure ...
The following link was very easy to find:
Fire Inside
Edited to add: Ad this wasn't that hard, either:
Fire engineering of steel and composite buildings
(I can read the whole article, but I fear that many of you will only be access the abstract. Let me know.)
The most interesting point is that the steel reached a temperature of just over 1100 degrees Celsius, at which point the beams should have failed, but the composite post-n-beam designed had enough redundancy not to. The second most interesting point is that in a test in which 25% of the wood fuel was replaced by polystyrene, this temperature was reached in only 5 minutes.
The following link was very easy to find:
Fire Inside
Edited to add: Ad this wasn't that hard, either:
Fire engineering of steel and composite buildings
(I can read the whole article, but I fear that many of you will only be access the abstract. Let me know.)
The most interesting point is that the steel reached a temperature of just over 1100 degrees Celsius, at which point the beams should have failed, but the composite post-n-beam designed had enough redundancy not to. The second most interesting point is that in a test in which 25% of the wood fuel was replaced by polystyrene, this temperature was reached in only 5 minutes.
This is exactly what I was saying; People talk back and fourth, fire blah blah blah steel blah blah blah etc
But I am talking about the REALITY! Real world ! It should be very easy to proove the fire "did it" theory. It is planty of steel structures all over the world... for example Deutche Bank building ! Put it on fire... "and whatch the building collapse! NOT.
End of story.
But I am talking about the REALITY! Real world ! It should be very easy to proove the fire "did it" theory. It is planty of steel structures all over the world... for example Deutche Bank building ! Put it on fire... "and whatch the building collapse! NOT.
End of story.
QUOTE (Daru+Sep 26 2007, 04:53 PM)
... for example Deutche Bank building ...
Was not a trussed design, but rather a traditional post-n-beam. It makes a big difference as the two links in my previous post demonstrate.
You really ought to do some research before you post. Do you know why?
Was not a trussed design, but rather a traditional post-n-beam. It makes a big difference as the two links in my previous post demonstrate.
You really ought to do some research before you post. Do you know why?
What some people, who is defending the fire fairytail, seems not understand is, that in the future people will laugh at them...similar that people laugh now at the "Earth is flat" theory!
It is all documented here what the so called "experts" are saying. It will be kept here on record. A fire can destroy a steelstructure CD style!
Think about it.
It is all documented here what the so called "experts" are saying. It will be kept here on record. A fire can destroy a steelstructure CD style!
Think about it.
These are not "so called" experts.
They are REAL experts.
In FIRE and BUILDINGS.
Read the Link provided http://www.sciencenews.org/articles/20070825/bob9.asp
Andy Buchanan
Dept. of Civil Engineering
University of Canterbury
Doug Foutch
National Science Foundation
Jean-Marc Franssen
National Fund for Scientific Research Belgium
Univ. de Liège,
William Grosshandler
Building and Fire Research Laboratory
Allen S. Hay
Fire Department New York
Nestor Iwankiw
Hughes Associates, Inc.
Venkatesh Kodur
Civil and Environmental Engineering
Susan Lamont
Arup Fire
James Milke
Rm. 3104F
J.M. Patterson Building
Department of Fire Protection Engineering
Amit H. Varma
School of Civil Engineering
Purdue University
Shyam Sunder
Building and Fire Research Laboratory
National Institute of Standards and Technology
In comparison, what are YOUR credentials Daru?
So far all you have done is a lot of HAND WAVING
Sorry, but that isn't the least bit compelling.
Arthu
They are REAL experts.
In FIRE and BUILDINGS.
Read the Link provided http://www.sciencenews.org/articles/20070825/bob9.asp
Andy Buchanan
Dept. of Civil Engineering
University of Canterbury
Doug Foutch
National Science Foundation
Jean-Marc Franssen
National Fund for Scientific Research Belgium
Univ. de Liège,
William Grosshandler
Building and Fire Research Laboratory
Allen S. Hay
Fire Department New York
Nestor Iwankiw
Hughes Associates, Inc.
Venkatesh Kodur
Civil and Environmental Engineering
Susan Lamont
Arup Fire
James Milke
Rm. 3104F
J.M. Patterson Building
Department of Fire Protection Engineering
Amit H. Varma
School of Civil Engineering
Purdue University
Shyam Sunder
Building and Fire Research Laboratory
National Institute of Standards and Technology
In comparison, what are YOUR credentials Daru?
So far all you have done is a lot of HAND WAVING
Sorry, but that isn't the least bit compelling.
Arthu
QUOTE (Alan (ex elevator man)+Sep 26 2007, 06:09 PM)
Say wha?? An "unconnected single length of steel" would be analogous to a single link of a chain, PERIOD. That's not a chain at all, it's what the words connote, a single link all by itself. Man, you guys twist yourself around all crazy trying to make something fit into a conspiracy.
*edited to change the bolded "link" from "piece".
the trusses were more like chain mail than chain link. there were trusses running perpendicular to the main trusses.
*edited to change the bolded "link" from "piece".
the trusses were more like chain mail than chain link. there were trusses running perpendicular to the main trusses.
QUOTE
The towers were bought down by explosives that nobody saw planted, that left no visible or audio evidence when they were triggered, couldn't be heard in the background of 911 calls that terminate with the collapse of the towers, and left no chemical evidence...
In fact, most video recordings include the sound of explosions during and prior to the collapse of all three buildings.
http://www.google.com/search?hl=en&q=wtc%2...ions%2C+youtube
Confirmation bias in the Trippy mind will surely turn a pathological deaf ear to such physical evidence.
http://www.google.com/search?hl=en&q=wtc%2...ions%2C+youtube
Argumentum ad verecundiam is not physics, Arturio.
QUOTE
the sound of explosions during and prior to the collapse of all three buildings
Explosions, because it was really loud, when the buildings fell. Every sensible person would've expected them to collapse in dead silence.
QUOTE (Al Khwarizmi - step-by-step+Sep 27 2007, 04:47 PM)
In fact, most video recordings include the sound of explosions during and prior to the collapse of all three buildings.
http://www.google.com/search?hl=en&q=wtc%2...ions%2C+youtube
Confirmation bias in the Trippy mind will surely turn a pathological deaf ear to such physical evidence.
http://www.google.com/search?hl=en&q=wtc%2...ions%2C+youtube
Argumentum ad verecundiam is not physics, Arturio.
first of all, I don't care for your insinuations and implications.
Second of all...
After having listened to the first two videos in both videos, with industrial Deejay high performance headphones, rather then ear buds.
I can honestly say I have no idea what you're talking about, in fact, I found it somewhat annoying that in the second video the people who made it, who are claiming it backs up the cd misconception, faded the sound out at the times when they are claiming explosions occured, so that you can't actually hear anything.
If you were trying to prove explosions, I would have thought the logical thing to try and do would be to try and isolate the sounds in question, but no, they just faded them to silence.
But then again, logic and conspirancy theorists generally aren't well acquainted.
