"The towers couldn't have fallen that way..."

reply to post by psikeyhackr


Surely someone with an engineering degree would not have difficulty understanding:

There is no explanation for why the top 29 stories did not fall down the side.

The top 29 stories, in aggregate had a center of mass, as does any object. Nevermind that it was a construction and comprised of thousands and thousands of separate components all joined together...oh, wait....do keep that in mind, it will be addressed later.

Back to the center of mass (wish I had an illustration, probably is one somewhere online).

Which way does gravity on Earth always act through a mass? Yes, correct...straight downwards. 90 degrees to the tangent of the Earth's surface, and in the direction of the center of the planet. So, imagine the top 29 floors as a *cube* (or, really, a cuboid, since a proper cube has equal lengths on all sides).

This cuboid has a center of mass, as mentioned. In fact, due to the general distribution of the individual masses *inside*, and as part of its structure, I'd think it's safe to say the center of mass was (approximately) in the geometric center of the cuboid. (You may argue it was not *exactly* centered, but it certainly was not far from center).

Now then.....absent a lateral (sideways) application of force (there was none), the only force acting on the cuboid is gravity. In order for the upper 29 story-cuboid to "fall down the side", the center of mass would have to be displaced sideways far enough so that the structure beneath was no longer beneath. A 22° tilt was insufficient for this (and here an illustration would be helpful, one could draw it to scale --- this is where "scale" is useful, in terms of modelling and understanding the principles).

Now, as to what I said to keep in mind.....this cuboid of 29 stories was not a proper, *perfect* solid cuboid....it was an assembly of many constituent components, all of which would eventually be over-stressed dramatically, and in a chaotically in terms of the timing of each piece, and when it failed. This is all, again, due to gravity. Gravity was the over-riding force involved here, once the primary structural integrity was diminished (from airplane impact).

Gravity never let up of course, never changed....but, the fires now are continuing to weaken and cause more over-stresses, progressively, randomly, and rapidly in some cases.

The top 29 floors had no impetus to "slide" horizontally at all...if for no other reason than the fact it did not have a smooth, undisturbed "bottom" plane, that was on top of another smooth, undisturbed "top" plane. It was jagged, "prickly", and many connections held, but eventually too many had failed to allow those remaining to continue to support the load...the load again from?? Gravity.

Also, even as the upper 29 stories canted, it was acting as a lever, on the portion that was starting to crush down on the one side...the parts that were being "pulled" on the other side gave way pretty quickly, long before the center of mass could "tilt" over far enough to allow the whole mass to fall free of the lower intact structure.

Then, once the tremendous Potential Energy (its mass multiplied by its height above the surface of the Earth) of the upper cuboid, its total mass in aggregate, the force of gravity.acted as it fell...that force exerted by gravity did all the final crushing and breaking work, all the way down.

Originally posted by psikeyhackr
The compression of the core of the north tower has to be explained.

psik

You should ask the survivors from stair well B that question, They probably also saw the distribution of concrete and steel on each level as it went past them.

Originally posted by ProudBird
reply to post by psikeyhackr

 

Surely someone with an engineering degree would not have difficulty understanding:

There is no explanation for why the top 29 stories did not fall down the side.

The top 29 stories, in aggregate had a center of mass, as does any object. Nevermind that it was a construction and comprised of thousands and thousands of separate components all joined together...oh, wait....do keep that in mind, it will be addressed later.

Back to the center of mass (wish I had an illustration, probably is one somewhere online).

Which way does gravity on Earth always act through a mass? Yes, correct...straight downwards. 90 degrees to the tangent of the Earth's surface, and in the direction of the center of the planet. So, imagine the top 29 floors as a *cube* (or, really, a cuboid, since a proper cube has equal lengths on all sides).

This cuboid has a center of mass, as mentioned. In fact, due to the general distribution of the individual masses *inside*, and as part of its structure, I'd think it's safe to say the center of mass was (approximately) in the geometric center of the cuboid. (You may argue it was not *exactly* centered, but it certainly was not far from center).

