Consider again the question of the slow decay of WTC 1 until t0, the moment of collapse initiation.
We will use the crush-down equation in normalized form, with a stretch (squash) of 0:
ZZ" + (Z')^2 - Z = F(Z)
to first note that in the undamaged tower, F(Z) = Z is the situation with no drop. Now assume, from work of poster NEU-FONZE, that the drop grow exponentially over time,
Z = a*exp(bt)
where a = Z0 is the relative elevation (measured from the top) of the buckling portion of the exterior walls. We have
Z' = bZ and Z" = b^2Z
so pluging into the crush-down equation and re-arranging,
Z(2b^2Z - 1) = F(Z)
which holds until the capacity limit of the supporting structure is reached and collapse commences. Since the resisting force must be positive,
2b^2*a*exp(bt) > 1
and at t = 0,
b > sqrt(1/(2a)) = 1.69 (in normalized units).
Now this is not what I previously put into the program, so I'll retry it with this equation for the force.
I want to thank poster einsteen and also Carter Elliot for motivating me, each in their own way, to properly think this through.
Oops. The resisting force must be negative (upwards), so
2b^2*a*exp(bt) < 1
2b^2*a*exp(bt) < 1
What a surprise! 
There is enough data to show that the linear force hypothesis is strongly to be preferred to that worked out in the previous two posts. While this does not rule out the theory developed by NEU-FONCE, it strongly suggests that another hypothesis does about ten times as well in explicating the data.
There is enough data to show that the linear force hypothesis is strongly to be preferred to that worked out in the previous two posts. While this does not rule out the theory developed by NEU-FONCE, it strongly suggests that another hypothesis does about ten times as well in explicating the data.
QUOTE (David B. Benson+Nov 12 2007, 09:10 PM)
There is enough data to show that the linear force hypothesis is strongly to be preferred to that worked out in the previous two posts. While this does not rule out the theory developed by NEU-FONCE, it strongly suggests that another hypothesis does about ten times as well in explicating the data.
That sounds important. What sort of physical interpretation does the linear force hypothesis have considering the structure, etc? At least, how does it differ from NEU-FONZE's theory?
PS an extraction on the two center antenna dishes just finished as I wrote the above. No new technology employed yet, same stuff as the F4 tail work. We'll see how the data (in this case, frames 720-930) comes out - in just a few. (Edit: cruddy, in fact; re-running with new thresholds)
That sounds important. What sort of physical interpretation does the linear force hypothesis have considering the structure, etc? At least, how does it differ from NEU-FONZE's theory?
PS an extraction on the two center antenna dishes just finished as I wrote the above. No new technology employed yet, same stuff as the F4 tail work. We'll see how the data (in this case, frames 720-930) comes out - in just a few. (Edit: cruddy, in fact; re-running with new thresholds)
QUOTE (OneWhiteEye+Nov 12 2007, 02:29 PM)
What sort of physical interpretation does the linear force hypothesis have considering the structure, etc?
At least, how does it differ from NEU-FONZE's theory?
It says that the force is F(Z) = Z(1-a(Z-Z0)) for parameter a such that the standard deviation is minimum, sd = 0.012 meters. Since F(Z) = Z describes a stable structure's resistance, it implies that the resistance has reached the critical maximum that the structure can supply and declines over time. Not what I had expected and indeed, there might be a better function to use for the force.
NEU-FONZE showed that under certain assumptions, Z is an exponential in time. I showed in the prior posts the consequences for the force.
At least, how does it differ from NEU-FONZE's theory?
It says that the force is F(Z) = Z(1-a(Z-Z0)) for parameter a such that the standard deviation is minimum, sd = 0.012 meters. Since F(Z) = Z describes a stable structure's resistance, it implies that the resistance has reached the critical maximum that the structure can supply and declines over time. Not what I had expected and indeed, there might be a better function to use for the force.
NEU-FONZE showed that under certain assumptions, Z is an exponential in time. I showed in the prior posts the consequences for the force.
QUOTE (David B. Benson+Nov 12 2007, 10:02 PM)
It says that the force is F(Z) = Z(1-a(Z-Z0)) for parameter a such that the standard deviation is minimum, sd = 0.012 meters. Since F(Z) = Z describes a stable structure's resistance, it implies that the resistance has reached the critical maximum that the structure can supply and declines over time. Not what I had expected and indeed, there might be a better function to use for the force.
NEU-FONZE showed that under certain assumptions, Z is an exponential in time. I showed in the prior posts the consequences for the force.
Ok, thank you, that helps. My understanding of the exponential form is that it is the failure of an ever increasing number of supports per unit time as the load is redistributed amongst the fewer remaining supports. The linear form - I'm not sure I have a mental picture of that (but is that even important?)
Does accurate subpixel data help? The next run was pretty good.
XY data (frames, pixels) for center two dishes - Frames 720-930 - X horizontal blue, Y vertical green
GIF animation showing calculated x,y center AND pixels contributing to calculation
There are known improvements to make, most notably on the technique itself as this is still one pass per pixel, no intelligence except channel brightness tests. Camera jitter can possibly be removed/minimized directly after analysis on the 101 AveofA facade. Despite the shortcomings, I believe it is the best to date and essentially correct wrt overall magnitude.
NEU-FONZE showed that under certain assumptions, Z is an exponential in time. I showed in the prior posts the consequences for the force.
Ok, thank you, that helps. My understanding of the exponential form is that it is the failure of an ever increasing number of supports per unit time as the load is redistributed amongst the fewer remaining supports. The linear form - I'm not sure I have a mental picture of that (but is that even important?)
Does accurate subpixel data help? The next run was pretty good.
XY data (frames, pixels) for center two dishes - Frames 720-930 - X horizontal blue, Y vertical green
GIF animation showing calculated x,y center AND pixels contributing to calculation
There are known improvements to make, most notably on the technique itself as this is still one pass per pixel, no intelligence except channel brightness tests. Camera jitter can possibly be removed/minimized directly after analysis on the 101 AveofA facade. Despite the shortcomings, I believe it is the best to date and essentially correct wrt overall magnitude.
QUOTE (OneWhiteEye+Nov 12 2007, 03:37 PM)
My understanding of the exponential form is that it is the failure of an ever increasing number of supports per unit time as the load is redistributed amongst the fewer remaining supports.
The linear form - I'm not sure I have a mental picture of that (but is that even important?)
Does accurate subpixel data help?
Yes. This is what everybody thought ought to occur.
At this stage, no, it doesn't matter.
Yes! Of course it will! Calculation is only conjecture without supporting data. (I'm not quite ready for it yet, however.)
The linear form - I'm not sure I have a mental picture of that (but is that even important?)
Does accurate subpixel data help?
Yes. This is what everybody thought ought to occur.
At this stage, no, it doesn't matter.
Yes! Of course it will! Calculation is only conjecture without supporting data. (I'm not quite ready for it yet, however.)
Doing only the top dish was even better, as the above animation would suggest (the self-checking feature of this analysis is a plus).
XY data (frames, pixels) for center TOP dish - Frames 720-930 - X horizontal blue, Y vertical green
XY data (frames, pixels) for center TOP dish - Frames 720-930 - X horizontal blue, Y vertical green
QUOTE (OneWhiteEye+Nov 12 2007, 04:09 PM)
Doing only the top dish was even better, as the above animation would suggest (the self-checking feature of this analysis is a plus).
XY data (frames, pixels) for center TOP dish - Frames 720-930 - X horizontal blue, Y vertical green
This is very good. Looking at it suggests that my t0 is a bit too late. This might explain some of the problems.
XY data (frames, pixels) for center TOP dish - Frames 720-930 - X horizontal blue, Y vertical green
This is very good. Looking at it suggests that my t0 is a bit too late. This might explain some of the problems.
Another poor fit: I used a S-curve, arctan. In detail,
F(Z) = Z(1- a*(pi/2 + arctan(b*(Z-c))))
The best bit occurs when b*(Z-c) is quite negative, so the arctan is almost -pi/2 and the 'curve' is essentially constant. So this looks just like the attempts to use F(Z) = kZ, and gives equally bad results, about the same as the exponential.
F(Z) = Z(1- a*(pi/2 + arctan(b*(Z-c))))
The best bit occurs when b*(Z-c) is quite negative, so the arctan is almost -pi/2 and the 'curve' is essentially constant. So this looks just like the attempts to use F(Z) = kZ, and gives equally bad results, about the same as the exponential.
Broomsticks don't work well either ---
Assume the south wall of WTC 1, in the bow-in area, can be simplified to two rods pinned top and bottom and to each other in the middle, as in
|
|
with a non-linear spring in the middle which holds the rods in the vertical position until enough load is applied at the top, at which time the spring allows the bow-in, as in
\
/
and holds that position so long as the load does not increase. But at that small angle, say x, the center of mass of the entire top block shifts slightly to the left, by (1/2)sin(x), increasing the load on the rods and spring. The larger load can equally well be viewed as a declining resistive force:
F(Z,x) = Z(1 - a*sin x)
for some parameter a.
The small angle x is given by
x = arccos(1-delta)
where delta = (Z-Z0)/b
for parameter b representing the length of each of the rods.
Simple, possibly even elegant, but it is substantially less explanatory of the data than the merely linear
F(Z) = Z(1- k(Z-Z0))
although no physical understanding of this equation seems to be forthcoming yet...
Assume the south wall of WTC 1, in the bow-in area, can be simplified to two rods pinned top and bottom and to each other in the middle, as in
|
|
with a non-linear spring in the middle which holds the rods in the vertical position until enough load is applied at the top, at which time the spring allows the bow-in, as in
\
/
and holds that position so long as the load does not increase. But at that small angle, say x, the center of mass of the entire top block shifts slightly to the left, by (1/2)sin(x), increasing the load on the rods and spring. The larger load can equally well be viewed as a declining resistive force:
F(Z,x) = Z(1 - a*sin x)
for some parameter a.
The small angle x is given by
x = arccos(1-delta)
where delta = (Z-Z0)/b
for parameter b representing the length of each of the rods.
Simple, possibly even elegant, but it is substantially less explanatory of the data than the merely linear
F(Z) = Z(1- k(Z-Z0))
although no physical understanding of this equation seems to be forthcoming yet...
DBB -
I appreciate the fact that you derived the equation that I was too lazy to derive myself.
The notion that I'd had when proposing it was that it would (I'd guessed) have provided a descent-versus-time that would've described the interval prior to t0, where the height of the tower descended (somehow) by 20cm in the time between impact and t0. The notion being that it would start out immeasurably slow but would pick up speed until the collapse speeds were apparent.
The angle-rate in the two-broomstick model would be a function of the angle itself (from vertical), accelerating as the Cg (at the hinge-point) displaced from the vertical axis above the point of support.
It may well be that the solution to this problem is a differential equation, which would explain the exponential term in the curve-matched equation you derived.
Just a thought, and you have my apologies for my laziness. (It's an equation I should've derived myself when I proposed the model.)
I appreciate the fact that you derived the equation that I was too lazy to derive myself.
The notion that I'd had when proposing it was that it would (I'd guessed) have provided a descent-versus-time that would've described the interval prior to t0, where the height of the tower descended (somehow) by 20cm in the time between impact and t0. The notion being that it would start out immeasurably slow but would pick up speed until the collapse speeds were apparent.
The angle-rate in the two-broomstick model would be a function of the angle itself (from vertical), accelerating as the Cg (at the hinge-point) displaced from the vertical axis above the point of support.
It may well be that the solution to this problem is a differential equation, which would explain the exponential term in the curve-matched equation you derived.
Just a thought, and you have my apologies for my laziness. (It's an equation I should've derived myself when I proposed the model.)
QUOTE (wcelliott+Nov 13 2007, 02:07 PM)
... the exponential term in the curve-matched equation you derived.
... you have my apologies for my laziness.
These are possible forms of the resistive force used in solving the B&V crush-down equation and finding the best fitting values of parameters. Earlier I tried a exponential form and that was strongly worse that the linear form. This sin form is better than that, but still substantially worse than the linear form.
De nada.
... you have my apologies for my laziness.
These are possible forms of the resistive force used in solving the B&V crush-down equation and finding the best fitting values of parameters. Earlier I tried a exponential form and that was strongly worse that the linear form. This sin form is better than that, but still substantially worse than the linear form.
De nada.
Just checked that at no time up to t0 was the (linearly declining) force zero. So there is never even a millisecond of free fall.
Time in seconds; measured drop in meters; calculated drop (linearly declining force model) in meters; speed in meters per second.
-3.94 0.000 0.000 0.000
-3.28 0.022 0.000 0.000
-3.25 0.000 0.000 0.000
-2.70 0.039 0.000 0.001
-2.59 0.000 0.001 0.001
-2.46 0.000 0.001 0.002
-2.01 0.039 0.002 0.005
-1.90 0.022 0.003 0.006
-1.86 0.000 0.003 0.007
-1.54 0.058 0.006 0.014
-1.46 0.022 0.007 0.016
-1.28 0.000 0.011 0.025
-1.11 0.022 0.016 0.036
-1.05 0.058 0.019 0.041
-0.79 0.000 0.033 0.073
-0.77 0.022 0.034 0.076
-0.64 0.039 0.046 0.103
-0.45 0.065 0.070 0.156
-0.38 0.063 0.082 0.181
-0.25 0.106 0.108 0.238
-0.21 0.130 0.120 0.264
0.00 0.190 0.189 0.418
0.00 0.260 0.189 0.418
CODE
-3.94 0.000 0.000 0.000
-3.28 0.022 0.000 0.000
-3.25 0.000 0.000 0.000
-2.70 0.039 0.000 0.001
-2.59 0.000 0.001 0.001
-2.46 0.000 0.001 0.002
-2.01 0.039 0.002 0.005
-1.90 0.022 0.003 0.006
-1.86 0.000 0.003 0.007
-1.54 0.058 0.006 0.014
-1.46 0.022 0.007 0.016
-1.28 0.000 0.011 0.025
-1.11 0.022 0.016 0.036
-1.05 0.058 0.019 0.041
-0.79 0.000 0.033 0.073
-0.77 0.022 0.034 0.076
-0.64 0.039 0.046 0.103
-0.45 0.065 0.070 0.156
-0.38 0.063 0.082 0.181
-0.25 0.106 0.108 0.238
-0.21 0.130 0.120 0.264
0.00 0.190 0.189 0.418
0.00 0.260 0.189 0.418
Note: The times for the second column is slightly different (up to 3 milliseconds) from the times for the third and fourth columns. This clearly makes little difference.
Ignore the last line, a program oddity only.
Seffen's equation (12) does such a bad job of matching the data that I may have misunderstood the role of beta, having taken it to be (Z-Z0).
I forgot if someone already determined the acceleration of the Landmark tower ? I remember that OneWhiteEye's plots almost fitted perfectly but they were scaled.
ps. I've uploaded the "RAW" file again because the original one was expired http://www.megaupload.com/?d=6F72WLB8
ps. I've uploaded the "RAW" file again because the original one was expired http://www.megaupload.com/?d=6F72WLB8
Aha! Seffen's beta = s(Z-Z0)
and with this, his equation (12) reduces to the B&V crush-down equation. So what he has is quite a nice bit of work.
and with this, his equation (12) reduces to the B&V crush-down equation. So what he has is quite a nice bit of work.
It's probably already been posted, but does anybody know off the top of their head what the *max-load/sqft* was for the WTC towers? Plus some idea of what the design margin was...
You wouldn't expect a hi-rise like the WTC to allow a tenant to store gravel in their rental space, so I'd expect that figure to be somewhere in their lease agreement. Likewise, an average #/sqft would be one value, and a peak (for heavy office items like safes) to be another. It'd be a moot issue in most situations, but I'd think it'd be critical when slabs of concrete from the floor above would be landing on relatively strong pieces of office furniture, like safes, which would tend to focus the force into small footprints on the floor, exceeding peak load limits (including their margins).
Kinda like the "fat lady in high heels" leaving divots in marble floors.
(BTW, the safes I'm referring-to are the Moslers that look like filing cabinets, but are made of plate-steel, used routinely for storing sensitive/classified documents.)
You wouldn't expect a hi-rise like the WTC to allow a tenant to store gravel in their rental space, so I'd expect that figure to be somewhere in their lease agreement. Likewise, an average #/sqft would be one value, and a peak (for heavy office items like safes) to be another. It'd be a moot issue in most situations, but I'd think it'd be critical when slabs of concrete from the floor above would be landing on relatively strong pieces of office furniture, like safes, which would tend to focus the force into small footprints on the floor, exceeding peak load limits (including their margins).
Kinda like the "fat lady in high heels" leaving divots in marble floors.
(BTW, the safes I'm referring-to are the Moslers that look like filing cabinets, but are made of plate-steel, used routinely for storing sensitive/classified documents.)
QUOTE (wcelliott+Nov 15 2007, 01:52 PM)
It's probably already been posted, but does anybody know off the top of their head what the *max-load/sqft* was for the WTC towers? Plus some idea of what the design margin was...
Whatever is standard for office space. Maybe 22 lb/sqft? It's in NCSTAR1--2A somewhere.
But I doubt it matters much. The truss seats were not designed to handle the excess energy provided by the impact of the crushed materials above.
Whatever is standard for office space. Maybe 22 lb/sqft? It's in NCSTAR1--2A somewhere.
But I doubt it matters much. The truss seats were not designed to handle the excess energy provided by the impact of the crushed materials above.
QUOTE
But I doubt it matters much. The truss seats were not designed to handle the excess energy provided by the impact of the crushed materials above.
Agreed.
trippy - the THERMATE TORCH AT GROUND ZERO guy, lied again:
================
I find this part of the post especially amusing, because it was not that long ago that Al was trying to convince me that devices such as this did not exist, and were not used in the transport of materials out of ground zero.
===============
I find this lie particularly amusing.
Note the absence of direct quotations from the liar.
I think you should be warned against lying, Trippy, because lying for the purpose of character assassination isn't science.
Is it?
========================================
And I am still waiting from your references wcelliot
But I am not waiting for yet another authoritarian assertion.
I am not waiting for a chemical chain reaction either - I am waiting for a real world reference to a 10 microsecond duration for an explosive pressure pulse.
Note that your fellow conspirator Arthur posted a pulse that endured for 3.3 milliseconds, while your fellow conspirator Trippy posted a pulse that endured for .67 seconds.
Note that both of these pulses contradicted your authoritatrian assertion.
Note that I will continue to request a reference until you provide one, or withdraw your claims.
Note that these requests will accumulate with your unsubstatiated claims, so that my list now includes
Note bene, wcelliot.
================
I find this part of the post especially amusing, because it was not that long ago that Al was trying to convince me that devices such as this did not exist, and were not used in the transport of materials out of ground zero.
===============
I find this lie particularly amusing.
Note the absence of direct quotations from the liar.
I think you should be warned against lying, Trippy, because lying for the purpose of character assassination isn't science.
Is it?
========================================
And I am still waiting from your references wcelliot
But I am not waiting for yet another authoritarian assertion.