The fact of the matter is, that to joe public, the sound of structural steel undergoing catastrophic brittle failure probably would sound like a gun shot going off, or an explosion, because there is a significant amount of energy stored in those structural components. And as far as pressure waves goes, hmm, let me see, we're compressing how many cubic meters of air in what fraction of a second... Gee, I wonder how pressure waves, or shockwaves could possibly form... Then there's the undeniable fact that we have photographic evidence of the fact that large bodies of steel and concrete were coliding at significant speeds... That couldn't possibly be a source for noises that sound like explosions... Could it? No... It's too obvious (note the sarcasm).
And as far as the onset of the pressure waves goes... Let me see... Maybe it's called progressive collapse for a reason...
Maybe it occurs because it starts with a severly damaged and heated floor collapsing onto the floor below it... Nawww, that couldn't possibly be it could it. That'd be too obvious (again, note the sarcasm).
And yes, I have seen/heard the video that was taken from much closer to ground zero where you can actually hear what (I assume) is the actual process of the pancaking, but once again, nowhere is there anything that sounds like an explosion (and I at least can say that I have heard many explosions).
But I suppose that, no doubt, you will have some form of objection, or wave your arms about how i've been brainwashed by the american government, or blither about real time editing and filtering.
Actually, on second thoughts.
After listening to this one:
http://www.youtube.com/watch?v=jAKfBA8lBYg...related&search=
Another couple of times, I can hear what they're talking about, and I must say...
They're slow rumbles, not explosions.
And if you look carefully each one is associated with an expulsion of smoke at the same level which is analgous with the 'squibs' that people talk about during the later part of the collapse.
If the timing they give it is correct, then the first floor fell 17 seconds before the fall became visible externally. If I'm interpreting what I'm seeing and hearing correctly, and this video footage is accurate, then it seems like three floors fell onto the floor below the one that appears to be the most fire damaged on the facade which looks like a black 'ring' that extends around the visible faces of the building.
After listening to this one:
http://www.youtube.com/watch?v=jAKfBA8lBYg...related&search=
Another couple of times, I can hear what they're talking about, and I must say...
They're slow rumbles, not explosions.
And if you look carefully each one is associated with an expulsion of smoke at the same level which is analgous with the 'squibs' that people talk about during the later part of the collapse.
If the timing they give it is correct, then the first floor fell 17 seconds before the fall became visible externally. If I'm interpreting what I'm seeing and hearing correctly, and this video footage is accurate, then it seems like three floors fell onto the floor below the one that appears to be the most fire damaged on the facade which looks like a black 'ring' that extends around the visible faces of the building.
Another question for the conspiracy theorists.
How is it that footage from inside the tower, shot during the collapse records no explosions, even though there's enough of a direct passage through the elevator shafts for burning jet fuel to make from the 78th floor (or which ever) all the way down to the lobby.
http://www.youtube.com/watch?v=s-RlKF1B9Hk...related&search=
How is it that footage from inside the tower, shot during the collapse records no explosions, even though there's enough of a direct passage through the elevator shafts for burning jet fuel to make from the 78th floor (or which ever) all the way down to the lobby.
http://www.youtube.com/watch?v=s-RlKF1B9Hk...related&search=
QUOTE (Al Khwarizmi - step-by-step+Sep 27 2007, 12:47 AM)
Argumentum ad verecundiam is not physics, Arturio.
Actually that definition of a logical fallacy applies to Authorities OUTSIDE their field.
http://philosophy.lander.edu/logic/authority.html
None of those Authorities are OUTSIDE their field though.
ALL are TRAINED in the field and all have STUDIED the subject in great detail.
So, NO, Al, it's not an invalid argument to appeal to this list of EXPERTS and their REASONED analysis of the event to refute Daru's use of the term "so called experts".
Arthur
QUOTE (Trippy+Sep 26 2007, 11:24 PM)
If the timing they give it is correct, then the first floor fell 17 seconds before the fall became visible externally. If I'm interpreting what I'm seeing and hearing correctly, and this video footage is accurate, then it seems like three floors fell onto the floor below the one that appears to be the most fire damaged on the facade which looks like a black 'ring' that extends around the visible faces of the building.
This is of interest. (Remember, I am video challenged.)
Which tower?
This is of interest. (Remember, I am video challenged.)
Which tower?
QUOTE (David B. Benson+Sep 28 2007, 06:41 AM)
This is of interest. (Remember, I am video challenged.)
Which tower?
And I'm geographically challenged. Heh.
I can never remember which is which, but the video I was referring to is the second one to go down, the one with the mast...
Isn't that the same one that... Err... Einsteen was doing his analysis of?
Which tower?
And I'm geographically challenged. Heh.
I can never remember which is which, but the video I was referring to is the second one to go down, the one with the mast...
Isn't that the same one that... Err... Einsteen was doing his analysis of?
QUOTE (Trippy+Sep 27 2007, 11:48 AM)
And I'm geographically challenged. Heh.
I can never remember which is which, but the video I was referring to is the second one to go down, the one with the mast...
Isn't that the same one that... Err... Einsteen was doing his analysis of?
The second to fall was the North Tower, WTC 1. Yes, einsteen has considered it. So have I and several others.
So now I am very interested in as much timing and visual detail as you can obtain.
First, from what direction is the video taken? (If you are not sure, I'll do what I can to help out, because this is quite important. Recall that WTC 1 tilted almost directly due south. That should be enough to determine the approximate azimuth of the camera.)
Do you have a way to stop frame the video and check the timing yourself? I ask because 17 seconds is considerably longer than NIST's estimate. However, that does not mean it is wrong.
Three floors partially collapsing? Are you sure? NCSTAR 1--6 or NCSTAR1--D implies that that floors 98 and 97 partially collapsed, I suppose onto floor 96, but I'd have to reread it to be sure.
Anyway, as much detail as you can provide will be appreciated!
I can never remember which is which, but the video I was referring to is the second one to go down, the one with the mast...
Isn't that the same one that... Err... Einsteen was doing his analysis of?
The second to fall was the North Tower, WTC 1. Yes, einsteen has considered it. So have I and several others.
So now I am very interested in as much timing and visual detail as you can obtain.
First, from what direction is the video taken? (If you are not sure, I'll do what I can to help out, because this is quite important. Recall that WTC 1 tilted almost directly due south. That should be enough to determine the approximate azimuth of the camera.)
Do you have a way to stop frame the video and check the timing yourself? I ask because 17 seconds is considerably longer than NIST's estimate. However, that does not mean it is wrong.
Three floors partially collapsing? Are you sure? NCSTAR 1--6 or NCSTAR1--D implies that that floors 98 and 97 partially collapsed, I suppose onto floor 96, but I'd have to reread it to be sure.
Anyway, as much detail as you can provide will be appreciated!
QUOTE (newton+Sep 26 2007, 07:51 PM)
the trusses were more like chain mail than chain link. there were trusses running perpendicular to the main trusses.
Only in the two-way areas, that is, the corners.
These were ordinary, one-way trusses to which additional support was added at the construction site. I don't yet fully understand the details.
Only in the two-way areas, that is, the corners.
These were ordinary, one-way trusses to which additional support was added at the construction site. I don't yet fully understand the details.
I think the audio that they're analysing is from a reporter that's closer to ground zero then the images they're showing.
If you watch the video, although it's hard to isolate to emphasize, but the puff of smoke does seem to fade between the first two events.
http://www.youtube.com/watch?v=jAKfBA8lBYg
I wish I had access to better quality video, and to the original audio track, it's mildly frustrating.
