9/11 was an inside job

psikeyhackr

Too bad you didn't bother to read them, it would have forstalled you making idiotic statements like this...

The only concrete in either Tower 1 or 2 above ground level was the lightweight covering of the floor trusses and the equipment floors(density of the concrete, area of the floor trusses and depth of the cover is all information contained in the reports, as well as total weight of the equipment floors and all equipment on those floors). The Twin Towers had no weight bearing structural concrete at all above the ground floor with the exception of the equipment floors

Yes they do, pointing out that the center of mass had no time to move from the center of the acre sized footprint of the building in the short time after collapse initiated. The tilt rotated around that center of gravity(putting the interface in shear)and then the center of mass fell directly downward, as the center of mass has no choice but to do. Huge buildings do not have the structural strength to topple off to the side, and no force was available to push it over the side(such as an earthquake or foundation collapse). NIST has diagrams and everything detailing this effect

They admit nothing as they have done nothing but investigate what happened, the aircraft impact damage was extensively studied, there's a whole pdf dedicated to that one subject. The Towers survived the plane impacts, blast damage to the cheap, spray on fire insulation and several hundred thousand pounds of fuel caused massive fires that weakened the surviving structure to the point of failure and once the building fell ONE FLOOR the surviving structure, largely because of it's design elements, could only slow the avalanche a few percentage points.

No, what Truthers do is pseudo-scientific farce, NIST does the real thing.

What caused the events of 9-11 was religious extremism and physics, nothing else was required nor evident.

Grumpy

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...You're serious about this?? You're really serious.

OK. I'm not a physicist, so this is off the top of my head. How does the square law relate to the rigidity of building materials? Paper crumples. Concrete doesn't.

Yes. The realization that such a model would have no relevance to the question unless I could replicate the fragility of materials within it, or scale physics down to apply to such a model in the small scale in the same way that it really applies to massive structures.

Which I guess means reworking gravitation on my toolbench. Sorry, but I'm not rated for a zero-point field outside the city limits. Maybe you should call Green Lantern.

Here's a probably relevant biological example: a mouse dropped from height does not experience the same relative damage that an elephant dropped over a size-equivalent distance does.

 

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So explain all of the sources from before 9/11 that say this:

The towers, made from 200,000 tons of steel and 425,00 cubic yards of concrete

http://www.abqjournal.com/news/metro/104998metro11-01-03.htm

The so called light weight concrete was 110 lb. per cubic foot whereas the NORMAL concrete was 150 lb. per cubic foot. Not all that much difference. The nice thing about electronic documents is there searchability. I looked at every mention of concrete in the entire report. The NIST never specifies the total amount of concrete in the towers and in 4 years not one person has supplied a number and reported its location in the report. Nitwits just keep claiming it is there.

The center of gravity of the tilted top portion of the south tower is also never mentioned in the report. Searching and checking "center of gravity" and "center of mass" was much easier than searching on concrete. It is mentioned much less often. They used "center of mass" when they were talking about the plane, and "center of gravity" for the simulated components for their computer model.

Since the NIST admit that the core supported 53% of the weight of the building the location of the center of mass is important because it did not have to move outside that acre of floor, only outside the area of the core. That is another subject not discussed. Ryan Mackey also implies it would have to move beyond the outer edge of the building. We are constantly bombarded with this over simplified, nonsense physics.

psik

 

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Pot meet kettle.

 

The square cube law relates to strength of material in relation to its size and weight and is important to modeling that behavior of a very large massive object on a small scale.

Suppose we built a 1/10 scale model of the WTC of the exact same material. It would be 136 feet tall and 20 feet wide. But because it is 3 dimensional it would weigh 1/1000th as much but the cross sectional area of the steel columns would be 1/100th the area. So in fact the model would be TEN TIMES as strong as the WTC in relation to its own weight.

How can you do a gravitational collapse that depends on weight and strength if the model is actually STRONGER THAN THE REAL THING.