I am not waiting for a chemical chain reaction either - I am waiting for a real world reference to a 10 microsecond duration for an explosive pressure pulse.
Note that your fellow conspirator Arthur posted a pulse that endured for 3.3 milliseconds, while your fellow conspirator Trippy posted a pulse that endured for .67 seconds.
Note that both of these pulses contradicted your authoritatrian assertion.
Note that I will continue to request a reference until you provide one, or withdraw your claims.
Note that these requests will accumulate with your unsubstatiated claims, so that my list now includes
- a 10 microsecond pulse in air (not the chemical reaction - a chemical reaction isn't a shockwave)
- DARPAS request for a microphone tailored for recording explosions, and
- propagation of sound in air as Direct Current.
Note bene, wcelliot.
QUOTE (Al Khwarizmi - step-by-step+Nov 16 2007, 04:25 PM)
trippy - the THERMATE TORCH AT GROUND ZERO guy, lied again:
================
I find this part of the post especially amusing, because it was not that long ago that Al was trying to convince me that devices such as this did not exist, and were not used in the transport of materials out of ground zero.
===============
I find this lie particularly amusing.
Note the absence of direct quotations from the liar.
I think you should be warned against lying, Trippy, because lying for the purpose of character assassination isn't science.
Is it?
========================================
See... Here's what's really amsuing.
First we have Alwhatshisname claiming the following in this post that:
Also, Trippy, learn to REFERENCE YOUR CLAIMS.
I can not find such a thing as a "thermate cutter" for sale anywhere on earth.
http://www.google.com/search?hl=en&q=%22thermate+cutter%22
and - "Your search - "thermite cutter torch" - did not match any documents."
and - "Your search - "thermate cutter torch" - did not match any documents."
Capice??
REFERENCE YOUR CLAIMS.
Then we have him making this post:
and - "Your search - "thermite cutter torch" - did not match any documents."
and - "Your search - "thermate cutter torch" - did not match any documents."
Capice??
REFERENCE YOUR CLAIMS.
Then we have him making this post:
============================
Flashback:
common sense:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Yet none of you can explain your thermite nonsense. How did the thermite burn SIDEWAYS through the steel?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Linear_Thermite.jpg
So as it turns out, it's not me that's lying after all.
In the first post he claims that no such device is for sale anywhere on earth, followed by an implication that such a device doesn't exist, period.
Then in the second post he posts a picture of this very type of device, and then goes on to accuse me of lying for pointing out the contradiction in his posts.
Note bene, idiot, I've explained ALL of this MORE THAN ONCE.
Are you DENSE?!?
When you take the 26,700 feet-per-second detonation speed WHICH I'VE ALREADY PROVIDED THREE REFERENCES FOR (AND YOU CAN GOOGLE A DOZEN MORE JUST AS EASILY AS I CAN) and you RUN THE CALCULATIONS for a FOUR INCH BLOCK - YOU GET 10 MICROSECONDS!!! MAYBE LESS, DEPENDING ON WHERE YOU PUT THE DETONATOR.
I'VE ALSO EXPLAINED THAT ANY RECORDING OF AN EXPLOSION THAT LASTS LONGER THAN 10 MICROSECONDS IS ARTIFACT, FROM THE REFLECTIONS OF THE INITIAL 10 MICROSECOND BLAST OFF THE ENVIRONMENT, AND ACTUALLY DERIVED THE "N-SHAPED" SLOPE. THE "N-SHAPE" IS WHAT YOU GET WHEN YOU GET REFLECTIONS FROM THE ENVIRONMENT. Whether that's 3.3milliseconds of artifact or 3.3seconds of artifact, it's all artifact except the first 10microseconds.
I said originally that I remembered the DARPA RFP but those go back a long way, I've been reading DARPA RFPs for twenty years, and they've only recently put up a website, and they don't archive everything. I already said that I wasn't having any luck finding that particular RFP. But I'll tell you what, I'm currently working on a DARPA program, so the next time I run into the DARPA program manager, I'll ask him about it and see if he knows where it is.
And I never said anything about sound generating electrical current, the "DC" term, as I've already explained (needlessly, for everyone BUT YOU). just refers to the zeroth-frequency component AS I'VE ALREADY EXPLAINED!
And, just so you know, I've reported you for calling people liars, when the real problem is that YOU'RE JUST TOO STUPID TO UNDERSTAND PLAIN ENGLISH!!!
Even people who are *nuts* are still supposed to be capable of doing simple math!
Hey Al, what's (0.25feet)/(26,700 feet/second) in YOUR universe?
Note bene, idiot, I've explained ALL of this MORE THAN ONCE.
Are you DENSE?!?
When you take the 26,700 feet-per-second detonation speed WHICH I'VE ALREADY PROVIDED THREE REFERENCES FOR (AND YOU CAN GOOGLE A DOZEN MORE JUST AS EASILY AS I CAN) and you RUN THE CALCULATIONS for a FOUR INCH BLOCK - YOU GET 10 MICROSECONDS!!! MAYBE LESS, DEPENDING ON WHERE YOU PUT THE DETONATOR.
I'VE ALSO EXPLAINED THAT ANY RECORDING OF AN EXPLOSION THAT LASTS LONGER THAN 10 MICROSECONDS IS ARTIFACT, FROM THE REFLECTIONS OF THE INITIAL 10 MICROSECOND BLAST OFF THE ENVIRONMENT, AND ACTUALLY DERIVED THE "N-SHAPED" SLOPE. THE "N-SHAPE" IS WHAT YOU GET WHEN YOU GET REFLECTIONS FROM THE ENVIRONMENT. Whether that's 3.3milliseconds of artifact or 3.3seconds of artifact, it's all artifact except the first 10microseconds.
I said originally that I remembered the DARPA RFP but those go back a long way, I've been reading DARPA RFPs for twenty years, and they've only recently put up a website, and they don't archive everything. I already said that I wasn't having any luck finding that particular RFP. But I'll tell you what, I'm currently working on a DARPA program, so the next time I run into the DARPA program manager, I'll ask him about it and see if he knows where it is.
And I never said anything about sound generating electrical current, the "DC" term, as I've already explained (needlessly, for everyone BUT YOU). just refers to the zeroth-frequency component AS I'VE ALREADY EXPLAINED!
And, just so you know, I've reported you for calling people liars, when the real problem is that YOU'RE JUST TOO STUPID TO UNDERSTAND PLAIN ENGLISH!!!
Shh, AL does not need to see this, it might confuse him since he is an expert professional, just keep it to yourself.
the recording system, and the O.T. estimation is based on measuring the relative propagation time of shock waves to piezoelectric sensors (Δt = 0.445sec, see Fig. 7) and the absolute GPS time of the waves arrival to a hydrophone (see Fig.8), co-located with the sensors (see Chapter 7.2 below). For the largest explosion we obtained the exact moment of detonating electric fuses, connected to detonating cord, that initiated the charge (see Fig. 3). The finite detonation time of the detonating cord (the length of about 70-75 m), estimated as about 10 msec (~ 70m : 7000m/sec), was also considered. The recording system time was continuously synchronized with GPS and under 500 samples per second provided an accuracy better than 5 msec.
http://www.gii.co.il/html/seis/DeadSea99/PROGREP26.doc
Remember reading about this when I helped Ashland oil company do sound studies from explosions on my own property in the late 1990s.
It takes 10 msec just for the detonation cord to go off, then the explosive has to follow that in another 10 msec or more!
wcelliot
--------------------
______|_________
That's what an explosive detonation looks like in the time domain,
-------------------
That's an assertion you are clearly unwilling to reference. When Trippy and Arthur rushed to your aide as you floundered for evidence, they provided an infrasonic pulse with a duration of 670,000 microseconds, and a shockwave blast with a duration of 3,300 microseconds.
Both of these cases contradicted your assertion.
No amount of technical jargon woven into bafflegab can alter the fact that both of these cases contradict your baseless, anti-scientific claim.
When I ask you to reference your claims, you respond with hostility and abuse.
previously
wcelliot:
=========
A point (of many) that goes straight over your head (because it's untrue), is that the acoustic spectrum of a 10microsecond spike goes all the way from DC to a MegaHertz, so it includes spectral energy in all bands, including the audio band (40-20,000Hz).
=========
1) a blast "spike" is not a sound wave, but you still conflate the two.
2) you repeatedly assert a 10µs duration of "spike" without substantiation.
3) Trippy's infrasound N-"spike" endured to the contrary for 2,050,000µs.
4) Arthur's "Typical HE pressure/time curve" for a blast endured to the contrary for 3,300µs
WHY?
5) A 10µs "acoustic" (*cough*) "spike" that produced a wave of DC in the air would be quite fantastical and electrical, but it would not be acoustic.
subsequently:
wcelliot:
====================
And the "DC component" of a spectrum is routine language of the art, everyone (except you) understand it to refer to the zeroth-order component of a spectrum. Given the choice of "DC" or "zeroth-order component of a spectrum", I'll continue to use "DC" for the spectral component at zero frequency.
====================
Terms of the Art.
wcelliot
--------------------
______|_________
That's what an explosive detonation looks like in the time domain,
-------------------
That's an assertion you are clearly unwilling to reference. When Trippy and Arthur rushed to your aide as you floundered for evidence, they provided an infrasonic pulse with a duration of 670,000 microseconds, and a shockwave blast with a duration of 3,300 microseconds.
Both of these cases contradicted your assertion.
No amount of technical jargon woven into bafflegab can alter the fact that both of these cases contradict your baseless, anti-scientific claim.
When I ask you to reference your claims, you respond with hostility and abuse.
previously
wcelliot:
=========
A point (of many) that goes straight over your head (because it's untrue), is that the acoustic spectrum of a 10microsecond spike goes all the way from DC to a MegaHertz, so it includes spectral energy in all bands, including the audio band (40-20,000Hz).
=========
1) a blast "spike" is not a sound wave, but you still conflate the two.
2) you repeatedly assert a 10µs duration of "spike" without substantiation.
3) Trippy's infrasound N-"spike" endured to the contrary for 2,050,000µs.
4) Arthur's "Typical HE pressure/time curve" for a blast endured to the contrary for 3,300µs
WHY?
5) A 10µs "acoustic" (*cough*) "spike" that produced a wave of DC in the air would be quite fantastical and electrical, but it would not be acoustic.
subsequently:
wcelliot:
====================
And the "DC component" of a spectrum is routine language of the art, everyone (except you) understand it to refer to the zeroth-order component of a spectrum. Given the choice of "DC" or "zeroth-order component of a spectrum", I'll continue to use "DC" for the spectral component at zero frequency.
====================
Terms of the Art. MARK LANE: What is a plausible denial?
E. HOWARD HUNT: Denial that is believable.
LANE: Is that a term of art within the CIA?
HUNT: In the intelligence community it means a story that is plausible, it could be believed by a substantial number of people. Plausibly denying, a denial that is believable, that is credible.
LANE: Do you recall testifying on June 28, 1974, in the case of United States versus Ehrlichman, page 761, were you asked these questions, and did you make these answers:
"Question. What was the reason given, or was any reason given, why you and Mr. Liddy couldn't perform this operation?
"Answer. Because of our connection with the White House and the fact that plausible denial would have to be maintained.
"Question. You said plausible denial would have to be maintained?
"Answer. Yes.
"Question. Would you explain what you mean by that?
"Answer. "The principle of plausible denial is simply if an operation or action is later disclosed, for example, as an action of the United States government, the government can plausibly deny it, deny any involvement or connection with the action."
Do you recall those questions and answers?
HUNT: Yes.
LANE: Would you accept as a fair definition which you gave, when you testified as to what a plausible denial is?
HUNT: Yes.
---Hunt. vs. Liberty Lobby, Plausible Denial, p.p. 261-262, Mark Lane, 1991
6) DC means Direct Current - it is a term of the electrical art.
7) DC is not part of the audio spectrum (or any spectrum), does not propagate in air, and by definition does not oscillate. A continuous non-modulated voltage that consumes dynamic range, when present in electrical signals used to produce and record sound, is thus represented on spectral distribution graphs as a zero frequency (no sound) component - a non-acoustic artifact of poorly engineered electrical equipment:
The acoustic spectrum of an explosion will never contain DC, because DC is direct current.
A 10µs "acoustic" (*cough*) "spike" that propagates as DC in the air would be quite fantastical and electrical, but it would not be acoustic.
===================================
Fast Fourier Transform Spectrum Analyser applet: guidance notes
===================================
The acoustic spectrum of an explosion will never contain DC, because DC is direct current.
A 10µs "acoustic" (*cough*) "spike" that propagates as DC in the air would be quite fantastical and electrical, but it would not be acoustic.
===================================
Fast Fourier Transform Spectrum Analyser applet: guidance notes
===================================
Add DC level / random noise
You can optionally add a constant DC level (bias or offset) and/or simulated random noise to the signal by checking the appropriate checkbox and entering the amount of the DC offset or noise level (in volts) in the text field. The values chosen should reflect the fact that the basic signal amplitude is fixed [in this applet] at 1V. The effects of adding a DC offset or random noise are discussed later.
[...]
Effect of adding a constant DC level
Select a sine wave signal of frequency 1000 Hz. Check the "Add DC level" check box, enter a value of 0.5 (volts) in the text field for the amount of the DC offset, and plot the signal. The graph should show a sine wave shifted upwards by the 0.5 V offset (remember the sine wave itself has an amplitude of 1 V).
You should find that the spectrum consists of a line at 1000 Hz, due to the sine wave,
together with a line at zero frequency, with a height of 0.5 V.
This zero frequency component is due to the DC level.
--------------------------------------------------
http://www.dsptutor.freeuk.com/index.htm
The acoustic spectrum resulting from an explosion will never contain DC, because DC is electrical not acoustic (akoustikos - to hear).
DC offset is an artifact of poorly engineered equipment in the recording path.
(see also, particle collisions)
Your calculation of the duration of a chemical reaction is not a reference to the duration of an expanding shockwave, nor is it a reference to the duration or properties of sound produced in the wake of the shockwave. In a world of cause an effect, the duration of a chemical reaction does not determine the duration of any resulting sound. The chemical reaction is not the sound of an explosion.
The shockwave resulting from the chemical reaction is also not the sound of an explosion: nevertheless, your 10 microsecond blast assertion -- contradicting Arthur's "typical" blast duration---requires a real world reference.
i) Please provide a 10 microsecond shockwave reference contradicting that supplied by Arthur, or withdraw your 10 microsecond claim.
ii) Please also provide a reference to DARPAs specification for development of a microphone for recording explosions.
These are your novel claims, and it is your scientific obligation to support them.
stundie
You introduced an analysis by a "sound engineer" who uses non-professional weird terminology (sonogram) and spends a lot of time analysing a fraudulent soundtrack.
The southtower collapse shot, showing rapid inward pull on the perimeter columns of the east face at collapse onset, is quite a famous one. But the soundtrack accompanying the original version of the clip does not include any obvious explosive noises, or crashes or pops. In fact, the original soundtrack has been stripped and replaced.
see for yourself:
http://au.youtube.com/watch?v=K8dX3foxozQ
When I find doctored recordings masquerading as evidence, I always ask: Who benefits?
You're entitled to your own opinion.
NeuF - Were you one of the people AlK's repeatedly called a liar?
Are you having any trouble understanding the 10-microsecond-detonation explanation?
Maybe next time AlK calls me a liar for knowing enough arithmetic to calculate (0.25feet/26,700 feet/second), you'll express your opinion on *his* comments. So far, I haven't heard you object to his calling me a liar.
Actually, however "awful" the comments were, both statements were absolutely correct. Abdullah Azim was the only physics student I had that flunked, and he flunked each quiz more than once (in Keller-Plan Physics, you're required to keep taking quizes on each chapter until you pass one), and for many of the chapters, he took every quiz available (usually about eight, two questions each) and in a couple instances, failed the same quiz twice, after having taken all the quizes, retaking one he'd already taken, had the questions and answers explained to him, and failing it a second time.
And I don't think my comment about how quickly my other students grasped new concepts was either offensive or racist. But I can certainly see how someone who hates Jews could be offended by my statement. Still, I don't see that as being a valid reason to retract the statement.
And AlK didn't retract his insult, calling me (and others) a "liar" when there's clearly no evidence supporting his original insult, he reasserted it, claiming among other things that I never provided support for my "10 microsecond C-4 blast duration", which I think I've explained to-death here.
So how about someone asking AlK to retract his baseless accusations?
Actually, however "awful" the comments were, both statements were absolutely correct. Abdullah Azim was the only physics student I had that flunked, and he flunked each quiz more than once (in Keller-Plan Physics, you're required to keep taking quizes on each chapter until you pass one), and for many of the chapters, he took every quiz available (usually about eight, two questions each) and in a couple instances, failed the same quiz twice, after having taken all the quizes, retaking one he'd already taken, had the questions and answers explained to him, and failing it a second time.
It may be true, but its not relevant to the discussion, and in its generalization it does appear racist.
Remember, Al's namesake is the source of the word Algebra.
http://www-groups.dcs.st-and.ac.uk/~histor...-Khwarizmi.html
Arthur .
Reminding me of the fact that "newton" took the name of one of the greatest physicists of all time, and yet...
I'm not saying that Arabs aren't intelligent, I'm saying that AlK reminds me of the stupidest physics student I ever had.
I'm aware that we owe much of the foundation of "western science" to the discoveries of the Arabs.
Ironically, we owe the concept of "zero" to the Arab mathematicians, and yet AlK seems to be having problems understanding what that zeroth-term in a spectrum refers to.
Even after I'd explained it more than once.
Reminding me of the fact that "newton" took the name of one of the greatest physicists of all time, and yet...
I'm not saying that Arabs aren't intelligent, I'm saying that AlK reminds me of the stupidest physics student I ever had.
I'm aware that we owe much of the foundation of "western science" to the discoveries of the Arabs.
Ironically, we owe the concept of "zero" to the Arab mathematicians, and yet AlK seems to be having problems understanding what that zeroth-term in a spectrum refers to.
Even after I'd explained it more than once.
Hi wcelliot!
I think it's a question of what could be misconstrued from one's comments, mate.
It 'came across' as racist even though it may not have been intended in that 'generalised' light. I too read it as 'racistsounding.
Whether AlK will or will not apologise for any unfounded insult to YOU is NOT a reason or justification for you not being the better man; by UNILATERALLY retracting without any demand fo quid pro quo from AlK.
THAT will put the blowtorch on AlK's own integrity even hotter. No? hehehe.
Cheers and play nice guys!
RC.
.
================
I find this part of the post especially amusing, because it was not that long ago that Al was trying to convince me that devices such as this did not exist, and were not used in the transport of materials out of ground zero.
===============
I find this lie particularly amusing.
Note the absence of direct quotations from the liar.
I think you should be warned against lying, Trippy, because lying for the purpose of character assassination isn't science.
Is it?
========================================
See... Here's what's really amsuing.
First we have Alwhatshisname claiming the following in this post that:
QUOTE (Al Khwarizmi - step-by-step+Oct 22 2007, 07:48 PM)
Also, Trippy, learn to REFERENCE YOUR CLAIMS.
