Physics Prof Says Bombs not Planes brought down wtc

When considering the concrete floors in the towers and the forces applied to them, it is helpful to keep in mind that they were only 4 inches thick. To help visualize just how thin that was in relationship to the floor as a whole consider this:

A standard potato chip averages about 55/1000 of an inch thick. If an average potato chip is 2 inches long by 2 inches wide, then the ratio of the area to the thickness is around 73. the equivalent area of floor space that would have the same area to thickness ratio for a thickness of 4 inches is about 25 square feet.

The tower floors were almost an acre in size.




Edit:

To continue the analogy further, to represent the tower floors in potato chips, you would need an area 6’8” square covered with potato chips to get the equivalent size of the tower floor plan based on the thickness of a standard potato chip.

I’m getting hungry



[edit on 16-12-2005 by HowardRoark]

Originally posted by bsbray11
Maybe you missed the fact that the safety factor ratings make the weights totally irrelevant, anyway, eh? The given weight could be 2 kg per floor, and (if we had the amount of weight each floor could withstand before 75% failure) we could still find out when the momentum was depleted.

Actually since the safety factor is only accounting for static loads, it is the safety factor which is completely irrelevant. The energy of the caps hitting the next floor is the real issue. No one designs buildings with dynamic loads in mind. No one plans on the top ten floors of their building falling onto the next floor.

Originally posted by billybob
the floor trusses pulled in the exterior columns, causing bowing. now, because the clips that hold these floor trusses to the exterior columns were the weakest link in the structure, they gave out, which caused all the core columns and the perimeter columns to also give out, which caused the 'cap' or the broken off top piece of the building, to fall one floors worth of height in freefall, which then translated the entire gravity accelerated weight of the cap instantly on the remaining lower part. once the global collapse was initiated, global collapse was inevitable.

did i get it right, howard?

Pretty close, except that it might not have been even necessary for the clips to have failed at all since a buckle tends to be self propagating. Once the exterior columns started to buckle inward, the entire structural system was imperiled. Even if the clips never failed at all, the buckle would have gotten progressively worse until the whole column system failed.

Look again, this isn’t just one or two columns, it is the entire side of the building that is starting to buckle inward.

Wecomeinpeace,

Just as I had suspected; no work, no calculation, no answer, nothing! I knew you werent going to be able to do this INCREDIBLY SIMPLE air resistance calculation.

Your good at calculating freefalls in vacuums, but when you throw in air resistance, all of a sudden, you dont even know where to start. I intentionally thought up THE SIMPLEST air resistance problem I could, and you still couldnt even touch it. You have proven my whole point that I have been saying all along about you and your buddies. You had a chance to prove me wrong, that your smarter than I thought, but instead you just get egg on your face.

I think it's funny how you know all the terms and concepts; drag coefficients, how air resistance is proportional to the object's current velocity, etc., yet you cant even solve a simple relevant math problem that involves them.

I dont see how you can expect to get the calculations for the hard evidence backing your demolition theory if you cant even calculate and object falling down with air resistance. Calculating a collapsing sky scraper is way more complex than that. I dont even see why you even bother googling this stuff if you cant actually use and apply the knowledge. It kind of defeats the purpose doesnt it? Whats the point of looking all that stuff up if the only thing you are going to do is calculate freefall in a vacuum and some KE calculations?

This totally proves my point, you dont know what you are talking about, you dont know what you are doing. Stp acting like you "know the truth", and that you're "so scientific" about it.

So, I'm calling your bluff here and now. I know extremely little about air resistance calculations, and I'll wager the same is true for most folks here, but YOU apparently are the expert. So go ahead and DO the calculations. Show us how much air resistance the structure and individual components would have encountered across the collapse and tell us what influence it would have had, if any, on the collapse times, and the distribution of debris. Here are the NIST reports on the buildings and collapses, which should have all the figures you need to work it out:
wtc.nist.gov...
We're not experts, we never claimed to be, but YOU do, bob. When I come across problems that I need assistance with, I U2U people who ARE experts like Valhall and ask for advice. But I'm sure you won't need that, because again, you're a scientific genius. So go ahead and show us. Put your money where your mouth is.

So you know all the concepts and terms, and know better than me of course, and can tell Im full of it, but once you have to get mathematical, you only know "extremely little"? okay, right..

