Has Anyone Seen A Realistice Explanation For Free Fall Of The Towers?

[WildCat]

A CT'er would point out that the Windsor building in Madrid suffered some collapse in the upper levels but maintained its integrity.

And a rational thinker would point out that the Madrid tower was a concrete structure, and the only part that collapsed entirely was the section made of steel.

Madrid supports the accepted view of what happened, not the conspiracy nutter view.

 

[Belz...]

Except for the components that are forced outwards and don't make contact with the standing components that remain. This is what einsteen is trying to discuss.

REALLY ? That's fascinating. How exactly are they forced outwards if they DON'T make contact with other components ?

If a CT'er expressed such an opinion here they would be quietly put in their place. "I really don't see..." is just waffle. Have you done the calculations? Please present them.

Gumboot is correct: a great deal of energy is NOT required to initiate the collapse, specifically because gravity is a source of tremendous force, in this case, all on its own. All you need is for a single floor to fail.

So you're likening a 400m steel-framed building, with considerable cross-bracing, to a horizontal line of dominoes each of which is unconnected to its neighbour? Lines of falling dominoes don't accelerate. The analogy is flawed in so many ways it's nearly pointless discussing it.

The simplest examples are usually those least understood. His point, if I may, was to illustrate how little energy can be required to initiate a chain reaction.

A CT'er would point out that the Windsor building in Madrid suffered some collapse in the upper levels but maintained its integrity.

Two words: CONCRETE CORE. The only thing that failed at those floors was the STEEL.

 

[R.Mackey]

It's fair to analyse your post the way CT'ers posts get analysed.

Hello again, GlennB.

In this post, down towards the bottom, I showed einsteen how to do a rough calculation to see what percentage of material would have to be totally ejected to make much difference in (a) collapse time or (b) halting collapse entirely.

It's a very large fraction.

At collapse initiation, there is no debris falling away from the structure, since the blocks haven't begun to fragment yet. After initiation, even if every new floor hit was completely ejected, the collapse would still progress, and only slightly slower, according to conservation of momentum.

Greening does not require the upper block remains "intact" as you claim. All he uses is the block's momentum, which is the same regardless of its condition, be it a monolithic chunk or a big pile of baby powder.

It's up to you guys to show otherwise. I support einsteen if he wants to go ahead with this calculation. And please don't use Excel... get help from an academic if you don't know what you're doing.

-----

I guess I'll join in on the "qualification" party --

B.A. Mathematics / B.A. Physics
M.S. Aeronautics
Eng. Aeronautics
10 years at NASA, currently senior technical staff, task manager, and PI

I am not a structural engineer, though I have studied related fields of solid mechanics, FEA, etc.

I'd also prefer you try to find holes in my arguments than worry about my resume. But I am not completely talking out of my hat.

 

[David Wong]

REALLY ? That's fascinating. How exactly are they forced outwards if they DON'T make contact with other components ?

I believe they think explosives were there in a quantity great enough to actually eject most of the building outward when they detonated.

Which would be a lot.

 

[Hellbound]

Except for the components that are forced outwards and don't make contact with the standing components that remain. This is what einsteen is trying to discuss.

I don't think anyone is arguing that no material was forced out. In fact, debris was found several blocks away, and buildings damaged in a a large radius.

If a CT'er expressed such an opinion here they would be quietly put in their place. "I really don't see..." is just waffle. Have you done the calculations? Please present them.

True, but we really don't have to get into complex math yet. I'll explain in a moment.

So you're likening a 400m steel-framed building, with considerable cross-bracing, to a horizontal line of dominoes each of which is unconnected to its neighbour? Lines of falling dominoes don't accelerate. The analogy is flawed in so many ways it's nearly pointless discussing it.

Not really pointless, althoguh I'd agree that dominoes are a poor analogy. Tinker Toys or Erector Sets, that might get us somewhere. And the same basic principles apply. You remove some of the supports and braces on the lower parts of the structure (especially with weight and load on the upper portions) and the structure falls. You don't have to have enough energy to move every pice of the structure. Just enough for some supporting members to be removed. The rest of the energy comes from the enormous gravitational potential energy stored in a building.

A CT'er would point out that the Windsor building in Madrid suffered some collapse in the upper levels but maintained its integrity.

Others have pointed this out. The Windsor was a combination steel/concrete structure. Only the concrete portions remained standing, the steel portions collapsed completely.


Now, on the amount of material ejected. We really only have to agree on one aspect to put this pretty well to rest:

Do you believe that the fall of ten floors (the area above the damaged portion in WTC1) has enough energy to collapse one floor?

