Sound Analysis of Plasco Collapse

[Tony Szamboti]

You're almost there. People were recording the plasco collapse from very, very close by. The absence of any detectable explosive sounds in fact indicates the absence of any high explosives. You need to find another explanation for the expulsions, such as floors collapsing variously in a fire-induced progressive collapse.

There were significant sounds recorded on audio at the beginning of the Plasco collapse and they were analyzed and shown to have the pressure pulse form of explosive noise and not that of impact noise. There is a difference which you can see on pdf page 26 in the paper Fundamentals of Acoustics by Colin Hansen here

http://www.who.int/occupational_health/publications/noise1.pdf

These pulses also seem to be too close together to have been from falling and impacting floors. The time between the seven pulses, measured over a 511 millisecond period, at the beginning of the collapse, ranges from 40 to 120 milliseconds, varying randomly, with no regular pattern of getting shorter as time went on.

Table 1 below shows (1) the time of each impulse in the video, (2) the interval between each impulse, and (3) the cumulative time elapsed since the first impulse. Figure 6 is a visualization of the audio analysis.

....
The occurrence of seven separate impulses is consistent with video of the south face taken directly from the south,12 which does not show an explosion emanating from one point. Rather, it shows a number of explosions emanating along the same floor from the center of the south face to the east side of the south face.


The audio analysis application Photosounder was used to conduct an analysis of the audio from this video: Source: https://youtu.be/0jz-GXXkxI8
.

Content from external source

http://www.ae911truth.org/images/PDFs/Plasco_Building_Report_2.20.17.pdf

 

[Cedtomcat]

I seen somewhere there was gaz bottle in the building.

If the time code in you table is in seconds, then the explosion happen before the collapse ( even more if you take the speed of sound into account). The thesis of the explosion of the gaz bottles is more logical than a CD ( except if they put the explosive on the top floors of the building, that would be hazardous for a CD)

 

[benthamitemetric]

There were significant sounds recorded on audio at the beginning of the Plasco collapse and they were analyzed and shown to have the pressure pulse form of explosive noise and not that of impact noise. There is a difference which you can see on pdf page 26 in the paper Fundamentals of Acoustics by Colin Hansen here

http://www.who.int/occupational_health/publications/noise1.pdf

These pulses also seem to be too close together to have been from falling and impacting floors. The time between the seven pulses, measured over a 511 millisecond period, at the beginning of the collapse, ranges from 40 to 120 milliseconds, varying randomly, with no regular pattern of getting shorter as time went on.

Your approach is fundamentally flawed because the logical jump you use to rule out that the sounds came from the floors collapsing is to assume the floors were pancaking serially on a whole floor-by-floor basis. All you have to do is watch more than one angle of video of the collapse to see that was not the case. Different parts of different floors were collapsing around the structure in different orders, driven by the internal mechanics of the collapse. The pattern of sound you identified is entirely consistent with the sounds of the floors collapsing as seen.

 

[Nada Truther]

There were significant sounds recorded on audio at the beginning of the Plasco collapse and they were analyzed and shown to have the pressure pulse form of explosive noise and not that of impact noise.

Are they in any way timed with the visible expulsions of air that some are claiming are "Explosions"? It seems odd that something will explode, and then some time later, we see the result of the explosion several floors below, don't you think?

 

[Nada Truther]

Why not include the hypothesis that explosions and molten metal might indicate the involvement of incendiaries/explosives?

Should we not also include the hypothesis that the Keebler elves were set up in there making cookies, in an attempt to branch out into the middle east in these times of economic uncertainty; and it was some sort of chemical reaction, or a "new guy" that didn't understand the chocolate chip to flour to egg ratio and caused an explosion that took the building down?

No, because there is NO EVIDENCE to support this, and it is therefore silly nonsense.

 

[Tony Szamboti]

Your approach is fundamentally flawed because the logical jump you use to rule out that the sounds came from the floors collapsing is to assume the floors were pancaking serially on a whole floor-by-floor basis. All you have to do is watch more than one angle of video of the collapse to see that was not the case. Different parts of different floors were collapsing around the structure in different orders, driven by the internal mechanics of the collapse. The pattern of sound you identified is entirely consistent with the sounds of the floors collapsing as seen.

On the contrary, what you are saying has essentially no likelihood of occurrence. It would be incredible to have seven separate partial floor collapses, all occurring within a half a second total time frame, that also produced very sharp pressure pulses which mimicked that of an explosive and not an impact.

Did you read the Acoustics article I linked to?