I can not find such a thing as a "thermate cutter" for sale anywhere on earth.
http://www.google.com/search?hl=en&q=%22thermate+cutter%22
QUOTE
Did you mean: "thermite cutter"
In the Name of All who Died on 9/11, We Must Act Now « Friends of ...
After all, how would the FDNY know that Building 7 was rigged with thousands of thermate cutter charges to “pull”? Does that not suggest that the FDNY ...
21stcenturycicero.wordpress.com/2007/09/11/in-the-name-of-all-who-died-on-911-we-must-act-now/ - 156k - Cached - Similar pages
TruthBurn: Updates Sept. 6, 2007
I did get one bid from a shadowy tech person with ex-defense contacts in Virginia to build 2 sol-gel thermate cutter charges. The price was $10000.00 per ...
911truthburn.blogspot.com/2007/09/updates-sept-4-2007.html - 91k - Cached - Similar pages
BPVideo
I believe that the proposal I outline here can draw more attention to the notion of thermate cutter charges being used to bring down the World Trade ...
bpathvideo.blogspot.com/ - 43k - Cached - Similar pages
Forums - WTC molten metal question...
Thermate cutter charges, used by the US military, used on the WTC towers and ... There is no scientific way to disapprove that thermate cutter charges were ...
www.rottentomatoes.com/vine/showthread.php?t=480283 - 53k - Cached - Similar pages
Re: metallic microspheres 5% of WTC dust
But that would seem to imply that there were thermate cutter charges ... thermate cutter charges all over the place. Hence if the cutter charges ...
sci.tech-archive.net/Archive/sci.physics/2007-06/msg00109.html - 10k - Cached - Similar pages
In the Name of All who Died on 9/11, We Must Act Now « Friends of ...
After all, how would the FDNY know that Building 7 was rigged with thousands of thermate cutter charges to “pull”? Does that not suggest that the FDNY ...
21stcenturycicero.wordpress.com/2007/09/11/in-the-name-of-all-who-died-on-911-we-must-act-now/ - 156k - Cached - Similar pages
TruthBurn: Updates Sept. 6, 2007
I did get one bid from a shadowy tech person with ex-defense contacts in Virginia to build 2 sol-gel thermate cutter charges. The price was $10000.00 per ...
911truthburn.blogspot.com/2007/09/updates-sept-4-2007.html - 91k - Cached - Similar pages
BPVideo
I believe that the proposal I outline here can draw more attention to the notion of thermate cutter charges being used to bring down the World Trade ...
bpathvideo.blogspot.com/ - 43k - Cached - Similar pages
Forums - WTC molten metal question...
Thermate cutter charges, used by the US military, used on the WTC towers and ... There is no scientific way to disapprove that thermate cutter charges were ...
www.rottentomatoes.com/vine/showthread.php?t=480283 - 53k - Cached - Similar pages
Re: metallic microspheres 5% of WTC dust
But that would seem to imply that there were thermate cutter charges ... thermate cutter charges all over the place. Hence if the cutter charges ...
sci.tech-archive.net/Archive/sci.physics/2007-06/msg00109.html - 10k - Cached - Similar pages
and - "Your search - "thermite cutter torch" - did not match any documents."
and - "Your search - "thermate cutter torch" - did not match any documents."
Capice??
REFERENCE YOUR CLAIMS.
Then we have him making this post:
QUOTE (->
| QUOTE |
| Did you mean: "thermite cutter" In the Name of All who Died on 9/11, We Must Act Now « Friends of ... After all, how would the FDNY know that Building 7 was rigged with thousands of thermate cutter charges to “pull”? Does that not suggest that the FDNY ... 21stcenturycicero.wordpress.com/2007/09/11/in-the-name-of-all-who-died-on-911-we-must-act-now/ - 156k - Cached - Similar pages TruthBurn: Updates Sept. 6, 2007 I did get one bid from a shadowy tech person with ex-defense contacts in Virginia to build 2 sol-gel thermate cutter charges. The price was $10000.00 per ... 911truthburn.blogspot.com/2007/09/updates-sept-4-2007.html - 91k - Cached - Similar pages BPVideo I believe that the proposal I outline here can draw more attention to the notion of thermate cutter charges being used to bring down the World Trade ... bpathvideo.blogspot.com/ - 43k - Cached - Similar pages Forums - WTC molten metal question... Thermate cutter charges, used by the US military, used on the WTC towers and ... There is no scientific way to disapprove that thermate cutter charges were ... www.rottentomatoes.com/vine/showthread.php?t=480283 - 53k - Cached - Similar pages Re: metallic microspheres 5% of WTC dust But that would seem to imply that there were thermate cutter charges ... thermate cutter charges all over the place. Hence if the cutter charges ... sci.tech-archive.net/Archive/sci.physics/2007-06/msg00109.html - 10k - Cached - Similar pages |
and - "Your search - "thermite cutter torch" - did not match any documents."
and - "Your search - "thermate cutter torch" - did not match any documents."
Capice??
REFERENCE YOUR CLAIMS.
Then we have him making this post:
============================
Flashback:
common sense:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Yet none of you can explain your thermite nonsense. How did the thermite burn SIDEWAYS through the steel?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Linear_Thermite.jpg
So as it turns out, it's not me that's lying after all.
In the first post he claims that no such device is for sale anywhere on earth, followed by an implication that such a device doesn't exist, period.
Then in the second post he posts a picture of this very type of device, and then goes on to accuse me of lying for pointing out the contradiction in his posts.
I'm not going to dignify that second 'post' except to say that if Al had bothered to actually read the Wikipage it aknowledges the use of the term to also refer to a medical ultrasound.
None of this changes the fact that Sonogram, Sonograph, and Spectrograph are all used interchangeably.
None of this changes the fact that Sonogram, Sonograph, and Spectrograph are all used interchangeably.
QUOTE
And I am still waiting from your references wcelliot
But I am not waiting for yet another authoritarian assertion.
I am not waiting for a chemical chain reaction either - I am waiting for a real world reference to a 10 microsecond duration for an explosive pressure pulse.
Note that your fellow conspirator Arthur posted a pulse that endured for 3.3 milliseconds, while your fellow conspirator Trippy posted a pulse that endured for .67 seconds.
Note that both of these pulses contradicted your authoritatrian assertion.
Note that I will continue to request a reference until you provide one, or withdraw your claims.
Note that these requests will accumulate with your unsubstatiated claims, so that my list now includes
a 10 microsecond pulse in air (not the chemical reaction - a chemical reaction isn't a shockwave)
DARPAS request for a microphone tailored for recording explosions, and
propagation of sound in air as Direct Current.
Note bene, wcelliot.
But I am not waiting for yet another authoritarian assertion.
I am not waiting for a chemical chain reaction either - I am waiting for a real world reference to a 10 microsecond duration for an explosive pressure pulse.
Note that your fellow conspirator Arthur posted a pulse that endured for 3.3 milliseconds, while your fellow conspirator Trippy posted a pulse that endured for .67 seconds.
Note that both of these pulses contradicted your authoritatrian assertion.
Note that I will continue to request a reference until you provide one, or withdraw your claims.
Note that these requests will accumulate with your unsubstatiated claims, so that my list now includes
a 10 microsecond pulse in air (not the chemical reaction - a chemical reaction isn't a shockwave)
DARPAS request for a microphone tailored for recording explosions, and
propagation of sound in air as Direct Current.
Note bene, wcelliot.
Note bene, idiot, I've explained ALL of this MORE THAN ONCE.
Are you DENSE?!?
When you take the 26,700 feet-per-second detonation speed WHICH I'VE ALREADY PROVIDED THREE REFERENCES FOR (AND YOU CAN GOOGLE A DOZEN MORE JUST AS EASILY AS I CAN) and you RUN THE CALCULATIONS for a FOUR INCH BLOCK - YOU GET 10 MICROSECONDS!!! MAYBE LESS, DEPENDING ON WHERE YOU PUT THE DETONATOR.
I'VE ALSO EXPLAINED THAT ANY RECORDING OF AN EXPLOSION THAT LASTS LONGER THAN 10 MICROSECONDS IS ARTIFACT, FROM THE REFLECTIONS OF THE INITIAL 10 MICROSECOND BLAST OFF THE ENVIRONMENT, AND ACTUALLY DERIVED THE "N-SHAPED" SLOPE. THE "N-SHAPE" IS WHAT YOU GET WHEN YOU GET REFLECTIONS FROM THE ENVIRONMENT. Whether that's 3.3milliseconds of artifact or 3.3seconds of artifact, it's all artifact except the first 10microseconds.
I said originally that I remembered the DARPA RFP but those go back a long way, I've been reading DARPA RFPs for twenty years, and they've only recently put up a website, and they don't archive everything. I already said that I wasn't having any luck finding that particular RFP. But I'll tell you what, I'm currently working on a DARPA program, so the next time I run into the DARPA program manager, I'll ask him about it and see if he knows where it is.
And I never said anything about sound generating electrical current, the "DC" term, as I've already explained (needlessly, for everyone BUT YOU). just refers to the zeroth-frequency component AS I'VE ALREADY EXPLAINED!
And, just so you know, I've reported you for calling people liars, when the real problem is that YOU'RE JUST TOO STUPID TO UNDERSTAND PLAIN ENGLISH!!!
QUOTE (Al Khwarizmi - step-by-step+Nov 15 2007, 10:25 PM)
Note that your fellow conspirator Arthur posted a pulse that endured for 3.3 milliseconds, while your fellow conspirator Trippy posted a pulse that endured for .67 seconds.
So Al, now you think we are CONSPIRATORS in 9/11?????
Whoooo Hoooo, break out the tin foil.
Arthur
So Al, now you think we are CONSPIRATORS in 9/11?????
Whoooo Hoooo, break out the tin foil.
Arthur
QUOTE
Whoooo Hoooo, break out the tin foil.
Even people who are *nuts* are still supposed to be capable of doing simple math!
Hey Al, what's (0.25feet)/(26,700 feet/second) in YOUR universe?
QUOTE (wcelliott+Nov 16 2007, 08:33 AM)
Note bene, idiot, I've explained ALL of this MORE THAN ONCE.
Are you DENSE?!?
When you take the 26,700 feet-per-second detonation speed WHICH I'VE ALREADY PROVIDED THREE REFERENCES FOR (AND YOU CAN GOOGLE A DOZEN MORE JUST AS EASILY AS I CAN) and you RUN THE CALCULATIONS for a FOUR INCH BLOCK - YOU GET 10 MICROSECONDS!!! MAYBE LESS, DEPENDING ON WHERE YOU PUT THE DETONATOR.
I'VE ALSO EXPLAINED THAT ANY RECORDING OF AN EXPLOSION THAT LASTS LONGER THAN 10 MICROSECONDS IS ARTIFACT, FROM THE REFLECTIONS OF THE INITIAL 10 MICROSECOND BLAST OFF THE ENVIRONMENT, AND ACTUALLY DERIVED THE "N-SHAPED" SLOPE. THE "N-SHAPE" IS WHAT YOU GET WHEN YOU GET REFLECTIONS FROM THE ENVIRONMENT. Whether that's 3.3milliseconds of artifact or 3.3seconds of artifact, it's all artifact except the first 10microseconds.
I said originally that I remembered the DARPA RFP but those go back a long way, I've been reading DARPA RFPs for twenty years, and they've only recently put up a website, and they don't archive everything. I already said that I wasn't having any luck finding that particular RFP. But I'll tell you what, I'm currently working on a DARPA program, so the next time I run into the DARPA program manager, I'll ask him about it and see if he knows where it is.
And I never said anything about sound generating electrical current, the "DC" term, as I've already explained (needlessly, for everyone BUT YOU). just refers to the zeroth-frequency component AS I'VE ALREADY EXPLAINED!
And, just so you know, I've reported you for calling people liars, when the real problem is that YOU'RE JUST TOO STUPID TO UNDERSTAND PLAIN ENGLISH!!!
Shh, AL does not need to see this, it might confuse him since he is an expert professional, just keep it to yourself.
the recording system, and the O.T. estimation is based on measuring the relative propagation time of shock waves to piezoelectric sensors (Δt = 0.445sec, see Fig. 7) and the absolute GPS time of the waves arrival to a hydrophone (see Fig.8), co-located with the sensors (see Chapter 7.2 below). For the largest explosion we obtained the exact moment of detonating electric fuses, connected to detonating cord, that initiated the charge (see Fig. 3). The finite detonation time of the detonating cord (the length of about 70-75 m), estimated as about 10 msec (~ 70m : 7000m/sec), was also considered. The recording system time was continuously synchronized with GPS and under 500 samples per second provided an accuracy better than 5 msec.
http://www.gii.co.il/html/seis/DeadSea99/PROGREP26.doc
Remember reading about this when I helped Ashland oil company do sound studies from explosions on my own property in the late 1990s.
It takes 10 msec just for the detonation cord to go off, then the explosive has to follow that in another 10 msec or more!
Chainsaw -
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
Turns out that Seffen's equation (12) expresses the same dynamics as what I have called modified Beck, not B&V. Since Seffen uses a compression ratio (inverse stretch), I went ahead to do a comparison of the two somewhat different dynamics. Other than slightly different parameters, the two models agree essentially equally well with the data.
Only the Seffen crush-down equation or else the B&V crush-down equation correctly describes the dynamics.
But just now I cannot tell which.
But just now I cannot tell which.
Chainsaw, I just want to be clear that I didn't mean for my rant to sound like I was upset with you personally, I'm just psst that AlK will read what you posted and try to bludgeon me with a warped interpretation of it.
QUOTE (David B. Benson+Nov 17 2007, 12:30 AM)
Only the Seffen crush-down equation or else the B&V crush-down equation correctly describes the dynamics.
But just now I cannot tell which.
i'll help you, ...neither is right.
But just now I cannot tell which.
i'll help you, ...neither is right.
QUOTE (newton+Nov 16 2007, 06:43 PM)
...neither is right.
Then with your vast knowledge of Newtonian dynamics, you'll be able to write the paper proving that assertion and having it published in the ASCE J. Engg. Mechanics.
Then with your vast knowledge of Newtonian dynamics, you'll be able to write the paper proving that assertion and having it published in the ASCE J. Engg. Mechanics.
QUOTE (wcelliott+Nov 16 2007, 09:21 PM)
Chainsaw -
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
Good points.
Conclusive evidence for explosives isnt going to come through analyses of sound recordings, but in the proof of events like the basements getting shredded, and the squibs exceeding what was possible without them.
Video proof of Basement Explosions
Direct Evidence for Explosives, by Crocket Grabbe PhD.
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
Good points.
Conclusive evidence for explosives isnt going to come through analyses of sound recordings, but in the proof of events like the basements getting shredded, and the squibs exceeding what was possible without them.
Video proof of Basement Explosions
Direct Evidence for Explosives, by Crocket Grabbe PhD.
Well, at least the author argued against the "High Energy Lasers" theory.
He missed out on a couple of other pretty obvious points, though, like considering what happened to the air inside the towers when the towers were collapsing. I supposed he expected to find dense layers of solidified air in the basement trapped between the floors' rubble.
He missed out on a couple of other pretty obvious points, though, like considering what happened to the air inside the towers when the towers were collapsing. I supposed he expected to find dense layers of solidified air in the basement trapped between the floors' rubble.
QUOTE (wcelliott+Nov 16 2007, 09:21 PM)
Chainsaw -
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
Have you ever worked with explosives?
Detcord is used in conjunction with electric detonators the electric detonators only trigger the detcord or other initial shock charge.
There are detonators that trigger directly blasting caps, however they are seldom used with C4.
An electric detonator is only a way to ignite the inital shock charge that sets off the main explosive, usually detcord.
PS. I fully understand your post and it's intent and your right about the shock wave reflections except for the small spike of a detonator initiation like detcord that is often lost in the sound recordings.
I wasn't assuming that the C-4 charge was detonated by det-cord, but by an electric detonator.
If you have a recording of the det-cord-detonated explosive, then part of the recording is of the det-cord going-off (which isn't part of any "characteristic waveform for explosives", as AlK's been asserting exists), it would be an artifact of the specific instance of that particular set-up.
If the explosives detonated were blocks of C-4 of the size specified (about 4-inches), then the blocks detonated at the rate of 26,700 feet-per-second, and that ends up taking about 10 microseconds for the C-4 to go from solid to gas. Any sound recording of that blast would be one sharp spike associated with that 10 microsecond blast, plus the myriad reflections of that blast's shockwave reflecting off all surfaces of its environment, all those reflections delayed from the propagation-path, and attenuated by the reflection coefficient of the material, and also simply lower-intensity as the shockwave expanded spherically, given that the same amount of energy is being distributed over a spherical surface expanding at the speed of sound (once outside the immediate "blast zone").
The CENTRAL POINT of all these discussions that everyone else seems to miss is that all recordings of explosions provided are recording of the REFLECTIONS of the detonation off the surfaces of the blast's environment. Change the nature of the environment and you'll have a different-sounding explosion. No "characteristic waveform" for an explosion exists, other than a single spike that's on the order of 10 microseconds wide and too intense for most microphones to detect without saturation. Any audio digital recording will be undersampled (a 40kHz sampling rate is sufficient for 20kHz bandwidth, and 1/40kHz = 25 microseconds) so you get ONE SAMPLE that's at MAXVAL plus DEAD SILENCE before and after.
If someone wishes to assert that explosives have some "characteristic waveform", then they need to provide a recording that samples at a rate adequate to characterize the waveform that starts and stops in about 10 microseconds and has enough samples in that interval to pick up whatever waveform is "characteristic" to that blast. (Which, itself, will be driven by the shape of the charge - rectangular block/sphere/blob, and where the detonator was placed - center/edge/somehwere in between.)
Someone post a link to an explosive charge going-off that has no solid structures/materials within 100 feet (including the ground itself), and show me how that waveform compares to an explosive going off inside a structure. Aside from the initial spike, there will be NO CORRELATION.
Have you ever worked with explosives?
Detcord is used in conjunction with electric detonators the electric detonators only trigger the detcord or other initial shock charge.
There are detonators that trigger directly blasting caps, however they are seldom used with C4.
An electric detonator is only a way to ignite the inital shock charge that sets off the main explosive, usually detcord.
PS. I fully understand your post and it's intent and your right about the shock wave reflections except for the small spike of a detonator initiation like detcord that is often lost in the sound recordings.
In the "explosives brought-down the towers" theory, I've assumed that they aren't thinking that the explosive charges were detonated using det-cord, but rather electrically triggered detonators/"blasting caps".
If there are any loonies out there who want to correct me on their delusions, please advise, I just assumed you're all thinking of some sinister government agent in a trenchcoat and dark sunglasses with a handheld transmitter with a Big Red Button triggering the explosives.
Definitely, if det-cord is detonating the C-4 charge, it makes its own noise, and that would have its own acoustic contribution (which would change from one situation to the next, as its sound would be bouncing all over the environment, too).