Now then.....absent a lateral (sideways) application of force (there was none), the only force acting on the cuboid is gravity. In order for the upper 29 story-cuboid to "fall down the side", the center of mass would have to be displaced sideways far enough so that the structure beneath was no longer beneath. A 22° tilt was insufficient for this (and here an illustration would be helpful, one could draw it to scale --- this is where "scale" is useful, in terms of modelling and understanding the principles).

What idiotic drivel.

The top 29 stories were 67% taller than they were wide. The core supported 53% of the structures weight. So if the center of mass was beyond the edge of the core then the weight would have been on the perimeter columns on one side and no weight on the other. So that tilted portion should have crushed more of one side of the lower structure and further increased the tilt. It should have fallen down the side.

That it had to be completely beyond the lower portion is total nonsense.

psik

reply to post by psikeyhackr




This is basic physics. And geometry and trigonometry.

Really, might want to study up on that.

This fallacious reasoning that the top portion should have "toppled over" comes from an incorrect assumption based on a person's "intuitive" feelings, from experience with small inanimate objects. (And, very, very bad "science" and physics depicted in many Hollywood films and TV shows).

Make a scale drawing, in order to comprehend. Be sure to get the dimensions all to scale, and the proper angles.
Then, on the drawing, see where the center (rough it out to the center of the outline of the moving portion, the upper 29 stories).

Maybe someone has a CAD program or something that they can use, to do this and then post it?


ETA, found this verbal explanation:

NOVA: The Towers collapsed essentially straight down. Was there any chance they could have tipped over?

Eagar: It's really not possible in this case. In our normal experience, we deal with small things, say, a glass of water, that might tip over, and we don't realize how far something has to tip proportional to its base. The base of the World Trade Center was 208 feet on a side, and that means it would have had to have tipped at least 100 feet to one side in order to move its center of gravity from the center of the building out beyond its base. That would have been a tremendous amount of bending. In a building that is mostly air, as the World Trade Center was, there would have been buckling columns, and it would have come straight down before it ever tipped over.

NOVA: The Collapse: An Engineer's Perspective


ETA - 2

Summary

The center of gravity (CG) is where all of the weight of an object appears to be concentrated. This point is the average distribution of the weight of the object. The center of gravity of an object can also be found experimentally.

Free rotation of an object is always around its center of gravity. An object will tip over when the CG lies outside the object's support. The greatest force is applied through he center of gravity.

www.school-for-champions.com...


Of course, in the earlier explanation, I always referred to "Center of Mass" which, in the Earth's gravitational field and in the situation we are examining, the equivalent to Center of Gravity.

Interesting you mention Thomas Eagar, an "engineer" who thinks there were 90,000 Litres of fuel on each alleged airplane, when there were only 37,000 litres. An engineer who cannot even calculate something as simple as fuel load is going to solve something as complex as 9/11?

www.tms.org...

Since this guy can't even do basic mathematics, how did he get his engineering license?

This is basic physics. And geometry and trigonometry. Really, might want to study up on that.

You and your engineer buddy Eagar might want to study up on first grade mathematics, before we get to the complex stuff like physics, geometry and trigonometry.

Originally posted by SphinxMontreal
Interesting you mention Thomas Eagar, an "engineer" who thinks there were 90,000 Litres of fuel on each alleged airplane, when there were only 37,000 litres. An engineer who cannot even calculate something as simple as fuel load is going to solve something as complex as 9/11?

www.tms.org...

Since this guy can't even do basic mathematics, how did he get his engineering license?

Why do you say "alleged airplane"?

reply to post by SphinxMontreal


He is an engineer, not a pilot and certainly not an aviation expert. This in no way invalidates his physics knowledge.

In fact, he likely presumed that the airplanes that hit the WTC were fueled to capacity. A B-767-200ER DOES have a total capacity of 91,000 litres. (American 11 was a 767-200ER. United 175 was not an ER).

boeing.com...

It is simply that he did his calculations before it was widely understood (after investigations into the actual, live mass of the 767s was determined, based on the airlines' own data) what the actual fuel quantities were.

Removing that excess fuel lowers the airplane weight by 90,000 or 95,000 pounds, so take that into account when considering the Kinetic Energy of the impacts.

Originally posted by TheMatrixusesYou
reply to post by waypastvne

 

You say there was no thermite because........what.....they tested and found none?