It isn't hard to tell that all you are doing here is guessing, with no basis whatsoever, and you are ignoring what I am showing as far as the type of pulses and their high frequency in a short time frame.

 

[benthamitemetric]

On the contrary, what you are saying has essentially no likelihood of occurrence. It would be incredible to have seven separate partial floor collapses, all occurring within a half a second total time frame, that also produced very sharp pressure pulses which mimicked that of an explosive and not an impact.

Did you read the Acoustics article I linked to?

It isn't hard to tell that all you are doing here is guessing, with no basis whatsoever, and you are ignoring what I am showing as far as the type of pulses and their high frequency in a short time frame.

Please cite exactly what in the article you are referring to as being identified as the signature sound of "a pressure pulse of an explosive" and then demonstrate why each of the sounds you identify had to be such a sound and could not have been concrete falling against concrete or steel falling against concrete or steel against steel, etc..

As far as reality being incredible--well, sometimes it might seem that way subjectively, but such feelings aren't very useful for the purposes of our discussion. Do you see a whole floor by whole floor serial pancaking collapse happening in any of the videos? No. So why build your theory on the assumption that they happened?

 

[Oystein]

Perhaps there were no high explosives at all. There could have been incendiaries with additives that cause an expansion of gas, but not loud.

You essentially concede that there were no sounds of explosions consistent in loudness, brisance, timing and number with explosive demolition, and that therefore a different theory is needed.

Pease go ahead and sketch one that describes an incendiary demolition with rapidy expanding, but NOT expoding gas.

 

[Tony Szamboti]

Please cite exactly what in the article you are referring to as being identified as the signature sound of "a pressure pulse of an explosive" and then demonstrate why each of the sounds you identify had to be such a sound and could not have been concrete falling against concrete or steel falling against concrete or steel against steel, etc..

As far as reality being incredible--well, sometimes it might seem that way subjectively, but such feelings aren't very useful for the purposes of our discussion. Do you see a whole floor by whole floor serial pancaking collapse happening in any of the videos? No. So why build your theory on the assumption that they happened?

My argument is science based and objective. Yours would fit the subjective guess category as you don't provide a basis for what you are saying.

The types of pulses (explosive caused vs. impact caused) and their differences are discussed in Colin Hansen's article on pdf page 26. I did link it. Didn't you read it before typing your response?

The actual pulses are shown in the AE911Truth Preliminary Assessment.

My argument is that partial floor collapses could not produce those type of sharp rise and rapidly decaying pressure pulses. They are indicative of explosions. Even if there was no difference in the type of pulse, which there is, it is extremely unlikely that there would ever be a situation where there would be that many partial floor collapses impacting and creating pulses that close together. It also looks like they were intentional explosions, as random explosions would also be unlikely to be that closely grouped.

 

[benthamitemetric]

My argument is science based and objective. Yours would fit the subjective guess category as you don't provide a basis for what you are saying.

The types of pulses (explosive caused vs. impact caused) and their differences are discussed in Colin Hansen's article on pdf page 26. I did link it. Didn't you read it before typing your response?

The actual pulses are shown in the AE911Truth Preliminary Assessment.

My argument is that partial floor collapses could not produce those type of sharp rise and rapidly decaying pressure pulses. They are indicative of explosions. Even if there was no difference in the type of pulse, which there is, it is extremely unlikely that there would ever be a situation where there would be that many partial floor collapses impacting and creating pulses that close together. It also looks like they were intentional explosions, as random explosions would also be unlikely to be that closely grouped.

Can you cite me where in Colin Hansen's article it talks about the sound waves for impacts of concrete on concrete, steel on concrete, or steel on steel? I can't find the methodology you used to distinguish such sounds from "explosive" noises. All the AE911Truth paper says is "The impulses are each too short in duration to be impact-generated noise." It then cites to page 48 of the Hansen paper. Here is that page in its entirety for ease of reference:



Why do you think anything said on this page rules out impulse or impulse-like sounds the likes of which you have identified in the audio analysis visualization from being created by concrete-on-concrete, concrete-on-steel, or steel-on-steel collisions?

You act like you've made an actual argument, but none of your claims actually follow from the papers you cite or what everyone can easily see in the videos of the collapse.

EDIT: In fact, the audio visualizations you provide in the paper make the "impulses"you've identified look much more like type (b) sound waves based on their visual appearance:

 

[Tony Szamboti]

Can you cite me where in Colin Hansen's article it talks about the sound waves for impacts of concrete on concrete, steel on concrete, or steel on steel? I can't find the methodology you used to distinguish such sounds from "explosive" noises. All the AE911Truth paper says is "The impulses are each too short in duration to be impact-generated noise." It then cites to page 48 of the Hansen paper. Here is that page in its entirety for ease of reference:



Why do you think anything said on this page rules out impulse or impulse-like sounds the likes of which you have identified in the audio analysis visualization from being created by concrete-on-concrete, concrete-on-steel, or steel-on-steel collisions?