But, judging by the lighting, my best guess is that the footage is shot from the south, looking north. It's one of those bits of amateur footage that seems to have found it's way around the net.
QUOTE (Trippy+Sep 27 2007, 02:01 PM)
But, judging by the lighting, my best guess is that the footage is shot from the south, looking north. It's one of those bits of amateur footage that seems to have found it's way around the net.
Thank you again! Quite interesting clips.
NCSTAR1--6, page 156 (238 ordinal) states that there were no useful south views. Are you sure this is not from the north?
Anyway, NCSTAR1--6 mentions expulsions about 2 minutes prior to collapse and at the collapse, but does not seem to bother describing these 17 seconds. There is also no attempt to closely match events to the seismograph trace, which is quite a good idea, IMO.
Thank you again! Quite interesting clips.
NCSTAR1--6, page 156 (238 ordinal) states that there were no useful south views. Are you sure this is not from the north?
Anyway, NCSTAR1--6 mentions expulsions about 2 minutes prior to collapse and at the collapse, but does not seem to bother describing these 17 seconds. There is also no attempt to closely match events to the seismograph trace, which is quite a good idea, IMO.
QUOTE (Trippy+Sep 27 2007, 09:01 PM)
I think the audio that they're analysing is from a reporter that's closer to ground zero then the images they're showing.
If you watch the video, although it's hard to isolate to emphasize, but the puff of smoke does seem to fade between the first two events.
http://www.youtube.com/watch?v=jAKfBA8lBYg
I wish I had access to better quality video, and to the original audio track, it's mildly frustrating.
But, judging by the lighting, my best guess is that the footage is shot from the south, looking north. It's one of those bits of amateur footage that seems to have found it's way around the net.
those pics are from "911 eyewitness", and the sound was recorded two miles away in hoboken.
QUOTE (David B. Benson+Sep 28 2007, 09:46 AM)
Thank you again! Quite interesting clips.
NCSTAR1--6, page 156 (238 ordinal) states that there were no useful south views. Are you sure this is not from the north?
Anyway, NCSTAR1--6 mentions expulsions about 2 minutes prior to collapse and at the collapse, but does not seem to bother describing these 17 seconds. There is also no attempt to closely match events to the seismograph trace, which is quite a good idea, IMO.
IN all honesty?
I'm not an american citizen, and I've never been to New York.
I have no idea what direction the camera is pointing.
NCSTAR1--6, page 156 (238 ordinal) states that there were no useful south views. Are you sure this is not from the north?
Anyway, NCSTAR1--6 mentions expulsions about 2 minutes prior to collapse and at the collapse, but does not seem to bother describing these 17 seconds. There is also no attempt to closely match events to the seismograph trace, which is quite a good idea, IMO.
IN all honesty?
I'm not an american citizen, and I've never been to New York.
I have no idea what direction the camera is pointing.
QUOTE (Trippy+Sep 27 2007, 03:14 PM)
I have no idea what direction the camera is pointing.
Not only am I video challenged, but I am rather poor at photo-interpretation.
That said, it appears to me that your video clips seem a fairly good match to the clips from the Tim Main/Mike Ballou video in Figure 6--7 of NCSTAR1--6, page 162 (244 ordinal). If so, then this was shot from the ENE, approximately.
Not only am I video challenged, but I am rather poor at photo-interpretation.
That said, it appears to me that your video clips seem a fairly good match to the clips from the Tim Main/Mike Ballou video in Figure 6--7 of NCSTAR1--6, page 162 (244 ordinal). If so, then this was shot from the ENE, approximately.
Hello , I just ran in to this topic, and wanted to comment on wtc 7 (I'm Dutch so forgive me for my bad English)
I thought this could be interesting (some of you probably already watched(heard) this video)
www.youtube.com/watch?v=QajDxF9uEf4] A guy from Canada calls Jowenko in that video
A few days ago a guy here in Holland also called him , and Jowenko's is still convinced that wtc 7 was a controlled demolition and the towers were not CD's
This is his conclusion after studying the damage reports and construction drawings and more . He had the time to check other experts ( American demolition experts) opinions and talk things through. He doesn't see the big conspiracy ,he sees the possibility that the job is done on 9/11 for safety reasons. He is also willing to back up his claims with more technical information .
Is there any American demolition expert that did his story about WTC 7 on TV? I wonder .
I thought this could be interesting (some of you probably already watched(heard) this video)
www.youtube.com/watch?v=QajDxF9uEf4] A guy from Canada calls Jowenko in that video
A few days ago a guy here in Holland also called him , and Jowenko's is still convinced that wtc 7 was a controlled demolition and the towers were not CD's
This is his conclusion after studying the damage reports and construction drawings and more . He had the time to check other experts ( American demolition experts) opinions and talk things through. He doesn't see the big conspiracy ,he sees the possibility that the job is done on 9/11 for safety reasons. He is also willing to back up his claims with more technical information .
Is there any American demolition expert that did his story about WTC 7 on TV? I wonder .
Ah yes,
Building 7!
That's the WTC building that all the EXPERTS already KNOW was most certainly NOT a CD!
So who needs NIST,
or Jowenko,
when all these wise-guys with IQs > 160 already know.........
Building 7!
That's the WTC building that all the EXPERTS already KNOW was most certainly NOT a CD!
So who needs NIST,
or Jowenko,
when all these wise-guys with IQs > 160 already know.........
QUOTE (atmosphere+Sep 27 2007, 04:37 PM)
... I wonder .
I recommend going to
Debunking 911 Conspiracy Theories
to obtain the correct story about WTC 7, which is that damage plus fire eventually caused the building to collapse.
I recommend going to
Debunking 911 Conspiracy Theories
to obtain the correct story about WTC 7, which is that damage plus fire eventually caused the building to collapse.
QUOTE (NEU-FONZE+Sep 27 2007, 04:52 PM)
when all these wise-guys with IQs > 160 already know.........
And those of us, like me, who don't have IQs so high.
I'll take the Chief of the New York City Fire Department (Retired) at his word.
So ought you.
And those of us, like me, who don't have IQs so high.
I'll take the Chief of the New York City Fire Department (Retired) at his word.
So ought you.
I just posted this at a JREF thread re thermobarics:
As before, I don't think it's going to work. Even much higher pressure explosives will need to be drilled and placed to get you real pulverization.
The longer duration of a thermobaric explosion is non-linearly related to the damage it can inflict, just as the prior quote:
Thermobarics use an explosion to ignite fuel, often metallic fuel such as aluminum. The burning fuel creates a slower and more sustained shock wave than a conventional explosion, which makes it better at breaking down walls and destroying people and equipment, Burky said.
indicated. What the details are - and again, whether they are enough to pulverize 3,000 psi concrete - is still unknown to me. From http://www.structuremag.org/archives/2003/march/Blast.pdf
, FEMA at one time offered a free computer program to model the effects of explosives, but the link mentioned in the article is dead and searching for 'Nonlin' didn't get me anything. (There is also an 'AT Blast' program mentioned , supposedly available at http://www.oca.gsa.gov/, but I haven't looked at it.)
