The 9/11 Forum

Trippy wrote:Apparently my point wasn't as clear as I thought it was - in part, don't assume that because two things happen at the same time that there's neccessarily a causal relationship between them. Consider carefuly the wording that I have used, reread my posts, and then realize that i've already considered the points that you're making (or seem to be making).

OK, I just felt like a rant.

My sole point in bringing up the example of the lottery draw was to illustrate that sometimes, genuine coincidences happen.

Absolutely. I have used that argument a number of times around here, the last time didn't get me too far. Shortly thereafter, I declared a moratorium (for myself) on doing it and haven't pulled it out since. The timing, however, is purely coincidence.

If we accept the analysis that has been done, then there was a rumble 12 seconds before the building started collapsing, and again as the collapse progressed.

So what? How does that prove that explosives were involved?

Doesn't prove it.

...the only thing that I have suggested in this thread is that a collision has (or can have) the same acoustic properties as what's being described by no_body (short attack + Infrasound).

I agree with you on this. At least there could be similar properties up to a certain degree of examination. I also suspect one or more partial floor collapses in the seconds before initiation, regardless of the cause of initiation. If this were true, I'd also expect some sound to accompany it.

Whatever makes you feel better - I suggest you re-read the thread, initially (and primarily) the only thing that I have suggested in this thread is that a collision has (or can have) the same acoustic properties as what's being described by no_body (short attack + Infrasound). And you know what? I can't help but notice that not one single person has addressed that point, all that's been offered in response is insults and accusations.

You are right on the "bang". The sound could have been produced during the collapse initiation, or shortly before. Either by explosives, full or parcial collapse or by other non-WTC related sources, that's why this thread has a low priority for me. The value of the tape is small.

What part of my statement is ad-hominem?

I didn't want to accuse you of anything, I just wanted to say that the potecnial for this is there, so I suggest to call the paper ATMITD..........

I came was describing the experimental technique laid out in that specific paper as ham fisted and amatureish.

have read the paper, several times, and this is precisely one of the things he claims in it (when I have the opportunity, I'll direct you to where he makes this claim.

Read the paper again, he usses the separation as a supporting evidence.

You fail at basic chemistry. Have you read the paper? You obviously haven't understood what i've said, or why it's important.
The role of ferric oxide in alluminoferric thermite is as an oxidizer.
None of what you're saying here is even remotely implied by anything that i've said.
And yes, I expect that it was quite stable until it reached some temperature where it ignited, most things behave that way, what changes is the temperature.
I 'imagine' that the Iron was reduced before it was added to the mix, and this is true irrespective of whether we're talking about the Iron in Thermite, or the Iron in Tnemec 99 Red.

Ha, ho whoa?

The role of ferric oxide in alluminoferric thermite is as an oxidizer.

I agree.

None of what you're saying here is even remotely implied by anything that i've said.

Blatantly false, so false that it hurts. You sad that the DSC in air can't decide if the reaction was "thermitic" or simple burning. I replied you by saying that the material was clearly former Fe2O3 was clearly reduced to lower oxides and most probably to elementar iron, this iron formed droplets, suggesting molten state. And you can't get it both ways, Trippy. Either the carbon burns with air, relasing energy and somewhat heating the rest (which would left the Fe2O3 un-reduced) or the carbon/aluminium reacts with the Fe2O3, one or both of these materiasl serve as a reducing agent, hence there's no need for outside air.

This means that the reduction of grat part of the chips proves that the material is theremitc i.e. it produces molten metal without outside oxygen.

I expect that it was quite stable until it reached some temperature where it ignited, most things behave that way, what changes is the temperature.

Depens on the peaks, I'm not familliar with DSC, but I would expect that otherwise inert material with some ~ 15% of organics at most would burn over a long period of time in a DSC.

I 'imagine' that the Iron was reduced before it was added to the mix

Whoa, how? The chips clearly consist mainly of Fe2O3.

Tnemec 99 Red

OMG, read this.

http://michaelfury.wordpress.com/2009/0 ... ls-harrit/

And I could go on.

People like you do poisson this forum, sorry.

Any one care to discuss the topic at hand?, stop disrupting the thread with petty squabbles?
Both of you.

stock in trade hereabouts so it seems............

Trippy
I suggest you re-read the thread, initially (and primarily) the only thing that I have suggested in this thread is that a collision has (or can have) the same acoustic properties as what's being described by no_body (short attack + Infrasound). And you know what? I can't help but notice that not one single person has addressed that point, all that's been offered in response is insults and accusations.

I suggest you re-read the thread. Where 'insults' and 'accusations'?

As for collisions making this kind of sound?

A continuous rumble? I suggest you re-read the thread I have addressed this issue at least three times I think.

I have also asked you to desist from posting off topic, which you seem almost pathologically unable to do.