I challenged you on calculating fall with air resistance, which you proved you couldnt even touch, and here is where I show that I have the right to criticise you on that and to make that kind of challenge. Here's the calculations you should have been able to come up with:

the problem I gave you can be modeled with this differential equation:

v'(t) =9.8 -.5v(t)

.5 has to be negative, and g has to be positive even though gravity pulls downward, or it wont work. and the general solution to this is:

v(t)=19.6 + c*exp(-.5t)

assuming the intitial velocity is 0, we solve for c which is:
0=19.6 + c*exp(-.5*0)
0=19.6 + c*exp(0)
0=19.6 + c
-19.6 = c

so now we have the actual solution, which is:

v(t)=19.6 -19.6*exp(-.5t)

then multiply by -1 so downward direction is negative

v(t)=-1(19.6 -19.6*exp(-.5t))

v(t)= -19.6 + 19.6*exp(-.5t)

This solution tells me the velocity of the falling object at any given point in time, to find the object's position in space at any given point in time, I just integrate the actual solution to get:

P(t)= -19.6t - 39.2*exp(-.5t) + c

So we need to solve the the constant of integration c, which will give us the
correct initial position, 0.

0 = -19.6*0 - 39.2*exp(-.5*0) +c
0 = -39.2*exp(0) + c
0 =-39.2 + c
so c = 39.2

which makes

P(t)=-19.6t - 39.2*exp(-.5t) +39.2

to find out how long it takes the object to fall 157.9 meters, I
set P(t) = -157.9 and solve for t. I used the Newton-raphson method to get:

10.04272773 seconds

So it takes the object 10.04272773 seconds to fall 157.9 meters when the air resistance coefficient is .5 and initial velocity is zero! compare this time to 5.676661853 seconds which is freefall of 157.9 meters in a vacuum.

get Macmerdin to check this, he's supposedly a structural engineer, he should totally understand what I just did and can confirm it's correctness.

Now why couldnt you provide me this WCIP?



to bsbray,

Originally posted by bsbray11
When it comes to 9/11, again, we cannot provide figures because the information is not available. It isn't a matter of it being right or wrong, or being able or unable to provide calculations. We simply aren't being provided with the means.

so what neccesary figures have they failed to provide? give me a list.

Most of the problems that we've been describing, as LeftBehind has put it, with "essays," are based upon common sense when it comes to physics; the problems are based upon what you and I can observe and deduce, as on a daily basis, without having to do anything with mathematics. When you prick your finger and it squirts blood 12 feet into the air, then common sense would dictate that what you have is no ordinary finger prick. Would you have to whip out formulas and etc. to realize why something like that would be odd? If not, then what, to you, appears so normal about the lack of retardation in the collapse speeds? Do you not understand the principles behind momentum, or what? Surely you can respond to that question without having to ask for some sort of mathematical proof of its existence or of it being a problem in the first place; just watch any video of either collapse. I have no idea how you can put on being so enlightened when it comes to maths and sciences and blatantly disregard these obvious problems, with or without the math.

Well, I can see what you are saying in asking why do we not need math in judging that a big squirting finger prick is abnormal yet we would need it to determine weither a collapse was gravity driven or not. Its true, in many everyday instances, we dont need to whipout calculations to make accurate inferences. My answer to that would be that in some situations we have more experience in than others. A person has cut himself many more times in his life then he has observed live building collapses and demolitions. So based on his experience, his intuition will be more reliable and accurate than in situations he has less experience in. Another reason is in some situations, your inferering something really complicated based on a small set of observations. perhaps the evidence suggests that even the simnplest explanation will be very complex. While in others, your intuition says that very simple explanations can explain the small set of observations. In the situation, where the inference is complex, such as the orchestration of a big conspiracy, and the evidence to make the judgement is scarce, your judgement is more likely to be error prone, and our intuition fails. But if we turn to math and science in those situations, we can make more accurate and objective predictions by scientifically evaluating the evidence, creating models, and studying how the model predicts the evidence. basically, we make the most out of the evidence available in a situation where we wouldn need to make the best out of the evidence. We want to be right, we have little experience with the situation, we have few observations, and the simplest of the possible explanations is likely to be sophisticated and complex.







[edit on 17-12-2005 by bob2000]

There are some detailed reports here of the fires and temperatures reached and also the analysis of the steel recovered from the building, along with explanations for how the collapse initiated.