If the answer is yes, then even assuming 90% of the material is ejected then the collapse will continue progressively throughout the building. 10 floors is roughly 90% of the building. So making a few simplifications (assuming the fllors each had the same mass, etc), then each time it impacted a floor it could eject an amount of mass equal to the entire weight of that floor, and still maintain the same amount of mass as the original impacting section.

 

[kevin]

Master of flame wars. I have no other credentials. I'm just a computer programmer who's equipped with logic and reasoning skills beyond those of a common household rat.

You forgot to mention you're irrelevant.

 

[GlennB]

REALLY ? That's fascinating. How exactly are they forced outwards if they DON'T make contact with other components ?

Are you familiar with the concept of "vectors"? You seem to be assuming that anything falling must be falling straight down. A falling item in the collapse might be falling at anywhere from 0 to 89 degrees from the vertical - it's still falling - but will impart varying degrees of its energy to the structures below, depending on the angle of fall.

Gumboot is correct: a great deal of energy is NOT required to initiate the collapse, specifically because gravity is a source of tremendous force, in this case, all on its own. All you need is for a single floor to fail.

This looks like an assertion. I have a film to hand where a multi-storey building was blasted at the base (CD), fell one storey and just sat there, otherwise intact. Is that admissible?

The simplest examples are usually those least understood. His point, if I may, was to illustrate how little energy can be required to initiate a chain reaction.

It's fair to say that falling dominoes was a poor analogy. They don't accelerate.

Two words: CONCRETE CORE. The only thing that failed at those floors was the STEEL.

Accepted, but missing the point. That example was there to illustrate the weakness of impressive but inaccurate comparisons. it was there to weaken the CT argument, not support it (although spalling is an interesting subject that's worth debate)

(why do I have to enter some text outside the quote? )

 

[Belz...]

(why do I have to enter some text outside the quote? )

Because you're not using the quote function properly.

Are you familiar with the concept of "vectors"? You seem to be assuming that anything falling must be falling straight down.

Oh, golly. In order for a vector to exist, the object has to hit SOMETHING.

This looks like an assertion. I have a film to hand where a multi-storey building was blasted at the base (CD), fell one storey and just sat there, otherwise intact. Is that admissible?

I saw that film. I don't know what differences may or may not exist in struture between that building and WTCs 1 and 2, but I know it only fell one floor.

It's fair to say that falling dominoes was a poor analogy. They don't accelerate.

Are you saying that, in the case of the WTC, the effect would be even MORE prominent ?

Accepted, but missing the point.

I'm starting to get tired of reading that particular arrangement of words.

That example was there to illustrate the weakness of impressive but inaccurate comparisons. it was there to weaken the CT argument, not support it (although spalling is an interesting subject that's worth debate)

You said it remained standing, implying that it should have been the case for the WTC. How does this "weaken" the CT argument ?

 

[Pardalis]

Because you're not using the quote function properly.

I think he knows that. Red makes so much more of an impression...

 

[T.A.M.]

It would be a good idea to remember this thread, who ever it was who was talking about doing up a list of intellectuals to oppose the "scholars". Seems like there are quite a few people here who could easily out match them on qualifications alone.

TAM

 

[GlennB]

I think he knows that. Red makes so much more of an impression...

That's just childish. I wanted to put my comments next to the appropriate sections of the original post. If you have a preferred colour I'd be happy to oblige. Blue? Green? Yellow? Don't mind.

 

[Architect]

Hello again, GlennB.


I guess I'll join in on the "qualification" party --

B.A. Mathematics / B.A. Physics
M.S. Aeronautics
Eng. Aeronautics
10 years at NASA, currently senior technical staff, task manager, and PI

I am not a structural engineer, though I have studied related fields of solid mechanics, FEA, etc.

I'd also prefer you try to find holes in my arguments than worry about my resume. But I am not completely talking out of my hat.

So, to summarise there are a good few of us with qualifications absolutely coming out of our ears, postgrad as well as undergrad, and in many cases relevant to the matters at hand. I wonder if Chris and the CT brigade can say the same....

 

[T.A.M.]

The Scholars have a lot of people with advanced degrees, absolutely. No doubt. A huge percentage of them, particularly in their Full Time Membership, are degrees in areas totally unrelated to the events of 9/11.

I would venture even taking those on this board who have posted theres, and those who haven't, but who possess them, it would be comparative to the list they have of those who are "legitimately" qualified. Thats not to mention those here who are incredibly gifted with common sense, fantastic memories, and great debating skills, along with those of us who have advanced degrees that are in the areas of science, but not directly linked to the physics and engineering fields.

