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9/11 Physics from Non-Experts

You need to read up on this. They admitted their involvement to Al-Jazeera in 2002, prior to their arrest.
 
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R.Mackey said:
You need to read up on this. They admitted their involvement to Al-Jazeera in 2002, prior to their arrest.
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You are right. I need to read up on that.

Somehow I accidently got myself involved in a big discussion regarding the feasibility of CT. Anyone who's interested please start a new thread. I promise I will go nowhere near it.

Meanwhile, I would be very appreciative if you have any input regarding my post above (CDL, SDL, and LL).
 
GregoryUrich said:
Somehow I accidently got myself involved in a big discussion regarding the feasibility of CT. Anyone who's interested please start a new thread. I promise I will go nowhere near it.
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Of course, I fully understand, please continue to concentrate on the piece of the jigsaw that no matter how many times you reshape it, it will never fit into the big picture.
 
GregoryUrich said:
I'll have to get back to you Gravy, that's quite a homework assignment. It's late over here so you guys will have to find someone else to edify this evening.
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Yea. Nice retort.

Now take your time and 'get back to' him as soon as you can, m'kay?
 
GregoryUrich said:
Mackey, or anyone else,

2. Regarding core column fire proofing, I am considering using 2" gypsum everywhere. This will be a pain in the butt because I need to calculate the surface area for all of the columns but such is life. I am planning on ignoring tile because the majority of columns are unexposed.

3. Is it reasonable to assume spray on fire proofing for the floor beams and steel deck?
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I thought the columns had 3 inches of wallboard.

You could start at [URL="http://www.patriotsquestion911.com/."]http://www.patriotsquestion911.com/.[/URL]
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who on this long list has something useful. You did bring up this set of people. Who are the ones with the goods?
 
beachnut said:
who on this long list has something useful. You did bring up this set of people. Who are the ones with the goods?
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Don’t forget Beachnut he is not interested in the big discussion, he has said so. This is why he brings these things up, because he is not interested in the big picture.

If you are not interested Greg why bring it up ?
 
I haven't read this whole thread. Has anyone proposed this method already for calculating the weights of the upper WTC stories?

forum.physorg.com/index.php?showtopic=7444&view=findpost&p=122431

Basically, you sum the column loads on all 287 columns at one level to get the weight of the tower block above. You subtract two consecutive levels to get the weight of one typical storey (tenant floor, mechanical floor or hat truss floor)

This being based on the data NIST collated for the purposes of the Global Model, it should include everything, including the weight of the aircraft wreckage in the post-impact tables.

I've copied all these in Excel tables so as to get the weight of all the modeled floors.
 
stateofgrace said:
Don’t forget Beachnut he is not interested in the big discussion, he has said so. This is why he brings these things up, because he is not interested in the big picture.

If you are not interested Greg why bring it up ?
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He says he is not a 9/11 truth person, but posts the bigest 9/11 truth sites around.

Does Wesley Clark know he is on a list of fools? Do those on the list know they are on a list to fool idiots? [URL="http://www.patriotsquestion911.com/."]http://www.patriotsquestion911.com/ [/URL]
 
Upper block mass using values in NIST NCSTAR 1-6d, p240 in pdf (p176)

WTC1 column loads at 96-97 (loading due to stories 97-110; 14 stories)
peri: 11065 + 11145 + 8012 + 8040 = 38262 kips
core: 41633 kips
total: 79895 kips = 36.3E6 kg

WTC2 column loads at 81-82 (loading due to stories 82-110; 29 stories)
peri: 12367 + 12292 + 17728 + 17673 = 60060 kips
core: 71824 kips
total: 131884 = 59.9E6 kg

BZ estimates of upper block mass:

WTC1: 58E6 kg
WTC2: 87E6 kg

Compare BZ estimate with NIST values:

WTC1: 58/36.3 = 1.60
WTC2: 87/59.9 = 1.45

Compared with NIST values, BZ overestimated the upper block masses by 60% and 45%.
 