You act like you've made an actual argument, but none of your claims actually follow from the papers you cite or what everyone can easily see in the videos of the collapse.

EDIT: In fact, the audio visualizations you provide in the paper make the "impulses"you've identified look much more like type (b) sound waves based on their visual appearance:

When compared to types a) explosive generated noise and b) impact generated noise in the Hansen article on page 26 the impulses are the same as a), in that they rise and sharply decay. They don't continue ringing like those in b).

It doesn't matter if the impact is concrete-on-concrete, concrete-on-steel, or steel-on-steel. Impulsive noise due to an impact rings for a while and that due to an explosion decays rapidly. When coupled with the short interval the explosions occurred in, this is courtroom quality evidence for intentional explosions.

 

[benthamitemetric]

When compared to types a) explosive generated noise and b) impact generated noise in the Hansen article on page 26 the impulses are the same as a), in that they rise and sharply decay. They don't continue ringing like those in b).

It doesn't matter if the impact is concrete-on-concrete, concrete-on-steel, or steel-on-steel. Impulsive noise due to an impact rings for a while and that due to an explosion decays rapidly. When coupled with the short interval the explosions occurred in, this is courtroom quality evidence for intentional explosions.

You start with two extremely generalized wave forms presented as idealized examples of an explosive and a punch press, respectively, in a single paper published in 1951. You then take a sound clip from a video of the plasco collapse and transform it by expanding it along the y axis by a large multiple, a step that is not formalized or even suggested n the source from which you drew the wave forms. You then eye ball what you claim to be discrete sounds within a cluster of other sounds, another step not formalized or even suggested in the source you provided, and conclude that such aspects of the wave form--assuming they are discrete sounds and are measured in their vertically expanded form--look more like the idealized wave form presented in the book for explosives than the one presented for the punch press and therefore they must be the sounds of a series of discrete explosive events.

It's unbelievable how you can chain such a tenuous series of propositions together and convince yourself you have proven anything other than that you really, really want to believe there were explosives in the Plasco building.

Here are just a few of the obvious questions that you need to address:

What criteria did you use to identify the exact form of the alleged discrete sounds amidst the background noise?

Once clearly identified, what exact criteria did you use to determine, accounting for how you expanded the data vertically relative to the idealized wave forms, which of the two idealized wave forms was the closest match to the discrete sounds?

How did you conclude that the two idealized wave forms are sufficient signifiers in this context at all? Your source certainly does not describe them as being the wave forms that explosives or punch press impacts must have, let alone say they would typify concrete on concrete, steel on concrete, or steel on steel impact sounds. Is it really too much to ask that you actually compare the wave forms in question to the actual sounds you are trying to rule out?

And, by the way, did it not occur to you that, even if there were explosives, there would still have to be concrete on concrete, steel on steel, and steel on concrete impact sounds in your recording? Where do you think those are hiding in your wave form? Do you not wonder how you might have missed them and only found "explosive" sounds?

 

[Tony Szamboti]

You start with two extremely generalized wave forms presented as idealized examples of an explosive and a punch press, respectively, in a single paper published in 1951. You then take a sound clip from a video of the plasco collapse and transform it by expanding it along the y axis by a large multiple, a step that is not formalized or even suggested n the source from which you drew the wave forms. You then eye ball what you claim to be discrete sounds within a cluster of other sounds, another step not formalized or even suggested in the source you provided, and conclude that such aspects of the wave form--assuming they are discrete sounds and are measured in their vertically expanded form--look more like the idealized wave form presented in the book for explosives than the one presented for the punch press and therefore they must be the sounds of a series of discrete explosive events.

It's unbelievable how you can chain such a tenuous series of propositions together and convince yourself you have proven anything other than that you really, really want to believe there were explosives in the Plasco building.

Here are just a few of the obvious questions that you need to address:

What criteria did you use to identify the exact form of the alleged discrete sounds amidst the background noise?

Once clearly identified, what exact criteria did you use to determine, accounting for how you expanded the data vertically relative to the idealized wave forms, which of the two idealized wave forms was the closest match to the discrete sounds?