I defer to Chainsaw's experience with explosives, which is vastly greater than my own, but I'm not totally ignorant of the subject. My first job out of school was working for Schlumberger Well Services which uses C-4 to perforate well casings, and studying explosives and safe-handling techniques was part of the 13-week training course. Subsequent to that job, I've worked in the defense industry, and have on-occasion interfaced with missile designers and warheads are part of (most of) the system concepts. I'm mainly a "sensors and systems" guy, and I've written software that does the "sonogram/spectrogram/voice-print" conversion from time-based digital signals to spectrum-based signal processing, I've designed a digital signal processor that did acoustic "beamforming", focussing sound from multiple sensors to create a "virtual microphone" positioned anywhere in the environment (software selectable position), and I've computer-modelled sound propagation through various environments. I've also designed acoustic transducers that don't look like acoustic transducers for security applications, so that people doing bug-sweeps wouldn't know what it was if they were handed one.
So I don't consider myself a complete idiot on this particular topic.
If there are any loonies out there who want to correct me on their delusions, please advise, I just assumed you're all thinking of some sinister government agent in a trenchcoat and dark sunglasses with a handheld transmitter with a Big Red Button triggering the explosives.
Definitely, if det-cord is detonating the C-4 charge, it makes its own noise, and that would have its own acoustic contribution (which would change from one situation to the next, as its sound would be bouncing all over the environment, too).
I defer to Chainsaw's experience with explosives, which is vastly greater than my own, but I'm not totally ignorant of the subject. My first job out of school was working for Schlumberger Well Services which uses C-4 to perforate well casings, and studying explosives and safe-handling techniques was part of the 13-week training course. Subsequent to that job, I've worked in the defense industry, and have on-occasion interfaced with missile designers and warheads are part of (most of) the system concepts. I'm mainly a "sensors and systems" guy, and I've written software that does the "sonogram/spectrogram/voice-print" conversion from time-based digital signals to spectrum-based signal processing, I've designed a digital signal processor that did acoustic "beamforming", focussing sound from multiple sensors to create a "virtual microphone" positioned anywhere in the environment (software selectable position), and I've computer-modelled sound propagation through various environments. I've also designed acoustic transducers that don't look like acoustic transducers for security applications, so that people doing bug-sweeps wouldn't know what it was if they were handed one.
So I don't consider myself a complete idiot on this particular topic.
A small point about the final stretch (crush, inverse compaction ratio):
A reasonable estimate for the maximum stretch is about 0.54. Using NEU-FONZE's 6:1 compaction ratio, the final stretch would be 0.09. However my program keeps selecting a starting stretch in the range 0.41--0.51. So saying that is 0.48, the 6:1 compaction ratio gives 0.08. The examples with a stretch of only 0.05 are likely to have been exceptional cases.
A reasonable estimate for the maximum stretch is about 0.54. Using NEU-FONZE's 6:1 compaction ratio, the final stretch would be 0.09. However my program keeps selecting a starting stretch in the range 0.41--0.51. So saying that is 0.48, the 6:1 compaction ratio gives 0.08. The examples with a stretch of only 0.05 are likely to have been exceptional cases.
QUOTE (wcelliott+Nov 17 2007, 05:53 PM)
In the "explosives brought-down the towers" theory, I've assumed that they aren't thinking that the explosive charges were detonated using det-cord, but rather electrically triggered detonators/"blasting caps".
If there are any loonies out there who want to correct me on their delusions, please advise, I just assumed you're all thinking of some sinister government agent in a trenchcoat and dark sunglasses with a handheld transmitter with a Big Red Button triggering the explosives.
Definitely, if det-cord is detonating the C-4 charge, it makes its own noise, and that would have its own acoustic contribution (which would change from one situation to the next, as its sound would be bouncing all over the environment, too).
I defer to Chainsaw's experience with explosives, which is vastly greater than my own, but I'm not totally ignorant of the subject. My first job out of school was working for Schlumberger Well Services which uses C-4 to perforate well casings, and studying explosives and safe-handling techniques was part of the 13-week training course. Subsequent to that job, I've worked in the defense industry, and have on-occasion interfaced with missile designers and warheads are part of (most of) the system concepts. I'm mainly a "sensors and systems" guy, and I've written software that does the "sonogram/spectrogram/voice-print" conversion from time-based digital signals to spectrum-based signal processing, I've designed a digital signal processor that did acoustic "beamforming", focussing sound from multiple sensors to create a "virtual microphone" positioned anywhere in the environment (software selectable position), and I've computer-modelled sound propagation through various environments. I've also designed acoustic transducers that don't look like acoustic transducers for security applications, so that people doing bug-sweeps wouldn't know what it was if they were handed one.
So I don't consider myself a complete idiot on this particular topic.
wcelliott
I had always believed that you had some explosive knowledge, but most of the time C4 which requires a higher generation of energy in shock waves to cause it to explode, is exploded with either detcord or shock tubes not blasting caps.
Blasting caps usually are used on trinitrotoluenes not on C4 or RDX which require a stronger initial bang to ignite the charge than does TNT.
Some people confuse small shock tubes with blasting caps though, however they are not the same.
The benzene ring and three nitrogen covalent bonds make TNT inherently unstable, and easy to trigger, that is probably why the company that you worked for did not use Trinitrotoluene compounds.
You can at some instances recover a detonator signal, but only if the microphone that recovers it is withing very close range, the whole idea is to have the shock wave given off by the detonator, absorbed and trigger the main charge, so the shock waves from detonator do not travel well past the main charge and are extremely week.
All I was trying to point out is that it takes longer than AL claimed for a charge to ignite and burn and trigger the main charge.
I completely under stand what your saying about reflected shock-waves, I am just trying to limit the confusion, so that if some one does find a paper with a double peak, indicative of a detonator discharge before the main blast, it would help the readers of the forum to have an explanation of what they were actually seeing in the Data.
I just wanted people to know that such data does exist, and what it actually means.
Because I expect that AL will attempt to use such data in an argument against your sound argument.
Do not know if this is getting though clear and concisely though, I am just trying to save time by debunking a false argument before AL makes it!
If there are any loonies out there who want to correct me on their delusions, please advise, I just assumed you're all thinking of some sinister government agent in a trenchcoat and dark sunglasses with a handheld transmitter with a Big Red Button triggering the explosives.
Definitely, if det-cord is detonating the C-4 charge, it makes its own noise, and that would have its own acoustic contribution (which would change from one situation to the next, as its sound would be bouncing all over the environment, too).
I defer to Chainsaw's experience with explosives, which is vastly greater than my own, but I'm not totally ignorant of the subject. My first job out of school was working for Schlumberger Well Services which uses C-4 to perforate well casings, and studying explosives and safe-handling techniques was part of the 13-week training course. Subsequent to that job, I've worked in the defense industry, and have on-occasion interfaced with missile designers and warheads are part of (most of) the system concepts. I'm mainly a "sensors and systems" guy, and I've written software that does the "sonogram/spectrogram/voice-print" conversion from time-based digital signals to spectrum-based signal processing, I've designed a digital signal processor that did acoustic "beamforming", focussing sound from multiple sensors to create a "virtual microphone" positioned anywhere in the environment (software selectable position), and I've computer-modelled sound propagation through various environments. I've also designed acoustic transducers that don't look like acoustic transducers for security applications, so that people doing bug-sweeps wouldn't know what it was if they were handed one.
So I don't consider myself a complete idiot on this particular topic.
wcelliott
I had always believed that you had some explosive knowledge, but most of the time C4 which requires a higher generation of energy in shock waves to cause it to explode, is exploded with either detcord or shock tubes not blasting caps.
Blasting caps usually are used on trinitrotoluenes not on C4 or RDX which require a stronger initial bang to ignite the charge than does TNT.
Some people confuse small shock tubes with blasting caps though, however they are not the same.
The benzene ring and three nitrogen covalent bonds make TNT inherently unstable, and easy to trigger, that is probably why the company that you worked for did not use Trinitrotoluene compounds.
You can at some instances recover a detonator signal, but only if the microphone that recovers it is withing very close range, the whole idea is to have the shock wave given off by the detonator, absorbed and trigger the main charge, so the shock waves from detonator do not travel well past the main charge and are extremely week.
All I was trying to point out is that it takes longer than AL claimed for a charge to ignite and burn and trigger the main charge.
I completely under stand what your saying about reflected shock-waves, I am just trying to limit the confusion, so that if some one does find a paper with a double peak, indicative of a detonator discharge before the main blast, it would help the readers of the forum to have an explanation of what they were actually seeing in the Data.
I just wanted people to know that such data does exist, and what it actually means.
Because I expect that AL will attempt to use such data in an argument against your sound argument.
Do not know if this is getting though clear and concisely though, I am just trying to save time by debunking a false argument before AL makes it!
QUOTE
...in a relatively rare variety of aphasia, jargon aphasia, patients seem to have no anxiety at all about about their verbal deficit.
Daniel Dennett, Consciousness Explained. p.249.
Daniel Dennett, Consciousness Explained. p.249.
wcelliot
--------------------
______|_________
That's what an explosive detonation looks like in the time domain,
-------------------
That's an assertion you are clearly unwilling to reference. When Trippy and Arthur rushed to your aide as you floundered for evidence, they provided an infrasonic pulse with a duration of 670,000 microseconds, and a shockwave blast with a duration of 3,300 microseconds.
Both of these cases contradicted your assertion.
No amount of technical jargon woven into bafflegab can alter the fact that both of these cases contradict your baseless, anti-scientific claim.
When I ask you to reference your claims, you respond with hostility and abuse.
previously
wcelliot:
=========
A point (of many) that goes straight over your head (because it's untrue), is that the acoustic spectrum of a 10microsecond spike goes all the way from DC to a MegaHertz, so it includes spectral energy in all bands, including the audio band (40-20,000Hz).
=========
1) a blast "spike" is not a sound wave, but you still conflate the two.
2) you repeatedly assert a 10µs duration of "spike" without substantiation.
3) Trippy's infrasound N-"spike" endured to the contrary for 2,050,000µs.
4) Arthur's "Typical HE pressure/time curve" for a blast endured to the contrary for 3,300µs
WHY?
5) A 10µs "acoustic" (*cough*) "spike" that produced a wave of DC in the air would be quite fantastical and electrical, but it would not be acoustic.
subsequently:
wcelliot:
====================
And the "DC component" of a spectrum is routine language of the art, everyone (except you) understand it to refer to the zeroth-order component of a spectrum. Given the choice of "DC" or "zeroth-order component of a spectrum", I'll continue to use "DC" for the spectral component at zero frequency.
====================
Terms of the Art.
QUOTE (->
| QUOTE |
| ...in a relatively rare variety of aphasia, jargon aphasia, patients seem to have no anxiety at all about about their verbal deficit. Daniel Dennett, Consciousness Explained. p.249. |
wcelliot
--------------------
______|_________
That's what an explosive detonation looks like in the time domain,
-------------------
That's an assertion you are clearly unwilling to reference. When Trippy and Arthur rushed to your aide as you floundered for evidence, they provided an infrasonic pulse with a duration of 670,000 microseconds, and a shockwave blast with a duration of 3,300 microseconds.
Both of these cases contradicted your assertion.
No amount of technical jargon woven into bafflegab can alter the fact that both of these cases contradict your baseless, anti-scientific claim.
When I ask you to reference your claims, you respond with hostility and abuse.
previously
wcelliot:
=========
A point (of many) that goes straight over your head (because it's untrue), is that the acoustic spectrum of a 10microsecond spike goes all the way from DC to a MegaHertz, so it includes spectral energy in all bands, including the audio band (40-20,000Hz).
=========
1) a blast "spike" is not a sound wave, but you still conflate the two.
2) you repeatedly assert a 10µs duration of "spike" without substantiation.
3) Trippy's infrasound N-"spike" endured to the contrary for 2,050,000µs.
4) Arthur's "Typical HE pressure/time curve" for a blast endured to the contrary for 3,300µs
WHY?
5) A 10µs "acoustic" (*cough*) "spike" that produced a wave of DC in the air would be quite fantastical and electrical, but it would not be acoustic.
subsequently:
wcelliot:
====================
And the "DC component" of a spectrum is routine language of the art, everyone (except you) understand it to refer to the zeroth-order component of a spectrum. Given the choice of "DC" or "zeroth-order component of a spectrum", I'll continue to use "DC" for the spectral component at zero frequency.
====================
Terms of the Art. MARK LANE: What is a plausible denial?
E. HOWARD HUNT: Denial that is believable.
LANE: Is that a term of art within the CIA?
HUNT: In the intelligence community it means a story that is plausible, it could be believed by a substantial number of people. Plausibly denying, a denial that is believable, that is credible.
LANE: Do you recall testifying on June 28, 1974, in the case of United States versus Ehrlichman, page 761, were you asked these questions, and did you make these answers:
"Question. What was the reason given, or was any reason given, why you and Mr. Liddy couldn't perform this operation?
"Answer. Because of our connection with the White House and the fact that plausible denial would have to be maintained.
"Question. You said plausible denial would have to be maintained?
"Answer. Yes.
"Question. Would you explain what you mean by that?
"Answer. "The principle of plausible denial is simply if an operation or action is later disclosed, for example, as an action of the United States government, the government can plausibly deny it, deny any involvement or connection with the action."
Do you recall those questions and answers?
HUNT: Yes.
LANE: Would you accept as a fair definition which you gave, when you testified as to what a plausible denial is?
HUNT: Yes.
---Hunt. vs. Liberty Lobby, Plausible Denial, p.p. 261-262, Mark Lane, 1991
6) DC means Direct Current - it is a term of the electrical art.
7) DC is not part of the audio spectrum (or any spectrum), does not propagate in air, and by definition does not oscillate. A continuous non-modulated voltage that consumes dynamic range, when present in electrical signals used to produce and record sound, is thus represented on spectral distribution graphs as a zero frequency (no sound) component - a non-acoustic artifact of poorly engineered electrical equipment:
QUOTE
Many sound cards record with a slight DC offset, which means that direct current is introduced into the signal by the card, causing the center of the waveform to be off from the zero point in the waveform display. This is seen as the waveform being "shifted" above or below the center line in the Wave Display, and can cause a click or pop to be played at the beginning or end of the file.
---Cool Edit Pro, Glossary
---Cool Edit Pro, Glossary
The acoustic spectrum of an explosion will never contain DC, because DC is direct current.
A 10µs "acoustic" (*cough*) "spike" that propagates as DC in the air would be quite fantastical and electrical, but it would not be acoustic.
===================================
Fast Fourier Transform Spectrum Analyser applet: guidance notes
===================================
QUOTE (->
| QUOTE |
| Many sound cards record with a slight DC offset, which means that direct current is introduced into the signal by the card, causing the center of the waveform to be off from the zero point in the waveform display. This is seen as the waveform being "shifted" above or below the center line in the Wave Display, and can cause a click or pop to be played at the beginning or end of the file. ---Cool Edit Pro, Glossary |
The acoustic spectrum of an explosion will never contain DC, because DC is direct current.
A 10µs "acoustic" (*cough*) "spike" that propagates as DC in the air would be quite fantastical and electrical, but it would not be acoustic.
===================================
Fast Fourier Transform Spectrum Analyser applet: guidance notes
===================================
Add DC level / random noise
You can optionally add a constant DC level (bias or offset) and/or simulated random noise to the signal by checking the appropriate checkbox and entering the amount of the DC offset or noise level (in volts) in the text field. The values chosen should reflect the fact that the basic signal amplitude is fixed [in this applet] at 1V. The effects of adding a DC offset or random noise are discussed later.
[...]
Effect of adding a constant DC level
Select a sine wave signal of frequency 1000 Hz. Check the "Add DC level" check box, enter a value of 0.5 (volts) in the text field for the amount of the DC offset, and plot the signal. The graph should show a sine wave shifted upwards by the 0.5 V offset (remember the sine wave itself has an amplitude of 1 V).
You should find that the spectrum consists of a line at 1000 Hz, due to the sine wave,
together with a line at zero frequency, with a height of 0.5 V.
This zero frequency component is due to the DC level.
--------------------------------------------------
http://www.dsptutor.freeuk.com/index.htm
The acoustic spectrum resulting from an explosion will never contain DC, because DC is electrical not acoustic (akoustikos - to hear).
DC offset is an artifact of poorly engineered equipment in the recording path.
(see also, particle collisions)
Your calculation of the duration of a chemical reaction is not a reference to the duration of an expanding shockwave, nor is it a reference to the duration or properties of sound produced in the wake of the shockwave. In a world of cause an effect, the duration of a chemical reaction does not determine the duration of any resulting sound. The chemical reaction is not the sound of an explosion.
The shockwave resulting from the chemical reaction is also not the sound of an explosion: nevertheless, your 10 microsecond blast assertion -- contradicting Arthur's "typical" blast duration---requires a real world reference.
i) Please provide a 10 microsecond shockwave reference contradicting that supplied by Arthur, or withdraw your 10 microsecond claim.
ii) Please also provide a reference to DARPAs specification for development of a microphone for recording explosions.
These are your novel claims, and it is your scientific obligation to support them.
stundie
You introduced an analysis by a "sound engineer" who uses non-professional weird terminology (sonogram) and spends a lot of time analysing a fraudulent soundtrack.
The southtower collapse shot, showing rapid inward pull on the perimeter columns of the east face at collapse onset, is quite a famous one. But the soundtrack accompanying the original version of the clip does not include any obvious explosive noises, or crashes or pops. In fact, the original soundtrack has been stripped and replaced.
see for yourself:
http://au.youtube.com/watch?v=K8dX3foxozQ
When I find doctored recordings masquerading as evidence, I always ask: Who benefits?
Arthur
--------------------------
Since this time we have developed much better estimates of collapse time and clearly the RATE of fall of the towers was much slower than [Kausel's] free fall.
--------------------------
Did "we" slow down the video playback rate to achieve this miracle of Orwellian Revision?
--------------------------------
Yes, there were many more than 5 floors on fire in each tower.
So its no surprise that given the many shafts that ran all the way to the ground floor coupled with the rapid rate of collapse, that the air, at times, as it got expelled would have been very hot, to capable of creating burns.
--------------------------
You are invoking the same mechanism designed to account for high-velocity jets below the collapse front to explain why people were burnt and blasted by hot air at street level.
The temperature of the pistoned hot air and flames erupting at street level was hot enough to incinerate skin, but it was not hot enough to cause pyroclastic flows of dust and smoke?
Fantastic!
Arthur and the OCT team have done nothing to help us depict this amazing piston mechanism, so I composed this crude sketch based on their amazing powderizing piston-pancakes:
http://www.myfilestash.com/userfiles/alrea...ake_pistons.gif
Is this model hermetically sealed, or fulll of holes?
---------------------------
its HIGHLY LIKELY that at least one [linear thermite/thermate cutter] would have survived the collapse.
---------------------------
I find this claim surprising, given that the black box recorders were allegedly not found.
But since you are claiming that linear thermate cutters might survive collapse, it naturally follows that any linear thermate cutters ejected from the building as a consequence of the jetliner impact might also survive the fall.
