I know what happens in 2012.

[RainmanTime]

ruthless,

well, i did some digging, and i think i have an idea of how much energy that was. i was way off lol.

"The bomb had a yield of about 21 kilotons of TNT, or 8.78×1013 joules = 88 TJ"

You are showing more and more traits of thinking like an engineer everyday.

You have found an energy conversion factor! Go to the following web page, type in "3226" in the top box, then select "MegaJoules" in the left box, and finally select "kiloton [explosive]" in the right box. Hit the "convert" button and you will see the conversion!

http://www.onlineconversion.com/energy.htm

Still quote an explosive force (about 0.77 tons of TNT) but nothing like a Fat Man, of course!

RMT

 

[ruthless]

"Still quote an explosive force (about 0.77 tons of TNT) but nothing like a Fat Man, of course!"

thats still a purdy big boom. i learn new stuff everyday thanks to you guys, yall rock. :D

 

[Darby]

"The bomb had a yield of about 21 kilotons of TNT, or 8.78×1013 joules = 88 TJ"

a reference to the "fat man" bomb dropped in ww2.

its jaw dropping to think what the human mind is capable of.

ruthless,

It is especially jaw dropping when you consider that the 21 kt of yield was produced by the conversion of 1 gram (not a kilogram...a single gram) of mass to energy.

 

[ruthless]

mind boggling even.

 

[RainmanTime]

ruthless,

theres a few things i'd like to say, and i hope some people dont hate me too much for changing my opinion, but rmt, i think your right. after you told me how you believed the wtc's fell, ive been thinking about it and visualizing it. your scenario makes perfect sense.

That's nice, but even more important than "making sense" is the fact that all of this can be modeled and verified as true with existing physics. IOW, it can be shown to be a true and accurate representation of how the building came down. I could give you the equation for momentum (Mass*Velocity) and we could create a simulation program that shows that, even while the velocity of the falling top portion of the towers would eventually reach a constant (terminal) value, the mass of the falling object itself would continue to grow as each new floor collapsed. This is the VERY LARGE value of engineering that is so often "behind the scenes" that citizens of our country never see, never understand, and never come to appreciate how it has made such large differences in our lives.

the thing about it is, i dont know your physics very well at all, but my physics i know very well. i spent half my life devising my own system of physics, only to find out that i shouldve learned the real physics, cause without it, i cant tell anyone what im thinking.

And without wishing to sound insulting, the problem here could be "What if your physics is incorrect with respect to physics that has already been vetted as representing reality?" This is precisely what I am talking about when I speak of people who "think a certain event should happen a certain way" and use the excuse that "logically, it should be this way". Often times the reality of physical mechanics can go against what you think is logically true. Take for example aerodynamic forces (drag and lift) that I have been explaining to you. Most people who do not understand aerodynamics would say it is "logical" that if the airplane travels twice as fast that it should generate twice as much lift and drag. Sounds logical, right? But such a notion is WRONG because the physics of dynamic pressure (the quantity the lift and drag scale with) tells us that we would actually be producing FOUR TIMES as much lift and drag if we doubled the airspeed velocity. This is because dynamic pressure scales with the SQUARE of velocity. This is just one example, and there are plenty of other examples in solid mechanics (structures) that I am sure Indazona could highlight to us.

at the front of the wtc, the steel beams were sheared. they were not sheared in the backside, wich caused the balance of weight to shift to one side. the steel was strong, so it held it up, until fires softened the steel. it was probably already overloaded before the steel was softened, but not noticable. finally the steel that was left... scratch that, ive got a better idea, a visualization. grab a paperclip, unfold it, and straighten it out. now imagine that straight piecce of metal is a beam in the wtc. grab the top with your thumb and index finger, and roll your wrist. this is what i think happened to the collums left. the collums were twisted with great force, and once it started going, it wasnt about to stop. way too much weight.

would this assumption be correct rmt?

In general this is one valid way of thinking about it. It was CERTAINLY over-loaded before the fire softened the steel, but that is because designers design-in what is called "margin" or "factor of safety" so that it could keep standing even when a fair number of columns were severed. But I have highlighted in bold the words of yours that are most especially correct and pertinent. These words accurately describe the differential equation that governs column buckling forces with respect to lateral (sideways) deflection. A column holds its load the best when it is straight up and down (in-line with the gravity vector). As the column begins to deflect laterally (sideways), the more it deflects the greater the force becomes that tries to buckle the column. It is only the inherent rigidity of the column (Young's Modulus) that can counter this buckling tendency. SO now once the fire weakens the rigidity of the steel, it will reach a point where it CANNOT counter the lateral deflections... once the lateral deflection gets beyond a critical value, it keeps going until the ultimate failure of the column.

and about the planes in water, i think that when testing drag, water would be the ideal medium. but, i think when testing lift, water would be the worst medium.