In the report dealing with the steel there are a large number of pictures spanning many pages which you can look for signs of explosives in of the recovered steel..

Oh I thought I'd better add this - before some people get excited and start posting pictures showing that the steel was cut - your right some of it was cut when recovering it (just make sure you read before you get carried away):

wtc.nist.gov...

wtc.nist.gov...

[edit on 17-12-2005 by AgentSmith]

Originally posted by bob2000
get Macmerdin to check this, he's supposedly a structural engineer, he should totally understand what I just did and can confirm it's correctness.

Why would a structural engineer know anything about this? As said previously, we design using statics....not dynamics. Wind loads are not designed dynamically......they are designed with the intent of a static structure resisting the load (force) of the wind in a given area. Although, the derivatives and calculations look correct....I don't have the immediate knowledge to say yes or no. I haven't taken any aerodynamics classes nor did I state that I had the knowledge.

Edit: What we should do is ask a demolitions expert if it is possible to blow (modelled after a plane crash and subsequent heat) a floor and have the rest of the building come crashing down (imploading) upon itself. I would waiger that they would say you can't (given the fact that they need to do much more than just blow out a top floor (say 10 stories below the top) and have buildings impload upon themselves). I'm going to e-mail some demolitions guys now and see what they say.....BTW I'm going to try and stay away from 9/11 related speak with them so I can get a better answer.

[edit on 17-12-2005 by MacMerdin]

Originally posted by bob2000
10.04272773 seconds

So it takes the object 10.04272773 seconds to fall 157.9 meters when the air resistance coefficient is .5 and initial velocity is zero! compare this time to 5.676661853 seconds which is freefall of 157.9 meters in a vacuum.

now, that's for a sphere? is that what i understand? because, if you want to model the towers, a parachute is more apt.

an ACRE of floor space, howard? wow.

it takes a sphere 10 seconds to fall half the height of the towers? WOW! the towers only took two seconds more(or less, according to some estimations).

which side are you arguing for, bob2000, because that's some compelling math, there.

like air resistance ALONE should have made the towers take 15 or 20 seconds(just guesstimating based on 500 ft. in ten seconds for a SPHERE(aerodynamically efficient).

so, if your right bob2000, you have proven that the structure offered ZERO resistance to collapse, and maybe the towers were actually SUCKED to the earth by the vaccuum created by high explosives or thermobaric bombs or something.

excxcxcxcxcellent(rubbing hands together).

p.s. i'm not sure about the math, i'm just following the logic on this one, lol!

p.s.s. structural engineers don't generally need to calculate how fast thier buildings will FALL. HAHAHAHA!!!!!!!!! go, bob, go! YAY, bob!!



[edit on 17-12-2005 by billybob]

Originally posted by billybob
excxcxcxcxcellent(rubbing hands together).

p.s. i'm not sure about the math, i'm just following the logic on this one, lol!

I just realised the following and it makes me admire you, but:

If you are right:

* You will be destroyed - no-one significant to you will be alive. All of us following the path of the official line will be left and carry on with our lives..

If you are wrong:

* You will be imprisoned/executed for treason. All of us following the path of the official line will be left and carry on with our lives..

I admire you for your righteousness, I'm pretty sure I would do the same thing but I actually do see and understand how it could have hppened due to the plane impacts and fires. Did anyone know or not? Thats another story.......

[edit on 17-12-2005 by AgentSmith]

Originally posted by AgentSmith
I just realised the following and it makes me admire you, but:

If you are right:

* You will be destroyed - no-one significant to you will be alive. All of us following the path of the official line will be left and carry on with our lives..

If you are wrong:

* You will be imprisoned/executed for treason. All of us following the path of the official line will be left and carry on with our lives..

I admire you for your righteousness, I'm pretty sure I would do the same thing but I actually do see and understand how it could have hppened due to the plane impacts and fires. Did anyone know or not? Thats another story.......

well, cheers mr. smith.

luckily for me, i'm not american. lol!



later...........

i'm editing this.
there is no america. i had the wrong hat on when i wrote that. i AM theatened if i'm right. it will take time for the systems to reach me, though, i think, and, more importantly, i am willing die for the truth. i will not die for a lie, nor live knowingly and willingly under the yoke of one.