From
http://www.fema.gov/pdf/plan/prevent/rms/427/fema427_ch6.pdf (actually the .txt version)
indicated. What the details are - and again, whether they are enough to pulverize 3,000 psi concrete - is still unknown to me. From http://www.structuremag.org/archives/2003/march/Blast.pdf
, FEMA at one time offered a free computer program to model the effects of explosives, but the link mentioned in the article is dead and searching for 'Nonlin' didn't get me anything. (There is also an 'AT Blast' program mentioned , supposedly available at http://www.oca.gsa.gov/, but I haven't looked at it.)
From
http://www.fema.gov/pdf/plan/prevent/rms/427/fema427_ch6.pdf (actually the .txt version)
6.3.4 Direct Design Methods
The direct design approach (Figure 6-5) to be used for the structural protective
measures is to first design the building for conventional loads, then evaluate the
structureÕs response to explosive loads and augment the design, if needed. Finally,
the designer must make sure that all conventional load requirements are still met.
This approach ensures that the design meets all the requirements for gravity and
natural hazards in addition to air-blast effects. Take note that measures taken to
mitigate explosive loads may reduce the structureÕs performance under other types of
loads, and therefore an iterative approach may be needed. As an example, increased
mass generally increases the design forces for seismic loads, whereas increased mass
generally improves performance under explosive loads. Careful consideration
between the protective design consultant and the structural engineer is needed to
provide an optimized design.
Nonlinear dynamic analysis techniques are similar to those currently used in
advanced seismic analysis. Analytical models range from handbook methods to
equivalent single-degree-of-freedom (SDOF) models to finite element (FE)
representation. For SDOF and FE methods, numerical computation requires
adequate resolution in space and time to account for the high-intensity, short-
duration loading and nonlinear response (Figure 6-6). Difficulties involve the
selection of the model and appropriate failure modes, and finally, the interpretation
of the results for structural design details. Whenever possible, results are checked
against data from tests and experiments for similar structures and loadings.
Charts are available that provide damage estimates for various types of construction,
as a function of peak pressure and peak impulse, based on analysis or empirical data.
Military design handbooks typically provide this type of design information.
Components such as beams, slabs, or walls can often be modeled by a SDOF system
and the governing equation of motion solved by using numerical methods. There are
also charts available in text books and military handbooks for linearly decaying loads,
which provide the peak response and circumvent the need to solve differential
equations. These charts require only knowledge of the fundamental period of the ele-
ment, its ultimate resistance force, the peak pressure applied to the element, and the
equivalent linear decay time to evaluate the peak displacement response of the
system. The design of the anchorage and supporting structural system can be
evaluated by using the ultimate flexural capacity obtained from the dynamic analysis.
For SDOF systems, material behavior can be modeled using idealized elastic,
perfectly-plastic stress-deformation functions, based on actual structural support
conditions and strain-rate-enhanced material properties. The model properties
selected provide the same peak displace-ment and fundamental period as the actual
structural system in flexure. Furthermore, the mass and the resistance functions are
multiplied by mass and load factors, which estimate the actual portion of the mass or
load participating in the deflection of the member along its span.
For more complex elements, the engineer must resort to finite-element numerical
time integration techniques and/or explosive testing. The time and cost of the
analysis cannot be ignored when choosing design procedures. Because the design
process is a sequence of iterations, the cost of analysis must be justified in terms of
benefits to the project and increased confidence in the reliability of the results. In
some cases, an SDOF approach will be used for the preliminary design, and a more
sophisticated approach using finite elements, and/or explosive testing may be used
for the final verification of the design.
A dynamic nonlinear approach is more likely than a static approach to provide a
section that meets the design constraints of the project. Elastic static calculations are
likely to give overly conservative design solutions if the peak pressure is considered
without the effect of load duration. By using dynamic calculations instead of static, we
are able to account for the very short duration of the loading. Because the peak
pressure levels are so high, it is important to account for the short duration to
properly model the structural response. In addition, the inertial effect included in
dynamic computations greatly improves response. This is because by the time the
mass is mobilized, the loading is greatly diminished, enhancing response.
Furthermore, by accepting that damage occurs it is possible to account for the energy
absorbed by ductile systems through plastic deformation. Finally, because the loading
is so rapid, it is possible to enhance the material strength to account for strain-rate
effects.
In dynamic nonlinear analysis, response is evaluated by comparing the ductility (i.e.,
the peak displacement divided by the elastic limit displacement) and/or support
rotation (the angle between the support and the point of peak deflection) to
empirically established maximum values that have been established by the military
through explosive testing. Note that these values are typically based on limited testing
and are not well defined within the industry at this time. Maximum permissible
values vary, depending on the material and the acceptable damage level.
Levels of damage computed by means of analysis may be described by the terms
minor, moderate, or major, depending on the peak ductility, support rotation and
collateral effects. A brief description of each damage level is given below.
Minor: Nonstructural failure of building elements such as windows,
doors, cladding, and false ceilings. Injuries may be expected, and
fatalities are possible but unlikely.
Moderate: Structural damage is confined to a localized area and is usually
repairable. Structural failure is limited to secondary structural members such as
beams, slabs, and non-load-bearing walls. However, if the building has been
designed for loss of primary members, localized loss of columns may be
accommodated. Injuries and possible fatalities are expected.
Major: Loss of primary structural components such as columns or transfer girders
precipitates loss of additional adjacent members that are adjacent to or above the
lost member. In this case, extensive fatalities are expected. Building is usually not
repairable.
Generally, moderate damage at the design threat level is a reasonable design goal
for new construction.
6.3.5 Structural Elements
Because direct explosion effects decay rapidly with distance, the local response of
structural components is the dominant concern. General principles governing the
design of critical components are discussed below.
(emphasis mine)
And then the guy who claims that Building 7 blew up BEFORE WTC 1 fell.
What the heck is THAT about?
So there were NO 911 calls?
There were NO people KILLED in WTC 7 but now you are saying that they were blown up inside prior to people being evacuated.
Are you guys really THIS desperate?
Arthur
You are the one who is desperate.
Are these eyewitnesses lying?
That is what you seem to infer, and to claim they are "confused" doesn't wash with the data either.
They were there, you were not, some of them were first responders, so perhaps you should cut them some slack. In addition, this testimony is 180 degrees from "the official conspiracy theory".
http://www.911blogger.com/node/11678#comment
So, what exactly are you really trying to say?
QUOTE (R.Mackey;3002771+)
As before, I don't think it's going to work. Even much higher pressure explosives will need to be drilled and placed to get you real pulverization.
The longer duration of a thermobaric explosion is non-linearly related to the damage it can inflict, just as the prior quote:
QUOTE
Thermobarics use an explosion to ignite fuel, often metallic fuel such as aluminum. The burning fuel creates a slower and more sustained shock wave than a conventional explosion, which makes it better at breaking down walls and destroying people and equipment, Burky said.
indicated. What the details are - and again, whether they are enough to pulverize 3,000 psi concrete - is still unknown to me. From http://www.structuremag.org/archives/2003/march/Blast.pdf
, FEMA at one time offered a free computer program to model the effects of explosives, but the link mentioned in the article is dead and searching for 'Nonlin' didn't get me anything. (There is also an 'AT Blast' program mentioned , supposedly available at http://www.oca.gsa.gov/, but I haven't looked at it.)