Again, I can understand how you would "logically" think this way. But the reality of the physics clearly state the aerodynamic forces of drag AND lift are both directly dependent upon the density and viscosity of the fluid the body is moving through. Above and in the other thread I mentioned DYNAMIC PRESSURE, and you might not even know it but I gave you the equation for it. We use a symbol of a "q" with a bar over it ("q-bar") to represent dynamic pressure. And the equation goes like this:

q-bar = (1/2)*(Fluid Density)*(Fluid Velocity)^2

So simply by changing fluid from air to water, I can STILL produce the same dynamic pressures (which result in the same lift drag forces the airplane would see in air) but I can create those forces at MUCH lower fluid velocities in water, because water is so much more dense than air.

i really need to learn physics fully. i cant explain a thing im thinking without it. i am also undertsanding that the things i have observed, i did not realize all of the paramiters that were involved.

This is one of the joys I get out of teaching (God knows the pay ain't all that great!)... seeing the "light go on" above students' heads when they "get it". The stuff about aerodynamics that I have started to help you understand are REALLY basic and fundamental. But to a freshman engineering student they can seem quite difficult. I always enjoy telling my freshman classes that "if you think this is hard, just wait until the kinds of complex problems you will be able to solve if you make it to your junior and senior years! This stuff will be a CAKE WALK compared to that!" And without failure, I will always have a few students come back to my office when they finish junior or senior year and tell me "you were right...that early stuff was REALLY easy, and I understand it really well now. But it is amazing how I can now solve problems that are much more complex."

blah, blah, blah, i could go on forever. but the point is, i have ALOT to learn.

And the learning NEVER ends. The day an engineer stops being an effective engineer is the same day that engineer stops asking questions or trying to model reality so as to produce a better design. Once again, ruthless, I would encourage you to energize your life by looking into going back to school and studying science and engineering. You will not only learn a lot, you can create a very nice career for yourself, and you can contribute things to society that would benefit all mankind.

Do it... you have my support!
RMT

 

[ruthless]

"And without wishing to sound insulting, the problem here could be "What if your physics is incorrect with respect to physics that has already been vetted as representing reality?"

yeah, alot of my physics is incorrect. sometimes thats a tough pill to swallow, but i also realize that i never got to do any serious experiments, and i also realize that if i were to, i would not have fully understood everything. more importantly, i would not be able to convey anything i did learn. i have to be honest, i dropped out of school in the 6th grade. when i dropped out, i was learning about geometry, i never got any further than that. years later, i went and got my g.e.d. i just went up there and took the test. luckily i passed. /ttiforum/images/graemlins/smile.gif i know that i need to go back to school, and i will very soon. i have been looking at online colleges, and im thinking about msu. when i was young, i wanted more than anything to have a normal "routine." and for about 7 years now, ive had a pretty normal routine. what i didnt realize when i was a kid was, its harder than a mofo to break a routine once you get used to it! anxiety sucks, and i hate making excuses.
imagine having to jump into a lake of hungry crocodiles, i akin the way i feel to that. lol

i am going to force myself to go. you and darby have more than inspired me to go. i look up to both of yall, and i hope that one day i can communicate on your level. as a matter of fact, i think im going to go talk to a few people, and make some phone calls and see what i can come up with.

and thank you for the words of encouragement, it means alot.

 

[Guest]

Are we still on the 9/11 Theory? If so, can I dump some questions here so I screw up people's thoughts and arguments?

If fire can make it so the TT's colapsed, why have skyscrapers gone through fires (older buildings no less) and survived? Don't say because they old - the technology was less efficient.

If the weight of the plane, even, the fire and the weight of the plane plus damage, caused the TT's to fall, why have other skyscrapers, who also have had planes gone into them... survived?

How many support structures are there? And could an aluminium (unneccessary and obvious detail) plane really break a through a steel one?

Why didn't the fire suppression systems kick in?

Why did it require an explosion for the building to colapse, if weight was the problem?

Why was it marked pancake when the colapsing floors had an incredibly fast decent (and had even sprayed - and damaged, other nearby buildings)?

Why did the TT's (who had never done this before, ever) practiced massive evacuation drills only weeks before the event? Who where those people who entered the building after the massive evacuation drills?

Why would it take a large group of people to plant explosives? Why not a very fast crack force, or an automated system? Why not a single person over a long period of time?

If it was destroyed by explosives, how could we be sure it was the government?

Why was the CIA aware of the planes, but did nothing?

Why did the local airspace radar not raise an alarm?

Why didn't the airport radar raise an alarm?

Who were the first people on the scene? Why were they so fast?

Why aren't there any damn parachutes on the roof?

Why were no helicopters scrambled to rescue people from the roof?

Why hasn't an investigation been held into the debris to see exactly how it colapsed?

Why has information on 9/11 been withheld?

Why does an army demolition expert believe explosives were used?

What would the government have to gain if they were to do this? If not the government, why would the terrorists, or even, anyone, want to destroy the TT's? Why do it on a day when the fewest amount of people would be there?

How comes, if there was a fight onboard one of the planes, that the planes both hit their targets relatively level?

Have fun.

 

[RainmanTime]

ruthless,

and for about 7 years now, ive had a pretty normal routine. what i didnt realize when i was a kid was, its harder than a mofo to break a routine once you get used to it! anxiety sucks, and i hate making excuses.