[edit on 17-12-2005 by billybob]

Originally posted by billybob
luckily for me, i'm not american. lol!

Nor am I! LOL

Originally posted by billybob

Originally posted by bob2000
10.04272773 seconds

So it takes the object 10.04272773 seconds to fall 157.9 meters when the air resistance coefficient is .5 and initial velocity is zero! compare this time to 5.676661853 seconds which is freefall of 157.9 meters in a vacuum.

now, that's for a sphere? is that what i understand? because, if you want to model the towers, a parachute is more apt.

an ACRE of floor space, howard? wow.

it takes a sphere 10 seconds to fall half the height of the towers? WOW! the towers only took two seconds more(or less, according to some estimations).

um, notice I said 10 seconds IF, key word here, IF, the air resistance is changing at a rate proportional to 50% of the falling objects current velocity. Thats where the .5 figure comes from. Did you not see me say "10 seconds if the drag coefficient is .5" or did you some how miss that part? obviously, in real life, falling spheres dont experience air resistance that changes at a rate proportional to 50% its current velocity. THats too much resistance, thats unrealistic. This was purely a hypothetical challenge to prove WCIP cant calculate squat, and it did the job well.

to clear things up, drag coefficient of .5 does not measure an objects shape, like a sphere. Thats the value given to the rate of change of how much opposing resistance the falling object is experiencing propotional to it's current velocity. WCIP has no clue what he is talking about. in no way does .5 have anything to do with a sphere or object's shape. This is an incredibly simple air resistance calculation, shape is not being taken into account here. Again, WCIP has no clue what he is talking about, he couldnt even touch the math problem. All he can do is google formulas from websites.

*SNIP* and now you do for assuming the calculations where for a sphere falling through the same kind of air the WTC fell through. If you had any logic, you could look at my differential equation, and compare the drop times and conclude that my mathematical example could not mean its a sphere, or if it was, it couldnt be falling through any kind of low density air. The fall time was too slow for a sphere falling through air on earth. spheres just dont experience that kind of resistance falling through air on earth. Oh but instead, you conclude it means the WTC fell super fast, and that im stupid or something. you got it backwards buddy. *SNIP I even stated the figures were pulled out of the air, totally hypothetical, of course you cant use my instance to explain the WTC collapse or make any of those kinds of comparisons

which side are you arguing for, bob2000, because that's some compelling math, there.

If your using my calculation to use for evidence for 911 theories, *SNIP*. It was a hypothetical problem to test WCIP; the air resistance was too high for it to apply to real life. re-read what I wrote above.

so, if your right bob2000, you have proven that the structure offered ZERO resistance to collapse, and maybe the towers were actually SUCKED to the earth by the vaccuum created by high explosives or thermobaric bombs or something.

yeah, re-read what I typed above, my example doesnt apply to 911. the resistance was totally hypothetical

excxcxcxcxcellent(rubbing hands together).

*SNIP*

p.s. i'm not sure about the math, i'm just following the logic on this one, lol!

of course you dont now about the math. how shocking

p.s.s. structural engineers don't generally need to calculate how fast thier buildings will FALL. HAHAHAHA!!!!!!!!! go, bob, go! YAY, bob!!

But they should know differential equations




[edit on 17-12-2005 by bob2000]

Mod Edit: Civility & Decorum.

Mod Note: Terms & Conditions Of Use – Please Review This Link.

Mod Note: Warnings – Please Review This Link.



[edit on 17/12/2005 by Mirthful Me]

On the topic of the thread:

After all your foaming and spitting at the mouth, bob, I still fail to see how the air resistance of a falling ball has ANY relevance whatsoever beyond you attempting to prove to everybody how smart you are. My guess is that air resistance of the falling structure would have a negligible effect on the collapse times. But hey, I know nothing right?...therefore whatever I say, the exact opposite MUST be the truth. And so since the air resistance DID have more than a negligible effect, it only serves to bring the free fall time even closer to the observed collapse times! We've been calculating fall time in vacuum and comparing that to the tower collapse times which were higher, but adding in air resistance will only push that free fall time UP nearer to the actual times. If free fall in vacuum is 9.22 seconds, but free fall in air is 10 or 12 seconds or more, well whadyya frikkin know that means that according to NIST and Eagar, the towers pretty much DID fall in free fall, without any mechanical resistance being provided by the structure beneath! So what exactly is your rude-arsed, self-eulogizing, immature point, bob? Are you also a dumbarse conspiracy theorist now, or did you just trip yourself up in your rabid desperation to prove how mega-smart you are?