How did you conclude that the two idealized wave forms are sufficient signifiers in this context at all? Your source certainly does not describe them as being the wave forms that explosives or punch press impacts must have, let alone say they would typify concrete on concrete, steel on concrete, or steel on steel impact sounds. Is it really too much to ask that you actually compare the wave forms in question to the actual sounds you are trying to rule out?

And, by the way, did it not occur to you that, even if there were explosives, there would still have to be concrete on concrete, steel on steel, and steel on concrete impact sounds in your recording? Where do you think those are hiding in your wave form? Do you not wonder how you might have missed them and only found "explosive" sounds?

It is not the height of the wave in the y-axis that determines whether it represents the explosive wave form or the impact wave form. It is the fact that it is a single wave, which is what occurs in the explosive generated noise, as opposed to multiple waves in the impact generated noise, that determined the type.

 

[Mick West]

It is not the height of the wave in the y-axis that determines whether it represents the explosive wave form or the impact wave form. It is the fact that it is a single wave, which is what occurs in the explosive generated noise, as opposed to multiple waves in the impact generated noise, that determined the type.

So do you think this conclusively proves it was deliberately destroyed with explosives?

 

[DasKleineTeilchen]

So do you think this conclusively proves it was deliberately destroyed with explosives?

seems to me tony already said something like that:

this is courtroom quality evidence for intentional explosions.

 

[Mick West]

"courtroom quality evidence" is a meaningless descriptor. Both prosecution and defense present evidence in court, but only one side is correct.

 

[benthamitemetric]

It is not the height of the wave in the y-axis that determines whether it represents the explosive wave form or the impact wave form. It is the fact that it is a single wave, which is what occurs in the explosive generated noise, as opposed to multiple waves in the impact generated noise, that determined the type.

You don't address 95% of what I said, but ok let's focus in your the last bastion of your argument and put aside the other gaping holes in it for now.

Focusing on that argument, it turns out, I actually gave you and AE911Truth way too much credit and missed your most glaring mistake.

Here's AE911Truth's analysis again:



Here's the idealized wave forms to which you are comparing the discrete sounds you believe you've identified:



The alleged discrete sound waves you've identified are identified using the presence of audio frequencies, not decibels, on the y-axis (the relative decibel levels for the frequencies over time seem to be indicated by a color scale of blue to yellow, but the key to that scale is not provided and the alleged discrete sounds that are claimed to exist based on frequency identification are not isolated and presented as decibel level graphs). Your source on sound type identification, meanwhile, has presented you with one very generalized means of sound type identification--looking at the intensity and duration of decibel levels for a single, discretely-identified sound.

No where in your presentation is there even an actual graph of the decibel levels of the alleged discrete sounds in question for us to even use for the comparison you purport to make (which, as I noted above, is flawed in several other glaring ways, anyway). This highlights your why your lack of a methodology for isolating the alleged discrete sounds in question is such a failing.

You are comparing completely different things and there is zero support for your methodologies in your cited source.

 

[Tony Szamboti]

You don't address 95% of what I said, but ok let's focus in your the last bastion of your argument and put aside the other gaping holes in it for now.

Focusing on that argument, it turns out, I actually gave you and AE911Truth way too much credit and missed your most glaring mistake.

Here's AE911Truth's analysis again:



Here's the idealized wave forms to which you are comparing the discrete sounds you believe you've identified:



The alleged discrete sound waves you've identified are identified using the presence of audio frequencies, not decibels, on the y-axis (the relative decibel levels for the frequencies over time seem to be indicated by a color scale of blue to yellow, but the key to that scale is not provided and the alleged discrete sounds that are claimed to exist based on frequency identification are not isolated and presented as decibel level graphs). Your source on sound type identification, meanwhile, has presented you with one very generalized means of sound type identification--looking at the intensity and duration of decibel levels for a single, discretely-identified sound.

No where in your presentation is there even an actual graph of the decibel levels of the alleged discrete sounds in question for us to even use for the comparison you purport to make (which, as I noted above, is flawed in several other glaring ways, anyway). This highlights your why your lack of a methodology for isolating the alleged discrete sounds in question is such a failing.

You are comparing completely different things and there is zero support for your methodologies in your cited source.

I am not comparing apples and oranges. You are injecting nonsense into it such as y-axis elongation and concrete-on-concrete vs steel-on-concrete etc. The y-axis was not altered in the analysis. That is the way the software presented it. The material isn't a factor either, as no impact will mimic an explosive generated noise, no matter what material is used. All that matters is the single wave form of the explosive generated noise (which is what we have from the Plasco audio) vs. the multiple wave form of the impact generated noise (which it is certainly not).