Not only do you have my support, you have my respect. I may have related this story to you before (or not) but there is a young guy who works for me (~27 years old) who is actually DOING reliability engineering, yet he has no degree. He will never get promoted, his raises will be substandard, and he can never go to another company without that degree. He is stuck, but he has "natural talent". However, he is not only stuck in his routine, but each time I push him to go back to school all he can do is make excuses. And let me tell you, I push and goad him and explain to him his "long term outlook without a degree" on a weekly basis. I try to get him to look past 30, look past 40, and into his 50s and consider just how much he will NOT be making and that his life will NEVER be more comfortable than it is now. He will always be on the edge, paycheck to paycheck, and will never be able to afford a house (here in California).

You, however, have something he does not have: The knowledge that ONLY YOU can hold yourself back, and you do it by making excuses for why you "can't". My father constantly told me "All the 'I can'ts' lay in the cemetary six feet under!" YOU HAVE THE RIGHT OUTLOOK AND YOU HAVE GOTTEN BEYOND THE BIGGEST MENTAL BLOCKADE!

I will guarantee you one thing for certain: Once you have that degree and are working in your chosen field I GUARANTEE you that you will ALWAYS look back and say "I am glad I did that" and you will NEVER look back and say "I regret doing that". And I would even surmise that your family will say the same thing! /ttiforum/images/graemlins/smile.gif

Whenever you need any advice or support, you let me know, my friend.
RMT

 

[Packerbacker]

As I understand it, the girders were constructed around a central core, so that a large open, commmercially valuable, space would be created between the central core and the steel exterior.Tying the central core and the outside skin together were steel trusses which were bolted with a pair of 1/2" bolts on one end and a pair of 5/8" bolts on the other end.

As a result of careless handling, chunks of the foam (we have a technology that seems to be vulnerable to foam)were knocked off, exposing the steel of the truss frame. Not insulated, the steel of the truss frame expanded in the hot air created by the burning interior with the result that they sagged. I suspect that what happened, then, was that the bolt threads stripped and the concrete slab flooring supported by the trusses collapsed. From there on it was pancake city.

Sometime later I saw a video of the sought after Osama b.L. who said the collapse exceeded even his own expectations(he was trained as an engineer). He thought maybe a couple of floors would go and that would be about it.

 

[RainmanTime]

Rusty,

I am not going to try to answer all of your questions, as I think I realize they are pretty much a "grab bag". But some of them can be answered with very accurate, technical answers. I am assuming you would like to learn and understand the answers, and not throwing them out thinking you know the answers or that they are already satisfactorially answered by certain folks who pitch conspiracy theories. So here are some answers. If you don't agree, would like to discuss them, or would like more details, by all means let me know:

If fire can make it so the TT's colapsed, why have skyscrapers gone through fires (older buildings no less) and survived? Don't say because they old - the technology was less efficient.

Efficiency and performance are two different things. The first answer is that you are forgetting that other buildings that experienced fires were not flown into by airplanes traveling at 500 mph, thereby destroying much of their load-bearing structure. A fire may weaken steel in a conventional building fire, but how many of them have lost a LOT of their load-bearing members as well?

Also, the "older technology" for building is much more fundamental and much more rigid than the WTC towers. You COULD NOT use that same highly rigid (and older) building technology in buildings as tall as the WTC towers. That was why the WTC towers were new technology...because it was needed to make the towers that tall AND retain a lot of useable space. Conventional technology uses "box truss" design where the entire building has a regular "skeleton" inside. That means a LOT of redundant load-bearing paths. The WTC towers are best described as a single "core" with a structural "tube" formed by the outside skin. Think of a toilet paper tube. The other walls of the tube provide its rigidity. Break a lot of the columns on the outside of one (or more) sides of the WTC tower "tube", and THEN add fire to weaken the steel columns that remain to hold the load, and you have a MUCH different situation than conventional technology buildings. They really are apples and oranges.

If the weight of the plane, even, the fire and the weight of the plane plus damage, caused the TT's to fall, why have other skyscrapers, who also have had planes gone into them... survived?

Please give me the examples and let us deal with them on a case by case basis. I had no idea we had such a plethora of airplanes hitting tall buildings in our history!

The only other one I know of was about 1 year after 9-11 when a light (general aviation) airplane ran into a tall building in Florida. Just comparing the mass, momentum, and energy of that plane with the large jets of 9-11 should answer the question of why that building did not fall.

How many support structures are there? And could an aluminium (unneccessary and obvious detail) plane really break a through a steel one?

I think it should be obvious because we actually SAW real (aluminum) airplanes penetrate the steel columns of the outer tube of the WTC towers. Perhaps you could make your question more specific so I could understand what you are really getting at?

Why didn't the fire suppression systems kick in?

Some did, but on lower floors from where the airplane penetrated, where they did no good. The sprinkler systems utilized central "standpipes" that were located in the core of the towers. The cores of both towers were significantly damaged by the airplanes as they penetrated, thus severing the standpipe lines that would be used to carry high pressure water to the damaged floors.

Why did it require an explosion for the building to colapse, if weight was the problem?

