Merged David Chandler (ae911) sez "WTC7 was in free fall part of the time"

[Dave Rogers]

Could something similar have happened at the bottom of WTC7?

Well, there was a fire which was moving around as it exhausted fuel in different areas. What would have been a little tricky was sealing the sides of a building that, as photographs show, had some gaping holes in the south wall and southwest corner, and several windows broken along the east wall.

Transform quickly also the nitrogen in the air into some less voluminous gas and you can create a local bubble of underpressure.

Can you suggest an appropriate chemical reaction? Nitrogen tends to be relatively inert, and the reaction would have to be very fast to overcome the leakage of air in from the sides.

Of course air will be sucked in from the sides to eliminate this bubble - the underpressure will hardly be applied to the building above - but you never know what clever engineers are up to these days and evil persons misuse.

This is known as the "appeal to magic".

Dave

 

[Disbelief]

Weight (kg) or load (kg) = mass (kg). Yes, I am an engineer. What are you?

As others have pointed out, weight and mass are not the same thing and I would expect an engineer to understand that. If you want to know what my profession and training are in, you can always locate the expertise thread since I clearly spell it out.

 

[Heiwa]

As others have pointed out, weight and mass are not the same thing and I would expect an engineer to understand that.

Yes, yes - I understand that (as should be clear from above), that weight is a force (N) but to make that force/weight easier to understand I divide by g and present the force/weight in kilograms (easy to understand) which happens to be the mass of the object the force is acting on. In a similar way I sometimes define a force in tonnes! Children, my audience, know what a tonne of rock is but hardly what 10 000 N is!

BTW - don't you find it strange that NIST can not inform what software they used to analyse, to identify the failures, to keep track of loose parts, etc, that would simulate the WTC7 collapse as described in the NIST report?

I find it amazing. NIST presents a final report of a structural collapse ... and they cannot tell us what tool (software) they used to do the 1 000 000's + of calculations involved. Or did they do it long-hand? And what units were used?

 

[Heiwa]

This is known as the "appeal to magic".

Dave

Not really! Vacuum is not magic. It creates big forces that applied on masses accelerates the masses (when you get the units right). And topic is why WTC7 intact top part accelerates so fast during collapse! I suggest vacuum assists (down below in the lower part). FGS, it is not a conspiracy theory. It is a suggestion based on real physics. Not the NWO Hollywood stuff produced by NIST that most JREF-posters believe is reality. Sometimes I believe this Shyam Sunder is working for Hollywood to improve his standard of living .

 

[~enigma~]

Good, simple question. Remember the (children's) experiment with a lit candle inside an upside down glass jar with its opening below water? The candle burns for a while and then the flame dies. And water rises into the jar. You know what happened! The oxygen in the air reacted with the carbon of the candle and became carbon(di)oxide that has less volume than air (which is 21% or so oxygene, the rest is mostly nitrogen). The volume of air was reduced and produced an under pressure inside the jar - water was sucked in.
Could something similar have happened at the bottom of WTC7? Transform quickly also the nitrogen in the air into some less voluminous gas and you can create a local bubble of underpressure. Of course air will be sucked in from the sides to eliminate this bubble - the underpressure will hardly be applied to the building above - but you never know what clever engineers are up to these days and evil persons misuse.
I still wonder how these strange pieces of junk came about seen in the WTC7rubble. Not by released potential energy for sure.
And what kind of structural damage software is NIST using to describe the collapse?
It is questions like those that should be answered first to sort out this mystery (conspiracy).

Alchemy brought WTC 7 down. You do realize your digging yourself really deep don't you?

 

[Ragnarok]

As far as I understand you can even see the tilt in this video:

http://www.dailynewscaster.com/2008...e-of-building-seven-and-north-tower-collapse/

Yes, and before the building even starts moving, there are a large number of windows along the right side of the image ( .55 secs in.), seemingly blasted out. Anyone want to offer an explanation for that?

 

[Dave Rogers]

Not really! Vacuum is not magic.

The appeal to magic is committed when you correctly identify the problem with your hypothesis (the impossibility of creating a good seal around the lower structure to allow the vacuum to be created), then dismiss it by saying that you're sure some clever engineer can come up with a way of doing it. Your hypothesis rests on the bare assertion that this is possible, despite the physical difficulties involved. As a clever engineer who's good at coming up with explanations for physical impossibilities, why don't you suggest a mechanism yourself?

Dave

 

[Mr.Herbert]

Yes, and before the building even starts moving, there are a large number of windows along the right side of the image ( .55 secs in.), seemingly blasted out. Anyone want to offer an explanation for that?

You are mistaken. Perhaps you have not had the opportunity to watch a non truther video that shows the complete collapse.

Gravy does a great job here:

http://wtc7lies.googlepages.com/wtc7videoincludingeastmechanicalpenthous

I suggest you go there to educate yourself.

 

[Dave Rogers]

Yes, and before the building even starts moving, there are a large number of windows along the right side of the image ( .55 secs in.), seemingly blasted out. Anyone want to offer an explanation for that?