No actually, they left it alone both times there was an investigation. You can't convince truthers (by definition) that a building will collapse in a controlled demo from a fire here and a fire there. Especially when you look at all the surrounding buildings closest to towers 1 and 2. Why didn't they come completely down? No. They're left half-standing from what you would expect from pyroclastic debris close to the towers. If they came down like building 7, you might have a case.

You're not serious, are you?

There was no pyroclastic debris. It was a dust cloud filled with fireproofing, pulverized concrete, paper, and ash. If you want proof that it was not pyroclastic, ask the people who were INSIDE the cloud. Cars and such were burnt due to burning debris hitting them. It's that simple.

It also was not a "fire here and a fire there." The fire spanned multiple floors of WTC 7 and burned for almost 7 hours before a single column failed and led to a global collapse. Most of the buildings around the complex had to be deconstructed, and the Deutsch Bank actually killed a couple people in an accidental fire before being completely taken down.

Honestly, you're arguing from a base of ignorance at the moment. You should perhaps sit back and learn from the people here who have done more research.

Originally posted by Varemia

Originally posted by TheMatrixusesYou
reply to post by waypastvne

 

You say there was no thermite because........what.....they tested and found none?

No actually, they left it alone both times there was an investigation. You can't convince truthers (by definition) that a building will collapse in a controlled demo from a fire here and a fire there. Especially when you look at all the surrounding buildings closest to towers 1 and 2. Why didn't they come completely down? No. They're left half-standing from what you would expect from pyroclastic debris close to the towers. If they came down like building 7, you might have a case.

You're not serious, are you?

There was no pyroclastic debris. It was a dust cloud filled with fireproofing, pulverized concrete, paper, and ash. If you want proof that it was not pyroclastic, ask the people who were INSIDE the cloud. Cars and such were burnt due to burning debris hitting them. It's that simple.

It also was not a "fire here and a fire there." The fire spanned multiple floors of WTC 7 and burned for almost 7 hours before a single column failed and led to a global collapse. Most of the buildings around the complex had to be deconstructed, and the Deutsch Bank actually killed a couple people in an accidental fire before being completely taken down.

Honestly, you're arguing from a base of ignorance at the moment. You should perhaps sit back and learn from the people here who have done more research.

Thanks for your reply.

Pyroclastic clouds were there, just not on the outskirts as they started to cool, but hey, I'm not an expert.
And I appreciate the sentiment that my education is lacking, but I refuse to play that game. I've watched this thread from its inception and marvel at the numbers being thrown around on both sides with neither side convincing the other of their intellectual prowess.

It doesn't take a rocket scientist, architect, engineer, or a chalk board to see that building 7 came down in controlled demolition, which is a science in itself. Cutter charges have to be placed in myriad locations and precise timing to achieve the perfection that is this controlled demo in bldg 7. This would have taken weeks if not months to accomplish. Please. I find the logic severely deficient trying to explain controlled demo with some fires on a few floors. Even if it were on every floor, it still wouldn't happen.

How something is done comes secondary to why something is done and you all are arguing over the how. This can only mean that non-truthers can not possibly grasp the why as they find it fitting to argue the how. You can't grasp that someone might undermine this great America from within.

Want a little trivia that so parallels this problem? I'll give you one guess who is guilty of the largest loss of product, or shrinkage, in a company. Hopefully you guessed right: the employee. Yes--the insider. The one who knows the ins and outs.

So I'm sure you're fully convinced that we were and are necessarily still at war for a genuine reason to preserve our freedom and that the Gulf of Tonkin that started our involvement in the Vietnam war really happened.

And all you said about the buildings surrounding the WTC had to be deconstructed, but said nothing about why they didn't fall in a free fall collapse and some of those buildings were closer to bldgs 1 and 2 than 7 was.

reply to post by TheMatrixusesYou


So, you're saying WTC 7 was a controlled demolition because it is obvious that it was a controlled demolition. This is circular logic at its best.

The reason that the other buildings didn't collapse is that they either were not on fire as much, didn't sustain enough damage, or were simply designed in a different manner with primary supports not affected.

It's not even funny having to explain this.

Originally posted by ProudBird
reply to post by psikeyhackr

 

This is basic physics. And geometry and trigonometry.

Really, might want to study up on that.