You seem too concerned with your ego, lack emotional maturity and get easily sidetracked.

Collisions do cause bangs there's absolutely no doubt in my mind that this is a statement of fact.

You've made your point.

peterene1 wrote:
You are right on the "bang". The sound could have been produced during the collapse initiation, or shortly before. Either by explosives, full or parcial collapse or by other non-WTC related sources, that's why this thread has a low priority for me. The value of the tape is small.

Can you take your mock squabble somewhere else then?

This is disruptive.

no_body wrote:Any one care to discuss the topic at hand?, stop disrupting the thread with petty squabbles?
Both of you.

Yes, yes, I must agree and insist it be taken elsewhere. There are already multiple threads for all variants of thermites.

stock in trade hereabouts so it seems............

I've seen some awesome OTs on this forum, this thread not so. My apologies.

peterene1 wrote:

Whatever makes you feel better - I suggest you re-read the thread, initially (and primarily) the only thing that I have suggested in this thread is that a collision has (or can have) the same acoustic properties as what's being described by no_body (short attack + Infrasound). And you know what? I can't help but notice that not one single person has addressed that point, all that's been offered in response is insults and accusations.

You are right on the "bang". The sound could have been produced during the collapse initiation, or shortly before. Either by explosives, full or parcial collapse or by other non-WTC related sources, that's why this thread has a low priority for me. The value of the tape is small.

Thankyou.

peterene1 wrote:

What part of my statement is ad-hominem?

I didn't want to accuse you of anything, I just wanted to say that the potecnial for this is there, so I suggest to call the paper ATMITD..........

Thankyou.

peterene1 wrote:

I came was describing the experimental technique laid out in that specific paper as ham fisted and amatureish.

have read the paper, several times, and this is precisely one of the things he claims in it (when I have the opportunity, I'll direct you to where he makes this claim.

Read the paper again, he usses the separation as a supporting evidence.

Correct, but I didn't claim that it was his only evidence, I just stated that he claimed it as evidence.

peterene1 wrote:

You fail at basic chemistry. Have you read the paper? You obviously haven't understood what i've said, or why it's important.
The role of ferric oxide in alluminoferric thermite is as an oxidizer.
None of what you're saying here is even remotely implied by anything that i've said.
And yes, I expect that it was quite stable until it reached some temperature where it ignited, most things behave that way, what changes is the temperature.
I 'imagine' that the Iron was reduced before it was added to the mix, and this is true irrespective of whether we're talking about the Iron in Thermite, or the Iron in Tnemec 99 Red.

Ha, ho whoa?

Yeah, there's a small, but fundamental error in that statement, I caught it, and was about to correct it when I saw your reply.

peterene1 wrote:

The role of ferric oxide in alluminoferric thermite is as an oxidizer.

I agree.

Good

peterene1 wrote:

None of what you're saying here is even remotely implied by anything that i've said.

Blatantly false, so false that it hurts. You sad that the DSC in air can't decide if the reaction was "thermitic" or simple burning. I replied you by saying that the material was clearly former Fe2O3 was clearly reduced to lower oxides and most probably to elementar iron, this iron formed droplets, suggesting molten state. And you can't get it both ways, Trippy. Either the carbon burns with air, relasing energy and somewhat heating the rest (which would left the Fe2O3 un-reduced) or the carbon/aluminium reacts with the Fe2O3, one or both of these materiasl serve as a reducing agent, hence there's no need for outside air.

Elsewhere I have produced evidence that suggests otherwise - the only requirement for producing Iron rich globules is a sufficiently reducing environment.

I'll go digging and see if I can find the proof for you, but burning crude oil that's contaminated with Iron Oxide will produce Iron rich spheres.

The Iron oxide is behaving as an oxidizing agent, not a reducing agent, what I'm suggesting is that the production of the iron rich spheres was incidental to the combustion of the carbon.

And again, you're close to the point, but just missing the mark.

peterene1 wrote:This means that the reduction of grat part of the chips proves that the material is theremitc i.e. it produces molten metal without outside oxygen.

But there is nothing in Harrit's paper that demonstrates that the chips behave in this way, because his differential calorimtry was conducted in air, rather than an inert atmosphere.

peterene1 wrote:

I expect that it was quite stable until it reached some temperature where it ignited, most things behave that way, what changes is the temperature.

Depens on the peaks, I'm not familliar with DSC, but I would expect that otherwise inert material with some ~ 15% of organics at most would burn over a long period of time in a DSC.

They're small samples, small samples burn rapidly.

peterene1 wrote:

I 'imagine' that the Iron was reduced before it was added to the mix

Whoa, how? The chips clearly consist mainly of Fe2O3.