They don't seem to be "blasted out", as there's no sign of debris being blown outwards. The window apertures appear to lose their reflectivity abruptly. The simple, non-conspiratorial explanation would be that the building was flexing in that area, and that the flexure was enough to break the windows.

Dave

 

[Ragnarok]

If Building 7 was not controlled demolition then I would think that the collapse would be studied to determine how building demolition experts can use this mechanism of spontaneous symetrical collapse so that the expense of explosives, labor, and time could be avoided in the future.

Any comments?

 

[Ragnarok]

They don't seem to be "blasted out", as there's no sign of debris being blown outwards. The window apertures appear to lose their reflectivity abruptly. The simple, non-conspiratorial explanation would be that the building was flexing in that area, and that the flexure was enough to break the windows.

Dave

No, the windows seem to turn the same colour as the broken windows dotted along the left of the building( presumably nearer the fire source). If the windows were broken by air pressure from the building shifting out of line of sight, why were these effects not more random, or at least, less specific? There didn't seem to be any other places along that face that it happened to? Although it is odd that nothing happened to the windows on the wall at a right angle to it?

 

[Grizzly Bear]

"If Building 7 was not controlled demolition then I would think that the collapse would be studied to determine how building demolition experts can use this mechanism of spontaneous symetrical collapse so that the expense of explosives, labor, and time could be avoided in the future."

Any comments?

Cutting corners for the sake of saving a few bucks is asking for legal litigation if not imprisonment of any demolition company personnel that decides to use uncontrolled methods to meet such ends.

Apparently your source doesn't care for the public dangers posed by setting the structure on fire for several hours uncontrolled or the likelihood of the building causing collateral damage when collapsed (Fitterman Hall comes to immediate attention). That statement you quoted is quite bluntly either brain dead stupidity or blatant sarcasm. I won't try to presume which.

 

[Ragnarok]

Cutting corners for the sake of saving a few bucks is asking for legal litigation if not imprisonment of any demolition company personnel that decides to use uncontrolled methods to meet such ends.

Apparently your source doesn't care for the public dangers posed by setting the structure on fire for several hours uncontrolled or the likelihood of the building causing collateral damage when collapsed (Fitterman Hall comes to immediate attention). That statement you quoted is quite bluntly either brain dead stupidity or blatant sarcasm. I won't try to presume which.

When you put it like that, fair dos.

And my post after that?*


* Apologies, I thought you was Dave there. You can still reply if you want!

 

[Dave Rogers]

No, the windows seem to turn the same colour as the broken windows dotted along the left of the building( presumably nearer the fire source). If the windows were broken by air pressure from the building shifting out of line of sight, why were these effects not more random, or at least, less specific? There didn't seem to be any other places along that face that it happened to? Although it is odd that nothing happened to the windows on the wall at a right angle to it?

I suggest you go back and read my post again, then respond to the post I actually made, rather than the one you'd like me to have made. In particular, I didn't mention air pressure, for the very simple reason that those window breakages don't look like they were caused by it.

Dave

 

[Ragnarok]

I suggest you go back and read my post again, then respond to the post I actually made, rather than the one you'd like me to have made. In particular, I didn't mention air pressure, for the very simple reason that those window breakages don't look like they were caused by it.

Dave

Oh, so they are 'window breakages' now, and not 'changes in reflective structure'*? So, are you saying that some kind of torque strain caused this effect?


* Although I can see how they might mean the same thing.

 

[Dave Rogers]

Oh, so they are 'window breakages' now, and not 'changes in reflective structure'*? So, are you saying that some kind of torque strain caused this effect?


* Although I can see how they might mean the same thing.

Yes, it looks to me like flexure of the structure caused windows to break*, and the broken windows look like broken windows elsewhere in the structure. There doesn't appear to be any blast involved.

Dave

*Which is why I said "...the flexure was enough to break the windows".

 

[CHF]

Why do truthers have such a hard time understanding the concept of gravity?

 

[Ragnarok]

missed the edit.

If so, how does that fit into a sequence of 'expulsions' elsewhere, where they rise up the building, instead of fall, as you'd expect if air was pushing the windows out. Does your flexing building account for that?

 

[Ragnarok]

Why do truthers have such a hard time understanding the concept of gravity?

Call me what you will, but since when have questions caused any harm? You don't have to respond. You don't even have to read it, if you are that fed up.

Toddle off, "Friends" might be on.

 

[Grizzly Bear]

missed the edit.

If so, how does that fit into a sequence of 'expulsions' elsewhere, where they rise up the building, instead of fall, as you'd expect if air was pushing the windows out. Does your flexing building account for that?

The expulsions from what I understand are based on similar dynamics as what we saw with the towers, material such as ash, soot (products of the interior fire), and other light weight materials were forced out via air pressure as the structure collapsed. Given that the failure in WTC 7 happened lower in the structure relative to what was seen with the towers, the difference in the behavior isn't that terribly surprising in so far as I can tell.