From
http://www.fema.gov/pdf/plan/prevent/rms/427/fema427_ch6.pdf (actually the .txt version)
QUOTE (->
| QUOTE |
Thermobarics use an explosion to ignite fuel, often metallic fuel such as aluminum. The burning fuel creates a slower and more sustained shock wave than a conventional explosion, which makes it better at breaking down walls and destroying people and equipment, Burky said. |
indicated. What the details are - and again, whether they are enough to pulverize 3,000 psi concrete - is still unknown to me. From http://www.structuremag.org/archives/2003/march/Blast.pdf
, FEMA at one time offered a free computer program to model the effects of explosives, but the link mentioned in the article is dead and searching for 'Nonlin' didn't get me anything. (There is also an 'AT Blast' program mentioned , supposedly available at http://www.oca.gsa.gov/, but I haven't looked at it.)
From
http://www.fema.gov/pdf/plan/prevent/rms/427/fema427_ch6.pdf (actually the .txt version)
6.3.4 Direct Design Methods
The direct design approach (Figure 6-5) to be used for the structural protective
measures is to first design the building for conventional loads, then evaluate the
structureÕs response to explosive loads and augment the design, if needed. Finally,
the designer must make sure that all conventional load requirements are still met.
This approach ensures that the design meets all the requirements for gravity and
natural hazards in addition to air-blast effects. Take note that measures taken to
mitigate explosive loads may reduce the structureÕs performance under other types of
loads, and therefore an iterative approach may be needed. As an example, increased
mass generally increases the design forces for seismic loads, whereas increased mass
generally improves performance under explosive loads. Careful consideration
between the protective design consultant and the structural engineer is needed to
provide an optimized design.
Nonlinear dynamic analysis techniques are similar to those currently used in
advanced seismic analysis. Analytical models range from handbook methods to
equivalent single-degree-of-freedom (SDOF) models to finite element (FE)
representation. For SDOF and FE methods, numerical computation requires
adequate resolution in space and time to account for the high-intensity, short-
duration loading and nonlinear response (Figure 6-6). Difficulties involve the
selection of the model and appropriate failure modes, and finally, the interpretation
of the results for structural design details. Whenever possible, results are checked
against data from tests and experiments for similar structures and loadings.
Charts are available that provide damage estimates for various types of construction,
as a function of peak pressure and peak impulse, based on analysis or empirical data.
Military design handbooks typically provide this type of design information.
Components such as beams, slabs, or walls can often be modeled by a SDOF system
and the governing equation of motion solved by using numerical methods. There are
also charts available in text books and military handbooks for linearly decaying loads,
which provide the peak response and circumvent the need to solve differential
equations. These charts require only knowledge of the fundamental period of the ele-
ment, its ultimate resistance force, the peak pressure applied to the element, and the
equivalent linear decay time to evaluate the peak displacement response of the
system. The design of the anchorage and supporting structural system can be
evaluated by using the ultimate flexural capacity obtained from the dynamic analysis.
For SDOF systems, material behavior can be modeled using idealized elastic,
perfectly-plastic stress-deformation functions, based on actual structural support
conditions and strain-rate-enhanced material properties. The model properties
selected provide the same peak displace-ment and fundamental period as the actual
structural system in flexure. Furthermore, the mass and the resistance functions are
multiplied by mass and load factors, which estimate the actual portion of the mass or
load participating in the deflection of the member along its span.
For more complex elements, the engineer must resort to finite-element numerical
time integration techniques and/or explosive testing. The time and cost of the
analysis cannot be ignored when choosing design procedures. Because the design
process is a sequence of iterations, the cost of analysis must be justified in terms of
benefits to the project and increased confidence in the reliability of the results. In
some cases, an SDOF approach will be used for the preliminary design, and a more
sophisticated approach using finite elements, and/or explosive testing may be used
for the final verification of the design.
A dynamic nonlinear approach is more likely than a static approach to provide a
section that meets the design constraints of the project. Elastic static calculations are
likely to give overly conservative design solutions if the peak pressure is considered
without the effect of load duration. By using dynamic calculations instead of static, we
are able to account for the very short duration of the loading. Because the peak
pressure levels are so high, it is important to account for the short duration to
properly model the structural response. In addition, the inertial effect included in
dynamic computations greatly improves response. This is because by the time the
mass is mobilized, the loading is greatly diminished, enhancing response.
Furthermore, by accepting that damage occurs it is possible to account for the energy
absorbed by ductile systems through plastic deformation. Finally, because the loading
is so rapid, it is possible to enhance the material strength to account for strain-rate
effects.
In dynamic nonlinear analysis, response is evaluated by comparing the ductility (i.e.,
the peak displacement divided by the elastic limit displacement) and/or support
rotation (the angle between the support and the point of peak deflection) to
empirically established maximum values that have been established by the military
through explosive testing. Note that these values are typically based on limited testing
and are not well defined within the industry at this time. Maximum permissible
values vary, depending on the material and the acceptable damage level.
Levels of damage computed by means of analysis may be described by the terms
minor, moderate, or major, depending on the peak ductility, support rotation and
collateral effects. A brief description of each damage level is given below.
Minor: Nonstructural failure of building elements such as windows,
doors, cladding, and false ceilings. Injuries may be expected, and
fatalities are possible but unlikely.
Moderate: Structural damage is confined to a localized area and is usually
repairable. Structural failure is limited to secondary structural members such as
beams, slabs, and non-load-bearing walls. However, if the building has been
designed for loss of primary members, localized loss of columns may be
accommodated. Injuries and possible fatalities are expected.
Major: Loss of primary structural components such as columns or transfer girders
precipitates loss of additional adjacent members that are adjacent to or above the
lost member. In this case, extensive fatalities are expected. Building is usually not
repairable.
Generally, moderate damage at the design threat level is a reasonable design goal
for new construction.
6.3.5 Structural Elements
Because direct explosion effects decay rapidly with distance, the local response of
structural components is the dominant concern. General principles governing the
design of critical components are discussed below.
(emphasis mine)
David:
I certainly take any expert at his word...
It's NIST I wonder about!
My prediction is that NIST will never issue a final report on WTC 7.
It's better that way!
I certainly take any expert at his word...
It's NIST I wonder about!
My prediction is that NIST will never issue a final report on WTC 7.
It's better that way!
QUOTE (NEU-FONZE+Sep 27 2007, 05:06 PM)
My prediction is that NIST will never issue a final report on WTC 7.
They are certainly taking their time about it.
My current understanding is that an interim report is due this December. Then there will be a period for Public Comment. Then they will write either the next interim report or the final report.
So your prediction could possible come true: They might go on writing interim reports until doomsday.
In the meanwhile, the interviews with the firemen and fire chiefs at various levels (and now a quotation from the head of the whole department at the time) make it abundantly clear what occurred: damage plus a long fire led to the collapse.
NIST is putting in a lot of effort to fill in the details. I suppose it is worth it.
They are certainly taking their time about it.
