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Split Thread henryco's new paper

BigAl said:
Dodge much?

There were no noises heard at WTC on 9/11 that were consistent in timing, loudness or brisance with man-made demolition.
Click to expand...

Many witnesses and recorded HUGE EXPLOSIONS and also many smaller explosions (POPS) running in all directions in the building with FLASHES
 
ktesibios said:
O RLY?

By a strange coincidence I've lately become interested in learning about the characteristics of authentic demolition blasts as recorded in internet videos. To that end I've been garnering soundtracks of real demolitions from YouTube, capturing the audio with Wiretap Pro, a program which intercepts the data going to the computer's sound card and records it as an audio file.

Ultimately I hope to be able to provide some statistics on such parameters of interest as risetime and spectral distribution. However, even with the relatively crude tools I have available at workplace #1 we can examine a few of those soundtracks and see if we can determine just which frequencies you would have to filter out to suppress the sound of chaped charges going off.

Let's start with the demolition of the Landmark Tower in Texas. I selected the first four blasts (selection is shown in the waveform display below)
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b841a85bd149.jpg[/qimg]
and did an FFT spectrum analysis of the selected portion:
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b841ada2e751.jpg[/qimg]

The horizontal axis is logarithmic with the major divisions being 1 kHz apart. The vertical axis is linear in decibels, 6 dB/div.

You'll notice that while there is quite a bit of bass, the spectrum is nearly flat out past 3 kHz and continuous. Now let's look at a time-versus-spectral density display for the same selection:
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b841a85a8741.jpg[/qimg]
Horizontal axis is time, linear, 1 second/div. Vertical axis is frequency, linear, 1 kHz/div. Intensity within a frequency bin is denoted by color, with brighter colors indicating higher amplitude.

The individual blasts show up nicely in this display; they're hard to distinguish in the waveform display because each succeeding blast goes off before the sound of the previous one has finished bucketing around the gutted building. You'll notice that each shows a continuous spectrum with considerable energy out beyond 5 kHz. This is consistent with the audible fact that instead of going "BOOM" or "Whoom", the explosions go
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b842798d0c77.jpg[/qimg]
BAM! BAM! BAM-BAM-BAM!
So, if you want to use filtering to remove the sound of the explosions, you would have to take out everything between DC and 6 kHz or so. The technical term for doing this is "making your recording utterly unintelligible and useless".

Now, let's look at a couple more demolition soundtracks. The Everglades Hotel:
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b8419e88978b.jpg[/qimg]
spectrum
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b842a72d4f7b.jpg[/qimg]
spectrogram

The Kingdome in Seattle:
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b8419e8c0026.jpg[/qimg]
spectrum
[qimg]http://www.internationalskeptics.com/forums/imagehosting/3784b842a72e5add.jpg[/qimg]
spectrogram

They both have something in common with the Landmark demolition: the explosions produce continuous spectra with plenty of energy up into the midrange. The notion that frequency-selective filtering could remove the blasts from the recording without introducing painfully obvious artifacts is nothing short of laughable.

I've experimented with using some digital single-ended noise reduction techniques to try to remove the blast sounds. Multiband noise gating had no effect because, as I tried to explain to femr2 above, the blasts have a higher amplitude than the background sound and consequently just open the gates wide. Using spectral subtraction with the first blast as a sample of the "noise" to be reduced just turned the entire track into something that sounded like R2D2 inciting a riot in an aviary.

Which is more probable- that the eevil gummint has some magical technique for removing the sound of explosions from audio recordings without leaving a trace and has done this with every WTC collapse video floating around the 'net, or that people with an axe to grind or a twisted sense of humor have occasionally added phony sound tracks to existing videos and uploaded them to YouTube just to wind-up rubes who, in the immortal words of Honest John Barlow "won't know enough to do any smart checking"?
Click to expand...

First, as for the video we are discussing the exercice is not to filter the sound of explosions isolated and without background but the sound of many explosions (like a gun machine) in a the huge background noise of a collapsing building.

Second: even considering your data i see really no problem: you just have to apply a time dependent filtering and smooth of course (not just a perfect filter). Nowodays People know how to transform almost any signal into any other one, smoothly, even your voice into mine.

You can also add to the track the sound of an amplified loud noise of the part of the demolition without explosions...

What do you want people to believe? that its not possible to perform such an elementary transformation of the signal ? Most of these people went to the cinema and they saw the apparantly well living tyranausaurus of Jurissak Park yet it disappeared 60 millions years ago. Your attemps here are just ridiculous!
 
henryco said:
Many witnesses and recorded HUGE EXPLOSIONS and also many smaller explosions (POPS) running in all directions in the building with FLASHES
Click to expand...