This fallacious reasoning that the top portion should have "toppled over" comes from an incorrect assumption based on a person's "intuitive" feelings, from experience with small inanimate objects. (And, very, very bad "science" and physics depicted in many Hollywood films and TV shows).

Make a scale drawing, in order to comprehend. Be sure to get the dimensions all to scale, and the proper angles.
Then, on the drawing, see where the center (rough it out to the center of the outline of the moving portion, the upper 29 stories).

Maybe someone has a CAD program or something that they can use, to do this and then post it?


ETA, found this verbal explanation:

NOVA: The Towers collapsed essentially straight down. Was there any chance they could have tipped over?

Eagar: It's really not possible in this case. In our normal experience, we deal with small things, say, a glass of water, that might tip over, and we don't realize how far something has to tip proportional to its base. The base of the World Trade Center was 208 feet on a side, and that means it would have had to have tipped at least 100 feet to one side in order to move its center of gravity from the center of the building out beyond its base. That would have been a tremendous amount of bending. In a building that is mostly air, as the World Trade Center was, there would have been buckling columns, and it would have come straight down before it ever tipped over.

NOVA: The Collapse: An Engineer's Perspective

ETA - 2

Summary

The center of gravity (CG) is where all of the weight of an object appears to be concentrated. This point is the average distribution of the weight of the object. The center of gravity of an object can also be found experimentally.

Free rotation of an object is always around its center of gravity. An object will tip over when the CG lies outside the object's support. The greatest force is applied through he center of gravity.

www.school-for-champions.com...

Of course, in the earlier explanation, I always referred to "Center of Mass" which, in the Earth's gravitational field and in the situation we are examining, the equivalent to Center of Gravity.

edit on Sun 16 October 2011 by ProudBird because: (no reason given)

Does using the word trigonometry help you convince yourself that you are intelligent?

How can any engineers figure out where the center of mass of the top 29 stories was if they don't know the distributions of steel and concrete? So why aren't they asking? Where was the center of mass relative to the stationary core below? So the 29 stories should have crushed one side of the building. A straight down collapse makes NO SENSE. So the physics profession not bringing up the subject for TEN YEARS is extremely curious.

Sure, let's pretend the grade school physics is SO HARD.

psik

reply to post by Varemia


I immediately regret my tone in my last post.

What appeared to be a circular argument by extension as you put it was my saying, "Why are you afraid to see things for what they are or could possibly be?"

Then the argument I was making concerning the nearby buildings to bldgs 1 and 2 should apply to all buildings in that vicinity. Apparently to my logic only since my ignorance is at its pinnacle, building 7 should look like all those other buildings that were merely tattered and fallen upon by fiery, yet non-pyroclastic material. Bldg 7 was the only one of those to have fallen in what appears to be a controlled demo and you are one example of a person not even considering that possibility or the possibility that we've been had.

Sorry to lay the stress on so thick.

reply to post by TheMatrixusesYou


I consider the possibility. However, I consider it highly unlikely due to the explanation present which incorporates independently verifiable, observable facts in order to be true.

There has simply been no evidence for demolition charges. Jones' thermite is not evidence of charges. It is evidence of aluminum and iron-oxide in dust samples.

I'd place my sureness to be around 70-80% for the official story regarding the collapses, and around 5% for demolitions. the other 15-25% is just up in the air or other.

reply to post by psikeyhackr


This is a good, brief video of Tower 2 upper section as it begins to rotate down, at the corner where impact occurred.

Watch very carefully. Gravity, and physics.

It did not just "fall off" of the top, because it couldn't; the structure beneath was giving way, due to the force of the KE, as PE was converted into KE. The moment of leverage, from the initial rotation onset, ended when the pivot point was lost, crumbling beneath the onslaught of the KE from the mass above.



Even a grade-schooler can see what is happening there. And, we are only seeing part of the story, and from a distance where all the millions of details of things happening can't be seen --- and many things are happening simultaneously inside, that can't be seen (but computer models can give us a *look*, with at least approximations, if only someone or some team with access to a supercomputer would take the time and resources to do the work programming the factors).