My current understanding is that an interim report is due this December. Then there will be a period for Public Comment. Then they will write either the next interim report or the final report.
So your prediction could possible come true: They might go on writing interim reports until doomsday.
In the meanwhile, the interviews with the firemen and fire chiefs at various levels (and now a quotation from the head of the whole department at the time) make it abundantly clear what occurred: damage plus a long fire led to the collapse.
NIST is putting in a lot of effort to fill in the details. I suppose it is worth it.
Some interesting stuff re thermobarics at alt.engr.explosives, e.g.
http://groups.google.com/group/alt.engr.ex...2cd0b4c0278bf1f
http://groups.google.com/group/alt.engr.ex...2cd0b4c0278bf1f
Here is completely new information on explosions at WTC7 before the towers fell, just released eyewitness testimony on the Achilles Heel of 9/11.
http://www.911blogger.com/node/11678#comment
9/11 WAS AN INSIDE JOB AND IT IS LONG PAST TIME FOR A REAL CRIMINAL INVESTIGATION
http://www.911blogger.com/node/11678#comment
9/11 WAS AN INSIDE JOB AND IT IS LONG PAST TIME FOR A REAL CRIMINAL INVESTIGATION
Back for ANOTHER spanking?
As the guy says:
And then the guy who claims that Building 7 blew up BEFORE WTC 1 fell.
What the heck is THAT about?
So there were NO 911 calls?
There were NO people KILLED in WTC 7 but now you are saying that they were blown up inside prior to people being evacuated.
Are you guys really THIS desperate?
Arthur
As the guy says:
QUOTE
this guy said it was "pulsed speech" that led him to assume it was a countdown, then in his latest video he says it WAS a countdown.
And then the guy who claims that Building 7 blew up BEFORE WTC 1 fell.
What the heck is THAT about?
So there were NO 911 calls?
There were NO people KILLED in WTC 7 but now you are saying that they were blown up inside prior to people being evacuated.
Are you guys really THIS desperate?
Arthur
One of the things that mystifies me is that conspiracy theorists seize on survivors of WTC 1 & WTC 2 saying things like "It was LIKE a bomb went off" as if that some how validates their claims.
And yet.
I was watching that Doco about Rick what's his name, the guy who saved 2700 people in one of the towers, predicted both the 1993 attacks, and the september 11 attacks (that they were inevitable, rather then the days). I even recognized one of the clips as being included in a Youtube video's that's supposed to prove that it was an inside job.
But you know what?
Not one single conspiracy theorist has ever acknowledged the fact that there were survivors that made comments like "As soon as the plan hit we knew the building was coming down".
And yet.
I was watching that Doco about Rick what's his name, the guy who saved 2700 people in one of the towers, predicted both the 1993 attacks, and the september 11 attacks (that they were inevitable, rather then the days). I even recognized one of the clips as being included in a Youtube video's that's supposed to prove that it was an inside job.
But you know what?
Not one single conspiracy theorist has ever acknowledged the fact that there were survivors that made comments like "As soon as the plan hit we knew the building was coming down".
QUOTE (adoucette+Sep 27 2007, 06:58 PM)
And then the guy who claims that Building 7 blew up BEFORE WTC 1 fell.
What the heck is THAT about?
So there were NO 911 calls?
There were NO people KILLED in WTC 7 but now you are saying that they were blown up inside prior to people being evacuated.
Are you guys really THIS desperate?
Arthur
You are the one who is desperate.
Are these eyewitnesses lying?
That is what you seem to infer, and to claim they are "confused" doesn't wash with the data either.
They were there, you were not, some of them were first responders, so perhaps you should cut them some slack. In addition, this testimony is 180 degrees from "the official conspiracy theory".
http://www.911blogger.com/node/11678#comment
So, what exactly are you really trying to say?
Because that was a 47 story building that had many THOUSANDS of tennents.
If what he said was true, that the damage was done BEFORE either tower collapsed, then you would have THOUSANDS of people IN THE TOWER who could/would backing up his statement, not to mention 9/11 call logs etc etc etc.
But you DON'T have any of that.
Which is why it takes 6 years for this "180" degree news to come out.
Only at THIS time and distance from the event could such a lie last for even a short time.
But it WON'T last.
Why?
Because there is ABSOLUTELY no physical/forensic evidence to back this up.
But STILL you believe it?
I mean think of it Craig,
HOW is all this damage going to happen in an OCCUPIED building and YET there not be ONE fatality.
There is ONLY one reason that there were no Fatalities in Building 7 and that's because it was virtually empty by the time WTC 1 fell and caused all that damage.
Arthur
If what he said was true, that the damage was done BEFORE either tower collapsed, then you would have THOUSANDS of people IN THE TOWER who could/would backing up his statement, not to mention 9/11 call logs etc etc etc.
But you DON'T have any of that.
Which is why it takes 6 years for this "180" degree news to come out.
Only at THIS time and distance from the event could such a lie last for even a short time.
But it WON'T last.
Why?
Because there is ABSOLUTELY no physical/forensic evidence to back this up.
But STILL you believe it?
I mean think of it Craig,
HOW is all this damage going to happen in an OCCUPIED building and YET there not be ONE fatality.
There is ONLY one reason that there were no Fatalities in Building 7 and that's because it was virtually empty by the time WTC 1 fell and caused all that damage.
Arthur
quicknthedead
No, we are saying YOU and the rest of the woo woos are lying, AGAIN. What is it with you ALWAYS having to be so wrong about so many things so much of the time??? Use your brains as something other than a spacer so that the vacuum in your head doesn't pull your ears together!!!
Face it Craig, your credibility is NIL, it is automatically assumed that if you say it, it MUST be a lie, or did you think we would forget the firetruck in the back window of a BMW???(Actually, a third brake light, but why bother with a little thing called FACTS, huh Craig???) Even Jesus can't restore your scientific reputation, so don't bother quoting him. Lying-for-Jesus is still a sin, last I checked.
The eyewitnesses heard loud sounds, but since not one valid shred of evidence for the presence of any explosives anywhere in the WTC complex was ever found, those loud sounds could not have been explosives.
People often say tornadoes sounded "just like a freight train" yet we do not expect to find train tracks wherever one goes, do we??? (so, OK, firetruck...you probably do go looking for tracks!!!)
Hadn't seen much mention of your paper lately, Ross won't talk about it at all. But I haven't seen a retraction yet either, how 'bout it??? Confession is good for the soul, time to come to Jesus, admit your mistakes and move on.
Or not.
Grumpy 
QUOTE
Are these eyewitnesses lying?
No, we are saying YOU and the rest of the woo woos are lying, AGAIN. What is it with you ALWAYS having to be so wrong about so many things so much of the time??? Use your brains as something other than a spacer so that the vacuum in your head doesn't pull your ears together!!!
Face it Craig, your credibility is NIL, it is automatically assumed that if you say it, it MUST be a lie, or did you think we would forget the firetruck in the back window of a BMW???(Actually, a third brake light, but why bother with a little thing called FACTS, huh Craig???) Even Jesus can't restore your scientific reputation, so don't bother quoting him. Lying-for-Jesus is still a sin, last I checked.