I wouldn't think so, but there is a phenomena captured by the Naudet bros that requires some explaining.
Linear thermate cutters might work:
slow motion frames:
http://history-bytes.blogspot.com/2007/10/...-phenomena.html
============================
Also, my post defining the word [url=
http://dictionary.reference.com/search?q=sonogram]"sonogram" from dictionary.com[/url] (spectrum free) was deleted by an anonymous party without explanation or trace, and and I have received a 40% warning level in one installment, also without explanation.
Defamation and calumny and misrepresentation by government shills, on the other hand, is evidently quite acceptable.
Not a very transparent or fair forum, it would seem.
--------------------------
Since this time we have developed much better estimates of collapse time and clearly the RATE of fall of the towers was much slower than [Kausel's] free fall.
--------------------------
Did "we" slow down the video playback rate to achieve this miracle of Orwellian Revision?
--------------------------------
Yes, there were many more than 5 floors on fire in each tower.
So its no surprise that given the many shafts that ran all the way to the ground floor coupled with the rapid rate of collapse, that the air, at times, as it got expelled would have been very hot, to capable of creating burns.
--------------------------
You are invoking the same mechanism designed to account for high-velocity jets below the collapse front to explain why people were burnt and blasted by hot air at street level.
The temperature of the pistoned hot air and flames erupting at street level was hot enough to incinerate skin, but it was not hot enough to cause pyroclastic flows of dust and smoke?
Fantastic!
Arthur and the OCT team have done nothing to help us depict this amazing piston mechanism, so I composed this crude sketch based on their amazing powderizing piston-pancakes:
http://www.myfilestash.com/userfiles/alrea...ake_pistons.gif
Is this model hermetically sealed, or fulll of holes?
---------------------------
its HIGHLY LIKELY that at least one [linear thermite/thermate cutter] would have survived the collapse.
---------------------------
I find this claim surprising, given that the black box recorders were allegedly not found.
But since you are claiming that linear thermate cutters might survive collapse, it naturally follows that any linear thermate cutters ejected from the building as a consequence of the jetliner impact might also survive the fall.
I wouldn't think so, but there is a phenomena captured by the Naudet bros that requires some explaining.
Linear thermate cutters might work:
slow motion frames:
http://history-bytes.blogspot.com/2007/10/...-phenomena.html
============================
Also, my post defining the word [url=
http://dictionary.reference.com/search?q=sonogram]"sonogram" from dictionary.com[/url] (spectrum free) was deleted by an anonymous party without explanation or trace, and and I have received a 40% warning level in one installment, also without explanation.
Defamation and calumny and misrepresentation by government shills, on the other hand, is evidently quite acceptable.
Not a very transparent or fair forum, it would seem.
Alk -
You REALLY need to take a physics class.
After you take a remedial READING class.
I've already explained EVERY OBJECTION directed at me in your post, more than once.
None of the other recordings of "explosions" were of the explosives themselves detonating in-absence of reflective surfaces. A loud bang will echo off all surfaces in all directions. If you want to assert that explosives have a "characteristic waveform" then you should, first, record only an explosive going-off, not in a building, not on the ground, not in a bell factory, not in a church's organ pipe...
When you find a recording of an explosive itself going off, THEN let's talk about whether explosions have a "characteristic waveform".
And thanks, lots for your explanation of what "DC current" means. I must've missed that when I got my bachelors' in electrical engineering, and my Masters in electrical engineering.
And when you design sensors for a living, as I do, the term "DC" is routinely understood to refer to the zeroth-frequency component, which, when discussing sound, refers to the ambient pressure of the air (e.g., 14.7psi). Anything that creates more gas in the atmosphere will increase this number (ever so slightly, but it *is* a zeroth-order term).
With explosives, there are two principle characteristics that distinguish them - their energy density (how many Joules/kg they release when they detonate) and their *detonation rate*, which determines how fast the explosive changes from solid to gas, measured as a velocity. Detonation rate is exactly what it sounds like - the speed that the explosive detonates at. Initiate a detonation on one end of a block of C-4, and the detonation propagates from that end to the other at the *detonation rate*, of 26,700 feet/second (give or take). I've already posted a reference for this number. You can Google "C-4 detonation rate" yourself. The energy density of C-4 (or any other high-explosive isn't particularly remarkable, coal releases more energy when it burns than C-4 does when it detonates. What makes it capable of cutting steel is that it releases that energy is a very short amount of time (the "detonation rate"), which makes that unremarkable amount of energy a remarkable amount of *power*. If it released that amount of energy over the course of seconds or even milliseconds (as low-explosives do), it wouldn't do the slightest bit of damage to steel.
As for your continued assertion that a detonation isn't *sound*, OK, what did your microphone detect? Chi? Feng-sui? Prana? Or was the recording made using dowsing rods?
And BTW, you got the warnings for calling us liars, in two separate posts, which I reported. The moderators apparently agreed with me that your rhetoric was abusive and unwarranted.
You REALLY need to take a physics class.
After you take a remedial READING class.
I've already explained EVERY OBJECTION directed at me in your post, more than once.
None of the other recordings of "explosions" were of the explosives themselves detonating in-absence of reflective surfaces. A loud bang will echo off all surfaces in all directions. If you want to assert that explosives have a "characteristic waveform" then you should, first, record only an explosive going-off, not in a building, not on the ground, not in a bell factory, not in a church's organ pipe...
When you find a recording of an explosive itself going off, THEN let's talk about whether explosions have a "characteristic waveform".
And thanks, lots for your explanation of what "DC current" means. I must've missed that when I got my bachelors' in electrical engineering, and my Masters in electrical engineering.
And when you design sensors for a living, as I do, the term "DC" is routinely understood to refer to the zeroth-frequency component, which, when discussing sound, refers to the ambient pressure of the air (e.g., 14.7psi). Anything that creates more gas in the atmosphere will increase this number (ever so slightly, but it *is* a zeroth-order term).
With explosives, there are two principle characteristics that distinguish them - their energy density (how many Joules/kg they release when they detonate) and their *detonation rate*, which determines how fast the explosive changes from solid to gas, measured as a velocity. Detonation rate is exactly what it sounds like - the speed that the explosive detonates at. Initiate a detonation on one end of a block of C-4, and the detonation propagates from that end to the other at the *detonation rate*, of 26,700 feet/second (give or take). I've already posted a reference for this number. You can Google "C-4 detonation rate" yourself. The energy density of C-4 (or any other high-explosive isn't particularly remarkable, coal releases more energy when it burns than C-4 does when it detonates. What makes it capable of cutting steel is that it releases that energy is a very short amount of time (the "detonation rate"), which makes that unremarkable amount of energy a remarkable amount of *power*. If it released that amount of energy over the course of seconds or even milliseconds (as low-explosives do), it wouldn't do the slightest bit of damage to steel.
As for your continued assertion that a detonation isn't *sound*, OK, what did your microphone detect? Chi? Feng-sui? Prana? Or was the recording made using dowsing rods?
And BTW, you got the warnings for calling us liars, in two separate posts, which I reported. The moderators apparently agreed with me that your rhetoric was abusive and unwarranted.
metamars
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
QUOTE
* A new mathematical analysis of the collapse of the World Trade Centre has been published by a Cambridge University academic
PhysOrg, September 11, 2007
http://www.physorg.com/news108737007.html
I wonder if Professor Jones could get this level of positive publicity for an unpublished paper?
PhysOrg, September 11, 2007
http://www.physorg.com/news108737007.html
http://dictionary.reference.com/search?q=liar
This definition exists for a reason - and I don't mince words.
wcelliot
i) Please provide a 10 microsecond shockwave reference contradicting that supplied by Arthur, or withdraw your 10 microsecond claim.
ii) Please also provide a reference to DARPAs specification for development of a microphone for recording explosions.
These are your novel claims, and it is your scientific obligation to support them.
When you have done so, I will attend to your previous post
If you continue to make unscientific claims without references, I will report you.
This definition exists for a reason - and I don't mince words.
wcelliot
i) Please provide a 10 microsecond shockwave reference contradicting that supplied by Arthur, or withdraw your 10 microsecond claim.
ii) Please also provide a reference to DARPAs specification for development of a microphone for recording explosions.
These are your novel claims, and it is your scientific obligation to support them.
When you have done so, I will attend to your previous post
If you continue to make unscientific claims without references, I will report you.
Debate Online: Richard Gage, AE911Truth.org vs. Ron Craig, Explosives Engineer
For a list of upcoming appearances by Richard Gage, see Gage's Appearance Schedule
For a list of upcoming appearances by Richard Gage, see Gage's Appearance Schedule
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 06:42 AM)
metamars
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
I wonder if Professor Jones could get this level of positive publicity for an unpublished paper?
If Dr. Jones could do competent science I would say he could be published, I would really like to see actual impact studies from him on actual impacts, and how that affects many of his claims.
I would also like to see a more detailed description of the micro spheres, since they appear to be created from fly ash, from brown paper, I would like to know if it was a folder in a filing cabinet or some ones brown bagged lunch!
There are several claims I would like to see Dr. Jones actually back up with actual evidence.
IS it to much to ask that a scientist provide evidence to back up what he claims?
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
I wonder if Professor Jones could get this level of positive publicity for an unpublished paper?
If Dr. Jones could do competent science I would say he could be published, I would really like to see actual impact studies from him on actual impacts, and how that affects many of his claims.
I would also like to see a more detailed description of the micro spheres, since they appear to be created from fly ash, from brown paper, I would like to know if it was a folder in a filing cabinet or some ones brown bagged lunch!
There are several claims I would like to see Dr. Jones actually back up with actual evidence.
IS it to much to ask that a scientist provide evidence to back up what he claims?
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 12:53 AM)
Arthur
--------------------------
Since this time we have developed much better estimates of collapse time and clearly the RATE of fall of the towers was much slower than [Kausel's] free fall.
--------------------------
Did "we" slow down the video playback rate to achieve this miracle of Orwellian Revision?
Nope.
Good try though.
Arthur
--------------------------
Since this time we have developed much better estimates of collapse time and clearly the RATE of fall of the towers was much slower than [Kausel's] free fall.
--------------------------
Did "we" slow down the video playback rate to achieve this miracle of Orwellian Revision?
Nope.
Good try though.
Arthur
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 01:42 AM)
this website ... claimed that the paper was published when it wasn't.
No, METAMARS claimed it was published.
There is No Official stance taken one way or the other by Physorg.
Once again, trying to make a mountain out of a molehill I see.
Arthur
No, METAMARS claimed it was published.
There is No Official stance taken one way or the other by Physorg.
Once again, trying to make a mountain out of a molehill I see.
Arthur
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 12:53 AM)
--------------------------------
Yes, there were many more than 5 floors on fire in each tower.
So its no surprise that given the many shafts that ran all the way to the ground floor coupled with the rapid rate of collapse, that the air, at times, as it got expelled would have been very hot, to capable of creating burns.
--------------------------
You are invoking the same mechanism designed to account for high-velocity jets below the collapse front to explain why people were burnt and blasted by hot air at street level.
The temperature of the pistoned hot air and flames erupting at street level was hot enough to incinerate skin, but it was not hot enough to cause pyroclastic flows of dust and smoke?
We have no idea what caused the jets below the collapse fronts.
I doubt it was caused in the manner you illustrated, but then who knows EXACTLY what was happening during that collapse? The fact is its FAR beyond our ability to analyse the chaotic nature of the multitude of tower components as they collapsed.
Which is why no one has done so.
My guess is it had to do with structural failures in the elevator system, but it could be no more than a dropping car. You are welcome to your own GUESS, but don't try to use your GUESS as EVIDENCE.
As to the FINAL second of the collapse, where the velocities were very high, then the expulsion rate would have been correspondingly very high, so that someone standing "downwind" from one of the many BURNING OBJECTS on the ground, (like the one you provided a picture of) could easily be BURNT by the flare up caused by this collapse generated wind. There are certainly other possibilities, since in that last second or so of the crush down portion of the collapse would be when the very hot/burning layers of the towers would reach the ground.
So while some small parts of the entire collapse could have had high temp elements associated with it, to catagoize the dust plume as a PYROCLASTIC flow, as has been REPEATEDLY done by the CT'er community is clearly FALSE.
Arthur
Yes, there were many more than 5 floors on fire in each tower.
So its no surprise that given the many shafts that ran all the way to the ground floor coupled with the rapid rate of collapse, that the air, at times, as it got expelled would have been very hot, to capable of creating burns.
--------------------------
You are invoking the same mechanism designed to account for high-velocity jets below the collapse front to explain why people were burnt and blasted by hot air at street level.
The temperature of the pistoned hot air and flames erupting at street level was hot enough to incinerate skin, but it was not hot enough to cause pyroclastic flows of dust and smoke?
We have no idea what caused the jets below the collapse fronts.
I doubt it was caused in the manner you illustrated, but then who knows EXACTLY what was happening during that collapse? The fact is its FAR beyond our ability to analyse the chaotic nature of the multitude of tower components as they collapsed.
Which is why no one has done so.
My guess is it had to do with structural failures in the elevator system, but it could be no more than a dropping car. You are welcome to your own GUESS, but don't try to use your GUESS as EVIDENCE.
As to the FINAL second of the collapse, where the velocities were very high, then the expulsion rate would have been correspondingly very high, so that someone standing "downwind" from one of the many BURNING OBJECTS on the ground, (like the one you provided a picture of) could easily be BURNT by the flare up caused by this collapse generated wind. There are certainly other possibilities, since in that last second or so of the crush down portion of the collapse would be when the very hot/burning layers of the towers would reach the ground.
So while some small parts of the entire collapse could have had high temp elements associated with it, to catagoize the dust plume as a PYROCLASTIC flow, as has been REPEATEDLY done by the CT'er community is clearly FALSE.
Arthur
wcelliott:
You recently posted:
"Incidentally, Al, I tutored twenty students in Physics in Engineering school, and 17 of them got "A's". The only one who flunked was named "Abdullah Azim". I had several Jewish students, too. I *never* had to explain anyting to them twice."
I don't think we need this kind of remark on a physics forum. Unless you can explain your point - which looks decidedly racist to me - I think you should withdraw it!
You recently posted:
"Incidentally, Al, I tutored twenty students in Physics in Engineering school, and 17 of them got "A's". The only one who flunked was named "Abdullah Azim". I had several Jewish students, too. I *never* had to explain anyting to them twice."
I don't think we need this kind of remark on a physics forum. Unless you can explain your point - which looks decidedly racist to me - I think you should withdraw it!
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 12:53 AM)
I find this claim surprising, given that the black box recorders were allegedly not found.
But since you are claiming that linear thermate cutters might survive collapse, it naturally follows that any linear thermate cutters ejected from the building as a consequence of the jetliner impact might also survive the fall.
I wouldn't think so, but there is a phenomena captured by the Naudet bros that requires some explaining.
Linear thermate cutters might work:
slow motion frames:
http://history-bytes.blogspot.com/2007/10/...-phenomena.html
============================
No, there would have been far more Linear Thermate cutters and they wouldn't have been riding on a ~ 500 mph jet and they wouldn't have spent over an hour on the fire floors.
So the POINT is, NO EVIDENCE of Linear Thermite cutters was found.
NONE
NADA
ZIP
ZILCH
ZERO
Which means any theory that requires Linear Thermate Cutters has to FIRST prove that they were NECESSARY for the towers to collapse.
As NIST, B&Z, B&V etc have shown, they were not.
Arthur
ps (and that picture HARDLY looks like a THERMITE ANYTHING, talk about DESPERATE )
But since you are claiming that linear thermate cutters might survive collapse, it naturally follows that any linear thermate cutters ejected from the building as a consequence of the jetliner impact might also survive the fall.
I wouldn't think so, but there is a phenomena captured by the Naudet bros that requires some explaining.
Linear thermate cutters might work:
slow motion frames:
http://history-bytes.blogspot.com/2007/10/...-phenomena.html
============================
No, there would have been far more Linear Thermate cutters and they wouldn't have been riding on a ~ 500 mph jet and they wouldn't have spent over an hour on the fire floors.
So the POINT is, NO EVIDENCE of Linear Thermite cutters was found.
NONE
NADA
ZIP
ZILCH
ZERO
Which means any theory that requires Linear Thermate Cutters has to FIRST prove that they were NECESSARY for the towers to collapse.
As NIST, B&Z, B&V etc have shown, they were not.
Arthur
ps (and that picture HARDLY looks like a THERMITE ANYTHING, talk about DESPERATE
)QUOTE (adoucette+Nov 18 2007, 02:52 PM)
No, there would have been far more Linear Thermate cutters and they wouldn't have been riding on a ~ 500 mph jet and they wouldn't have spent over an hour on the fire floors.
So the POINT is, NO EVIDENCE of Linear Thermite cutters was found.
NONE
NADA
ZIP
ZILCH
ZERO
Which means any theory that requires Linear Thermate Cutters has to FIRST prove that they were NECESSARY for the towers to collapse.
As NIST, B&Z, B&V etc have shown, they were not.
Arthur
ps (and that picture HARDLY looks like a THERMITE ANYTHING, talk about DESPERATE )
"I find this claim surprising, given that the black box recorders were allegedly not found." Al
Ah, but they were found.Black Box Cover-Up
"A 9-11 rescue worker recently came forward to say he was told by FBI agents to “keep my mouth shut” about one of the “black boxes” a fellow firefighter helped locate at ground zero, contradicting the official story that none of the flight and cockpit data recorders were ever recovered in the wreckage of the World Trade Center (WTC) towers.
Honorary firefighter Mike Bellone claims he was approached by unknown bureau agents a short time after he and his partner, Nicholas DeMasi, a retired New York firefighter, found three of the four “black boxes” among the WTC rubble before January 2002..."
The criminal demeanor of the Bush administration is amazing.
No evidence of Linear Termite cutters?
" ABC News reported that, "the temperature at the core of "the pile," is near 2000 degrees Fahrenheit, according to fire officials, who add that the fires are too deep for firefighters to get to."
Connect the dots, you are leading the jack *** parade Arthur.
So the POINT is, NO EVIDENCE of Linear Thermite cutters was found.
NONE
NADA
ZIP
ZILCH
ZERO
Which means any theory that requires Linear Thermate Cutters has to FIRST prove that they were NECESSARY for the towers to collapse.
As NIST, B&Z, B&V etc have shown, they were not.
Arthur
ps (and that picture HARDLY looks like a THERMITE ANYTHING, talk about DESPERATE
)"I find this claim surprising, given that the black box recorders were allegedly not found." Al
Ah, but they were found.Black Box Cover-Up
"A 9-11 rescue worker recently came forward to say he was told by FBI agents to “keep my mouth shut” about one of the “black boxes” a fellow firefighter helped locate at ground zero, contradicting the official story that none of the flight and cockpit data recorders were ever recovered in the wreckage of the World Trade Center (WTC) towers.
Honorary firefighter Mike Bellone claims he was approached by unknown bureau agents a short time after he and his partner, Nicholas DeMasi, a retired New York firefighter, found three of the four “black boxes” among the WTC rubble before January 2002..."