That is why my model is PAPER. I could test the strength of the paper loops in relation to the weight of the washers so they are AS WEAK AS POSSIBLE in relation to the STATIC LOAD. Go to JREF and read their idiotic mantra STATIC AND DYNAMIC, STATIC AND DYNAMIC.

The paper loops can support the STATIC LOAD which is what the supports in a skyscraper must do. But they are crushed under the DYNAMIC LOAD. But that requires energy which slows the falling mass and eventually STOP IT.

The WTC was 400,000+ tons. Obviously it could not be built of paper. But a small model demonstrating the physical principles cannot be built of steel and concrete. Or if it can, I want to see it.

People confuse SCALE models with PHYSICS models. Mine is a physics model.

And Galileo figured out the square cube law 400 years ago. Grade school kids should know it today.

http://www.dinosaurtheory.com/scaling.html

psik

 

Oh yeah.

There is no gravity there. There is no acceleration.

There is no potential energy. There is no kinetic energy.

Your argument is so impressive.

I presume people's whose only argument is ridicule will only influence morons.

psik

 

psikeyhackr

They did not specifically separate out the concrete in the foundations(where all but a small amount was to be found)and the fact that there was absolutely no structural or weight bearing concrete in the Twin Towers above ground level, with the SOLE exception being the equipment floors. If you want to know how much concrete was above ground level, determine the area(about an acre)times the depth per floor(about 4 inches), multiply by the density and multiply by the number of floors(all information easily found in the NIST reports), then add in the equipment levels(detailed in the reports)and Viola! your question is answered!

It didn't even need to do that, once the steel beams were no longer lined up they supported no weight at all and fell past each other like a collapsing telescope. The structural strength of the core was only relevant as long as the beams were intact and under design conditions, the rotation of the top block bent or broke those connections due to shear forces(the bottom of the top block moved opposite the direction of the top of the block, but the center of gravity stayed over the footprint)and the beams in the top block fell past the beams of the remainder of the building, which provided no resistance at all as they passed. The building was mostly air(again, above ground level), it had no steel reinforced concrete structure(agl), even in the core. It was a tube in a tube with non structural load bearing truss floors(the floors provided bracing to keep the beams vertical). All structural loads were supplied by the steel beams in the core and the perimeter frame. Rubble did not need to overcome the strength of that frame, it only had to overcome the strength of the floor diaphragms(actually, only their connections). Without bracing even the strongest beams in the building would fall over like overcooked spaghetti or(as actually happened)fail under the load, the heat and the distortions caused by aircraft impact damage and bend and break, leading to a cascade of other structural failures and catastrophic, global collapse. The floor diaphragms actually pulled on the frames when they sagged, leading to even further distortions in the supporting beams, in places.

And where did the energy to move the several tens of thousands of tons of the top block sideways over 500 ft in under a second come from? You realize, I hope, that you are talking about MEGATONS of energy, even given 100% conversion into motion. How was all this energy applied in such a way as not to instantly vaporize the top block, crumple all it's steel and NOT vaporize a small segment of New York City? The top block's center of gravity remained fixed above the center of the footprint(within a few percentage points)and fell straight down and Ryan Mackey is ignorant, at best, in this opinion.

Again, all that is needed or evidenced to explain the events of 9-11 was religious extremism and physics. Nothing else required or in evidence.

Grumpy

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Ridicule is all you retarded truthers deserve. Talk about moron...I'm not the one who's spent some 4 years trying to figure out how much concrete was in the towers.

 

Correct. Which would make sense if the WTC was designed with materials that were designed to crush and absorb energy - and that had a central core that was not movable by any force that the model might see.

Of course the WTC was nothing like that.

Here's a model that's a bit closer to the scale of the WTC. It is knocked down by firing projectiles at it. The results are quite interesting. The first projectile knocks a hole in the structure - but it remains standing. (Is this sounding familiar yet?) The second projectile knocks another hole in the structure - and for a moment it still continues to stand. Then, as the structure starts to flex, the remaining load bearing members fail and it collapses. If you time it carefully you'll notice that it falls just slightly slower than freefall speeds. (Sounds a little more familiar now, perhaps?)

