Merged Core-led collapse and explosive demolition

You do realize that the building's steel would transmit the sounds as well? Especially to those still inside of it. Right?

You do realise I have never disputed that, furthermore that I have nothing to say about audibility and have said nothing about audibility? No? Despite my making it very clear in the very post you quote? No? Really? Sheesh...
 
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Neither of you have answered the question, so it stands.

By all means feel free to get the books out and attempt to render the effect of the structure between a BANG in the center of the core about 1200ft up the tower to a directional microphone at ground level about 100m from the base.

Have fun.

Make that 900ft up. Make that microphone a little higher and a bit farther away.
Make it directed at the region where ergo's explosions occur.
Just for honesty's sake.

Without attenuation, we can expect 130dB at half a mile. 136dB where you say.
To make it inaudible you need attenuation of what - 100dB?
Can we agree that, given background noises, a volume of 50dB would still be audible and recordable, even if not very pronounced? then you need to take off 86dB. That's a reduction of pressure by a factor of 426,114,725.
Not gonna happen.
 
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And yet no-one has done such a *calc*, making all such assertions based upon .... guesswork ? Intuition ? Belief ? Not good enough.
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Comparison with plenty of known explosions.
Yes good enough.
 
Anyone venturing to provide a useful response to the OP is going to have to get their hands dirty with...

a) Specific device position, especially height
b) The effect of all materials between sound source and receiver in terms of deflection and absorbtion

Render from source to receiver and see what amplitude you end up with.

Anything else is not going to answer the question, however much you may think other factors negate actually doing so.

Have fun ;)

Another daft 'theory' that you pose, dwell on and will fail to establish. 'POD's' attached remote controlled aircraft is so last year. lol.

It is far simpler to understand and gain real experience of how controlled demolition actually works and the characteristics of what such explosions produce. Very simple results and even simpler to detect. Only the gullible are fooled otherwise by talk of 'deflection' and 'absorbtion'. Clouding real experience and knowledge with intellectual dishonesty to fool the gullible doesnt work with the knowledgable.

Fortunately the knowledgable in the real world and away from ze internetz have the final answer to the 911 ct conundrum.

Been having fun for almost 10 years. lol.
 
Because if, as beachnut is so fond of saying, you got math and physics...which proves that even a single explosion high up in the tower would be easily picked up by a directional microphone at the base (or wherever else was tested) then you'd have a useful counter-argument to any discussion of BOOMS.

I've lost count of the number of times I've seen in print the base assertion...there were no BOOMS because you cannot hear them in the video record.

And yet no-one has done such a *calc*, making all such assertions based upon .... guesswork ? Intuition ? Belief ? Not good enough.

So why on earth would you NOT want or care to know this ?

Shouldn't be too difficult.

Have fun.

Irrelevent nonesense and another attempt at intellectual dishonesty to fool the stupid. I dont use your 'guess work' 'intuition' 'belief'. I could give you the calcs for the amount of explosive required and detailed specific placement of such explosives. I can tell you in what order those charges would likely be detonated and then direct you to the known characteristics and known residues expected.

But please feel free to elaborate and give us your 'smokin gun'. Be the one to do away with the 'guess work' 'intuition' 'belief'. Give us the 'calcs' that you crave for your theory to be real. I dont expect too mkuch from you, other than your usual mantra of 'pose, pause.....fail', 'wait and see', 'i'm working on it', 'I dont have a theory' etc etc.

Have fun.
 
What does an explosive sound like 1000 feet up in an office building?
Hmmm I don't know. However I do know what a large explosion 1000 feet underground sounds like on the surface. Anyone living in a mining town will be able to tell you that.
Its not that loud but you feel in in your feet and its enough to make you jump. Then again that's a much greater amount of material between source and observer than what would have taken place in manhattan in 2001.
 
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Your post demonstrates one of the things that reduces all discussion around here into almost worthless nonsense.

I plucked a question from the OP, which to paraphrase goes...

What is the effect of the intervening structure between a BOOM high up in the core of the tower and a microphone at ground level a distance from the base ?

I've yet to see a decent response. Doubt I will.

Personally I'd be quite interested in a decent stab at answering that kind of question, and most of you around here really should also find answering that a challenge, and quite illuminating, regardless of the outcome.

That you are throwing the question to one side by the strawman assumption that the question in isolation implies that there must be floor by floor explosives all the way to the base, in addition to the assumptions about my opinion on even explosives on a single floor...is why you are stuck.

Nonsense, it is demonstrated that the core collapsed last and thus the core did not collapse first(the premise in the OP, correct?)
Thus any discussion of what these core loacted explosions would sound like at ground level is irrellevent to this discussion is it not?

Determining what actually happens to the *volume* of a *boom* in such a scenario should be of interest to you all.

Since it is in no way connected to the reality of the situation in Manhattan on Sept 11/01 it may be of purely technical interest. If you wish to pursue the line of thought go ahead, it should perhaps go in the science and tech subforum though.
 
I don't know the extent with much accuracy
Of course you don't. You haven't bothered to try.

We are talking about an attenuation of 80dB here - that is immense, and nothing in the known design of the tower suggests that this super-reduction of noise could be approached.
What part of being interested in the basic question of how the actual structure affects such a pulse leads you into such polarised nonsense ?

In WHAT WAY do you think I'm suggesting that the result should be massive reduction to inaudible levels ? I've clearly said *I don't know*, but *would be interested in finding out*. Not guessing. Not applying baseless assertions such as folding in floor by floor explosives. Jebus :rolleyes:

All this enables us to estimate that complete muting of many massive detonations towards many recording location is extremely unplausible, and anyone suggesting this needs to work hard to convince us otherwise.
Did I suggest a massive detonation ?
Did I suggest many massive detonations ?

You don't have to be interested in answering my simpple rephrased question, but repeatedly folding in this kind of crap in dialogue with me is rather annoying.

Alright, alright. 1200ft wasn't misleading. It was completely wrong.
What planet are you on ? It's a height. Would work out not far from floor 98. I'd personally start at the roof if I was going to generate some numbers, then go down in 3 storey heights (or base up similarly). Such silly complaints just show your personal emotionally charged and motivated perspective. Learn to control your emotions.

Should I do every conceivable scenario? Sift through millions of configurations, and if I find one that makes complete silence for all known recording positions capitulate and congratulate ergo for his great science?
Emotive stuff :) No, just work out what ACTUALLY happens to the *volume* of a *boom* high up in the middle of the core of a WTC tower in between it's source and a directional microphone at another location, say at ground level 100m away. Seemples ;)

I don't think so. I think ergo should improve on his hypothesis to make it testable.
Do you really think I'm talking about anything but the paraphrased question ? :rolleyes:

Ahhh too bad you repeat the misleading completely false "1200ft" strawman. Femr, seriously, that smacks of transparent dishonesty. I don't like that at all.
ROFL. See previous response above.

Besides - ground level? Only 100m from base? Was there any known recording made at such an extreme location?
It really doesn't matter. Going through the process of defining the *model* would allow simple relocation and recalc. A useful end product.

Skinny compared to what they were at the base.
Irrelevant.

Quite impressive compared to smaller structures.
Not really. Surprisingly skinny.

I have answered it. You just don't like my answer because it isn't perfect.
Where's the math ?

Math isn't needed here to refute an outlandish idea, especially since that idea is not defined well enough.
My question is very simple. Go on, 'av at it ;)

Let me repeat: Appeal to Perfection fallacy. Just because I can't present you a full model and compute it through to spit out some dB value down to 3 digits to the right of the decimal point, doesn't mean the roughest of estimates isn't right and sufficient.
Not surprisingly, I do not agree :)

Are you having fun when being lied to?
Are you lying to me ? As I said...

The OP contains, as far as I'm concerned, not much beyond the question.
 
Make that 900ft up. Make that microphone a little higher and a bit farther away.
Make it directed at the region where ergo's explosions occur.
Just for honesty's sake.

Without attenuation, we can expect 130dB at half a mile. 136dB where you say.
To make it inaudible you need attenuation of what - 100dB?
Can we agree that, given background noises, a volume of 50dB would still be audible and recordable, even if not very pronounced? then you need to take off 86dB. That's a reduction of pressure by a factor of 426,114,725.
Not gonna happen.
No treatment of materials in between source and receiver at all.

Try harder.
 
Nonsense, it is demonstrated that the core collapsed last and thus the core did not collapse first(the premise in the OP, correct?)
Thus any discussion of what these core loacted explosions would sound like at ground level is irrellevent to this discussion is it not?
What a lot of nonsense. Core and perimeter destruction initiated within about a second of each other.

You are TRYING to say that core destruction TRAILED perimeter destruction, but you seem a bit hung-up on primitive dialogue.

The *conspiracy* question you think is being posed is this...

Would a single *boom* up at floor 98 just prior to release be picked up by all the video cameras ? Incorporating how that audio signal would be affected by the structure to a microphone about 100m from the base.

Fun eh ? :)

Since it is in no way connected to the reality of the situation in Manhattan on Sept 11/01 it may be of purely technical interest. If you wish to pursue the line of thought go ahead, it should perhaps go in the science and tech subforum though.
Perhaps. I think such a *calc* would be useful in many ways.
 
You do realise I have never disputed that, furthermore that I have nothing to say about audibility and have said nothing about audibility? No? Despite my making it very clear in the very post you quote? No? Really? Sheesh...

Sorry that was a misquote. Was meant for Femr :o

Your original post did remind me of something though. We have (sadly) a recording of a victim on the phone with 9-1-1 at the time of collapse. No deafening booms. 105th floor, Tower 2.

http://www.youtube.com/watch?v=6pMcaNuO8gs
 
Of course you don't. You haven't bothered to try.

Correct. Because it ain't necessary to approach perfection here.

What part of being interested in the basic question of how the actual structure affects such a pulse leads you into such polarised nonsense ?

Please explain why this is nonsense.

In WHAT WAY do you think I'm suggesting that the result should be massive reduction to inaudible levels ? I've clearly said *I don't know*, but *would be interested in finding out*. Not guessing. Not applying baseless assertions such as folding in floor by floor explosives. Jebus :rolleyes:

The question posed by ergo in the OP is only "interesting" or "reasonable" if there is at least a remote chance a-priori that the result would be a massive reduction to inaudible levels, because it is already established that no set of explosions was heard or recorded immediately prior to collapse initiation, and that explosives massive enough to collapse buildings are generally very loud (red font size=7, you get the drift) and many.

I did not assert "floor by floor explosives", but "explosives at intervalls" - which is ergo's hypothesis. I recommend you re-read ergo's first few posts in this thread to get up to task.

Did I suggest a massive detonation ?

You didn't, but the entire body of knowledge about explosive CDs does, as do the NIST experts.

Did I suggest many massive detonations ?

You didn't, but ergo did.

You don't have to be interested in answering my simpple rephrased question, but repeatedly folding in this kind of crap in dialogue with me is rather annoying.

Oh - I thought you wanted me to answer ergo's question. Now suddenly it is your rephrased question? Sorry, but I am going to stick with the OP in this thread.

What planet are you on ? It's a height. Would work out not far from floor 98. I'd personally start at the roof if I was going to generate some numbers,

Why start with the least relevant extremes? Clearly, ergo's hypothesis involves explosives around the 70th floor, and lower (possibly down to basement level), where charges would have to be larger as columns get thicker.
Suppose we find that there is a column near the roof that we could crack and not hear at the ground - would that validate ergo's hypothesis? NO! Because we also need to look at the larger charger lower down as recorded by devices higher up. So please let's start lower.

then go down in 3 storey heights (or base up similarly). Such silly complaints just show your personal emotionally charged and motivated perspective. Learn to control your emotions.

Ay, father. Thanks for lecturing me. I bow before ye. :rolleyes:

Emotive stuff :) No, just work out what ACTUALLY happens to the *volume* of a *boom* high up in the middle of the core of a WTC tower in between it's source and a directional microphone at another location, say at ground level 100m away. Seemples ;)

Not needed.

Do you really think I'm talking about anything but the paraphrased question ? :rolleyes:

I thought you were talking about the OP, along with a couple of clarifications by ergo.

It really doesn't matter. Going through the process of defining the *model* would allow simple relocation and recalc. A useful end product.

A useful excercise maybe, for practice.
Not necessary though to sort ergo's hypothesis where it belongs: Lala-land.

Not really. Surprisingly skinny.

That would depend on personal expectations, wouldn't it?
But irrelevant. The cross section of the columns needs not be measured against expectations, but against those of other, known CDs. (Sure, I haven't done that)

Where's the math ?

No math needed. I told you this several times. Why did you ignore it?
I saw a car crash the other day: One car pulled into the street without looking, the other didn't have a chance to stop or go around, so they crashed. Did I do the math on that? No. Am I correct? Yes. See, I didn't know exactly how fast each car was going, what the distance was when the first car appeared in the street, or how much grip the tires had. I just have seen enough cars driving and breaking to be able to estimate roughly if it was possible or impossible to avoid the crash. In that case, it was impossible. The second car went approx. 70km/h and had only approx. 5 meters. Now tell me: Did I need math? Did I need an exact model? 5 meters for 70km/h is pretty extreme, even if I don't calculate acceleration.

Not surprisingly, I do not agree :)

Ok. How many models do you require? How many elements per model? How many pairs of explosion location and device location? How many relevant digits to the dB number?
Please be specific.
Please be prepared to receive a few laughing dogs when your specific requirement reveals the appeal to perfection fallacy.

Are you lying to me ? As I said...

The OP contains, as far as I'm concerned, not much beyond the question.

The OP claims that a certain set of CD explosions in a video can't be discerned from other kinds of noises when it is patently obvious that the very loud and prominent explosions sounds can be easily discerned from any non-explosion sounds in that video. So he lied there. He later claims he meant that one can't tell much of a difference between the CD charges and the fireworks - which are not other kinds of noise but the very same kind of noises: explosions. That is the second lie.

I note that you are not concerned when a truther lies to you. A masochistic lie, too.
 
You have poor standards.

I have sufficient standards.
You have unrealistic and unnecessary standards.





Femr, I think you want to drive the point home that if someone ran the math, and could proof mathematically that his math results cover the entire range of possible values for all inputs, and the set of all results contains no scenario where no device would record any CD charge, then we could always reference that work and put to rest once and for all any theory of explosive demolition.

You are aiming too high, I think. It's impractical.
Besides, ergo would never believe the math anyway.
 
Glad to see the thread's so popular.

The core dropped first. Its remnants hung in the air for a bit, then they dropped.
 
Femr, I think you want to drive the point home that if someone ran the math, and could proof mathematically that his math results cover the entire range of possible values for all inputs, and the set of all results contains no scenario where no device would record any CD charge, then we could always reference that work and put to rest once and for all any theory of explosive demolition.

That could certainly be a potential output, and yes, that's why I suggested that most folks should, imo, be interested in the basic premise, though I don't think it would be necessary to go to the *all possible values* extent. A sub-set including limiting cases at extremes would probably do.

As I've also said, I don't know the *answer* so results could be surprising.

Only one way to find out though.
 
So if I were to say that an office partition completely attenuates the sound of a 2kg shaped charge, my assertion would stand as fact until someone mathematically proved otherwise?

What about filing cabinet systems, desks, marble slabs on the walls, heavy doors, concrete partitions, concrete encasement of beams in the core, the reinforced floors on the MER levels?
 
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