The eyewitnesses heard loud sounds, but since not one valid shred of evidence for the presence of any explosives anywhere in the WTC complex was ever found, those loud sounds could not have been explosives.
People often say tornadoes sounded "just like a freight train" yet we do not expect to find train tracks wherever one goes, do we??? (so, OK, firetruck...you probably do go looking for tracks!!!)
Hadn't seen much mention of your paper lately, Ross won't talk about it at all. But I haven't seen a retraction yet either, how 'bout it??? Confession is good for the soul, time to come to Jesus, admit your mistakes and move on.
Or not.
Grumpy
adoucette
I'm sorry, I didn't even bother to read what notsoquick posted, I did not realize just how woo woo his crap had become!!! Bombs going off in 7 prior to either tower collapsing??? This is not error, this is insanity!!! Do his friends and family know he is out running around unsupervised??? Is there such a thing as active stupidity??? Is there some kind of internet contest to see who can post the most ignorant crap??? Have they held a convention of woo woos lately???
I give up on the human race, we are doomed!!!
Grumpy
I'm sorry, I didn't even bother to read what notsoquick posted, I did not realize just how woo woo his crap had become!!! Bombs going off in 7 prior to either tower collapsing??? This is not error, this is insanity!!! Do his friends and family know he is out running around unsupervised??? Is there such a thing as active stupidity??? Is there some kind of internet contest to see who can post the most ignorant crap??? Have they held a convention of woo woos lately???
I give up on the human race, we are doomed!!!
Grumpy
QUOTE (adoucette+Sep 27 2007, 08:09 PM)
Because that was a 47 story building that had many THOUSANDS of tennents.
If what he said was true, that the damage was done BEFORE either tower collapsed, then you would have THOUSANDS of people IN THE TOWER who could/would backing up his statement, not to mention 9/11 call logs etc etc etc.
But you DON'T have any of that.
Which is why it takes 6 years for this "180" degree news to come out.
Only at THIS time and distance from the event could such a lie last for even a short time.
But it WON'T last.
Why?
Because there is ABSOLUTELY no physical/forensic evidence to back this up.
But STILL you believe it?
I mean think of it Craig,
HOW is all this damage going to happen in an OCCUPIED building and YET there not be ONE fatality.
There is ONLY one reason that there were no Fatalities in Building 7 and that's because it was virtually empty by the time WTC 1 fell and caused all that damage.
Arthur
Read and listen closely.
http://www.911blogger.com/node/11678#comment
They experienced the explosions when the building was practically deserted, so how can you write of "Thousands of tennents[sic]" who should have backed up their statements...when these people were not even in the building?
Maybe these new testimonies are true, for why would they lie?
Look at who has been running from an investigation from the beginning. The Bush-neocons breathe lies as second nature (to get their own way)...but enough of political. We are talking evidence here.
Why didn't the government listen to these people who experienced these things and make their testimonies public record? They speak of dead people in WTC7's lobby and explosions happening there before the towers fell?
Why were the numerous testimonies that point to something other than the OCT not brought into the public view for discourse and disclosure? What makes the OCT so special (especially when it comes from habitual liars)?
9/11 needs an investigation that leads to JUSTICE. There has not been one like that yet. This thing is rotten through and through, and more and more people are learning this everyday. The Commission did not even mention WTC7 in its report. Can you expect people to believe those who mislead?
Enough with questions. There are those whose testimonies should have become a matter of public record, and there is now more than enough evidence for a criminal investigation into 9/11, one that will lead, God willing, to prosecution and justice.
BTW, you did not give your opinion as a definitive answer as to whether or not these new testimonies are lies from the people who gave them. You only gave intimations.
If what he said was true, that the damage was done BEFORE either tower collapsed, then you would have THOUSANDS of people IN THE TOWER who could/would backing up his statement, not to mention 9/11 call logs etc etc etc.
But you DON'T have any of that.
Which is why it takes 6 years for this "180" degree news to come out.
Only at THIS time and distance from the event could such a lie last for even a short time.
But it WON'T last.
Why?
Because there is ABSOLUTELY no physical/forensic evidence to back this up.
But STILL you believe it?
I mean think of it Craig,
HOW is all this damage going to happen in an OCCUPIED building and YET there not be ONE fatality.
There is ONLY one reason that there were no Fatalities in Building 7 and that's because it was virtually empty by the time WTC 1 fell and caused all that damage.
Arthur
Read and listen closely.
http://www.911blogger.com/node/11678#comment
They experienced the explosions when the building was practically deserted, so how can you write of "Thousands of tennents[sic]" who should have backed up their statements...when these people were not even in the building?
Maybe these new testimonies are true, for why would they lie?
Look at who has been running from an investigation from the beginning. The Bush-neocons breathe lies as second nature (to get their own way)...but enough of political. We are talking evidence here.
Why didn't the government listen to these people who experienced these things and make their testimonies public record? They speak of dead people in WTC7's lobby and explosions happening there before the towers fell?
Why were the numerous testimonies that point to something other than the OCT not brought into the public view for discourse and disclosure? What makes the OCT so special (especially when it comes from habitual liars)?
9/11 needs an investigation that leads to JUSTICE. There has not been one like that yet. This thing is rotten through and through, and more and more people are learning this everyday. The Commission did not even mention WTC7 in its report. Can you expect people to believe those who mislead?
Enough with questions. There are those whose testimonies should have become a matter of public record, and there is now more than enough evidence for a criminal investigation into 9/11, one that will lead, God willing, to prosecution and justice.
BTW, you did not give your opinion as a definitive answer as to whether or not these new testimonies are lies from the people who gave them. You only gave intimations.
QUOTE (David B. Benson+Sep 28 2007, 12:17 AM)
In the meanwhile, the interviews with the firemen and fire chiefs at various levels (and now a quotation from the head of the whole department at the time) make it abundantly clear what occurred: damage plus a long fire led to the collapse.
In the firefighter stories at Firehouse.com, a transit is mention by Deputy Chief Peter Hayden. His is the only account of the 22 there which mentions the transit. I easily find hundreds of places where this account is mentioned, but only the one firsthand account of use of a transit.
Hayden: ... but also we were pretty sure that 7 World Trade Center would collapse. Early on, we saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that and we were pretty sure she was going to collapse.
I was wondering if anyone knew answers to any of the following questions:
Who ordered the transit be placed?
When was the order given?
Where was the transit placed?
Who was responsible for checking the transit?
How frequently was it checked?
What were the results?
From where was the transit procured? Is this standard firefighter equipment?
I realize that answers to some of these questions may never be available without access to the individual(s) involved that day.
In the firefighter stories at Firehouse.com, a transit is mention by Deputy Chief Peter Hayden. His is the only account of the 22 there which mentions the transit. I easily find hundreds of places where this account is mentioned, but only the one firsthand account of use of a transit.
QUOTE
Hayden: ... but also we were pretty sure that 7 World Trade Center would collapse. Early on, we saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that and we were pretty sure she was going to collapse.
I was wondering if anyone knew answers to any of the following questions:
Who ordered the transit be placed?
When was the order given?
Where was the transit placed?
Who was responsible for checking the transit?
How frequently was it checked?
What were the results?
From where was the transit procured? Is this standard firefighter equipment?