You then take the hundreds involved in NIST, and FEMA well...we all knew that anyway...

Still, if they every question the qualifications of the "JREF" crowd as they call us, we know we can tell them to stuff it.

 

[Architect]

The Scholars have a lot of people with advanced degrees, absolutely. No doubt. A huge percentage of them, particularly in their Full Time Membership, are degrees in areas totally unrelated to the events of 9/11.

Put it this way. I wouldn't visit my accountant because I had toothache, even if he is degree qualified.

 

[GlennB]

Do you believe that the fall of ten floors (the area above the damaged portion in WTC1) has enough energy to collapse one floor?

Yes, I do. The earlier reference to a building that just sat there after the ground floor was CD'd was of course irrelevant as the remaining structure was perched on solid ground, not the upper 90 storeys of a skyscraper.

If the answer is yes, then even assuming 90% of the material is ejected then the collapse will continue progressively throughout the building. 10 floors is roughly 90% of the building. So making a few simplifications (assuming the fllors each had the same mass, etc), then each time it impacted a floor it could eject an amount of mass equal to the entire weight of that floor, and still maintain the same amount of mass as the original impacting section.

I presume the 90% you quote is a typo and should read 10%. But assuming that then, yes, once the collapse was initiated the building would collapse to the ground. I'm not disputing that. The rate of fall, though, would depend on the rate of loss of material at each floor impact.
(The acceleration observed in the collapse has been explained by an accumulating mass of material that impacts each successive floor, causing that to collapse quicker than the previous floor. If I'm misunderstanding that principle then I'm very happy to be put straight)

This is what einsteen is trying to establish, and coming in for unwarranted slagging off (as we say in the UK) while he's attempting reasonable debate.

.

Is green OK?

 

[GlennB]

So, to summarise there are a good few of us with qualifications absolutely coming out of our ears, postgrad as well as undergrad, and in many cases relevant to the matters at hand. I wonder if Chris and the CT brigade can say the same....

Tread carefully. That's the way to sophism.
Some "well qualified" bods thought they'd discovered cold fusion a few years ago.

 

[William Rea]

Mature reply...which believe it or not, I actually expected.

I am sure the occasional flame will come, tis expected with life on the boards. You will find that those who debate you vigorously may use some words you may not like, such as "crap" or others, but as you said, you are new to this, they are not. Some of these guys have been here for years debating people, and I guess occasionally they get fed up, but I cant really speak for individuals.

Debate on, and I will resume watching, listening, and learning.

TAM

TAM, I have voluntarily decided to withdraw from the thread for a while to let the obvious hostility to my opinions recede and let the hot heads cool down a bit. Maybe then you guys can return to discussing what really matters and not go out of your way to be offended by anything I post.

I am not new to debating on forums but as I said I am new to the CT thing because it is something that I don't go out of my way to find on the internet.

I have to say that I trawled through several threads before deciding to join this forum and thought it might be a good place for skeptical debate with adults. it's a real shame that it turns out to be as childish and clique ridden as most other forums including the awful religious fundy sites. The pack mentality of rapid posting someone who is trying to formulate an idea is reprehensible. I have no problem being vigorously questioned about my opinions but I do object to the flaming etc and I despise the intellectual dishonesty of people who do it and then raise their hands saying it wasn't me Guv!

I will be back.

By the way I am a BSc (Hons) in Mechanical Engineering, and for the US people I guess I ought to add that I majored in structural properties of materials. I am a practical rather than academic Engineer hence I did not continue with any formal post graduate studies or research). I am currently working with high temperature non-ferrous superalloys as I have gained an extensive practical knowledge of metallurgy in my 20 years work experience (which I have become expert in despite my original degree being mechanical).

 

[William Rea]

Put it this way. I wouldn't visit my accountant because I had toothache, even if he is degree qualified.

But a Doctor or a vet might be able to help you out mightn't he.

 

[Architect]

But a Doctor or a vet might be able to help you out mightn't he.

Well that depends upon the cause, doesn't it? If it's an infected abscess then I'm sure they might get it and prescribe antibiotics, but I wouldn't think they could manage fillings or crowns.

Parallel: I understand basic structures, because it is an important part of the architecture curriculum, but frankly I couldn't do the calcs for anything complex. And you wouldn't want the engineer doing the architecture......

 

[William Rea]

Actually, I believe I brought up the trees....
-Andrew

Isn't that what I said?



Did I or didn't I, even Belz is arguing that I didn't bring up the tree analogy when I already stated I didn't. Like I also said, I had no idea that Judy Wood even existed when I made the intial description.



You guys are funny.