Offer to the Truth Movement: Let's Settle It

[Major_Tom]

Thanks for the effort and the offer, Ryan.

A person did an analysis recently which suggests the ejections witnessed to emerge from WTC1, around the 76th floor, can be detected far earlier than can be explained by a natural collapse.

http://www.youtube.com/watch?v=acTcwA_YHuA



I fail to see how this early motion can be attributed to air compression.

Thanks in advance for your thoughtful reply.

 

[R.Mackey]

It's not too fast at all. If there is a net pressurization, it would travel at the speed of sound, or approximately 343 meters per second. In the 0.72 seconds between detected motion and the onset of that particular dust jet, pressure could have risen as far away as 240 meters, or about 80 stories. The video actually disproves its own claim.

It is also possible the jet was caused by something before the collapse started. There are several "puffs" of smoke and dust that happened well before collapse, caused by local internal failures. See NCSTAR1-5A. It's possible that this particular jet was one of them.

Furthermore, the jet is too slow to be anything else. Its low speed proves a dynamic pressure of under 0.25 PSI, not destructive at all and utterly inconsistent with explosives. The fact that there are so few of them also indicates a random, rather than deliberate, origin. I discussed this last year with poster metamars, here.

 

[Major_Tom]

It's not too fast at all. If there is a net pressurization, it would travel at the speed of sound, or approximately 343 meters per second. In the 0.72 seconds between detected motion and the onset of that particular dust jet, pressure could have risen as far away as 240 meters, or about 80 stories. The video actually disproves its own claim.

So you attribute the net pressurization of floor 78 at the point witnessed to be quite natural?


Thanks for your response.


One last thing, just to be sure I understand you.

From your answer it seems that you suspect this was just a broken window, and the pressure as a function of time on the 77th floor as witnessed is quite indicative of the general pressure one can expect this floor to be at due to volume compression of the lower block.

It that pretty much your answer, that the entire 77th floor would be under such pressure at that time and this window just acts as a type of "measuring instrument" by which we can see the degree of such pressure?

It is also possible the jet was caused by something before the collapse started. There are several "puffs" of smoke and dust that happened well before collapse, caused by local internal failures.

By a "something" you must mean something naturally compressive, like local floor failure?

These two options would express your opinion correctly and completely?

 

[FineWine]

So you attribute the net pressurization of floor 78 at the point witnessed to be quite natural?


Thanks for your response.


One last thing, just to be sure I understand you.

From your answer it seems that you suspect this was just a broken window, and the pressure as a function of time on the 77th floor as witnessed is quite indicative of the general pressure one can expect this floor to be at due to volume compression of the lower block.

It that pretty much your answer, that the entire 77th floor would be under such pressure at that time and this window just acts as a type of "measuring instrument" by which we can see the degree of such pressure?




By a "something" you must mean something naturally compressive, like local floor failure?

These two options would your opinion correctly and completely?

Can you tell us why nobody who works in demolition thinks the collapses of the towers resemble controlled demoltions? Are they all in on it?

Thanks in advance for your answer.

 

[R.Mackey]

So you attribute the net pressurization of floor 78 at the point witnessed to be quite natural?

Yup. There's certainly no evidence that it was otherwise.

From your answer it seems that you suspect this was just a broken window, and the pressure as a function of time on the 77th floor as witnessed is quite indicative of the general pressure one can expect this floor to be at due to volume compression of the lower block.

It that pretty much your answer, that the entire 77th floor would be under such pressure at that time and this window just acts as a type of "measuring instrument" by which we can see the degree of such pressure?

I don't think it's a very good measuring instrument, because we don't know the state of the window before the dust jet came through. Recall this was a structure that got hit by a bloody airplane, and burned for an hour afterward -- that particular window could have been cracked, stressed, heated, could have had junk leaned against it, anything.

A better measurement would be to consider the average of the windows. Surely some of them were close to being intact, even if we don't know which ones. Windows tend to withstand no more than about 2 PSI before shattering, usually less than that. Since the dust jet is an isolated event, and not all the windows are shattering -- or even those nearby -- this is further evidence that the pressure at that time is low, viz. < 1 PSI. This is in good agreement with the 0.17 PSI estimate we arrive at from estimation of the jet speed. This pressure is also consistent with the pressure estimate from the BLGB paper, which models the collapse mathematically.

En finale, all of our various observations agree with each other, and the event is not at all surprising.

By a "something" you must mean something naturally compressive, like local floor failure?

These two options would your opinion correctly and completely?

That is a possibility. Or it could be any of numerous other things. I'm not sure I understand the last bit you asked, but hopefully the above clarifies.

 

[T.A.M.]

God if we are going to resurrect a thread, can we at least post on topic with the OP.

Jeesh...I thought someone had decided to agree to a truce.

TAM

 

[Major_Tom]

I don't think it's a very good measuring instrument, because we don't know the state of the window before the dust jet came through. Recall this was a structure that got hit by a bloody airplane, and burned for an hour afterward -- that particular window could have been cracked, stressed, heated, could have had junk leaned against it, anything.