The difference - this model was made with independent structural elements that were NOT designed to crush, and it had no indestructible core. They were quite strong individually, but not strongly attached to each other. Thus when enough of them failed the failure progressed rapidly and the entire model collapsed almost as fast as gravity could take it.

http://www.youtube.com/watch?v=NBbz2eIoVDQ

 

All you have to do is compute the volumes of all of the basement levels and you will see that only accounts for a bit more than 50% of 425,000 cubic yards and that assumes the basement are solid blocks with no empty space.

LOL

So your only real argument is TURN OFF YOU BRAIN AND BELIEVE WHAT YOU ARE TOLD.

So we are still left with no explanation for that 425,000 cubic yards.

psik

 

You just spent it believing the problem was solvable without the information.

But still neither you nor any engineering school has built a reasonable model that can completely collapse. Curious that it hasn't been done for such a simple physics problem. The nation that put men on the Moon can't supply such simple data. 10,000 page report for $20,000,000.

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And a citezenry that can't figure out it makes no sense.

psik

 

See above. Model built by Kettering University collapses completely. Cool video as well.

Next objection?

 

psikeyhackr

Actually, the footprint of the structure below ground level is several times the footprint of the building, and it was multifloor(subfloors, in this case). It is simply a fact that the Twin Towers were built without any load bearing concrete above street level. All the structural concrete was below street level. If you don't know that simple fact, you know nothing about how those buildings were constructed, nor do you understand even the simplest things about how they collapsed. But, since you're a truther, I repeat myself.

Grumpy

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But this is the point exactly. You cannot reproduce the physics of the collapse, since you cannot generate a model with materials that behave in the same way at the small scale. Or perhaps you could, but you'd be researching them a long, long time. Instead you've chosen a paper-and-washers way that does not approach the physics of the original system in the small scale. Paper is not a simulator of tiny concrete and steel. You cannot honestly expect it to behave in the same way. I'm no physicist, but it seems clear that the choice of materials influences the reaction in the model. There's no point discussing it.

 

Tiny concrete and steel would be TOO STRONG. Needles between the washers would not collapse at all. It would take a minimum of three for support.

How do you know they are not behaving in the same way? Did you even know what the square cube law was before I mentioned it?

Disabling the steel supports in the WTC from above would require energy. The only source of energy is the kinetic energy of the falling mass. Those supports had to be strong enough to hold the static load. Therefore it must slow down and have less energy to collapse the next level.

That is what my model does. It would be better with a bigger model, say ten tons with 50 or more levels 100 feet tall and each individual level designed to be as weak as possible but I don't gave the resources to do that. But our engineering schools do. So it is certainly curious that none of them has even mentioned trying to do it in ten years.

But then people who have decided what they prefer to believe just constantly come up with EXCUSES. 400 year old physics is too difficult for them.

But then aren't you implying that paper is stronger than steel. LOL

psik

 

The WTC complex was interconnected below ground but that does not mean those interconnections provided support. Constantly muddying the waters, eh Grumpy.

psik

 

psikeyhackr

The steel column's strength had no effect on slowing the collapses, as there was no connection(and therefore no way for them to exert any Resistance)once the collapse initiated(in fact, collapse was initiated by the bending, snapping and disconnection of the steel beams). The only thing the falling rubble had to overcome was the connections for the trusses that made up the floors. Even very strong steel beams exert no force on similar beams if they are not aligned vertically and braced in that vertical line(IE intact and as designed)but are instead falling past each other. You keep talking as if the designed in strength could slow down the vertical avalanche of debris and it just has no physical ability to do so, the weak link being the floor truss connections. Once they start bending, snapping and falling past each other they offer no resistance at all, and once the multi million pound upper block fell one floor(about 12-14 feet)no force on Earth other than solid rock was going to stop it or even slow it down appreciably(kinetic energy, look it up). Most of the truss supports in the lower levels of Tower 1 were found to have been stripped off the elements of the perimeter frame.

The Twin Towers were not steel reinforced concrete(like the Empire State building is), but had a perimeter frame and steel core connected through the hat frame with the floors formed from lightweight trusses designed only to carry that floor's loads and to brace the frame and core in a vertical position and only fastened to the inner and outer frames by angle iron and bolts. They contributed nothing to the structural strength of the buildings(other than bracing). It was a tube(the core)within a tube(the perimeter frame)tied together at the top by the hat frame and at three points(the equipment floors). Structurally, there was nothing else in the building, the floors being simple diaphragms to hold the offices, etc. and not capable of carrying structural level loads.

Actually, applying the square cube law, it is much stronger than the steel in the Towers and if not perforated heavily all around the perimeter and center to accurately represent the weakness of the floor truss connections it is useless garbage as legitimate science.

Troothers are the ones muddying the water. There was exactly ZERO structural concrete above ground level outside the equipment floors. All structural forces above ground level were supplied by the core and perimeter frames and it was the failure of these structural members due to damage and heat which caused the buildings to collapse, nothing else is necessary to explain the events. Keep beating that years long dead horse, it'll get back up any time now I'm sure.

Grumpy

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And the HORIZONTAL BEAMS in the core just happen to disappear because you don't mention them.

psik

 

psikeyhackr

They are, after all, irrelevant considering the floors took up the majority of the area of the footprint and would have had to play the largest part in any resistance, something they were woefully inadequate to do, being designed only strong enough to carry that floors load(times 1.5 or 2 depending on source), not any of the load to hold up the whole building.

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Plus, the majority of the cores were taken up by elevator shafts(that's why the core was there, conceivably the building could also be built without a core, just a perimeter frame with external elevators and acre sized clear floors with no beams at all). And an elevator shaft is mostly nothing in the vertical direction, you know.

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In Tower 2 the core could still be seen standing for a few moments after the collapse was at ground level for the floor debris and perimeter frame, probably because once the top block ceased to be a single mass the debris from the offset top(especially the hat truss structure that tied the core and perimeter frame together at the top)missed the core(the torque and shear forces "rubble-ized" the lower edge of the block almost instantly as it's area was where the initiation occurred). But like I said, since the beams were incapable of staying vertical without bracing, they soon snapped like extremely thin spaghetti and joined the rest of the rubble. The core was built much heavier than the floors and the outer perimeter frame was lightweight and strong for much the same reason and it has the same limitations as an empty soda can does. As long as it's not cut, bent, distorted, heated too much or overloaded it is a marvel of strength to weight, but when abused too much it collapses rapidly and catastrophically. Flying airliners full of fuel and people into it certainly qualifies as too much abuse, as subsequent events proved.

If they had done the same to the Empire State building there would probably have been an unholy mess, but the building would still be standing as it's steel is encased in concrete, not insulating foam(blocks and spray on)as used in the Twin Towers above ground(even the walls in the core were based on foam blocks, sheetrock being deemed too heavy and concrete out of the question). Plus the ESB is a lattice framed building with lots of cross beams throughout it's footprint something the Twin Towers only had in the core(about 1/4 of the footprint IIRC)and solid, steel reinforced, concrete floors directly connected to those cross beams(something the Twin Towers had none of, except on the equipment floors).

Grumpy

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The horizontal beams were BETWEEN the elevator shafts.

The NIST says the core supported 53% of the weight and you say the building could have been built without it.

BRILLIANT!

But then the trusses would have had to span 200 feet.

Even more BRILLIANT!

Urich says that 86 of the floors had the same design which you have shown us such pretty pictures of even though we have all seen them before, and before and before. But didn't the 10th LEVEL of the building have to support the weight of 100 more LEVELS. How many LEVELS did the 105th story have to support? But weren't the FLOORS the same? So what was the difference in the LEVELS?

The difference is unimportant because YOU say so?

psik