Do they? Nothing in Harrit's paper actually suggests this - if he had done some good, basic science, and, for example, gotten a sample of of the primer to use as a reference spectrum to compare his sample to, you might have a point.

peterene1 wrote:

Tnemec 99 Red

OMG, read this.

http://michaelfury.wordpress.com/2009/0 ... ls-harrit/

And I could go on.

People like you do poisson this forum, sorry.

[/quote]
Speak for yourself.

no_body wrote:Where 'insults' and 'accusations'?

Obfuscator?

You've made your point.

Obfuscator was your first response to this point, as I recall. While I will neither condone nor endorse any of the back and forth that's gone on since, this was not the best foot forward in counterargument, especially right out of the gate, wouldn't you agree? Now you acknowledge the point has some place in the debate; imagine how differently things might have gone had that sort of thing been your first response.

All:

There is a point where bickering becomes ridiculous enough to call a halt, distinct from recognizing the waste of time that is the result of most squabbles. In my view, it hasn't reached the level of foul, because I swing that way. However, the participants in the squabble may not agree but I will ask you to summon every effort to restrain yourself first, before forcing the point. I will especially enforce the right of the thread starter to keep this on topic.

Seriously, the thermite must go elsewhere. If I have to spend time pruning this topic instead of

- paying work
- taking measurements
- crafting my force function for testing B&L
- DISCUSSING THE TOPIC OF THIS THREAD

I will be ever so slightly resentful.

no_body wrote:Any one care to discuss the topic at hand?, stop disrupting the thread with petty squabbles?

How many times have I asked you (directly or indirectly) to address my point?

no_body wrote:

Trippy
I suggest you re-read the thread, initially (and primarily) the only thing that I have suggested in this thread is that a collision has (or can have) the same acoustic properties as what's being described by no_body (short attack + Infrasound). And you know what? I can't help but notice that not one single person has addressed that point, all that's been offered in response is insults and accusations.

I suggest you re-read the thread. Where 'insults' and 'accusations'?

How many times have you accused me of being a liar by suggesting that I'm obfuscating anything, deliberately or otherwise? I called you out on it at the time, and you just steamrolled right past it.

no_body wrote:As for collisions making this kind of sound?

A continuous rumble? I suggest you re-read the thread I have addressed this issue at least three times I think.

I thought you said that the sustain, and extended decay were due to echoes in an urban environment?
So why should a sharp noise from a collision experience any less echoing than the sharp noise from the detonation of demolition charges?

Quite aside from anything else, are you suggesting that an acre of steel and concrete that is that thin (relatively speaking) won't behave like a large, albeit very stiff membrane?

I suggest you look up a couple of ideas "Conservation of momentum" "Damped Harmonic Oscillation".

no_body wrote:I have also asked you to desist from posting off topic, which you seem almost pathologically unable to do.

Right, but this was when I first bought the B&B footage into the discussion, and initially stated that the noise could be created by a collision, and was discussing the effects of expelling that much air in such a short period of time - a topic which you introduced into the thread, not me.

no_body wrote:You seem too concerned with your ego, lack emotional maturity and get easily sidetracked.

Says the individual that backtracks and routinely engages in adhominem attacks (technically, this is also an adhominem attack, but i'm choosing to ignore it for the time being).

no_body wrote:

OneWhiteEye wrote:Some of it, just now. Pretty easy to be critical of the technique, but when I got here:



it became an entirely different story. Will finish it, gotta go.

The technique is apparently common in the music world, for restoring dynamics to flat mixes handy for tightening up live mixes, where there might be a bleed into the bass drum mic from other low end stage sources it restores punch!

You can use it on complete mixes, subtly to get every thing to pulse to the bass drum. Or so I'm informed.

Agreed. I've got hundreds of VST plugin instruments and effects and have played with digital synthesis and recording for many years. Let me explain. That's why my concerns were elevating through the first half of the video, when 'send effects' were added in to the chain one after the other. I totally understood the function of each and was quite wary of the fact that this could be an effective boom-box synthesizer, deriving its trigger pulses from any sort of spurious low frequency signal present, whether natural or artifact.

But... when it got to the gates triggering under similar (but not precisely the same) conditions, that immediately negated that entire class of concerns. Now there is no need to go to any lengths to determine if the beats are from spurious noise or localized sounds, the same pulses are present in two videos taken from locations far apart.

The issue now is to determine the nature and cause of those sounds.

OWE

I concur.

We've briefly discussed the Psyco-acoustic issues. Or subjective impressions.

Can I ask you how well do you think the Sauret sub bass triggered sounds fit in the overall picture?
What I mean is, given that they blend back into the -12dB soundscape after 200ms, does it sound natural?
Can you hear the early reflections reverberating? I suppose what I'm asking is are we hearing something similar to the sounds that might be heard if, as we can using audio software turn the city's noise down by 12dB?