The criminal demeanor of the Bush administration is amazing.
No evidence of Linear Termite cutters?
" ABC News reported that, "the temperature at the core of "the pile," is near 2000 degrees Fahrenheit, according to fire officials, who add that the fires are too deep for firefighters to get to."
Connect the dots, you are leading the jack *** parade Arthur.
That's it?
That's your evidence that the black boxes were found and the finding was covered up?
You know the devil is in the details RIGHT?
They are covering it up but they are also RIDING AROUND GROUND ZERO, where HUNDREDS of workers and thousands of pictures are being taken with the THREE boxes plainly visible in the back of their ATV????
Next point.
Its HIGHLY unlikely that THREE black boxes would be found at the same time.
That would mean ones were found from BOTH PLANES, but they would have been in different areas of the pile and at significantly different depths.
But the real reason you can tell this is a HOAX?
While the "black boxes" are "reddish-orange boxes with two white stripes" when they go in the plane, they WOULDN'T appear that way AFTER the crash/fire/collapse.
Example, this is the "black box" from Egypt Air that hit the WATER (no hour long fire or collapse)
This is the "Black box" from 587, into NY, at a relatively slow speed followed by fire.
The, point is they don't come out of wrecks looking like they went in.
Arthur
That's your evidence that the black boxes were found and the finding was covered up?
You know the devil is in the details RIGHT?
QUOTE
“They confronted me and told me to not to say anything,” recalled Bellone, referring to one of three reddish-orange boxes with two white stripes he saw in the back of DeMasi’s ATV.
They are covering it up but they are also RIDING AROUND GROUND ZERO, where HUNDREDS of workers and thousands of pictures are being taken with the THREE boxes plainly visible in the back of their ATV????
Next point.
Its HIGHLY unlikely that THREE black boxes would be found at the same time.
That would mean ones were found from BOTH PLANES, but they would have been in different areas of the pile and at significantly different depths.
But the real reason you can tell this is a HOAX?
While the "black boxes" are "reddish-orange boxes with two white stripes" when they go in the plane, they WOULDN'T appear that way AFTER the crash/fire/collapse.
Example, this is the "black box" from Egypt Air that hit the WATER (no hour long fire or collapse)
This is the "Black box" from 587, into NY, at a relatively slow speed followed by fire.
The, point is they don't come out of wrecks looking like they went in.
Arthur
QUOTE (beijingyankee+Nov 18 2007, 03:23 PM)
"I find this claim surprising, given that the black box recorders were allegedly not found." Al
Ah, but they were found.Black Box Cover-Up
"A 9-11 rescue worker recently came forward to say he was told by FBI agents to “keep my mouth shut” about one of the “black boxes” a fellow firefighter helped locate at ground zero, contradicting the official story that none of the flight and cockpit data recorders were ever recovered in the wreckage of the World Trade Center (WTC) towers.
Honorary firefighter Mike Bellone claims he was approached by unknown bureau agents a short time after he and his partner, Nicholas DeMasi, a retired New York firefighter, found three of the four “black boxes” among the WTC rubble before January 2002..."
The criminal demeanor of the Bush administration is amazing.
No evidence of Linear Termite cutters?
" ABC News reported that, "the temperature at the core of "the pile," is near 2000 degrees Fahrenheit, according to fire officials, who add that the fires are too deep for firefighters to get to."
Connect the dots, you are leading the jack *** parade Arthur.
Thank you beijingyankee the photos you posted definitely disprove the thermite cutting claims, nice to see you can prove your dishonesty with actual evidence that you provided, do you actually know what the yellow light in one of the photos is?
If you had ever used a torch beijingyankee, you would know that is a torch cut and could distinguish the cut pattern for yourself.
The other photo is not of molten steel and does not in anyway surport you cause!
Ah, but they were found.Black Box Cover-Up
"A 9-11 rescue worker recently came forward to say he was told by FBI agents to “keep my mouth shut” about one of the “black boxes” a fellow firefighter helped locate at ground zero, contradicting the official story that none of the flight and cockpit data recorders were ever recovered in the wreckage of the World Trade Center (WTC) towers.
Honorary firefighter Mike Bellone claims he was approached by unknown bureau agents a short time after he and his partner, Nicholas DeMasi, a retired New York firefighter, found three of the four “black boxes” among the WTC rubble before January 2002..."
The criminal demeanor of the Bush administration is amazing.
No evidence of Linear Termite cutters?
" ABC News reported that, "the temperature at the core of "the pile," is near 2000 degrees Fahrenheit, according to fire officials, who add that the fires are too deep for firefighters to get to."
Connect the dots, you are leading the jack *** parade Arthur.
Thank you beijingyankee the photos you posted definitely disprove the thermite cutting claims, nice to see you can prove your dishonesty with actual evidence that you provided, do you actually know what the yellow light in one of the photos is?
If you had ever used a torch beijingyankee, you would know that is a torch cut and could distinguish the cut pattern for yourself.
The other photo is not of molten steel and does not in anyway surport you cause!
QUOTE (NEU-FONZE+Nov 18 2007, 02:51 PM)
wcelliott:
You recently posted:
"Incidentally, Al, I tutored twenty students in Physics in Engineering school, and 17 of them got "A's". The only one who flunked was named "Abdullah Azim". I had several Jewish students, too. I *never* had to explain anyting to them twice."
I don't think we need this kind of remark on a physics forum. Unless you can explain your point - which looks decidedly racist to me - I think you should withdraw it!
I have to Agree with you NEU the statements did sound quite racist, I was surprised by that!
I did not expect such comments here.
You recently posted:
"Incidentally, Al, I tutored twenty students in Physics in Engineering school, and 17 of them got "A's". The only one who flunked was named "Abdullah Azim". I had several Jewish students, too. I *never* had to explain anyting to them twice."
I don't think we need this kind of remark on a physics forum. Unless you can explain your point - which looks decidedly racist to me - I think you should withdraw it!
I have to Agree with you NEU the statements did sound quite racist, I was surprised by that!
I did not expect such comments here.
QUOTE
I think you should withdraw it!
You're entitled to your own opinion.
NeuF - Were you one of the people AlK's repeatedly called a liar?
Are you having any trouble understanding the 10-microsecond-detonation explanation?
Maybe next time AlK calls me a liar for knowing enough arithmetic to calculate (0.25feet/26,700 feet/second), you'll express your opinion on *his* comments. So far, I haven't heard you object to his calling me a liar.
You experts: Why do MIT say it was concrete in the core ?:
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
QUOTE (wcelliott+Nov 18 2007, 07:38 PM)
And BTW, you got the warnings for calling us liars, in two separate posts, which I reported. The moderators apparently agreed with me that your rhetoric was abusive and unwarranted.
I also reported one of his posts, but for a different reason - I strongly resent the repeated allegations of being involved in illegal activities (For the post in question shilling, and paedophilia).
Two warnings for two different complaints makes sense.
Al K.
If you want to know what you actually got warned for, click on the number (40%) beside the bars. It's all detailed there.
I notice you're ignoring the fact that I have stated, more then once, that the sonogram I posted was recorded at a distance of several kilometers, and was of the detonation of unexploded munitions.
Although I find it mildly amusing that now the conspiracy theorists are arguing amongst themselves.
I also reported one of his posts, but for a different reason - I strongly resent the repeated allegations of being involved in illegal activities (For the post in question shilling, and paedophilia).
Two warnings for two different complaints makes sense.
Al K.
If you want to know what you actually got warned for, click on the number (40%) beside the bars. It's all detailed there.
I notice you're ignoring the fact that I have stated, more then once, that the sonogram I posted was recorded at a distance of several kilometers, and was of the detonation of unexploded munitions.
Although I find it mildly amusing that now the conspiracy theorists are arguing amongst themselves.
For the record, one of my very closest friends is a Iranian-born muslim who now lives here in the LA area.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
QUOTE (Daru+Nov 18 2007, 09:58 AM)
You experts: Why do MIT say it was concrete in the core ?:
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
The cores were 27.1 m by 43.4 m.
There were 47 box columns, which transitioned into wide flange rolled steel members high in the towers.
Some of the floor beams in the core were wrapped in concrete. These did not support gravity loads, except of course of the core floor, but rather lateral loads.
I would suppose this report was written rather early on, when there was considerable confusion regarding the actual design and construction of the towers.
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
The cores were 27.1 m by 43.4 m.
There were 47 box columns, which transitioned into wide flange rolled steel members high in the towers.
Some of the floor beams in the core were wrapped in concrete. These did not support gravity loads, except of course of the core floor, but rather lateral loads.
I would suppose this report was written rather early on, when there was considerable confusion regarding the actual design and construction of the towers.
QUOTE (Daru+Nov 18 2007, 04:58 PM)
You experts: Why do MIT say it was concrete in the core ?:
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
Do you know what infill panels are?
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
Do you know what infill panels are?
QUOTE (wcelliott+Nov 18 2007, 05:42 PM)
For the record, one of my very closest friends is a Iranian-born muslim who now lives here in the LA area.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
In your post the implication seems to be that the Jewish students were smarter, than the person with the Arab name, that I think was accidental on your part, but you should consider your words more carefully.
Semites yes but with key cultural, genetic, and ethnic differences.
It does not look well for the other members of this board for such remarks to be posted without a clarification on your part as to what you intended to say.
I think that NEU and I were only trying to bring that to your attention.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
In your post the implication seems to be that the Jewish students were smarter, than the person with the Arab name, that I think was accidental on your part, but you should consider your words more carefully.
Semites yes but with key cultural, genetic, and ethnic differences.
It does not look well for the other members of this board for such remarks to be posted without a clarification on your part as to what you intended to say.
I think that NEU and I were only trying to bring that to your attention.
QUOTE (Al Khwarizmi - step-by-step+Nov 18 2007, 06:42 AM)
metamars
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
I wonder if Professor Jones could get this level of positive publicity for an unpublished paper?
The peer review process can take a long time, with many revisions. I am more interested in the content of the paper than funkiness surrounding it's release. So, while the BBC got things wrong (I suspect deliberately so), at the end of the day, from a technical viewpoint, it doesn't matter. From a propaganda viewpoint, of course, that is another matter.
(BTW, a friend of mine with an amazing memory told me that BBC carried reports of explosions on 9/11, but stopped any mention of same by the following day).
It's a little unfair to Seffen to blame him for BBC's mistake. I don't blame him for answering every email put to him on the subject, though a brief statement explaining what happened would have been nice.
The peer review process is not all it's cooked up to be. I recently finished reading "Not Even Wrong" by Peter Woit. Read about the Bogdanov (?) affair, wherein not 1, not 2, but 3 peer reviewed physics journals got punked printing nonsense, each version of which was very close to each other. Reading this book will also illumine as to why, at least in the field of theoretical physics, there are very few physicists in the US (Europe can be freer) who are willing to rock the boat. Only 1 out of 8 freshly minted particle physics Ph.D.'s will get a tenured position, that likely won't occur until age 60 or so, and rocking the boat - by, e.g., trying to work on something radically different than the "failed idea" that string theory represents - will likely mean your chances of tenure drop to zero.
I don't think academic engineering is so bad, but I could be completely wrong about this. And that would be because string theorists don't need experimental apparati, while academic engineers are much more likely (I think) to test their theories, themselves. Hence, there are more financial levers that can be applied to them. (Note that in the case of string theorists, they don't, as a rule, make any predictions at all!)
Also, somewhat relevant, the question of how serious investigation into 911 can be suppressed by media is addressed by journalist Dave Lindorff at
http://arc.republicbroadcasting.org/Barret...1707_180000.MP3
http://arc.republicbroadcasting.org/Barret...1707_190000.MP3
Finally, if I understood Professor Jones' presentation in Connecticut correctly, his technical papers on the microspheres have been submitted to a journal, implying (to me) that the peer review process is still going on. Apparently, neither Seffen nor Jones wish to share the blow-by-blow details of this process (perhaps because the referees would hold this against them???). I asked about the status of this research in the stj911 forum a few weeks ago, and didn't get an answer.
--------------------
K.A. Seffen's (apparently a structural engineer) paper entitled "Progressive Collapse of the World Trade Centre: a Simple Analysis" is available at http://winterpatriot.pbwiki.com/f/seffen_simple_analysis.pdf
-------------------
The most impressive aspect of this paper was the fact that the BBC and this website both claimed that the paper was published when it wasn't. The BBC discretly corrected their report after the winterpatriot blog started making waves about that fact.
Meanwhile, Dr Seffen and the Journal of Engineering refused to answer emails requesting clarification of the publishing date.
And now the paper is available --- but not from the Journal of Engineering.
The paper, instead, can be found at winterpatriots' blog.
A BLOG!
http://winterpatriot.blogspot.com/search/l.../Keith%20Seffen
I am surprised that you don't consider this process to be unusual, metamars.
I wonder if Professor Jones could get this level of positive publicity for an unpublished paper?
The peer review process can take a long time, with many revisions. I am more interested in the content of the paper than funkiness surrounding it's release. So, while the BBC got things wrong (I suspect deliberately so), at the end of the day, from a technical viewpoint, it doesn't matter. From a propaganda viewpoint, of course, that is another matter.
(BTW, a friend of mine with an amazing memory told me that BBC carried reports of explosions on 9/11, but stopped any mention of same by the following day).
It's a little unfair to Seffen to blame him for BBC's mistake. I don't blame him for answering every email put to him on the subject, though a brief statement explaining what happened would have been nice.
The peer review process is not all it's cooked up to be. I recently finished reading "Not Even Wrong" by Peter Woit. Read about the Bogdanov (?) affair, wherein not 1, not 2, but 3 peer reviewed physics journals got punked printing nonsense, each version of which was very close to each other. Reading this book will also illumine as to why, at least in the field of theoretical physics, there are very few physicists in the US (Europe can be freer) who are willing to rock the boat. Only 1 out of 8 freshly minted particle physics Ph.D.'s will get a tenured position, that likely won't occur until age 60 or so, and rocking the boat - by, e.g., trying to work on something radically different than the "failed idea" that string theory represents - will likely mean your chances of tenure drop to zero.
I don't think academic engineering is so bad, but I could be completely wrong about this. And that would be because string theorists don't need experimental apparati, while academic engineers are much more likely (I think) to test their theories, themselves. Hence, there are more financial levers that can be applied to them. (Note that in the case of string theorists, they don't, as a rule, make any predictions at all!)
Also, somewhat relevant, the question of how serious investigation into 911 can be suppressed by media is addressed by journalist Dave Lindorff at
http://arc.republicbroadcasting.org/Barret...1707_180000.MP3
http://arc.republicbroadcasting.org/Barret...1707_190000.MP3
Finally, if I understood Professor Jones' presentation in Connecticut correctly, his technical papers on the microspheres have been submitted to a journal, implying (to me) that the peer review process is still going on. Apparently, neither Seffen nor Jones wish to share the blow-by-blow details of this process (perhaps because the referees would hold this against them???). I asked about the status of this research in the stj911 forum a few weeks ago, and didn't get an answer.
QUOTE (David B. Benson+Nov 18 2007, 05:42 PM)
The cores were 27.1 m by 43.4 m.
There were 47 box columns, which transitioned into wide flange rolled steel members high in the towers.
Some of the floor beams in the core were wrapped in concrete. These did not support gravity loads, except of course of the core floor, but rather lateral loads.
I would suppose this report was written rather early on, when there was considerable confusion regarding the actual design and construction of the towers.
DBB, Infill panels can be vertical, or horizontal they are simply infilled with concrete, so they were steel columns with concrete flooring where appropriate.
Does anyone see any inconsistency in that bath rooms and elevators were in the core, and that floors are necessary even in bath rooms?
PS. floors are part of the gravity load support system of all buildings they transfer gravity loads to columns!
There were 47 box columns, which transitioned into wide flange rolled steel members high in the towers.
Some of the floor beams in the core were wrapped in concrete. These did not support gravity loads, except of course of the core floor, but rather lateral loads.
I would suppose this report was written rather early on, when there was considerable confusion regarding the actual design and construction of the towers.
DBB, Infill panels can be vertical, or horizontal they are simply infilled with concrete, so they were steel columns with concrete flooring where appropriate.
Does anyone see any inconsistency in that bath rooms and elevators were in the core, and that floors are necessary even in bath rooms?
PS. floors are part of the gravity load support system of all buildings they transfer gravity loads to columns!
QUOTE (Chainsaw+,Nov 18 2007, 05:43 PM)
Do you know what infill panels are?
Yes. I also know what reinforced concrete means
Yes. I also know what reinforced concrete means
QUOTE (metamars+Nov 18 2007, 10:57 AM)
I don't think academic engineering is so bad, but I could be completely wrong about this.
In the United States at least, academic engineering is limited, if that is the right word, by the fact that the PhD engineers can always choose to find positions in government (DoE labs, for example) or industry.
From the acknowledgment at the end of Seffen's paper, it is clear that it has been accepted (presumably by ASCE J. Engg. Mechanics) and so will appear in print in about 10 months.
In the United States at least, academic engineering is limited, if that is the right word, by the fact that the PhD engineers can always choose to find positions in government (DoE labs, for example) or industry.
From the acknowledgment at the end of Seffen's paper, it is clear that it has been accepted (presumably by ASCE J. Engg. Mechanics) and so will appear in print in about 10 months.
QUOTE (Daru+Nov 18 2007, 11:58 AM)
You experts: Why do MIT say it was concrete in the core ?:
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
Because the research was done by two grad students who obviously MADE ERRORS.
Note they ALSO said this:
Fire resistance of the perimeter columns was provided by a layer of sprayed concrete around the three sides of each column. The concrete layer had a thickness of about 5cm and included ceramic fibers in the mix. The interior face of each column was fire protected with approximately 5cm thick layer of vermiculate plaster (Figure 16). The exterior sides of each perimeter column were covered by aluminum to which the window frames were fixed. It has been reported that passive fire protection was provided to the underside of the floor systems by a fire rated suspended ceiling. Specifics of fireproofing implemented on these buildings including which structural members were treated and to what level of fire resistance are still being investigated.
Obviously, the paper was prepared before the investigation into the structrual components was completed and obviously, they used the term CONCRETE loosely.
Arthur
"The 24mX42m core was composed
of 44 box columns. The core comprises steel beams and columns with reinforced concrete
infill panels designed to share part of the gravity loads..." (page 90)
web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf
Because the research was done by two grad students who obviously MADE ERRORS.
QUOTE
The authors extend their sincere thanks to Erdem Karaca and Au Ching, graduate students in the Department of Civil and Environmental Engineering of MIT, for their help in collecting and preparing information as a basis for the initial draft of this chapter.
Note they ALSO said this:
Fire resistance of the perimeter columns was provided by a layer of sprayed concrete around the three sides of each column. The concrete layer had a thickness of about 5cm and included ceramic fibers in the mix. The interior face of each column was fire protected with approximately 5cm thick layer of vermiculate plaster (Figure 16). The exterior sides of each perimeter column were covered by aluminum to which the window frames were fixed. It has been reported that passive fire protection was provided to the underside of the floor systems by a fire rated suspended ceiling. Specifics of fireproofing implemented on these buildings including which structural members were treated and to what level of fire resistance are still being investigated.