Umm no they don't.

Henri a quick question for you. How loud would explosives have to be to cut the columns in any of the buildings which collapsed?

if you dont' know, contact a local controlled demolitions company and ask.

Any explosives capable of cutting the columns would be EXTREMELY loud and would be recorded on any and all video taken from within a mile. yet there isn't any (that isn't truther created and spliced together)

Please, go and check with an expert.
 
henryco said:
BigAl said:
Dodge much?

There were no noises heard at WTC on 9/11 that were consistent in timing, loudness or brisance with man-made demolition.
Click to expand...

Many witnesses and recorded HUGE EXPLOSIONS and also many smaller explosions (POPS) running in all directions in the building with FLASHES
Click to expand...

Now, can anybody see what henryco did there?

Dave
 
henryco said:
Many witnesses and recorded HUGE EXPLOSIONS and also many smaller explosions (POPS) running in all directions in the building with FLASHES
Click to expand...

Thermite is an incendiary that can be used to reach very high temperatures and even sol-gel nanothermite could have been tuned for the same task : help weakening the steel structure as discretely as possible at many strategic points all over the building: sounds of huge explosions could have been completely avoided!

However it appears that the perpetrators did not even take this simple precaution (control of the mass medias is well enough) : not only pops and flashes but also huge explosions were heared ... some of them apparantly badly synchronized with the planes impacts!

What about this one:
http://www.911myths.com/index.php/A_WTC7_explosion_video
(and dont miss the funny comments on this page)

Rivets? bolts ? if someone crashing on the floor produced the explosion, surely it must have been a terrorist with his belt of explosives trigerred at the impact :confused:

F
 
henryco said:
Thermite is an incendiary that can be used to reach very high temperatures and even sol-gel nanothermite could have been tuned for the same task : help weakening the steel structure as discretely as possible at many strategic points all over the building: sounds of huge explosions could have been completely avoided!

However it appears that the perpetrators did not even take this simple precaution (control of the mass medias is well enough) : not only pops and flashes but also huge explosions were heared ... some of them apparantly badly synchronized with the planes impacts!

What about this one:
http://www.911myths.com/index.php/A_WTC7_explosion_video
(and dont miss the funny comments on this page)

Rivets? bolts ? if someone crashing on the floor produced the explosion, surely it must have been a terrorist with his belt of explosives trigerred at the impact :confused:

F
Click to expand...

Round hole, meet square peg. Frankly, I'm sick and tired of you trying to push this garbage down my throat. Huge buildings collapse, people heard all sorts of pops and pings and crashes and roars and explosions and other things. Your attempt at making that evidence of CD is pathetic.
 
What about this one:
http://www.911myths.com/index.php/A_...xplosion_video
(and dont miss the funny comments on this page)
Click to expand...
1°) How one big explosion can bring down this...

WTC_Fires_NBC_1_Still.jpg


SIX OR SEVEN HOURS LATER??????

2°) Where are the funny comments? The "Hungarian" word?

3°) Nine years later, you haven't a single clue about a controlled demolition.
 
twinstead said:
Round hole, meet square peg. Frankly, I'm sick and tired of you trying to push this garbage down my throat. Huge buildings collapse, people heard all sorts of pops and pings and crashes and roars and explosions and other things. Your attempt at making that evidence of CD is pathetic.
Click to expand...

Don't these truthers have anything better to do? Like getting a life for example?
 
henryco said:
Someone understands why here

http://911research.wtc7.net/mirrors/guardian2/wtc/seismic/WTC_LDEO_KIM.htm

they write in their seismic analysis that
"The energy propagated as seismic waves for ML 2.3 is about 10^6 to 10^7 J"
while the common formula linking ML to E would rather give 10^8 J ?

F H-C
Click to expand...
... just proved the ground shaking due to a gravity collapse may not of contributed to collapse of surrounding buildings. Wowzer

Your paper is a failure so you post junk from a truther site which debunks truthers.
 
henryco said:
Someone understands why here

http://911research.wtc7.net/mirrors/guardian2/wtc/seismic/WTC_LDEO_KIM.htm

they write in their seismic analysis that
"The energy propagated as seismic waves for ML 2.3 is about 10^6 to 10^7 J"
while the common formula linking ML to E would rather give 10^8 J ?

F H-C
Click to expand...

Looks like someone made a blooper. Their conclusion, that only a very small fraction of the collapse energy was converted into seismic energy, is still sound; it just looks like the coupling constant is a tenth of a percent rather than a few thousandths.