None of your complaints had merit. This is courtroom level evidence and in a real discussion of it in court you would be asked to show an impact could generate the wave form from the Plasco audio, which you would be unable to do. Only an explosive could do it. It is a direct indication for an explosive.

 

[benthamitemetric]

I am not comparing apples and oranges. You are injecting nonsense into it such as y-axis elongation and concrete-on-concrete vs steel-on-concrete etc. The y-axis was not altered in the analysis. That is the way the software presented it. The material isn't a factor either, as no impact will mimic an explosive generated noise, no matter what material is used. All that matters is the single wave form of the explosive generated noise (which is what we have from the Plasco audio) vs. the multiple wave form of the impact generated noise (which it is certainly not).

None of your complaints had merit. This is courtroom level evidence and in a real discussion of it in court you would be asked to show an impact could generate the wave form from the Plasco audio, which you would be unable to do. Only an explosive could do it. It is a direct indication for an explosive.

You are comparing two different y-axes. One is frequency (AE911Truth's graph) and the other is decibel level (your source's sound type identification graph). If you look at JUST the decibel level graph in the AE911Truth paper (at the top), it looks nothing like the idealized decibel graph for an explosion presented in your source:

Idealized form of explosion sound from source:



Decibel level graph presented by AE911Truth:



This decibel level graph is different from the frequency level graph you then provide and use (based on no cited methodology whatsoever) as the basis for your claim that there were explosive sounds:



You're right that there is no y-axis elongation--instead it was the use of a completely different variable on the y-axis. As a result, I missed just how far away away from your claim your actual evidence was. You just made me realize that you missed that too, seemingly because you just eye balled "What the software presented" and didn't take the time to understand it.

This is why they only let actual experts testify in court on these sorts of technical points. Just because you present something in a flashy graphic doesn't make it "court room level evidence." Maybe next time you should actually consult with the type of expert who could actually testify about sound level analysis in court before you pretend to have produced court room level evidence.

 

[Mick West]

I am not comparing apples and oranges. You are injecting nonsense into it such as y-axis elongation and concrete-on-concrete vs steel-on-concrete etc. The y-axis was not altered in the analysis. That is the way the software presented it. The material isn't a factor either, as no impact will mimic an explosive generated noise, no matter what material is used. All that matters is the single wave form of the explosive generated noise (which is what we have from the Plasco audio) vs. the multiple wave form of the impact generated noise (which it is certainly not).

None of your complaints had merit. This is courtroom level evidence and in a real discussion of it in court you would be asked to show an impact could generate the wave form from the Plasco audio, which you would be unable to do. Only an explosive could do it. It is a direct indication for an explosive.

Your argument is nonsensical. Here's the actual waveform of the seven "pulses"


Here's a close-up of one of them:


Your characterization of this as a "single waveform" is nonsensical.

Source is the YouTube video your paper cites, the "7" sounds are between 2 and 3 seconds. Attached. Analyzed with Adobe Audition.

 

[Mick West]

Can you cite me where in Colin Hansen's article it talks about the sound waves for impacts of concrete on concrete, steel on concrete, or steel on steel?

Concrete on concrete


Firecracker


44 magnum


Notice different time scales. The concrete on concrete decays much faster.

Tony's argument about the waveforms makes no sense at all.

 

[benthamitemetric]

Mick--could you show the decibel and frequency analyses for one of the known controlled demolition videos too? It looks to me that, to the extent we can eye ball patterns in the frequency analysis (which is not a sound methodology for actual analysis at all, but its a sufficient way to see how nonsensical AE911Truth's approach was given that's seemingly all they did), explosions seem to manifest themselves most loudly in the low frequencies, which is not necessarily the case for the seven "impulses" cited by AE911Truth. The explosive sounds also seem to be much more consistently spread across frequencies, while the "impulse" sounds cited by AE911Truth are a garbled collection of different frequencies with holes in certain ranges, much like the concrete impact example you provided.

 

[Mick West]

Mick--could you show the decibel and frequency analyses for one of the known controlled demolition videos too? It looks to me that, to the extent we can eye ball patterns in the frequency analysis (which is not a sound methodology for actual analysis at all, but its a sufficient way to see how nonsensical AE911Truth's approach was given that's seemingly all they did), explosions seem to manifest themselves most loudly in the low frequencies, which is not necessarily the case for the seven "impulses" cited by AE911Truth. The explosive sounds also seem to be much more consistently spread across frequencies, while the "impulse" sounds cited by AE911Truth are a garbled collection of different frequencies with holes in certain ranges, much like the concrete impact example you provided.