On the topic of bob: (others may wish to skip this, it's long and dull)

I honestly think you have some serious psychological problems. What is your issue with me? Do I remind you of your abusive father or something?

Here's how it's gone down since you came into the thread:

1. In your very first post, you simply started attacking and insulting everybody right from the word go, basically saying that we and all "conspiracy theorists" worldwide are idiots. You then proceeded to put words into everybody's mouths insisting that we claim the towers fell in complete free fall. Then you stated that we couldn't calculate or prove anything related to this statement which we never made in the first place, and which I realize now is in fact your strawman.

2. I took umbrage at your broad-reaching, childish insults and threw some sarcasm back at you.

3. You came back and restated how incredibly smart you are, then challenged me to calculate the air resistance on a falling ball.

4. I freely admitted that I don't know how to perform such a calculation, but since you DO I then asked you to perform the air resistance calculations NOT for a ball, which should be easily within your abilities if that is your area of study, but for the collapsing towers (which was the subject of your first insulting post), and to calculate the mechanical resistance that the structures beneath the caps would provide.

5. You come back and say, "HA! You can't perform the falling ball calculation so that proves you know absolutely nothing about anything". And then you went right ahead and showed us the dropped ball calculation which no one ever asked you to do. How old are you? 12?

6. Finally, you STILL failed to provide the calculations for air resistance of the structures (which are likely completely irrelevant), and the mechanical resistance provided by the structure (something we actually want to know).

You repeatedly and deliberately misquote me and others as saying we're "so scientific" when we never once said that. The only person making such claims around here is, in fact, YOU. MacMerdin is a structural engineer, I believe LaBTop is a chemist, and I think AgentSmith said he was a childhood prodigy. Do you see them insulting everyone and stating they have no place to comment if they can't calculate torsional stress on a multi-part assembly, or the change in internal energy in a complex chemical reaction? I personally have never claimed I was a scientist, nor an expert in ANYTHING, I simply post my opinion and put it out for discussion. I've been proven wrong countless times, but I'm learning as I go, and researching 9-11 has been an educational ride for me as it has many others here, I'll wager. But if you disagree with what I post, then address the content of what I post disproving it when you can, rather than attacking and insulting me and everybody else, challenging us to perform calculations that are simply irrelevant to the issue. If you can't disprove it, then bad luck, bob.

And while you're hanging around, why don't you challenge the debunkers to do your falling ball calculations and see if they can perform them. Because according to you if they can't do them, then they aren't qualified to comment on anything at all either. I'm pretty sure you will thus effectively exclude HowardRoark, LeftBehind, AgentSmith, et al from this thread and any and all future 9-11 threads. Bad luck for them, because Roark will be out of a job, and LeftBehind & Smith will be bored hanging around on UFO threads, BUT, the rest of us will still be here posting what we know about 9-11, and debating the things we're not sure about.

Moreover, in case you hadn't noticed, the title of this thread is "Physics Prof. Says Explosives..." referring to Professor Steven Jones of BYU. Guess what? This physics professor is what YOU would call a dumbarse conspiracy theorist, and by your reckoning doesn't know anything. He says the towers fell too fast. Why don't you email Professor Jones and tell him the debate is finished and that he is wrong? I'm sure he'd love to hear your arguments about balls. Do you think that all of the problems with the official story are just going to disappear because you can calculate the air resistance on a falling ball? Sorry, Ball-Man, but it doesn't work that way. And if you don't like it, once you've gotten over your little temper tantrum and your personal issues with me, you can either stick around and discuss the actual content of what we and others post, or you can just leave. No skin off our backs. Honestly I hope that you CAN perform the structural resistance calculations and put that portion of the debate to rest, because no one else, including NIST, has done or seemingly can do it. I think the reason you persisted with your falling ball calculation is because you can't calculate the air resistance that would act on the structure as it broke up into millions of pieces, despite this being your area of study. I think it's too complex for you. And I'm pretty damn sure that you can't calculate the mechanical resistance which the structure provided to the falling debris. But hey, I hope I'm wrong, so just go ahead and DO it if you can.