Of course, the paranoid view would be that an expected value for the coupling into seismic energy is a few thousandths of a percent and that, therefore, the energy released in the collapse was more than ten times greater than it should have been; but there's nothing in the paper to suggest any expected value for the coupling. This paper is presenting results of measurements of the coupling, and doesn't contain any theoretical prediction of the coupling at all; nor does it present any other examples where the coupling of energy from an explosion or collapse is calculated.

To claim, therefore, that there's a discrepancy in the measured value, would require that the erroneous 10^6 - 10^7 value was both true and false at the same time, because that's the only source for the value of the coupling constant that's implied in this paper. Not being a conspiracy theorist, I can't achieve that level of cognitive dissonance, though I'm sure Jim Hoffman would claim it represented scientific rigour.

Dave
 
I am coming after the battle but I just wanted to say that the sound demonstrated to be "mono" and "copy pasted" by 240-... are actually stereo and two different sounds. Just zoom the enveloppe in your browser and compare peaks from both sound : not the same (or you can use an image editor with layer transparancy to see that they don't fit).

I find it amusing to see everyone congratulate him and take for proven what's an especially cheesy argument. Pretty typical JREF : you guys come here to hear what you want/need to read. I see other "audio" post here, a matter I am a bit aware of. If you think there are other points that need double checking for you let me know - I am not patient to read everything and see if there's something else than nonsense.
 
Redford said:
I am coming after the battle but I just wanted to say that the sound demonstrated to be "mono" and "copy pasted" by 240-... are actually stereo and two different sounds. Just zoom the enveloppe in your browser and compare peaks from both sound : not the same (or you can use an image editor with layer transparancy to see that they don't fit).

I find it amusing to see everyone congratulate him and take for proven what's an especially cheesy argument. Pretty typical JREF : you guys come here to hear what you want/need to read. I see other "audio" post here, a matter I am a bit aware of. If you think there are other points that need double checking for you let me know - I am not patient to read everything and see if there's something else than nonsense.
Click to expand...

Great post.

You bump a dead thread and don't even attempt to explain what the **** you are talking about.

Next time try the quote feature.

You win the prize.
 
Redford said:
I am coming after the battle but I just wanted to say that the sound demonstrated to be "mono" and "copy pasted" by 240-... are actually stereo and two different sounds. Just zoom the enveloppe in your browser and compare peaks from both sound : not the same (or you can use an image editor with layer transparancy to see that they don't fit).

I find it amusing to see everyone congratulate him and take for proven what's an especially cheesy argument. Pretty typical JREF : you guys come here to hear what you want/need to read. I see other "audio" post here, a matter I am a bit aware of. If you think there are other points that need double checking for you let me know - I am not patient to read everything and see if there's something else than nonsense.
Click to expand...

Proof by zoomed image. Cool. Why not post the image and show us then?
 
Redford said:
I find it amusing to see everyone congratulate him and take for proven what's an especially cheesy argument. Pretty typical JREF : you guys come here to hear what you want/need to read.
Click to expand...

You feel that this is proven by the fact that you dispute the interpretation of a single, year-old post, on a forum that has threads totalling over 15,000 posts on the first page alone, and you're accusing us of confirmation bias?

Dave
 
Let's be clear.

I don't intend to try to convince the JREF's average Joe of anything. I would be a fool to try to. No one ever convinced you guyz of anything. I am not a magician.

Now some people here provides arguments and most of the time oversell them. What I can do with that is explain why the arguement will not convince a neutral, non zealot crowd (ie somenone neither from JREF nor Infowars). Which I did as would anyone with *real* experience of audio editing.

That being said, I don't need to get into details. I don't mind if you guys still think it's a good argument. You want to post it in a more open forum and look like an idiot ? Please be my guest.

My point is just that I don't want to let any doubt that 240... audio demo is crap. And that all of you who just can't zoom the image in your browser and compare the two enveloppe for differences are juste a joke. It tool me 30 sec. How hard can this be ?
 
Dave Rogers said:
You feel that this is proven by the fact that you dispute the interpretation of a single, year-old post, on a forum that has threads totalling over 15,000 posts on the first page alone, and you're accusing us of confirmation bias?

Dave
Click to expand...

I really don't see what you mean. This thread's date is off topic. You have one guy posting a really poor argument and all the other congratuling him. I can make fun of them anytime.

That being said, I am not saying that the same thing wouldn't happen on a truther forum. Although I'd say "way less often", but here I admit the bias ;-)
 
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