From:
Source: https://www.youtube.com/watch?v=i4eMgVv9jQI

This is the 2nd and 3rd bangs, over about 0.8 seconds



Of course a defining feature of explosions is that they are VERY LOUD. It's hard to determine levels from an audio file without lots more information. But if they were explosions they were remarkably quiet.

Compare with 0.8 seconds of Plasco:



And 0.8 seconds of concrete (cinderblock from 8 feet up) on concrete.


The Plasco frequency analysis much more resembles concrete on concrete.

But there's a variety of things it could be. To me it sounds more like something fracturing, like a floor slab cracking or breaking away.

 

[Tony Szamboti]

I have to wonder who Mick and Benthamitemetric consulted with.

I don't believe concrete slabs hitting concrete slabs would make the loud noise pulses we have on audio from Plasco, as the audio was taken from a significant distance.

Interestingly, it is guys like Mick and Bentham who want to say there is no noise from the Twin Towers, where slabs would have to be impacting in their natural collapse scenario. They seem to want it both ways. I think rational people can see that and it shows Mick and Bentham are not being rational and are simply hell bent on disproving use of explosives in the WTC and Plasco.

Edited to add: There is not a snowball's chance (in hell) that the loud cracks at the beginning of the Plasco collapse, which are seven distinct spikes within half a second, are floor impacts or some steel rupturing as Mick or benthamitemetric would have us believe.

 

[benthamitemetric]

I have to wonder who Mick and Benthamitemetric consulted with.

I don't believe concrete slabs hitting concrete slabs would make the loud noise pulses we have on audio from Plasco, as the audio was taken from a significant distance.

Interestingly, it is guys like Mick and Bentham who want to say there is no noise from the Twin Towers, where slabs would have to be impacting in their natural collapse scenario. They seem to want it both ways. I think rational people can see that and it shows Mick and Bentham are not being rational and are simply hell bent on disproving use of explosives in the WTC and Plasco.

Where did anyone say there was no noise from the collapse of the towers? The tower collapses were incredibly loud and most accounts from people who heard them collapse from nearby that I've read describe the sound of the collapses as an incredible roar. I'm sure there were tens of thousands of impact noises being generated very quickly in those events.

Instead of attacking me and Mick, maybe focus on actually developing a sensible, coherent evidence-based theory for what happened in the Plasco building. I'm guessing by your lack of rebuttal that even you realize the arguments you published in the AE911Truth paper re the "impulse" sounds actually make no sense and do not support your conclusions.

By the way, I, for one, didn't consult with anyone, but, then again, I'm not the one trying to convince people that what I'm claiming is "court room level evidence". It took me about an hour's worth of attention and a just handful of posts to home in on the vast array of issues with your purported methodology though. I'm sure an actual expert in frequency analysis could have ripped your work apart even more quickly and on even more levels. It's just obviously deficient work that does not follow from the source to which you cite.

If you were really interested in the truth, you'd be thanking me and Mick for showing you the many errors of your ways. You're now a few steps closer to the truth and are pouting because you wish the truth were something different. Not for nothing, but this is pattern I've been through several times with you.

EDIT re your edit: "There is not a snowball's chance (in hell) that the loud cracks at the beginning of the Plasco collapse, which are seven distinct spikes within half a second, are floor impacts or some steel rupturing as Mick or benthamitemetric would have us believe."

This is your classic move. It gets shown that a major aspect of one of your claims is demonstrably wrong and/or nonsensical and then you simply attempt to swap in an alternative claim without ever again addressing the claim was theretofore so important (in this case, that the shape of the alleged "impulse" sound waves was sufficiently close to the idealized form of an explosion sound wave set forth in your source for us to use such similarity as a means to definitively prove the "impulse" sound waves were explosions). You had already similarly jettisoned from this conversation the original claim that is was the rapid succession of the alleged "impulses" that proved they were controlled demolition charges (under the irrelevant assumption that they could not be caused by serially collapsing floors). Now you are moving on to focus on the relative loudness of the alleged "impulse" sounds, even though you do not have enough information to determine their actual volume level which is what your own source says you'd need to know to claim the relatively loudness was evidence of an explosive event, which I see Mick has already addressed below. Where will your argument go next? Why not just admit you made a series of mistakes and that you need to look at the issue anew?

 

[Mick West]

I have to wonder who Mick and Benthamitemetric consulted with.

Why would I consult with someone? As the former technical director of a video game company then digital audio is something I'm intimately familiar with. I've been using sampled audio and looking at waveforms since the 1980s. I'm not saying trust my opinion blindly, but please don't make vague insinuations about me consulting someone.