This is a crucial question that the conspiracy theorists MUST answer, because expert analysis says it was not required. This is what myself and Indazona have pointed out about Euler column buckling: If engineering analysis can show that the lost columns + fire heat was enough to induce buckling (and there was clear evidence that buckling was occurring) how can you make a case that it HAD TO BE brought down by explosives?

Why did the local airspace radar not raise an alarm?

Why didn't the airport radar raise an alarm?

Do you understand how air traffic control radars work? It would seem from these questions that you do not. Are you aware that the airplane transponders (which the terrorists turned off) are a primary component for identifying which airplane is which? What, specific, type of "alarm" do you think these radars have, or should have?

Why aren't there any damn parachutes on the roof?

How many "average folk" are trained in how to use a parachute much less skydive safely off a building? It is not as easy as you might think (and I have been trained to skydive and done it 3 times in my life). You could pose the same question about why are there not parachutes on commercial airplanes for every passenger? How often does an airplane have a problem in cruise flight where there is enough time for everyone to don parachutes and jump?

Why does an army demolition expert believe explosives were used?

Belief is not sufficient to show that explosives were actually used. He would not only have to provide evidence, but as mentioned above he would have to lay out why explosives were REQUIRED (i.e. Euler column buckling could not have possibly been the failure mode that brought them down).

How comes, if there was a fight onboard one of the planes, that the planes both hit their targets relatively level?

I could be wrong, but I get the feeling you are mixing up the WTC airplanes with the Flight 93 airplane that crashed in Pennsylvania. That was the airplane where we know the passengers struggled with the hijackers. I have seen nor heard no evidence that either of the two WTC-bound airplanes experienced a struggle between passengers and the hijackers. Certainly the first airplane to hit the WTCs, the passengers could have no idea what the hijackers were planning to do. And given how quickly the second airplane hit as well, it is unlikely the passengers on that airplane would have heard news that the first plane hitting was a purposeful terrorist act in enough time to react to their situation.

Some are good questions, some I think you simply need more knowledge about physics or the buildings themselves. Some are questions (mostly the ones I did not address) that cannot be answered by physics or engineering, as they are questions about why people acted, did not act, or knew what they knew.

RMT

 

[titorite]

And so once again the topic turns to 911...

the bolt threads stripped and the concrete slab flooring supported by the trusses collapsed. From there on it was pancake city.

I have read this too from the 911 commision. Follow my logic because if thier is a flaw in it I would like it pointed out.

First off it is my understanding that a fire can only burn as hot as its fuel which would be the jet gasoline. Now then the majority of this "jet gas" burned up on impact igniting everything flamable but ultimiatly expending the strongest fuel(the gas).

So the towers burn awhile. NOW THEN, for some reason the tower that was hit second fell first...but let us overlook that for now and continue. When it fell the feds would have the world believe that it was due to the trusses heating up , expanding and "popping" the collums out of place displaceing the weight and causeing collapse... Thing is we gotta go back to the tempature of the fire which was an open air fire so it wasn't burning that hot. Certianly if the fire could heat the trusses to the point where they expand then what we have to accept is that the trusses were heated to plasicity. PROBLEM even if the fire burned for hours it could never reach tempatures hot enough to expand the trusses due to the lack of oxygen(amongest many other factors), the fire was indeed being smoothered by itself as was the WTC design plan just incase the fire suppresion system failed...That WTC has one marvalous building... Let us assume that the fire had burned hot enough and long enough (two key critical points any 911 analyst must understand) to expand the trusses. The collums are much larger (which means they take longer to heat up) and sturdier than the trusses.
If the trusses expanded they would bend, break, and fall but they would not pop or bend the collums out of place. Trusses are weilded together and since they had already reached plasicity thier weilds would give before a gaint solid cast steel collum(you are aware that the inner collums are the size of moblie homes right? Thier HUGE) SO THEN even if all the trusses on one or two floors failed you still have 30 stories above of intact trusses and 70 stories below of solid trusses that would continue to hold the inner and outer core together. The floors were supported by beams which interscted the inner core so it is unlikely the loss of a few trusses would cause a critical failure. So the floors aren't gonna fall down over the support beams onto the floors below them.

You can also see pictures of pancaked buildings on an image search. In all the images I have seen the buildings relatively remained intact unlike with the WTC which turned into powder...Funny the lack of large concrete chunks considering how much concrete was in the core..why you'd figure in a pancake collapse that the breaking beams would of flung LARGE concrete chunks into New Jersy..but instead the concrete powderized...hmmmm Funny that.

And So no matter which why you want to argue it the North Tower fell... Then about some 20 odd minutes later the south tower which had been hit first , and had taken a direct impact into its inner core section, AND burned for about 45 minutes longer then its twin finnaly fell into its footprint...many hours later the 47 story Solomon building which suffered no plane impact would also fall into its footprint.

Of course Fire Fighters trained in structrual demolition and Silverstien the Fire Chief is another subject to contemplate altogether.

 

[titorite]

Hello rusty,

Who the heck are you? You kinda weird me out man. But I admire your stance for truth...so I guess you can't be that creepy...Then again god only knows right? Whats really stranger than strange though is you commenting on this thread with my position...I almost wanna ask if your a TT but I know you already stated no..so..ok then.