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shagster said:
Upper block mass using values in NIST NCSTAR 1-6d, p240 in pdf (p176)

WTC1 column loads at 96-97 (loading due to stories 97-110; 14 stories)
peri: 11065 + 11145 + 8012 + 8040 = 38262 kips
core: 41633 kips
total: 79895 kips = 36.3E6 kg

WTC2 column loads at 81-82 (loading due to stories 82-110; 29 stories)
peri: 12367 + 12292 + 17728 + 17673 = 60060 kips
core: 71824 kips
total: 131884 = 59.9E6 kg

BZ estimates of upper block mass:

WTC1: 58E6 kg
WTC2: 87E6 kg

Compare BZ estimate with NIST values:

WTC1: 58/36.3 = 1.60
WTC2: 87/59.9 = 1.45

Compared with NIST values, BZ overestimated the upper block masses by 60% and 45%.
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Or NIST underestimated. But what does it mean? It does not mean global collapse could not happen. That was proved on 9/11, global collapse did happen. Does global collapse happen with less weight? What about Ross, what did Ross use?

With less weight, does that mean the structure below is weaker too. If someone over estimates the upper weight, did they also over estimate the strength of the upper portion below the impact? It appears, no matter how you model the WTC, the WTC towers failed and fell due to impact and fire. I have to go back and talk to Robertson each time and he said the impacts were an order of magnitude greater than the impacts they had planned on for aircraft. 7 to 11 times greater impact energy from aircraft, and fire now inserted into the building, whereas if the plane was at design speed, most of the fire would be outside from the jet fuel.

Robertson had to have a say, he built the towers, he was the chief structural engineer. The buck stops with Robertson. See what he said. What do you think? Run the numbers, what is the minimum weight needed to sustain a global collapse?
 
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Welcome to the forum, Carefulplease and shagster. I've suspected that Bazant overestimated the upper block masses, but never looked further into it. Your method and numbers look good. According ot BZ and BV (2006), though, using NIST's masses would have also resulted in global collapse, and that's with the very conservative assumptions of equal load distribution and axial column loading. If that is true (my math and physics skills are poor), then the question of NIST's accuracy comes into play. I guess that's what Gregory Urich is working on.

Edit: shagster, your post is gone, but lives on in beachnut's memory. Did you forget something?
 
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I corrected some values in the post. Beachnut's post is the old one that has an error. I use 14 and 29 stories to represent the upper block mass above the central region of the aircraft impacts.
 
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GregoryUrich said:
You seem confident that it is more complex than I think it is. Are you an expert? How much do you know about my knowledge in related areas?
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I suggest you re-read my comment. You are the one who explicitly stated you were not a demolitions expert, and yet you confidently proclaimed that the alleged demolition could have been achieved with no more than two persons. I cannot see how you can reconcile these two things.

If you're not an expert, if you're not familiar with the workings of that industry/occupation, then on what basis do you make your claim that you can't imagine it taking more than two people? Just because you don't think it could be that complicated? Sorry, but that's just a complete guess on your part.

My comment was intended as a caution for you, or anyone else, that to assume that a task isn't complicated simply because on its face you can't perceive it as being complicated is an unwise assumption to make. There are usually many more details and technicalities to a particlar profession than may appear to be the case at face value. My example of retail flyers was an example attempting to illustrate that (and one I am familiar with since I used to work in that field).
 
The NIST FEA model that was used to calculate the lateral sway period of the towers agrees closely with measured lateral sway periods. The tower mass in the NIST model can't be far off from the actual value.
 
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The NIST global FEA model has surfaced on the web. Someone obtained it from NIST after requesting it and paying a reasonable processing fee for it. I've run it on SAP2000 software but only briefly. We should be able to extract the mass above any floor using the software. I haven't taken the time to do this yet.
 
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