I realize that answers to some of these questions may never be available without access to the individual(s) involved that day.
It seems the mad 9/11 flat earth conspirators have been run off for the most part. Now we just need to run the rest of the trolls out... 
QUOTE (quicknthedead+Sep 28 2007, 12:17 AM)
Read and listen closely.
http://www.911blogger.com/node/11678#comment
And I did just that. What I noticed is that the witness with the "edited" interview is inconsistent with the "uncovered" "portion". For one thing, the recording is slower paced than the tape, the guy talking stutters more, he's calmer than in the tape and there's a slight difference in his voice. It's a made up tape recording designed to create "evidence" you cannot uncover. If you can't find evidence for your belief that usually means it doesn't exist and you are WRONG.
http://www.911blogger.com/node/11678#comment
And I did just that. What I noticed is that the witness with the "edited" interview is inconsistent with the "uncovered" "portion". For one thing, the recording is slower paced than the tape, the guy talking stutters more, he's calmer than in the tape and there's a slight difference in his voice. It's a made up tape recording designed to create "evidence" you cannot uncover. If you can't find evidence for your belief that usually means it doesn't exist and you are WRONG.
wcelliott:
Appeal to ridicule is not a rational argument.
Try again.
Trippy:
Appeal to ridicule is not a rational argument.
Try again.
Trippy:...the sound of structural steel undergoing catastrophic brittle failure probably would sound like a gun shot going off, or an explosion.
I am a qualified audio engineer, and I don't use headphones.
I use Active Servo processed speakers with a flat frequency response from 20Hz - 20 kHz.
What you are asserting, irrrationaly, is this:
Any evidence of explosions that can be found---audio recordings and/or concordant witness reports---can be safely categorized by defenders of the official dogma as "catastrophic brittle failure."
Trippy logic begins with the premise that
(1) no explosives were used,
therefore,
(2) explosive sounds are "catastrophic brittle failure" accompanied by widespread misinterpretation and misreporting by those who were actually present.
Here is "Grumpy" asserting exactly the same PNAC "logic":
"THERE"S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
Arturio:
"THERE"S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
Arturio:Actually that definition of a logical fallacy applies to Authorities OUTSIDE their field.
The "outside field" version of argumentum ad verecundiam is only 21st century.
In previous times the argument from authority was a fallacy in which awe was substituted for evidence and reason.
Here is an example from your favorite kind of authority:
You say you don't like argument from authority?
Joshua, you wasted an entire post--the first on this page--spraying an appeal to ridicule at us all.
This anti-scientific character-assassins political strategy is extremely unethical, but, sadly, represents the majority of the content posted here by Official Conspiracy Dogmatists like yourself.
Shame on you.
QUOTE
Explosions, because it was really loud, when the buildings fell. Every sensible person would've expected them to collapse in dead silence.
Appeal to ridicule is not a rational argument.
Try again.
Trippy:
QUOTE (->
| QUOTE |
| Explosions, because it was really loud, when the buildings fell. Every sensible person would've expected them to collapse in dead silence. |
Appeal to ridicule is not a rational argument.
Try again.
Trippy:...the sound of structural steel undergoing catastrophic brittle failure probably would sound like a gun shot going off, or an explosion.
I am a qualified audio engineer, and I don't use headphones.
I use Active Servo processed speakers with a flat frequency response from 20Hz - 20 kHz.
What you are asserting, irrrationaly, is this:
Any evidence of explosions that can be found---audio recordings and/or concordant witness reports---can be safely categorized by defenders of the official dogma as "catastrophic brittle failure."
Trippy logic begins with the premise that
(1) no explosives were used,
therefore,
(2) explosive sounds are "catastrophic brittle failure" accompanied by widespread misinterpretation and misreporting by those who were actually present.
Here is "Grumpy" asserting exactly the same PNAC "logic":
QUOTE
The eyewitnesses heard loud sounds, but since not one valid shred of evidence for the presence of any explosives anywhere in the WTC complex was ever found, those loud sounds could not have been explosives.
"THERE"S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
Arturio:
QUOTE (->
| QUOTE |
| The eyewitnesses heard loud sounds, but since not one valid shred of evidence for the presence of any explosives anywhere in the WTC complex was ever found, those loud sounds could not have been explosives. |
"THERE"S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
Arturio:Actually that definition of a logical fallacy applies to Authorities OUTSIDE their field.
The "outside field" version of argumentum ad verecundiam is only 21st century.
In previous times the argument from authority was a fallacy in which awe was substituted for evidence and reason.
Here is an example from your favorite kind of authority:
QUOTE
James Quintiere, Ph.D., former Chief of the Fire Science Division of the National Institute of Standards and Technology (NIST), has called for an independent review of NIST's investigation into the collapses of the World Trade Center Towers on 9/11.
What's that?You say you don't like argument from authority?
Joshua, you wasted an entire post--the first on this page--spraying an appeal to ridicule at us all.
This anti-scientific character-assassins political strategy is extremely unethical, but, sadly, represents the majority of the content posted here by Official Conspiracy Dogmatists like yourself.
Shame on you.
Al Khwarizmi - step-by-step
Does he claim it was because of explosives???
Does he claim it was because of explosives???
Trippy logic begins with the premise that
(1) no explosives were used,
therefore,
(2) explosive sounds are "catastrophic brittle failure" accompanied by widespread misinterpretation and misreporting by those who were actually present.
1) Excellent logic, since absolutely no valid, physical evidence of their use was found, we MUST discard them as a possibility and move on.
2) A good possibility for the source of those explosives sounds. There were probably others as well.
Did this person see a bomb, or did he misinterpret something someone else said??? When told that the building was going to collapse, did he ASSUME it was because of a bomb???
He was wrong, there were no bombs in any of the buildings. Someone SAYING it was so, does not make it so, especially in the confusion of that day.
Grumpy
QUOTE
James Quintiere, Ph.D., former Chief of the Fire Science Division of the National Institute of Standards and Technology (NIST), has called for an independent review of NIST's investigation into the collapses of the World Trade Center Towers on 9/11.
Does he claim it was because of explosives???
QUOTE (->
| QUOTE |
| James Quintiere, Ph.D., former Chief of the Fire Science Division of the National Institute of Standards and Technology (NIST), has called for an independent review of NIST's investigation into the collapses of the World Trade Center Towers on 9/11. |
Does he claim it was because of explosives???
Trippy logic begins with the premise that
(1) no explosives were used,
therefore,
(2) explosive sounds are "catastrophic brittle failure" accompanied by widespread misinterpretation and misreporting by those who were actually present.
1) Excellent logic, since absolutely no valid, physical evidence of their use was found, we MUST discard them as a possibility and move on.
2) A good possibility for the source of those explosives sounds. There were probably others as well.
QUOTE
"THERE"S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
"Excuse me - did you say 'There's a BOMB in the building?'"
"Yes, THERE'S A BOMB IN THE BUILDING, clear the area!"
Did this person see a bomb, or did he misinterpret something someone else said??? When told that the building was going to collapse, did he ASSUME it was because of a bomb???
He was wrong, there were no bombs in any of the buildings. Someone SAYING it was so, does not make it so, especially in the confusion of that day.
Grumpy
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