I hope you don't mind if I address RAIN MAN TIME. I think he could still use some more imput into his perspective.

 

[titorite]

Rusty,

I am not going to try to answer all of your questions, as I think I realize they are pretty much a "grab bag".

Avoidence

that they are already satisfactorially answered by certain folks who pitch conspiracy theories.

riddicule

A fire may weaken steel in a conventional building fire, but how many of them have lost a LOT of their load-bearing members as well?

unsubstantiated or invented information. You can not know how many IF ANY "load-bearing members" (HUGE STEEL COLUMNS!) failed because the "load-bearing members" were never examined but instead shipped off to china for for recycling. And you certianly weren't inside the WTC to examin the Cloumns first hand.

Also, the "older technology" for building is much more fundamental and much more rigid than the WTC towers. You COULD NOT use that same highly rigid (and older) building technology in buildings as tall as the WTC towers. That was why the WTC towers were new technology

Which is why they are also refered to as "Supertalls" They set a new standard for the word skyscraper...also the WTC was a new architectural design. Technology and Architecture are two words with different meanings.

Break a lot of the columns on the outside of one (or more) sides of the WTC tower "tube", and THEN add fire to weaken the steel columns that remain to hold the load, and you have a MUCH different situation than conventional technology buildings.

Glad to see you know a little about it..However you should remember that the outter tube was also a steel mesh. Kinda like a screen on a porch door. You can poke a hole..heck you could stick your fist through a screen BUT the screen will not unravel.. You will have a hole yes but the rest of the screen will hold itself together. As for the problem with expanding trusses..I already explained that to in my reply to Packer.

Please give me the examples and let us deal with them on a case by case basis. I had no idea we had such a plethora of airplanes hitting tall buildings in our history! The only other one I know of was about 1 year after 9-11 when a light (general aviation) airplane ran into a tall building in Florida. Just comparing the mass, momentum, and energy of that plane with the large jets of 9-11 should answer the question of why that building did not fall.

The copy cat teenager that sacrificed his life to destroy some office space. I'm supprised you remember that. Yup, that was one dumb kid...Of course thier is the Empire State building but that was a differnt architectual design and a differnt kind of plane...apples and oranges No?

I think it should be obvious because we actually SAW real (aluminum) airplanes penetrate the steel columns of the outer tube of the WTC towers.

It should be equally obvious that the steel columns of the outerskin pale in comparision to the interior support columns.

The cores of both towers were significantly damaged by the airplanes as they penetrated, thus severing the standpipe lines that would be used to carry high pressure water to the damaged floors.

NOW THIS SENTENCE!!!..*chuckle*... To know how the cores were affected is to know where the planes impacted. The South tower was a direct dead on hit. The North tower however, was a corner clip..the plane impacted through the corner and the kinetic velocity and fireball missed the core of that building. So the standpipes should of been in complete working order in that building at least.

This is a crucial question that the conspiracy theorists MUST answer, because expert analysis says it was not required.

I am not a theorist. I do not have a complete hypothesis about 911. Thier is no scientific formula to apply here. All I have are my observations. One observation is the inner core. In a pancake collapse the concrete should of broken up into huge chunks not powderized...The giagantic interier columns should of remained intact, even in a pancake colapse I fail to see how you can envision the columns falling ontop of itself ...they have nowhere to fall they should of remained intact and swayed over landing on other buildings in complete monolithic sections to be cut up later to fit on semi trucks during clean up...The inner core was the anchor of the building which the beams intersected, even if the floor and the outer tube fell away from the core that doesn't expalain how a core fell into/ontop of itself. In the pancake collapse theory the core should ob been standing tall with loads of beams sticking out of it. Trusses did not support the vertical mountian of concrete and steel but since it did fall where were the giant boulder sized concrete chunks of core? ?? Shoot, show me some fist sized chunks of concrete. Am I to belive that the majority of concrete turns in to powder when it falls on top of itself? Even at terminal velocity concrete doesn't powder in the manner displayed by the WTC (it breaks) HOWEVER expolsives will damn sure bring the pressure needed to pulverize concrete....What kind of explosives? I don't know, refer back to the first two sentences of this paragraph. I can point out the inconsistencies but I can't insert truth when I am not certian what the truth is...I am only certian about the lies of 911.

Do you understand how air traffic control radars work? It would seem from these questions that you do not. Are you aware that the airplane transponders (which the terrorists turned off) are a primary component for identifying which airplane is which? What, specific, type of "alarm" do you think these radars have, or should have?

Now why is it when Rusty, brings up the whole radar thing you acknowledge him but ignore me when I bring it up? The American flight traffic control system has a failsafe system making it impossible for american airbusses to dissappear in american airspace. When the transponder is turned off the flight traffic controller that was assigned the plane no longer has the flight identification info on his screen. Instead he has the blip and at this point so does every other air traffic controler responsible for that airspace. The plane shows up on everyones screen now so that the other air traffic controlers can steer thier planes around the blip. Meanwhile the guy who lost his plane for a blip should be going apeshit on the inside while calmly explaining the situation to norad after radio contact proved negative. It is all SOP and the A.T.C.S. is well trained and more than capable in a crisis situation....Yet not only was SOP disreguarded on 911 but on 911 after the hijakers turned off thier transponders they enabled the planes stealth mode to avoid being seen as a blip. Officaly the planes lost ALL RADAR CONTACT for a period of time. Only by useing the commercial air busses stealth ablity could the hijakers avoid A.T.C. who would of been monitering and reporting the flight paths of the radar blips....oh wait a minute...commercial air busses don't have stealth technology. So how in the flying Duck did the dissappeare from radar?!?!

I don't have every answer. I do not know the complete truth..I am dead certain about the lies though. It isn't wise to ignore inconsistencies.

ME

 

[titorite]

Where in the heck is RMT and Packerbacker???...I wanna finish this conversation not that it was brought up again.

 

[indazona]

I was wondering when you were going to make some sort of claim in my area of expertise, Mr. Titorite. I noticed you were not able to refute any of the facts I put forth about how wrong your sources were in their structural analysis of steel and the weakening of its Young's Modulus. But as a result of your latest post, I am afraid I have to inform you that you have absolutely no clue what you are talking about in the realm of structural engineering. Period. I could actually show you wrong on several of the things you say, but why bother when I can make you look truly foolish by addressing one, choice analogy you put forward.

Glad to see you know a little about it.

Clearly RMT knows way more about structural engineering than you do. But I am more the expert in this area than he, which is why we decided that it was more appropriate for me to respond to your nonsense:

However you should remember that the outter tube was also a steel mesh. Kinda like a screen on a porch door. You can poke a hole..heck you could stick your fist through a screen BUT the screen will not unravel.. You will have a hole yes but the rest of the screen will hold itself together.

This is positively the most ridiculous (and highly incorrect) analogy that was ever floated about the WTC external structural skeleton. And I notice you do not even reference the silly fools who first floated it. Are you aware that it only took about 2 microseconds when someone first put forth this dreadfully wrong analogy for someone to point out what is obviously wrong with it? I shall now destroy any credibility you may have had in making claims about structural engineering concepts:

The external structural skeleton of the WTC towers was nothing like a "screen on a porch door" for one fundamentally simple reason: A screen on a porch is not a load bearing structure!It is NOT under compressive stress like the WTC exoskeleton was. This is precisely why a screen on a porch door does not deform, you nincompoop, because there are no compressive loads to do so! To draw this analogy shows how little you not only understand the concepts of structural stress and strain, but it also shows you are willing to parrot someone else's ignorant analogies, thinking they are valid. I know for a fact that RMT got a good laugh out of this silly analogy of yours, which isn't even yours, and I can also bet Mr. Darby was also smiling waiting for either RMT or myself to point out how poor of an analogy it is.

So as I see it, you can now either admit how foolish (and incorrect) that analogy is, and at the same time admit you know nothing about structural analysis to be able to make the kinds of claims you have, or you can ignore that you have once again been proven foolish, and try to change the subject yet again. The choice is yours. But if you don't cop your ignorance and admit you were wrong, I assure you that you left several other gems in this last post of yours that will make you look even more silly if I choose to address them.

 

[RainmanTime]

Now it's my turn to address the fallacies, partial information, and outright speculation associated with my area of expertise:

The American flight traffic control system has a failsafe system making it impossible for american airbusses to dissappear in american airspace. When the transponder is turned off the flight traffic controller that was assigned the plane no longer has the flight identification info on his screen. Instead he has the blip and at this point so does every other air traffic controler responsible for that airspace. The plane shows up on everyones screen now so that the other air traffic controlers can steer thier planes around the blip. Meanwhile the guy who lost his plane for a blip should be going apeshit on the inside while calmly explaining the situation to norad after radio contact proved negative. It is all SOP and the A.T.C.S. is well trained and more than capable in a crisis situation....Yet not only was SOP disreguarded on 911 but on 911 after the hijakers turned off thier transponders they enabled the planes stealth mode to avoid being seen as a blip. Officaly the planes lost ALL RADAR CONTACT for a period of time. Only by useing the commercial air busses stealth ablity could the hijakers avoid A.T.C. who would of been monitering and reporting the flight paths of the radar blips....oh wait a minute...commercial air busses don't have stealth technology. So how in the flying Duck did the dissappeare from radar?!?!

You know a tad bit about the Air Traffic Control system, but not nearly enough to paint a clear picture, and certainly not enough to answer your own question. First of all, you appear to not understand the difference between Primary Surveillance Radar (PSR) and Secondary Surveillance Radar (SSR), nor how they operate. Far from being some sort of "automatic" switchover (the ATC system is quite old and only now beginning to be upgraded to include automation), whenever an "enroute" controller loses an SSR response from an airplane (that is, its transponder squawk), that controller has to MANUALLY turn on the PSR (which is normally OFF) in order to "paint" the airplane and get a reading on its position.

So how did AA 77 "disappear from radar"? The thing you do not understand here is that there are some sectors interior to the continental US that are NOT covered by PSR, and that means they do not even have a PSR as a backup. AA 77 was in one of these areas when the hijackers turned off the transponder (which essentially made the SSR in that sector useless). Since there was no PSR in that sector that could be turned on, they were "blind" to where that airplane was. It was not until the airplane showed up on the Dulles TRACON PSR that they saw AA 77 again. It is all explained fairly well, and without a whole lot of difficult technical jargon, right here:

http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&node&contentId=A32597-2001Nov2

The part that you clearly did not understand, nor were able to explain, is described in the article as follows:

Primary radar is normally used only as a backup, and is usually turned off by controllers handling aircraft at altitudes above 18,000 feet because it clutters their screens. All aircraft flying above 18,000 feet are required to have working transponders.

If a plane simply disappears from radar screens, most controllers can quickly switch on the primary system, which should display a small plus sign at the plane's location, even if the aircraft's transponder is not working.

But the radar installation near Parkersburg, W. Va., was built with only secondary radar -- called "beacon-only" radar. That left the controller monitoring Flight 77 at the Indianapolis center blind when the hijackers apparently switched off the aircraft's transponder, sources said.

Once again we see you have a big mouth that likes to spout off on this forum as if you "know the lies", but in reality you are relating partial, or simply uninformed information. And besides that, I thought you made a promise that you were not going to respond anymore after you posted that long response with the BS "analysis" about steel weakening in the fires? So we see you are not even a man who stands by his own word. Nize.

RMT

 

[titorite]

Indazona,

Why are you incapable of being wrong? What happened to your critical thinking process and currently forbids you to accept the facts.

Yes do tell why the tower hit second fell first. And do tell why the building not hit by a plane at all fell around five in the afternoon. Do tell me everything you think...and if I did not respond to something you posted earlier I either missed it or you simply refused to understand what I wrote.

You are egear as a beaver to destroy me. ...(not imppressive).... You wanna defeat a stranger rather than make a friend...speaks volumes to your charicter.

You dislike my analogy of the outer mesh frame.

The steel mesh outer core is a load bearing structure. It supported the floors in conjunction with the inner core. The impact holes did not cause a critical failure. The Jet fuel burned up in one big fire ball.... if you hold a torch to a beam for only a few seconds your not gonna cut the beam...your not even gonna get the beam to give you a cherry bead... Never mind the fact that the WTC fireball did not burn anywhere near the tempature a weilding torch can produce... NEVER MIND THE FACT THAT HEATING UP LARGE SECTIONS OF IRON to plascisity is not possible in an open air fire enviroment. The structural damage itself was not that bad..the buildings withstood the impacts like champs like they were designed to do.

Gawd I need a break for a moment.... I feel like I am trying to explain to a teenager why it is impossible for one magical bullet to go through Kennedy, Connely, and Johnson from the 6th story window shaded by a tree.

You and RMT tear it up... I'll be back after while to again bring up the inconsistencies and out right distrotions of truth when I return.

Peace

 

[indazona]

Why are you incapable of being wrong? What happened to your critical thinking process and currently forbids you to accept the facts.

4. Use a strawman.
5. Sidetrack opponents w name calling, ridicule.

Yes do tell why the tower hit second fell first. And do tell why the building not hit by a plane at all fell around five in the afternoon.

17. Change the subject.

You are egear as a beaver to destroy me. ...(not imppressive).... You wanna defeat a stranger rather than make a friend...speaks volumes to your charicter.

7. Question motives.
18. Emotionalize, Antagonize, and Goad. (Tip: It works best when you are a good speller)

You dislike my analogy of the outer mesh frame.

Because it is a wholly invalid comparison that is without merit.
Because it says absolutely nothing about the outer perimeter columns of the WTC.
20. False evidence.

The steel mesh outer core is a load bearing structure.

And a screen in a porch door is not. Ergo your attempt at backwards logic did not work.
13. Alice in Wonderland Logic.

The Jet fuel burned up in one big fire ball

20. False evidence.
19. Ignore facts. (In this case the fact that there was other combustible material that caught fire and sustained the fire.)

if you hold a torch to a beam for only a few seconds your not gonna cut the beam.

19. Ignore facts. (In this case the facts and evidence for Euler column buckling)

Never mind the fact that the WTC fireball did not burn anywhere near the tempature a weilding torch can produce

19. Ignore facts. (In this case the fact that steel weakening at temperature can induce the onset of Euler column buckling, thereby foregoing the necessity for steel melting temperatures)

The structural damage itself was not that bad

19. Ignore facts. (In this case the fact that it was not only the structural damage that caused the collapse. Ignore that it was a compounding effect. Continue to ignore Euler column buckling)

Gawd I need a break for a moment.... I feel like I am trying to explain to a teenager

5. Sidetrack opponents w name calling, ridicule.

You and RMT tear it up... I'll be back after while to again bring up the inconsistencies and out right distrotions of truth when I return.