The area where the forces are most at work is where the individual pieces that comprise the structure of the building were failing, and the stresses were overwhelming the connections.....beyond its design capacity, because none of those connectors that held I-beams or other pieces of steel together were designed to withstand loads in the directions they were exposed to, as the collapse progressed. It was a cascade effect.

Too often, people seem to have the false impression that the building should have behaved as if it were a "solid and rigid mass".

(Just picture the infamous, and laughably wrong, Richard Gage, and his cardboard boxes!!).

It wasn't, but nevertheless, the total weight of all components can be added together to derive a sum total weight, and that mass didn't disappear once it began to fall, it used the force of gravity (or, gravity used it) to continue downward, wreaking destruction, which added more mass to the whole total debris, which kept going down, etc, etc.

Cascading.

reply to post by ProudBird


This simulation is a fairly interesting one. He alternates the strength and rigidity of the materials and such. If you watch a previous video, he actually shows how everything was modeled, from the trusses to the core beams and the exterior panels.

reply to post by Varemia


Really I'm only focusing on building 7, which has no argument with thermite either way. Since it is a stand alone situation and no one seems to be arguing it that much because there's already a ton to argue about with the other two buildings. While everyone argues over the twins, nothing gets accomplished except forehead banging.

If the building 7 collapse was the only thing to have happened on that day, people would be demanding answers, however they are distracted by the spectacle of the twins. I'm not saying that building 7 was the most important of the destruction, but with its perfect fall, it's removal from original investigation and it's relative distance from the twins compared to the other buildings....

It just seems that there is enough doubt there to justify our views. Enough to say, "ok. fair enough. let's officially investigate this."

Why all the resistance? Do you think that if it happens to cost $10 million to investigate, that that's going to be a problem with our budget?

And what if Building 7 was the main target and was hence thoroughly fishnetted with explosives inside(just bare with me here). Well then you have to convince some American haters to fly planes into the twins to create a large enough spectacle--enough of a distraction so when building 7 comes down, no one really cares much about it as the twins provide ample discussion. Even non-truthers could be right with their math concerning the twins, while the truthers could be right in spirit that this is an inside job.

Originally posted by Varemia
reply to post by TheMatrixusesYou

 

So, you're saying WTC 7 was a controlled demolition because it is obvious that it was a controlled demolition. This is circular logic at its best.

The reason that the other buildings didn't collapse is that they either were not on fire as much, didn't sustain enough damage, or were simply designed in a different manner with primary supports not affected.

It's not even funny having to explain this.

Building 7 was controlled demolition , and it was admitted (link below) ..... so why is it so hard to beleive the towers were too ? you saw the cuts in the steel ..... a collapse bends and buckles ... it doesnt cut straight lines , and it certainly doesnt leave clean cut square holes in the steel. They are trying to say it was a "pancake" collapse .... well ...where were the pancakes ? When the buildings were constructed they were designed to withstand a collision with an airplane (707 i think ? ), maybe multiple collisions depending on size and load.
So what i dont understand is why so many people start at - the impact - instead of looking further back , before "911" , shortly before "911" the towers were insured for the exact same scenario .......
The towers were shutdown just before "911" for maintanence after a power out .
NORAD and co were training for the exact same scenario, and were running a drill on the morning of "911" (but stood down for some reason ) ....
And FEMA were in New York on monday 10th september for a biochemical attack drill at pier 92 on wed 12th september, but for some reason denied claims of them being there on the day before "911" untill the claim was validated in 2004.

Check this out ..... and check out the FEMA book covers at the bottom of the page too
just a coincidence all those trucks and personnel were already there ? i think not.

whatreallyhappened.com...
(Building 7 admitted) -> www.youtube.com...

www.youtube.com... < watch all of this .... if youve still got doubts ... theres no helping you.

reply to post by psikeyhackr


You are as bad as ANOK another stuck record "what about the distrobution of the steel etc etc" I have said to you before one of your truther sites has LINKS to the drawings on line!!!

The south tower leaned to the area of impact damage it dropped down and in, it would pivot because of undamaged steel on the other side then as the structure started to break up it dropped down.

Why dont you like the other truthers work out POSSIBLE impact loads from the falling mass on the floor immediately below the imapct point, YOU keep going on about loads/mass etc, YOU think your washer model was accurate so lets see some CALCULATIONS washer physics man!