Man...I've had enough. If you'd come into the thread and said, "Hey folks, I've studied fluid mechanics in-depth and I can help clear some things up, or answer some questions", then things might have gone differently. I would have been first in line to U2U you some questions I have. Instead you decided to first a) insult everyone, and then b) do a ball calculation. Well done. If you want to debate the actual issue or provide us with some calculations which are actually relevant, then by all means do so. But I won't respond to any further posts in which I am the subject - I'm just not that an entertaining a topic, and by crikey neither are you. I'm happy for you that your balls have dropped, but I'd rather discuss the actual topic of the thread.


[edit on 2005-12-17 by wecomeinpeace]

I honestly think you have some serious psychological problems. What is your issue with me? Do I remind you of your abusive father or something?

lol, no. Every since I made my original post, you directly tried to shake my credibility, and so I just had to return in kind. You push me, I push back, thats just how I am. And the result was some off topic crap.

3. You came back and restated how incredibly smart you are, then challenged me to calculate the air resistance on a falling ball.

actually, I never specified the objects shape. I just specified the resistance it is experiencing, the .5 figure, which could come from just air or both object shape and air.

6. Finally, you STILL failed to provide the calculations for air resistance of the structures (which are likely completely irrelevant), and the mechanical resistance provided by the structure (something we actually want to know).

Im not an expert on this big 911 conspiracy, but occording to bsbray, NIST wont reveal the mechanical resistance provided by the structures. This is important if one wants to do the calculations.

Man...I've had enough. If you'd come into the thread and said, "Hey folks, I've studied fluid mechanics in-depth and I can help clear some things up, or answer some questions", then things might have gone differently. I would have been first in line to U2U you some questions I have. Instead you decided to first a) insult everyone, and then b) do a ball calculation. Well done. If you want to debate the actual issue or provide us with some calculations which are actually relevant, then by all means do so. But I won't respond to any further posts in which I am the subject - I'm just not that an entertaining a topic, and by crikey neither are you. I'm happy for you that your balls have dropped, but I'd rather discuss the actual topic of the thread.

So would I. But it seems to me that attacking people, discrediting other posters is all I see going on in this board. It seems to me that its hard to stay on topic. I dont really see any constructive posts going on. No one is even discussion the original topic in this thread. I only post everyonce in a while.




[edit on 17-12-2005 by bob2000]

Originally posted by bob2000
Every since I made my original post, you directly tried to shake my credibility, and so I just had to return in kind. You push me, I push back, thats just how I am. And the result was some off topic crap.

The point is that your original post was simply insults, credibility attacks, and a strawman argument. Some people don't react well to insults, funny that. You've shown that you know something about fluid mechanics. Awesome. Now do you think you can lay off the insults and maybe we can ask you some questions, or that you can post something relevant of your own accord?

Im not an expert on this big 911 conspiracy, but occording to bsbray, NIST wont reveal the mechanical resistance provided by the structures. This is important if one wants to do the calculations.

So I say again, go ahead and do them. Do the calculations for the air resistance encountered by the collapsing debris, which you implied are so important in your very first post, and then do the calculations for the mechanical resistance provided by the intact structure. There should be enough information in the NIST reports to calculate it to a reasonable level of accuracy.

Here's the link for all the reports:
wtc.nist.gov...
And here are the specific reports which focus on the design details:
wtc.nist.gov...

In there you'll find all manner of information on the structural design; the floor layouts, steel grades, concrete grades, structural component physical dimensions, assembly connection descriptions, design variations across the height of the buildings, and lots of other goodies.

The collapse times and the apparent lack of resistance provided by the structure is one of the biggest holes in the official story, and has never been addressed by the government, nor any of the institutions studying the collapses. But it doesn't take a physics genius to know that there's something wrong with this picture. Ya dig? So if you can help out, I'm sure we, Professor Jones, and the rest of the world will be forever in your debt.

But it seems to me that attacking people, discrediting other posters is all I see going on in this board.

You mean like your very first post in the thread and every one of your posts after that?

[edit on 2005-12-17 by wecomeinpeace]

There's a topic to this thread... please get back to it.

Originally posted by SkepticOverlord
There's a topic to this thread... please get back to it.

My apologies, Skeptic.

Onward, McDuff...

Covering ground already covered but...