11. Establish and rely upon fall-back positions.

You are vapid and transparent in your incessant drone of half-facts, non-facts, invalid analogies, and expressions of pseudo-expert opinions ("it should of collapsed" the way I say it should have). On top of that you use the exact same disinformation tactics that you accuse others of, as can be seen from my accounting above. Grow up, go to school, and stop ignoring those facts that don't suit what you wish to believe.

 

[jmpet]

I will tell you why the Twin Towers fell when other buildings did/have not. The Twin Towers were steel structures with an aluminum outer skin, and concrete/steel floors. The point they impacted was what- the 80th and 60th levels? The load bearing steel at the point of impact was designed to hold millions of tons simply because of the weight of the floors above. This means it was a lot of really thick steel.

The plane impacted, the steel supports stopped most of the plane and jet fuel goes all over the place (and down many elevator shafts). Everything in those floors of the WTC basically became a wick for this massive fire (what's the vapor point for plastics?).

And since steel transfers heat (and concrete insulates/absorbs heat), this fire started spreading to other floors- up and down the steel supports to the floors above and below; the surrounding floors roasted; furniture spontaneously combusted etc... (people trapped at the top floor- 200 feet above the point of impact were roasting too- those were the jumpers. Imagine the heat if you were 10 feet/one floor away.)

And that is where the problem with the Twin Towers comes into play- it's a steel building with an aluminum outer skin. Steel melts at 1525 or so degrees, aluminum melts at 2100 or so degrees and does not transfer heat like steel does- it bounces it back. The point of impact- - those five floors or so became a furnace, by definition: the outer skin held in the heat, the stuff inside and fuel added more heat and the giant hole the plane made was the bellows.

At this point, it becomes math- an insulated fire 200 feet X 200 feet X 50 feet with 10,000 gallons of jet fuel plus several tons of combustable items with a 25% air intake over one hour produces a central core heat in excess of 1525 degrees. How could it not?

(And even if the interior of this incredibly huge fire did not get that hot, it got hot enough. At 800 degrees, steel loses half its strength. And with hundreds of tons above, a collapse is inevitable.)

And as far as the building's collapse, we're talking thousands of tons of steel and concrete... we're talking exponential stress levels... the more it falls, the heavier it is/the more force it has/the faster it must fall. Explosives do not become necessary at this point.

And as far as WTC 7- when the jet fuel went all over the place, up to 20% of it went down the elevator shafts and down an underground tunnel to WTC 7.

 

[Darby]

titorite,

I've seen your replies on other non-Titor related threads so I know that you have the ability and inclination to think problems through before responding. I'm asking you to ponder the following:

First off it is my understanding that a fire can only burn as hot as its fuel which would be the jet gasoline. Now then the majority of this "jet gas" burned up on impact igniting everything flamable but ultimiatly expending the strongest fuel(the gas).

I want you to think about the above statement ..."the majority of the [fuel] burned up on impact". That's a lot of petroleum based fuel to burn within seconds.

If you stay with that position then you should consider the significance of what you're suggesting relative to the collapse of the building(s).

In our military arsenals we have a class of explosives called FAE's (fuel-air explosives). They are also sometimes refered to as "poor man's nukes". They employ from less than 100 gallons and up to about 300 gallons of gasoline or kerosene (jet fuel is nothing more than highly refined kerosene) as the explosive. A very complex atomizing mechanism causes the fuel to finely mist prior to the cannister impacting the ground and a delayed explosive ignites the fuel. It then detonates the fuel. The result is over-pressures on the order of 400-500 atmospheres and instant temperatures up to 4500 degrees (the surface of the sun is about 5,600 degrees). The destructive force is on the order of a low yield tactical nuclear device. To accomplish this it takes a mist/air ratio of about 85% to 95% air to mist (it depends on the fuel). Another aspect of FAE's, that differs from conventional explosives, is the duration of the over-pressure. Conventional explosives like C4 and TNT have burn rates that range up to ~22,000 ft/sec. The blast is huge but it's over in a fraction of a second. FAE's maintain the over-pressure for a few seconds because it takes a few seconds for the fuel to burn off. The result is a much more destructive force. To put it in terms relevent to our discussion, "the majority of the [fuel in an FAE] is burned up on impact".

In the case of the Towers we aren't talking about a couple of hundred gallons of fuel instantly igniting. We're talking about 8,000 to 11,000 gallons of fuel.

To get your almost instant consumption of the fuel you must have the equivalent of an FAE. To accomplish this you must have a fuel mist to air ratio on the same order of 85% - 95% air to fuel. That's a huge expansion in volume for the fuel. But if that had occured you would have had your poor man's nuke and it would have been huge. It should have not only dropped the towers it should have crushed them within seconds of the detonation.

If we don't have the proper fuel to air ratio and if we also don't have the majority of the fuel atomized then we have a normal "slow" burn-off of the fuel.

So the questions that you need to ponder are:

1. Where did the oxygen come from to instantly consume the fuel?

2. If the fuel was consumed almost instantly what happened to the release of energy associated with the detonation of the fuel?

3. If the majority of the fuel burned up on impact why did the Towers stay up for the period that they remained standing? Why weren't the instantly crushed in a "poor man's nuke" quasi-FAE detonation?