R Mackey, I haven't posted on this forum for some time and I assumed this would be an appropriate place to ask for your input on this single ejection which does puzzle me.

I appreciate your offer to address such questions and I won't pester you further if you suggest I shouldn't.


Just a tiny clarification on the above comment: If you attribute this ejection to the state of air pressure as function of time, how can the shape of the window hole affect the air ejection rate? If the quantity of air on floor 77 is much larger than the quantity of air escaping through this window (which I'm sure we won't dispute), how does could the shape of the hole in the window alter the velocity of air flow?

I would think that a system under pressure would eject air at a velocity proportional to the pressure and would not be dependant upon the particular shape of the hole (unless the hole is so large it depletes the air inside quickly or the hole is so small (like a crack) that air cannot freely move through it.

In short, if built-up pressure is the cause of the ejection, why wouldn't the speed of air flow directly relate to the air pressure inside?

Why couldn't we measure pressure P(t) by ejection speed?

 

[Furcifer]

R Mackey, I haven't posted on this forum for some time and I assumed this would be an appropriate place to ask for your input on this single ejection which does puzzle me.

I appreciate your offer to address such questions and I won't pester you further if you suggest I shouldn't.


Just a tiny clarification on the above comment: If you attribute this ejection to the state of air pressure as function of time, how can the shape of the window hole affect the air ejection rate? If the quantity of air on floor 77 is much larger than the quantity of air escaping through this window (which I'm sure we won't dispute), how does could the shape of the hole in the window alter the velocity of air flow?

I would think that a system under pressure would eject air at a velocity proportional to the pressure and would not be dependant upon the particular shape of the hole (unless the hole is so large it depletes the air inside quickly or the hole is so small (like a crack) that air cannot freely move through it.

In short, if built-up pressure is the cause of the ejection, why wouldn't the speed of air flow directly relate to the air pressure inside?

Why couldn't we measure pressure P(t) by ejection speed?

Venturi

 

[aggle-rithm]

Shape of the....window hole...?


...the hell...?

 

[R.Mackey]

Just a tiny clarification on the above comment: If you attribute this ejection to the state of air pressure as function of time, how can the shape of the window hole affect the air ejection rate? If the quantity of air on floor 77 is much larger than the quantity of air escaping through this window (which I'm sure we won't dispute), how does could the shape of the hole in the window alter the velocity of air flow?

It won't. Nor will size. Not much, anyway, under the assumption that there are numerous other paths for the air to escape and we aren't dealing with a blocked flow condition. I don't think I implied any shape effect.

I would think that a system under pressure would eject air at a velocity proportional to the pressure and would not be dependant upon the particular shape of the hole (unless the hole is so large it depletes the air inside quickly or the hole is so small (like a crack) that air cannot freely move through it.

In short, if built-up pressure is the cause of the ejection, why wouldn't the speed of air flow directly relate to the air pressure inside?

Why couldn't we measure pressure P(t) by ejection speed?

We can. As I said in the other thread, you can use the Bernoulli equation to come up with an estimate, and that estimate comes out to be about 0.17 PSI.

The other thing to keep in mind is that the airflow is slow enough to be considered incompressible -- so basically, everywhere in the structure between the collapsing floors, and the holes, the air is all flowing more or less steadily. If you work out the size of your "piston" and the location and size of the exits, you can estimate the airflow at any of them through a simple conservation of mass argument.

It'll be pretty rough, however, given the large number of fluid exits, and the rapid evolution of the problem. But for very rough numbers, i.e. comparing a subsonic pulse versus ejecta from an explosive, it's more than sufficient. There is nothing that requires explosives and cannot be explained through ordinary fluid mechanics.

 

[Dave Rogers]

Ryan, I think I should point out that Major Tom's motivation in asking these questions is not to settle any questions at all, but for the purpose of attacking your views on another forum that you've chosen not to join and on which you're not therefore in a position to defend them.

http://the911forum.freeforums.org/w...rged-before-the-collapse-initiation-t155.html

I understand the reaction of borderline nausea and disgust that some of the readers may have toward such "professional" knee-jerk reactions to the pressure question, since I have the same reaction.

I wanted to show the reader how the points in the video will be treated by our "experts".

You may want to reconsider whether to bother replying to someone whose motives are so obviously duplicitous. This is a transparent attempt to attack you in a forum where you can't defend yourself.

Dave

 

[R.Mackey]

While I thank you for looking after me, I don't think it's necessary. Major Tom will find that, since the answer I gave was scientifically accurate, his opportunities to use it for nefarious purpose are nil.

This isn't the first or even the tenth time they've done this with my words -- just go look at AboveTopSecret or any Truther forum. Anyone who's afraid of being quote-mined had better never interact with the Truth Movement at all, and even then it's a possibility.

 

[apathoid]

So what do you think it was, Major Tom? Surely you cannot be arguing that the phenomena witnessed is a "blast wave" of a explosive charge, right?