The gate envelope was chosen to match what we see in the sonograph, rapid short duration pulses 20ms, with what looks like at least two early reflections ( within 25 ms). When gate times are shortened in the rumble phase what emerges is a series of rapid short bursts. Someone here, who's built tunnels by blasting said it sounded like rapid multiple detonations, that's what he said you get when you do that - a rumble.

The next thing to draw your attention to is the seeming regularity with which they go off it's almost like a bell chiming, counting down, to me the impression is not one of random events. In the png you posted the sequencer tempo is set to 120 bpm each of the vertical lines is a beat, of the 5 beats the gaps are 33222 or 1.5s , 1.5s, 1s, 1s, 1s. 6 seconds, This is closer in the B&B, stronger signal with less reverb mush and cancellation than Sauret.

In a building demolition what do you hear loudest? The charges going off or the internal collapse collisions?

How much KE does a single floor slab have after a single floor drop ? 80MJ? if all that energy is converted to sound how loud would that be. Would the trusses cushion the blow, slow it down, make it less of a crack and more of a crush, wouldn't this characterise the sound of a random floor partially collapsing?

How much sound energy is released when a column snaps?

It seems these energies need to be quantified, any one know?

We could also find a Vegas demo video, one with a helicopter and analyse the sound from that for a comparison. It would have both explosions and presumably collisions.

I have tested steel many times and ripping apart a steel element in a lab is always associated with a BIG BANG. I have also inspected steel structures subject to failures (elements ripped apart) and all witnesses to the event have stated that what made them aware of the failure(s) was a BIG BANG! After that they went out to have a look what could have happened. Once it was a big, upper part (a crane) that had dropped on and impacted the structure below - a steel platform! There was, apart from the BIG BANG, a big dent in the platform ... and the crane had then bounced and landed somewhere else (actually beside the platform).

Heiwa wrote:I have tested steel many times and ripping apart a steel element in a lab is always associated with a BIG BANG. I have also inspected steel structures subject to failures (elements ripped apart) and all witnesses to the event have stated that what made them aware of the failure(s) was a BIG BANG! After that they went out to have a look what could have happened. Once it was a big, upper part (a crane) that had dropped on and impacted the structure below - a steel platform! There was, apart from the BIG BANG, a big dent in the platform ... and the crane had then bounced and landed somewhere else (actually beside the platform).

There's that as well - the fact that invariably, catastrophic brittle failure of rigid elements is invariably associated with an explosive release of energy, irrespective of whether or not chemical assistance is provided.

Trippy wrote:

Heiwa wrote:I have tested steel many times and ripping apart a steel element in a lab is always associated with a BIG BANG. I have also inspected steel structures subject to failures (elements ripped apart) and all witnesses to the event have stated that what made them aware of the failure(s) was a BIG BANG! After that they went out to have a look what could have happened. Once it was a big, upper part (a crane) that had dropped on and impacted the structure below - a steel platform! There was, apart from the BIG BANG, a big dent in the platform ... and the crane had then bounced and landed somewhere else (actually beside the platform).

There's that as well - the fact that invariably, catastrophic brittle failure of rigid elements is invariably associated with an explosive release of energy, irrespective of whether or not chemical assistance is provided.

Brittle failures occur in steel structures, e.g. a plate element is suddenly fractured from one edge to the other without any elastic or inelastic deformation. As the plate element then cannot transmit any load, the load path changes and other elements in the vicinity may suffer elastic and inelastic deformations.
The energy required to produce the brittle fracture of the plate is the energy required to rip apart molecules from one another, which results in quite high temperature (heat is released) at the tip of the fracture as it proceeds - very fast - through the plate material. You can study the surfaces of the fractured parts afterwards and find the starting point of the brittle failure.

Reason why the brittle fracture starts is usually a combination of a stress concentration and the properties of the material and the environment.

Brittle failures do go bang, as do collisions and explosions.

So we have consensus

no_body wrote:Brittle failures do go bang, as do collisions and explosions.

So we have consensus

I think the next steps are:

a) Correlate several audio streams from different camera sources, by distance, position and elevation.
b) *ray trace* the audio back to as near a positional source as is possible. (Stereo audio sources may help)
c) Correlate to similar audio spikes within WTC 2 footage.

(C) especially is important IMO, as a similar pattern with entirely different initial modes of failure would be quite a statistical anomaly.

Whether the process can result in any kind of conclusion is pretty unlikely as, as you say, similar spikes can be created by multiple very different sources, but we can at least rule out camera-local sources such as knocking the camera, and refine the analysis as much as is possible to result in a *definitive* audio study. If correlation to camera shake can also be conclusively proven, then that also will reduce the scope of any ensuing *debate*.

I hope that inter-personal dialog on this thread can now cease, and we can get to work refining the data.