I was reviewing the BBC Timeline for another project of mine this morning. And I watched the video report from Stephen Evans who was actually in the lobby of the North Tower as the first jet crashed. He talks of two or three explosions and feeling the building shake. (as another eye witness - that interview is further down the timeline)

Now I can understand that there may be a couple of explosions if the fuel tanks detonated separately ... but feeling the whole building shake - surely that initial blast from the jet fuel wouldn't have been big enough to 'shake the building'? Stephen was in the LOBBY not an upper floor.

Originally posted by hands
... but feeling the whole building shake - surely that initial blast from the jet fuel wouldn't have been big enough to 'shake the building'? Stephen was in the LOBBY not an upper floor.

Your kidding right? It would be more than enough to noticably shake the building.

Originally posted by HowardRoark
When considering the concrete floors in the towers and the forces applied to them, it is helpful to keep in mind that they were only 4 inches thick.

What Howard? No mention of the steel between floors or the fact that the columns were set up across multiple floors/staggered? Why, you left all that out as if there was nothing but concrete between each floor! I'd almost think you have some sort of agenda you're pushing here, for surely you know that the core columns were welded to span multiple floors, the perimeter columns were staggered, and there were steel trusses between floors. Hm.

Originally posted by LeftBehind
Actually since the safety factor is only accounting for static loads, it is the safety factor which is completely irrelevant. The energy of the caps hitting the next floor is the real issue. No one designs buildings with dynamic loads in mind. No one plans on the top ten floors of their building falling onto the next floor.

So? I'm sure no one expected a "progressive collapse," either, considering how freaking light the top floors were in comparison to all the lower floors that they allegedly utterly pulverized.

Originally posted by HowardRoark
Look again, this isn’t just one or two columns, it is the entire side of the building that is starting to buckle inward.

That photo needs to die, Howard. It shows buckling measurements for floors you can't even see for smoke. I'll accept there were a few buckled columns, but for how many buckled columns that thing alleges, without being able to see the columns, but only smoke, or aluminum facades or what-have-you, the thing is total bs.

Originally posted by bob2000
so what neccesary figures have they failed to provide? give me a list.

My god, Bob. Is three times the charm or what? Or four or however many times I've said this. I said it in the very post you're responding to here. I need to know how much momentum each floor could withstand on average before a 75% or maybe even 100% failure, in kg m/s.

A person has cut himself many more times in his life then he has observed live building collapses and demolitions. So based on his experience, his intuition will be more reliable and accurate than in situations he has less experience in. Another reason is in some situations, your inferering something really complicated based on a small set of observations.

So, to summarize, you don't really know if what happened in regards to the momentum was either possible or impossible via gravity. But you choose to assume the official story is correct anyway, despite this lack of knowledge, and play from the official side. You go attacking the demo theory on things that you don't know enough about to comment on, for which no calculations can yet be figured for missing numbers, and use the fact that numbers are missing to wrongly try to advance your case. Have I got it right so far? No doubt I've put a spin on it that you don't like, but that's it, right?

Again, I ask, why do you believe the official story? I has absolutely nothing going for it of the things you've asked us for, that we don't have the means to provide. They have the means to provide but won't do it, and won't let you see the numbers they have. And you have absolutely no problem believing these guys, or what, man?

Originally posted by MacMerdin
I'm going to e-mail some demolitions guys now and see what they say.....BTW I'm going to try and stay away from 9/11 related speak with them so I can get a better answer.

Good luck with that man.

I emailed a demo big company and they wouldn't answer a similar question I had for national security or some such bs. Though, rather than if a single floor failure would result in global collapse, my question was whether or not they could set off charges in any fashion they want. I already knew they could, and as someone would later point out to me, they even have videos on their site showing demolitions from mid-building. But they wouldn't even answer that question. National security. Wave of the hand. Move along.

Originally posted by bsbray11
But they wouldn't even answer that question. National security. Wave of the hand. Move along.

Please don't tell me you think they should answer question like that to any Tom, Dick or Harry that comes along?
Jeez, you'll complain that the Government let's things happen one minute, then criticise normal precautions the next. National Security responsibility also lies with private organisations and individuals such as yourself - you do realise that don't you? I'd have been disgusted if they responded with anything else.

A better method if you don't have any joy with anyone else would be to look for a relevent forum and search that for clues. If you don't find anything then try posing the question in there.