Obviously, the paper was prepared before the investigation into the structrual components was completed and obviously, they used the term CONCRETE loosely.
Arthur
QUOTE (Chainsaw,+Nov 18 2007, 10:58 AM)
Infill panels can be vertical, or horizontal they are simply infilled with concrete, so they were steel columns with concrete flooring where appropriate.
Yes, but AFAIK, none of the floor beams were infilled box beams. And it simply is the case that none of the box columns were filled with concrete.
Yes, but AFAIK, none of the floor beams were infilled box beams. And it simply is the case that none of the box columns were filled with concrete.
QUOTE (David B. Benson+Nov 18 2007, 06:53 PM)
Yes, but AFAIK, none of the floor beams were infilled box beams. And it simply is the case that none of the box columns were filled with concrete.
I know, just pointing out that reinforced concrete panels were the norm for the floors in the world trade center.
The reinforcement was a simple wire mess laid into the 4 inch slab as it was poured, My houses concrete slabs uses the same type of reinforcement.
It is common, I do not have any Idea why some one would conjecture that the cores were anything other than box columns with floor slabs from reading that paper it seems obvious to anyone educated in engineering or construction.
I know, just pointing out that reinforced concrete panels were the norm for the floors in the world trade center.
The reinforcement was a simple wire mess laid into the 4 inch slab as it was poured, My houses concrete slabs uses the same type of reinforcement.
It is common, I do not have any Idea why some one would conjecture that the cores were anything other than box columns with floor slabs from reading that paper it seems obvious to anyone educated in engineering or construction.
QUOTE (wcelliott+Nov 18 2007, 10:42 AM)
For the record, one of my very closest friends is a Iranian-born muslim who now lives here in the LA area.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
Nevertheless, your comment was awful (not only illogical, but wrong), and yet you try to wiggle away from it.
A simple retraction, which was called for, would have sufficed.
I've had/still have close friends with people from all parts of the world.
I don't hate people from other cultures, but I don't believe that every tradition of every culture is automatically worthy of respect. There cultures where women are raped as a "normal" part of courtship, there are cultures where pedophilia is considered "normal", there are cultures where a husband is *expected* to beat his wife if she voices a different opinion from her husband's, and there are cultures that sell their daughters into sexual slavery, simply because the parents had preferred a son but had a daughter instead.
I don't know what "race" AlK is (anybody see "Borat"?), and my comments weren't aimed at his "race". In point of fact, both Arabs and Jews come from the same "Semitic" race.
Nevertheless, your comment was awful (not only illogical, but wrong), and yet you try to wiggle away from it.
A simple retraction, which was called for, would have sufficed.
For those who have time, mood and energy to do some hard work
Charles Beck has recently posted a new version of the manuscript on-line, www.arxiv.org, physics-0609105,
I think it is this one
http://aps.arxiv.org/PS_cache/physics/pdf/0609/0609105v7.pdf
FYI, he likes responses
Charles Beck has recently posted a new version of the manuscript on-line, www.arxiv.org, physics-0609105,
I think it is this one
http://aps.arxiv.org/PS_cache/physics/pdf/0609/0609105v7.pdf
FYI, he likes responses
QUOTE
(not only illogical, but wrong
Actually, however "awful" the comments were, both statements were absolutely correct. Abdullah Azim was the only physics student I had that flunked, and he flunked each quiz more than once (in Keller-Plan Physics, you're required to keep taking quizes on each chapter until you pass one), and for many of the chapters, he took every quiz available (usually about eight, two questions each) and in a couple instances, failed the same quiz twice, after having taken all the quizes, retaking one he'd already taken, had the questions and answers explained to him, and failing it a second time.
And I don't think my comment about how quickly my other students grasped new concepts was either offensive or racist. But I can certainly see how someone who hates Jews could be offended by my statement. Still, I don't see that as being a valid reason to retract the statement.
And AlK didn't retract his insult, calling me (and others) a "liar" when there's clearly no evidence supporting his original insult, he reasserted it, claiming among other things that I never provided support for my "10 microsecond C-4 blast duration", which I think I've explained to-death here.
So how about someone asking AlK to retract his baseless accusations?
QUOTE (einsteen+Nov 18 2007, 02:14 PM)
http://aps.arxiv.org/PS_cache/physics/pdf/0609/0609105v7.pdf
Still has the same date. Are you sure it is a newer version?
Still has the same date. Are you sure it is a newer version?
QUOTE (Beck+)
The assumption of all 51 columns being the same appears to be corroborated by the floor plans:2 all CCs appear to have the same footprint.
Is he serious?
Arthur
Is he serious?
Arthur
QUOTE (adoucette+Nov 18 2007, 03:44 PM)
Is he serious?
Who he?
If Beck, his paper, in the version I read, contained many errors.
Who he?
If Beck, his paper, in the version I read, contained many errors.
QUOTE (wcelliott+Nov 18 2007, 04:50 PM)
Actually, however "awful" the comments were, both statements were absolutely correct. Abdullah Azim was the only physics student I had that flunked, and he flunked each quiz more than once (in Keller-Plan Physics, you're required to keep taking quizes on each chapter until you pass one), and for many of the chapters, he took every quiz available (usually about eight, two questions each) and in a couple instances, failed the same quiz twice, after having taken all the quizes, retaking one he'd already taken, had the questions and answers explained to him, and failing it a second time.
It may be true, but its not relevant to the discussion, and in its generalization it does appear racist.
Remember, Al's namesake is the source of the word Algebra.
http://www-groups.dcs.st-and.ac.uk/~histor...-Khwarizmi.html
Arthur .
QUOTE
Remember, Al's namesake is the source of the word Algebra.
Reminding me of the fact that "newton" took the name of one of the greatest physicists of all time, and yet...
I'm not saying that Arabs aren't intelligent, I'm saying that AlK reminds me of the stupidest physics student I ever had.
I'm aware that we owe much of the foundation of "western science" to the discoveries of the Arabs.
Ironically, we owe the concept of "zero" to the Arab mathematicians, and yet AlK seems to be having problems understanding what that zeroth-term in a spectrum refers to.
Even after I'd explained it more than once.
QUOTE (wcelliott+Nov 18 2007, 10:56 PM)
Reminding me of the fact that "newton" took the name of one of the greatest physicists of all time, and yet...
I'm not saying that Arabs aren't intelligent, I'm saying that AlK reminds me of the stupidest physics student I ever had.
I'm aware that we owe much of the foundation of "western science" to the discoveries of the Arabs.
Ironically, we owe the concept of "zero" to the Arab mathematicians, and yet AlK seems to be having problems understanding what that zeroth-term in a spectrum refers to.
Even after I'd explained it more than once.
Hi wcelliot!
I think it's a question of what could be misconstrued from one's comments, mate.
It 'came across' as racist even though it may not have been intended in that 'generalised' light. I too read it as 'racistsounding.
Whether AlK will or will not apologise for any unfounded insult to YOU is NOT a reason or justification for you not being the better man; by UNILATERALLY retracting without any demand fo quid pro quo from AlK.
THAT will put the blowtorch on AlK's own integrity even hotter. No? hehehe.
Cheers and play nice guys!
RC.
.
A preliminary test of resistive force functions, slowing down the collapse of WTC 1, shows that the is essentially no constant term, no term depending upon speed, S, alone, essentially no contribution from the term involving S*S, a small contribution for a term in Z, the location of the crushing front, and mostly a term involving Z*S.
Using just that term, consider a force action distance of S*dt for some small increment of time dt. Then the energy expended during that interval is
F(Z,S) = k*Z*S*S*dt
which is recognizable as proportional to the kinetic energy of the top block plus crushed mass. From BLGB we see that air movement and concrete comminution are proportional to S*S, so there is little of either over the period of measured drop.
However, a better testing method needs to be devised as the current one easily falls into various local minima. So this is only preliminary (and I would expect a somewhat larger contribution proportional to S*S).
Using just that term, consider a force action distance of S*dt for some small increment of time dt. Then the energy expended during that interval is
F(Z,S) = k*Z*S*S*dt
which is recognizable as proportional to the kinetic energy of the top block plus crushed mass. From BLGB we see that air movement and concrete comminution are proportional to S*S, so there is little of either over the period of measured drop.
However, a better testing method needs to be devised as the current one easily falls into various local minima. So this is only preliminary (and I would expect a somewhat larger contribution proportional to S*S).
QUOTE (David B. Benson+Nov 18 2007, 10:16 PM)
Still has the same date. Are you sure it is a newer version?
no idea, the date stamp is oct 2nd, 2007
no idea, the date stamp is oct 2nd, 2007
We discussed some of the issues when the first Beck paper came out. One of the main problems was the use of a static load safety factor to model the resistive force during a dynamic situation like a collapse. That leads to a fictitious inflated value of E1 which then requires fictitious 'additional sources of damage' to account for the observed collapse rate.
I never went through that but I remember that in that first post he mentioned a collapse time and Neu-Fonze said that since the collapse time was much higher nothing was violated or something like that. But if I look quickly at the current one it looks like something completely different, wtc7 and wtc2 are mentioned.
What I personally still don't understand is the crush-up and crush-down model at all. If that can be explained there is even no reason to read all those papers. In a thought experiment if you lift the world trade center about 10 meters (9 something feet) and drop it then I wouldn't expect a real crush-up, I would not expect that the story at the bottom (which is the strongest one) fails first and then the next one and so on. Instead I would expect that a whole shockwave goes through the building and that it breaks simultaneously at a couple of levels. The individual parts then will fall and recursively the same will be repeated. If you look at wtc7 that failed somewhere at the bottom we also see that it is not really a crush-up and if you look at CDs in slow motion it is also not really a crush-up.
What I personally still don't understand is the crush-up and crush-down model at all. If that can be explained there is even no reason to read all those papers. In a thought experiment if you lift the world trade center about 10 meters (9 something feet) and drop it then I wouldn't expect a real crush-up, I would not expect that the story at the bottom (which is the strongest one) fails first and then the next one and so on. Instead I would expect that a whole shockwave goes through the building and that it breaks simultaneously at a couple of levels. The individual parts then will fall and recursively the same will be repeated. If you look at wtc7 that failed somewhere at the bottom we also see that it is not really a crush-up and if you look at CDs in slow motion it is also not really a crush-up.
This is a good example of what I mean
http://www.youtube.com/watch?v=NqwP7HcI7GQ
This is initiated at the bottom. The front part at the left gives resistance and
you see the building break somewhere in the middle. It's the same effect as the plane
crashing on the wall, once a fuselage is broken it will no longer provide its maximal force.
A strict crush-up model for constant mass is in fact the crush-up equation X''(t)=1/x(t)
and stepwise it can be done using
v_next=sqrt(v_before^2+2[gh-E1/mass_before]) and so on,
where momentum transfer between floors is of course not needed.
http://www.youtube.com/watch?v=NqwP7HcI7GQ
This is initiated at the bottom. The front part at the left gives resistance and
you see the building break somewhere in the middle. It's the same effect as the plane
crashing on the wall, once a fuselage is broken it will no longer provide its maximal force.
A strict crush-up model for constant mass is in fact the crush-up equation X''(t)=1/x(t)
and stepwise it can be done using
v_next=sqrt(v_before^2+2[gh-E1/mass_before]) and so on,
where momentum transfer between floors is of course not needed.
Well Beck's paper is a real "slog" to read!
But after a quick skim I see one error at least:
On page 6 the observed collapse times are given as 13 sec for WTC 1 and 11 sec for WTC 2. (Which is ok). However, on page 8, the calculated times are given as 11 sec for WTC 1 and 13 sec for WTC 2 !!!! Probably a typo........
But after a quick skim I see one error at least:
On page 6 the observed collapse times are given as 13 sec for WTC 1 and 11 sec for WTC 2. (Which is ok). However, on page 8, the calculated times are given as 11 sec for WTC 1 and 13 sec for WTC 2 !!!! Probably a typo........
beijingyank
Weren't you banned for your abusive posts???
No, it was not. In fact no previously molten steel was found anywhere in the WTC complex. That is simply a lie spread by know nothing troothers.
No, it was not. In fact no previously molten steel was found anywhere in the WTC complex. That is simply a lie spread by know nothing troothers.
collapse times close to free fall
Another troother lie.
Squibs are another lie the troothers tell, no evidence of any kind supports any kind of explosives.
Squibs are another lie the troothers tell, no evidence of any kind supports any kind of explosives.
controlled demolition
Only if you know nothing about the evidence.
Again, that old troother lie, no steel was melted.
Again, that old troother lie, no steel was melted.
Calculations on the Possible Use of Thermite to Melt Sections of the WTC Core Columns
A whole lot of troother lies in a single paper.
You're really not doing any better this time, yank. Maybe you ought to find somewhere else, they might believe these lies, we don't.
Grumpy
AlK - And you don't get how sine waves might add differently from reflections of always-positive pressure waves from an explosion?
Here's one hint: A reflected sine wave has peaks AND TROUGHS.
Here's another hint: A reflected BLAST is ALWAYS POSITIVE.
DA.
You're in WAY OVER YOUR HEAD when you argue acoustics with me.
Piezoelectrics are better at detecting high-frequency components of sound than other microphones, and they actually have DC-RESPONSE!!!. Meaning that they can detect/measure the ABSOLUTE PRESSURE as well as detect sounds.
Maybe you should re-read the quotes you provided. They're all true. What were YOU doing in 1984? I was working as a Senior Staff Scientist for SAIC. Were you even out of diapers back then?
Weren't you banned for your abusive posts???
QUOTE
Evidence of molten steel was found at the very base of the WTC towers, and is a matter of public record.
No, it was not. In fact no previously molten steel was found anywhere in the WTC complex. That is simply a lie spread by know nothing troothers.
QUOTE (->
| QUOTE |
| Evidence of molten steel was found at the very base of the WTC towers, and is a matter of public record. |
No, it was not. In fact no previously molten steel was found anywhere in the WTC complex. That is simply a lie spread by know nothing troothers.
collapse times close to free fall
Another troother lie.
QUOTE
no real record of a massive explosion (although numerous claims of sounds of smaller explosions and observations of demolition squibs)
Squibs are another lie the troothers tell, no evidence of any kind supports any kind of explosives.
QUOTE (->
| QUOTE |
| no real record of a massive explosion (although numerous claims of sounds of smaller explosions and observations of demolition squibs) |
Squibs are another lie the troothers tell, no evidence of any kind supports any kind of explosives.
controlled demolition
Only if you know nothing about the evidence.
QUOTE
characterized by a (relatively) non-explosive, huge energy release necessary to melt (some) steel
Again, that old troother lie, no steel was melted.
QUOTE (->
| QUOTE |
| characterized by a (relatively) non-explosive, huge energy release necessary to melt (some) steel |
Again, that old troother lie, no steel was melted.
Calculations on the Possible Use of Thermite to Melt Sections of the WTC Core Columns
A whole lot of troother lies in a single paper.
You're really not doing any better this time, yank. Maybe you ought to find somewhere else, they might believe these lies, we don't.
Grumpy
QUOTE (beijingyankee+Nov 19 2007, 01:44 PM)
"The free-fall times and pools of molten steel are entirely different matters. They are a matter of public record, observed by many individuals. So we have evidence of molten steel in the basement; the FEMA report saying molten steel was not to blame, just weakened floor joist bolts; collapse times close to free fall; no real record of a massive explosion (although numerous claims of sounds of smaller explosions and observations of demolition squibs). The immediate conjecture supported by direct observation is the following: controlled demolition, characterized by a (relatively) non-explosive, huge energy release necessary to melt (some) steel...Evidence of molten steel was found at the very base of the WTC towers, and is a matter of public record. Calculations on the Possible Use of Thermite to Melt Sections of the WTC Core Columns
Irrelevant the photos in question did not show molten steel or molten metals of any kind!
Ha Collapsing building should compress air that can lead to explosion, also the sound of explosions is just the blast Shock wave breaking the sound barrier any thing that breaks the sound barrier will create an explosive like boom including breaking steel columns especially if they are Square hollows steel the perfect resonance tubes DA.
Can you please give me and example of an UN natural effect that could lead to some event that might in any way be suspicious without going to Quote Cherry picking and with data to back it up please?
Your case is just unwarranted speculation without actual factual evidence to back it up so far all I have seen is dishonesty, and deceit.
Do you actually have a case at all for what you believe?
Irrelevant the photos in question did not show molten steel or molten metals of any kind!
Ha Collapsing building should compress air that can lead to explosion, also the sound of explosions is just the blast Shock wave breaking the sound barrier any thing that breaks the sound barrier will create an explosive like boom including breaking steel columns especially if they are Square hollows steel the perfect resonance tubes DA.
Can you please give me and example of an UN natural effect that could lead to some event that might in any way be suspicious without going to Quote Cherry picking and with data to back it up please?
Your case is just unwarranted speculation without actual factual evidence to back it up so far all I have seen is dishonesty, and deceit.
Do you actually have a case at all for what you believe?
QUOTE (Chainsaw,+Nov 19 2007, 08:03 AM)
Do you actually have a case at all for what you believe?
No.
No.
QUOTE (David B. Benson+Nov 19 2007, 05:16 PM)
No.
Then I would suggest he take his metaphysical, Pseudo Science comments to one of the good forums that deals in religion not a physics forum that deals in empirical data and actual science.
Some here are actually investigating the truth in the data and evidence of 9/11/2001, it does no good to make comments that you know can not be proved and are strictly emotional appeals.
Then I would suggest he take his metaphysical, Pseudo Science comments to one of the good forums that deals in religion not a physics forum that deals in empirical data and actual science.
Some here are actually investigating the truth in the data and evidence of 9/11/2001, it does no good to make comments that you know can not be proved and are strictly emotional appeals.
Resistive force approximations for WTC 1 data:
constant term: non-zero but very small.
Z term: small. Recall that assuming no acceleration or speed, the crush-down equation states that F(Z) = Z for stability. Since the constant is on the order of 0.0001 we see that little contribution is obtained from the design of the tower.
S term: zero.
Z*S term: large. (1.26) Most of the resistance is obtained by consuming some of the kinetic energy.
S*S term: 0.00005. Not much due to moving air or comminuting concrete during the interval of observation.
Crush-down began within 3 milliseconds of the time poster NEU-FONZE selected, frame 917 or 918. Impressive.
I doubt I can say more than these tentative remarks from this data. I am ready to use the full frame by frame data when poster OneWhiteEye is ready...
constant term: non-zero but very small.
Z term: small. Recall that assuming no acceleration or speed, the crush-down equation states that F(Z) = Z for stability. Since the constant is on the order of 0.0001 we see that little contribution is obtained from the design of the tower.
S term: zero.
Z*S term: large. (1.26) Most of the resistance is obtained by consuming some of the kinetic energy.
S*S term: 0.00005. Not much due to moving air or comminuting concrete during the interval of observation.
Crush-down began within 3 milliseconds of the time poster NEU-FONZE selected, frame 917 or 918. Impressive.
I doubt I can say more than these tentative remarks from this data. I am ready to use the full frame by frame data when poster OneWhiteEye is ready...
Something occurred to me, I don't know if it's been discussed before, but regarding the source of those "microspheres", the WTC basement was devastated in the previous terrorist attack (the truck bomb), and clean-up and repair of that damage must've included a lot of cutting torches and welding operations.
How do we know that the "microspheres" weren't just left over from that attack and restoration effort?
How do we know that the "microspheres" weren't just left over from that attack and restoration effort?
QUOTE (einsteen+Nov 19 2007, 06:10 AM)
A strict crush-up model for constant mass is in fact the crush-up equation X''(t)=1/x(t)
No.
(1-s)YY" + Y = F(Y)
No.
(1-s)YY" + Y = F(Y)
Yes and No
No because I forgot g, Yes because the force is assumed constant
I had to write x''=-1+1/x(t), which is in fact F=constant->1 and s=0
What I'm wondering a little bit, you are trying to fit the measured curves into the model and as far as I can see that leads to a certain function of the force. Are there already things that can be concluded from the work ?
No because I forgot g, Yes because the force is assumed constant
I had to write x''=-1+1/x(t), which is in fact F=constant->1 and s=0
What I'm wondering a little bit, you are trying to fit the measured curves into the model and as far as I can see that leads to a certain function of the force. Are there already things that can be concluded from the work ?
QUOTE (einsteen+Nov 19 2007, 03:06 PM)
Yes and No
No because I forgot g, Yes because the force is assumed constant
I had to write x''=-1+1/x(t), which is in fact F=constant->1 and s=0
What I'm wondering a little bit, you are trying to fit the measured curves into the model and as far as I can see that leads to a certain function of the force. Are there already things that can be concluded from the work ?
No.
s= 0, g normalized to 1, constant force F:
YY" + Y = F
or
Y" = F/Y - 1.
==========
Yes, I can conclude that for crush-down, the assumption of a constant resistive force and a constant stretch (squash) is strongly poorer at explaining the data that assuming the resistive force varies with Z or Z, or that the stretch varies with Z or S. (The or is inclusive, of course). Further, the assumption that the resistive force is proportional to Z is substantially poorer at explaining the data than a resistive force of
F(Z,S) = a*Z + b*Z*S
or other, more complex equations which incorporate the above two terms.
With more data it may be possible to reach a stronger conclusion.
No because I forgot g, Yes because the force is assumed constant
I had to write x''=-1+1/x(t), which is in fact F=constant->1 and s=0
What I'm wondering a little bit, you are trying to fit the measured curves into the model and as far as I can see that leads to a certain function of the force. Are there already things that can be concluded from the work ?
No.
s= 0, g normalized to 1, constant force F:
YY" + Y = F
or
Y" = F/Y - 1.
==========
Yes, I can conclude that for crush-down, the assumption of a constant resistive force and a constant stretch (squash) is strongly poorer at explaining the data that assuming the resistive force varies with Z or Z, or that the stretch varies with Z or S. (The or is inclusive, of course). Further, the assumption that the resistive force is proportional to Z is substantially poorer at explaining the data than a resistive force of
F(Z,S) = a*Z + b*Z*S
or other, more complex equations which incorporate the above two terms.
With more data it may be possible to reach a stronger conclusion.
QUOTE (wcelliott+Nov 19 2007, 09:34 PM)
Something occurred to me, I don't know if it's been discussed before, but regarding the source of those "microspheres", the WTC basement was devastated in the previous terrorist attack (the truck bomb), and clean-up and repair of that damage must've included a lot of cutting torches and welding operations.
How do we know that the "microspheres" weren't just left over from that attack and restoration effort?
The chemistry mostly some would have been formed in the clean up of that some could have actually come from burned paint.
http://www.edisoncoatings.com/html/Potassi...asonry_pai.html
Iron oxide and Aluminum oxide are also used in paint.
It is not a problem we can not find sources of micro-spheres the problem is to many sources to track down the source without further data on the micro spheres themselves.
It is like trying to find a needle in a stack of needles, unless we can find distinguishing marks we do not know which needle is the needle were looking for!
How do we know that the "microspheres" weren't just left over from that attack and restoration effort?
The chemistry mostly some would have been formed in the clean up of that some could have actually come from burned paint.
http://www.edisoncoatings.com/html/Potassi...asonry_pai.html
Iron oxide and Aluminum oxide are also used in paint.
It is not a problem we can not find sources of micro-spheres the problem is to many sources to track down the source without further data on the micro spheres themselves.
It is like trying to find a needle in a stack of needles, unless we can find distinguishing marks we do not know which needle is the needle were looking for!
Collapse initiation:
When columns are overloaded, they first shorten axially (elastic) and then begin to bow (inelastic). In the elastic phase the resisting force can be taken as nearly constant. But when bowing, I suspect that the resisting force declines somewhat. In continuum mechanics, everything is (approximately) linear at a small enough scale. So this might help explain why a linearly declining force appears to be the best approximation.
Then, of course, with continued overloading, the columns kink bend. At this point the 'broomstick' model applies, but by then crush-down has begun.
[This comes from reading Seffen's paper, which is most clearly written.]
When columns are overloaded, they first shorten axially (elastic) and then begin to bow (inelastic). In the elastic phase the resisting force can be taken as nearly constant. But when bowing, I suspect that the resisting force declines somewhat. In continuum mechanics, everything is (approximately) linear at a small enough scale. So this might help explain why a linearly declining force appears to be the best approximation.
Then, of course, with continued overloading, the columns kink bend. At this point the 'broomstick' model applies, but by then crush-down has begun.
[This comes from reading Seffen's paper, which is most clearly written.]
thanks for the article on the blackboxes, beijingyankee. I did say "allegedly" not found!
wcelliot
= = = = = = = = = =
All those echoes smear-out the 10 microsecond impulse into something that's low-enough frequency
for your ears to hear.
= = = = = = = = = =
FALSE:
http://www.myfilestash.com/userfiles/alrea...rb_spectral.gif
--- 88kHz sampling rate
--- 0.01 second burst of 30kHz sine wave with reverberation in a simulated church.
--- spectral distribution (Blackman-Harris, 4096 bands).
= = = = = = = = = =
I was PROGRAMMING sonogram software for IDENTIFYING small aircraft by their engine/prop-noises back in 1985. Were you even born yet?
= = = = = = = = = =
= = = = = = = = = =
I also designed an acoustic phased-array aperture,
= = = = = = = = = =
= = = = = = = = = =
I'm currently working on a DARPA program
= = = = = = = = = =
= = = = = = = = = =
I'm mainly a "sensors and systems" guy,
and I've written software that does the "sonogram/spectrogram/voice-print" conversion
from time-based digital signals to spectrum-based signal processing,
= = = = = = = = = =
= = = = = = = = = =
I've designed a digital signal processor that did acoustic "beamforming",
focussing (sic) sound from multiple sensors
to create a "virtual microphone" positioned anywhere in the environment (software selectable position),
= = = = = = = = = =
= = = = = = = = = =
and I've computer-modelled sound propagation through various environments.
= = = = = = = = = =
http://www.myfilestash.com/userfiles/alrea...G/reverb_01.gif
= = = = = = = = = =
The N-shaped waveform that Trippy provided showed a vertical leading edge
= = = = = = = = = =
FALSE:
http://www.myfilestash.com/userfiles/alrea...infra-spike.gif
(0.49 Hz pulse, at low resolution on the time axis)
http://www.myfilestash.com/userfiles/alrea...-pulse-zoom.gif
(0.49Hz, at high resolution on the time axis)
Trippys' 0.49Hz infrasonic triangular waveform at an intermediate resolution:
http://www.myfilestash.com/userfiles/alrea...9Hz_N-pulse.gif
The triangular waveform has a fundamental component (0.49Hz) and odd-numbered (N) harmonics (3rd/5th/7th, etc), which decrease rapidly in amplitude at the rate of 1/N[sup]2[/sup] (ref.)
Therefore,
the 3rd harmonic (1.47Hz) will be present at 1/9th the amplitude of the fundamental,
the 5th harmonic (2.45Hz )will be present at 1/25th the amplitude of the fundamental,
the 7th harmonic (3.43Hz) will be present at 1/49th the amplitude of the fundamental,
the 9th harmonic (4.41Hz) will be present at 1/81th the amplitude of the fundamental,
the 11th harmonic (5.39Hz) will be present at 1/144th the amplitude of the fundamental,
the 13th harmonic (6.37Hz) will be present at 1/169th the amplitude of the fundamental,
the 15th harmonic (7.35Hz) will be present at 1/225th the amplitude of the fundamental,
the 17th harmonic (8.33Hz) will be present at 1/289th the amplitude of the fundamental,
the 19th harmonic (9.31Hz) will be present at 1/361th the amplitude of the fundamental,
and so on into indiscriminable obscurity----in this case, before the lowest frequency in the human spectrum has been reached
( i.e., at the 41st harmonic (20.09Hz), being at 1/1681th the amplitude of the fundamental frequency).
Trippys' 0.49Hz infrasonic triangular waveform:
http://www.myfilestash.com/userfiles/alrea...-spect_tall.gif
Fast-Fourier-Transform Spectral Distribution
(16384 bands, Blackman-Harris window)
quod erat demonstrandum
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
chainsaw
==========
the relative propagation time of shock waves to piezoelectric sensors
==========
SHHHH! Don't let the "sensors and systems guy" see this - he might think that you need a MICROPHONE in order to record the pressure and duration of a blast. On the other hand, his multiple sensor-sound beamformed virtual microphone placed anywhere in the explosive environment (software selectable) might perform better than your quaint little crystal!
chainsaw
=============
All I was trying to point out is that it takes longer than AL claimed for a charge to ignite and burn and trigger the main charge.
=============
I made no claims about how long it takes to detonate a charge, or how long it takes for the entire mass of explosive to be consumed. I refrained from doing so because a chemical reaction is not a sound, and in much the same way that DC isn't.
Sound is a cascade of particle collisions (only 1.5kb!) propagating as a pattern of compressed and rarified regions in a medium ---- or something like that.
wcelliot
= = = = = = = = = =
All those echoes smear-out the 10 microsecond impulse into something that's low-enough frequency
for your ears to hear.
= = = = = = = = = =
FALSE:
http://www.myfilestash.com/userfiles/alrea...rb_spectral.gif
--- 88kHz sampling rate
--- 0.01 second burst of 30kHz sine wave with reverberation in a simulated church.
--- spectral distribution (Blackman-Harris, 4096 bands).
= = = = = = = = = =
I was PROGRAMMING sonogram software for IDENTIFYING small aircraft by their engine/prop-noises back in 1985. Were you even born yet?
= = = = = = = = = =
= = = = = = = = = =
I also designed an acoustic phased-array aperture,
= = = = = = = = = =
= = = = = = = = = =
I'm currently working on a DARPA program
= = = = = = = = = =
= = = = = = = = = =
I'm mainly a "sensors and systems" guy,
and I've written software that does the "sonogram/spectrogram/voice-print" conversion
from time-based digital signals to spectrum-based signal processing,
= = = = = = = = = =
= = = = = = = = = =
I've designed a digital signal processor that did acoustic "beamforming",
focussing (sic) sound from multiple sensors
to create a "virtual microphone" positioned anywhere in the environment (software selectable position),
= = = = = = = = = =
= = = = = = = = = =
and I've computer-modelled sound propagation through various environments.
= = = = = = = = = =
http://www.myfilestash.com/userfiles/alrea...G/reverb_01.gif
= = = = = = = = = =
The N-shaped waveform that Trippy provided showed a vertical leading edge
= = = = = = = = = =
FALSE:
http://www.myfilestash.com/userfiles/alrea...infra-spike.gif
(0.49 Hz pulse, at low resolution on the time axis)
http://www.myfilestash.com/userfiles/alrea...-pulse-zoom.gif
(0.49Hz, at high resolution on the time axis)
Trippys' 0.49Hz infrasonic triangular waveform at an intermediate resolution:
http://www.myfilestash.com/userfiles/alrea...9Hz_N-pulse.gif
The triangular waveform has a fundamental component (0.49Hz) and odd-numbered (N) harmonics (3rd/5th/7th, etc), which decrease rapidly in amplitude at the rate of 1/N[sup]2[/sup] (ref.)
Therefore,
the 3rd harmonic (1.47Hz) will be present at 1/9th the amplitude of the fundamental,
the 5th harmonic (2.45Hz )will be present at 1/25th the amplitude of the fundamental,
the 7th harmonic (3.43Hz) will be present at 1/49th the amplitude of the fundamental,
the 9th harmonic (4.41Hz) will be present at 1/81th the amplitude of the fundamental,
the 11th harmonic (5.39Hz) will be present at 1/144th the amplitude of the fundamental,
the 13th harmonic (6.37Hz) will be present at 1/169th the amplitude of the fundamental,
the 15th harmonic (7.35Hz) will be present at 1/225th the amplitude of the fundamental,
the 17th harmonic (8.33Hz) will be present at 1/289th the amplitude of the fundamental,
the 19th harmonic (9.31Hz) will be present at 1/361th the amplitude of the fundamental,
and so on into indiscriminable obscurity----in this case, before the lowest frequency in the human spectrum has been reached
( i.e., at the 41st harmonic (20.09Hz), being at 1/1681th the amplitude of the fundamental frequency).
Trippys' 0.49Hz infrasonic triangular waveform:
http://www.myfilestash.com/userfiles/alrea...-spect_tall.gif
Fast-Fourier-Transform Spectral Distribution
(16384 bands, Blackman-Harris window)
quod erat demonstrandum
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
chainsaw
==========
the relative propagation time of shock waves to piezoelectric sensors
==========
SHHHH! Don't let the "sensors and systems guy" see this - he might think that you need a MICROPHONE in order to record the pressure and duration of a blast. On the other hand, his multiple sensor-sound beamformed virtual microphone placed anywhere in the explosive environment (software selectable) might perform better than your quaint little crystal!
chainsaw
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All I was trying to point out is that it takes longer than AL claimed for a charge to ignite and burn and trigger the main charge.
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I made no claims about how long it takes to detonate a charge, or how long it takes for the entire mass of explosive to be consumed. I refrained from doing so because a chemical reaction is not a sound, and in much the same way that DC isn't.
Sound is a cascade of particle collisions (only 1.5kb!) propagating as a pattern of compressed and rarified regions in a medium ---- or something like that.
QUOTE (David B. Benson+Nov 19 2007, 11:41 PM)
Collapse initiation:
When columns are overloaded, they first shorten axially (elastic) and then begin to bow (inelastic). In the elastic phase the resisting force can be taken as nearly constant. But when bowing, I suspect that the resisting force declines somewhat. In continuum mechanics, everything is (approximately) linear at a small enough scale. So this might help explain why a linearly declining force appears to be the best approximation.
Then, of course, with continued overloading, the columns kink bend. At this point the 'broomstick' model applies, but by then crush-down has begun.
[This comes from reading Seffen's paper, which is most clearly written.]
Graphs of compressive strain vs. time for a column with initial imperfection are shown in Fig. 9 of Experimental and theoretical studies of columns under axial impact by Ari-Gur , Weller and Singer. Graphs are shown of both numerical computation and experimental data, which are in good agreement.
While the impacts that this graph represents resulted in plastic deformation, compressive strain fluctuated greatly, more or less evenly about compression = 0, after about .25 m sec. (I assume compression = 0 mean calibrated to the static load, though I'm not sure about this.)
In a quasi-static calculation, peak load = static load, and it's duration is infinite.
In a real life impact, things are different..... Things are more different, still, if your theoretical model assumes that
1) column bottoms are constrained in the vertical direction, for purposes of calculation, (even though this involves the logically inconsistent act of maintaining such a constraint indefinitely, while also assuming that a finite-duration collapse front passes these lower ends by, thereby not providing them "a leg to stand on")
2) the impacting mass is not every bit as elastic as the mass being impacted.
What load profile does Seffen calculate? I haven't read the paper through, but I'd be willing to guess that he doesn't bother. If that's the case, that's not the best way to study an impact problem, now is it?
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
For a solution of 2 exactly equal rods impacting longitudinally (zero gravity
) , elastic regime, see Impact by Goldsmith. Interestingly, when they part company, they are undergoing no (intra-rod) longitudinal motion, at all.
When columns are overloaded, they first shorten axially (elastic) and then begin to bow (inelastic). In the elastic phase the resisting force can be taken as nearly constant. But when bowing, I suspect that the resisting force declines somewhat. In continuum mechanics, everything is (approximately) linear at a small enough scale. So this might help explain why a linearly declining force appears to be the best approximation.
Then, of course, with continued overloading, the columns kink bend. At this point the 'broomstick' model applies, but by then crush-down has begun.
[This comes from reading Seffen's paper, which is most clearly written.]
Graphs of compressive strain vs. time for a column with initial imperfection are shown in Fig. 9 of Experimental and theoretical studies of columns under axial impact by Ari-Gur , Weller and Singer. Graphs are shown of both numerical computation and experimental data, which are in good agreement.
While the impacts that this graph represents resulted in plastic deformation, compressive strain fluctuated greatly, more or less evenly about compression = 0, after about .25 m sec. (I assume compression = 0 mean calibrated to the static load, though I'm not sure about this.)
In a quasi-static calculation, peak load = static load, and it's duration is infinite.
In a real life impact, things are different..... Things are more different, still, if your theoretical model assumes that
1) column bottoms are constrained in the vertical direction, for purposes of calculation, (even though this involves the logically inconsistent act of maintaining such a constraint indefinitely, while also assuming that a finite-duration collapse front passes these lower ends by, thereby not providing them "a leg to stand on")
2) the impacting mass is not every bit as elastic as the mass being impacted.
What load profile does Seffen calculate? I haven't read the paper through, but I'd be willing to guess that he doesn't bother. If that's the case, that's not the best way to study an impact problem, now is it?
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
For a solution of 2 exactly equal rods impacting longitudinally (zero gravity
) , elastic regime, see Impact by Goldsmith. Interestingly, when they part company, they are undergoing no (intra-rod) longitudinal motion, at all.
QUOTE
0.01 second burst of 30kHz sine wave with reverberation in a simulated church.
--- spectral distribution (Blackman-Harris, 4096 bands).
--- spectral distribution (Blackman-Harris, 4096 bands).
AlK - And you don't get how sine waves might add differently from reflections of always-positive pressure waves from an explosion?
Here's one hint: A reflected sine wave has peaks AND TROUGHS.
Here's another hint: A reflected BLAST is ALWAYS POSITIVE.
DA.
You're in WAY OVER YOUR HEAD when you argue acoustics with me.
Piezoelectrics are better at detecting high-frequency components of sound than other microphones, and they actually have DC-RESPONSE!!!. Meaning that they can detect/measure the ABSOLUTE PRESSURE as well as detect sounds.
Maybe you should re-read the quotes you provided. They're all true. What were YOU doing in 1984? I was working as a Senior Staff Scientist for SAIC. Were you even out of diapers back then?
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