I don't believe concrete slabs hitting concrete slabs would make the loud noise pulses we have on audio from Plasco, as the audio was taken from a significant distance.

But the point here is that your claims about the waveform are nonsensical. You made specific claims about the shape of the waveform, saying:

The material isn't a factor either, as no impact will mimic an explosive generated noise, no matter what material is used. All that matters is the single wave form of the explosive generated noise (which is what we have from the Plasco audio) vs. the multiple wave form of the impact generated noise (which it is certainly not).

Which is clearly nonsense, as I hope you realize by now. If you want to make new claims about it just being "too loud", then retract your claims about the shape of the waveform.

 

[Oystein]

I have to wonder who Mick and Benthamitemetric consulted with.

Personalized insinuation, lie by innuendo.

I don't believe concrete slabs hitting concrete slabs would make the loud noise pulses we have on audio from Plasco, as the audio was taken from a significant distance.

Argument from incredulity

...Edited to add: There is not a snowball's chance (in hell) that the loud cracks at the beginning of the Plasco collapse, which are seven distinct spikes within half a second, are floor impacts or some steel rupturing...

Bare assertion.

The usual TSz MO.

Watch for insults coming very soon, to complete the circle.

 

[Mick West]

If you want to make new claims about it just being "too loud"

A claim which a pretty ridiculous if you watch and listen to the entire video a few times. The few cracks of noise that are claimed as being loud explosions (in red oval here) are much quieter than the subsequent collapse of the building long after any possible explosions. In fact comparing them to the collapse shows them to resemble smaller discreet events that would in aggregate make up the total collapse. i.e. things breaking, falling, and impacting inside the building.

 

[deirdre]

I have to wonder who Mick and Benthamitemetric consulted with.

Wonder no more...

 

[DasKleineTeilchen]

that the loud cracks at the beginning of the Plasco collapse, which are seven distinct spikes within half a second, are floor impacts or some steel rupturing as Mick or benthamitemetric would have us believe.

exactly thats what it is; cracking connections, failing from the heavy load forced by the upper third of the building, right before floors and parts of them are falling on each other. when you crack a pen with enough force into half, you get a snap-sound, almost like a gunshot-sound.

 

[Mick West]

exactly thats what it is; cracking connections, failing from the heavy load forced by the upper third of the building, right before floors and parts of them are falling on each other. when you crack a pen with enough force into half, you get a snap-sound, almost like a gunshot-sound.

The sequence of sounds reminds me of tree felling, specifically when a tree barber chairs. There's some snapping cracking noises as the structure of the tree starts to fail, then a big rush of them as it actually falls. Example @1:11 here
Source: https://youtu.be/9O7H9qWdquk?t=1m11s

 

[DasKleineTeilchen]

Nobody here has shown how floor impacts could possibly produce the sharp cracks we hear at the beginning of the Plasco collapse.

exactly thats what it is; cracking connections, failing from the heavy load forced by the upper third of the building, right before floors and parts of them are falling on each other.

 

[DasKleineTeilchen]

Below is a link to a paper on gunshot acoustics and the Plasco waveforms looks similar to those shown in it.

when you crack a pen with enough force into half, you get a snap-sound, almost like a gunshot-sound.

 

[Mick West]

Tony has been suspended from this thread for one day for repeated violation of the no-click policy

 

[benthamitemetric]

I've done quite a bit more research over the past two days on the acoustic emissions of concrete. It turns out that this is a heavily studied area with hundreds of published papers as acoustic emissions are a reliable way to monitor masonry for failure.

The large majority of papers on the subject are behind a paywall, but here is a relatively thorough Master's Thesis on the topic by Jun Zhou of Michigan Technological University that is freely available.

To Tony's point on the loudness of the sounds at issue, which actually cannot be definitely measured as the exact origin of the sounds was unknown and the recording device was not properly calibrated to the task, here's an interesting note on just how unexpectedly loud fracture failures can be:


(Pg. 33)

Just look at those short wave forms generated from acoustic emissions (as converted to voltage by the sensors), and the breaking of pencil lead can come in at over 90 decibels, which is the same level as a shouted conversation:



(Decibel chart from here)

Concrete was actually in the same ballpark, maxing out around 90 decibels while cracking under stress:


(Pg. 38)

Another freely available paper, which focuses on acoustic emissions from concrete bridge girders, provides a helpful graphic describing the expected characteristics of such acoustic emissions:



(Pg. 14)

Yes, that's right, the authors here note that acoustic emissions from concrete fracturing are usually of a short duration, ranging from a few microseconds to a few milliseconds, which directly contradicts Tony's claims that only explosives create short duration sound waves.

The same paper also found more 90+ dB acoustic emissions (among dozens of other near simultaneous acoustic emissions) from stressed concrete:


(Pg. 78)

Again, there are literally hundreds of papers like this. Of the 15-20 that I perused, they all showed similar graphics and noted similar conclusions re the loudness and characteristics of acoustic emissions from concrete.

Tony and AE911Truth got every single aspect of this issue wrong, used nonsensical techniques, and didn't even know what they were attempting to rule out. Their approach to this issue has been thoroughly debunked and their claimed conclusions should be disregarded. They have done nothing to distinguish the alleged "impulse" sounds in their recording from non-explosive sounds, let alone to prove that such "impulse sounds" were definitively explosives.

 

[Mick West]

When @Tony Szamboti posted earlier his post was deleted for "No Click" violation (bare links are not allowed, and must be accompanies with a relevant excerpt, and/or screenshots sufficient that people don't have to click on the link). I suggested he repost with the waveforms he's referring to, to scale. He declined to do so.

His deleted post was:

Nobody here has shown how floor impacts could possibly produce the sharp cracks we hear at the beginning of the Plasco collapse. They also have not debunked the reality that the seven distinct waveforms, recorded over the 0.511 second period, are not ringing types like those from impacts and that they resemble those from explosive generated noise.

Below is a link to a paper on gunshot acoustics and the Plasco waveforms looks similar to those shown in it.

http://www.montana.edu/rmaher/publications/maher_aac_0406.pdf

The waveforms in the paper are:







Note these are stereo separated waves, so you should only look at one channel, let's say the red one.

So what then do the Plasco waveforms resemble? note the last three graphs are 0.03 seconds long, so let's take 0.03 seconds of of the first crack in the Plasco sound.



Clearly this resembles neither the paper's gunshot shock wave (which is only 0.0002 second long), or the blast wave which is characterized by a sharp peak and rapid clean decay.

And here's an actual demolition noise, from 1515 Flagler


I'm presuming Tony did not post because he found there really was no similarity. I invite correction.

Perhaps tomorrow I might experiment with snapping some stone tiles in two and seeing what that looks like.

 

[Tony Szamboti]

The concrete or steel cracking notion proffered by some here, in their attempt to find a natural explanation for the seven discrete sharp acoustic pulses occurring within 0.511 seconds at the beginning of the Plasco collapse, is not viable.

Those type of sharp acoustic pulses can be shown to have one cause, and it is a sonic boom from a point source, and that can only be due to an explosive.

 

[benthamitemetric]

The concrete or steel cracking notion proffered by some here, in their attempt to find a natural explanation for the seven discrete sharp acoustic pulses occurring within 0.511 seconds at the beginning of the Plasco collapse, is not viable.

Those type of sharp acoustic pulses can be shown to have one cause, and it is a sonic boom from a point source, and that can only be due to an explosive.

(Emphasis added.)

A telling use of the passive voice. Who can show that and when will they make an appearance in this thread?

 

[Inti]

(Emphasis added.)

A telling use of the passive voice. Who can show that and when will they make an appearance in this thread?

The concrete or steel cracking notion proffered by some here, in their attempt to find a natural explanation for the seven discrete sharp acoustic pulses occurring within 0.511 seconds at the beginning of the Plasco collapse, is not viable.

Those type of sharp acoustic pulses can be shown to have one cause, and it is a sonic boom from a point source, and that can only be due to an explosive.

It will be interesting to see whether you make good on that promise.

"can be shown" in this sense usually implies that it can be shown to the reasonable satisfaction of a consensus of experts in a field. Is that what you believe can be done?

My confidence is undermined by your misuse of the term "sonics boom" for an explosive sound. Surely a sonic boom is caused by compression waves when an object exceeds the speed of sound, for instance the tip of a cracking whip, an aircraft etc.

It looks as if you were throwing out 'sciencey talk' fairly loosely.

 

[Mick West]

Those type of sharp acoustic pulses can be shown to have one cause, and it is a sonic boom from a point source, and that can only be due to an explosive.

An astonishingly definitive claim Tony. I certainly hope you can back it up. .

Here's a cleaner image of a waveform I extracted (attached uncompressed audio file for reference).


There's two somewhat different sounds there. The second one (which follows the first by only 0.2 seconds) is shorter and more abrupt. Would you say that both of these "sharp acoustic pulses" can only be due to an explosion? Or just one?

[Edit] Image resizing kind of messed those up. Here the two wavesforms: