9/11 Physics: "You Can't Use Common Sense"

Now fang, its wasn't 100' at the base, let's re-diagram koko's handiwork for a moment.

That's 10 miles square and a 1000 feet high. 52,800' x 52,800'x 1000'. He's right, it will resist lateral forces because it's a very low, very gradual mountain (or a really big hill)..........

 

I was understanding the space in the middle to be hollow. The outside wall 100' at the base and 1' at the top.

 

Proportionally it's still the same though.

Look at us, trying to decipher his ramblings. I will admit, it's more fun than to try and figure out what koko is "trying" to write. Like a puzzle, I love puzzles.

 

Hmm.. Well, since the wall is at a 2.17 degree angle, that certainly does create confusion as to what is meant by 100' at the base. I was assuming 100' x 100' width perpendicular to the beam, but it could be 100'x100' wide where it contacts the ground. Instead of a square column, it would be sort of a wide flat one. That would make the area moment of inertia much smaller, and make the resistance to the bending moment much less.

Thank God we don't let truthers engineer buildings.

 

The core could have stood by itself.

psik

 

Says who?

 

If it is anchored to the ground, it can still buckle and snap. The columns were not continuous solids. They were thirty-foot lengths stuck together. When you have a bunch of them misaligned and vibrating, they tend to separate and fall down.

But what has this to do with WTC? Are you aware of a concept called "scale?"

In your childish fantasy world, yes. In this time/space continuum, no.

 

Figure out the obvious. Physics is incapable of giving a damn who says what.

The core was 47 columns connected by horizontal beams every 12 feet. The density of columns was more than double that of a normal skyscraper with columns 30 feet apart. Without the floors outside the core there would be a lot less weight for them to support. As it was the core supported 53% of the building's weight. The core kept the perimeter from swaying not the other way around.

psik

 

It could support the weight in a more-or-less straight vertical line, So could a beer can support a typical line backer, as long as it was not dented. Dent it and somebody goes on the floor.

Do you ever think these things out all the way?

 

holy (*)(*)(*)(*)oid batman, you think a column that would hold up the wtc would buckle under its own weight free standing? I got all day, prove it. I never heard of such ridiculous (*)(*)(*)(*) as that.

 

Of course, it would. The whole structure was inter-connected. Strip off part of its lateral bracing and set it to vibrating by pounding on it with multi-ton hammers and it will shake itself apart.

 

I did not say use some force to prove that force would knock it down, we know that. I said the application of no force it would stand forever, hence fangs claim and those who support him is utter bull(*)(*)(*)(*) on its face

 

Just having the floors ripped loose would apply a force to knock it down.

 

there were no floors attached, you are confused.

 

In the real world, the columns had floors attached, so any model without them is meaningless.

 

no it had meaning because it proved fang and all his supporters dead wrong about the floor trusses.

 

This is supposed to be a discussion of facts which can be observed and test in the real world. Your fantasy world is irrelevant.

 

Let's think about this, since it's so obvious.

Your claim is that the building designers decided that the core supports itself, but they might as well waste millions of dollars engineering and constructing a load bearing outer wall that carries 47% of the building's weight?

Yeah, there's something here that's obvious, and it's not the structural capacity of the core.

Radio tower antenna carry 100% of their own gravitational load, yet they still require guy wires to remain standing. In fact, the guy wires ADD to the gravitational load that the tower must bear.

If you can figure out why the tower requires guy lines (it's not because of wind), then you can figure out why the core of the WTC would not have stood without the outer walls.

Hint:

 

yes it would

 

That is not what I said.

The simple fact is they could not build it so it could not support itself. It is easy to compute that it has double the column density of a "normal" skyscraper with columns 30 feet apart.

How much live load are radio towers designed to handle? You keep trying to compare this to a single column to bring up your buckling issue. The core was a 3 dimensional array with 47 columns arranged 85 feet by 135 feet. So the width of the base was about 8% of the height.

Why don't you just build a model that can collapse and show the world? Oh yeah, no engineering has managed that yet.

psik

 

What does that have to do with anything? I thought this was about math and physics. How many "normal" skyscrapers have a slenderness ratio the size of the WTC core?

And no, the core was not built so that it could support itself. The entire structure was raised in completed levels. The core never remained unrestrained by outer walls for more than a couple of floors.

There's a very good reason for this, and it has everything to do with effective column length.

Again:



Referring back to the radio tower analogy, the WTC towers were raised the same way a radio tower is raised. The main column is pinned during construction with guy lines as modular sections of tower are placed at the top. They don't wait until the end to tension guy lines, they are tensioned as the tower is constructed. This allows the tower to be pinned at its top, reducing its effective length each time a pin is placed. In the formula above K represents the effective column length factor. For a column that is pinned at the top and fixed at the bottom this factor is 0.699.

For a cantilevered column like the WTC, the effective length factor is 2. Any moron that knows how to divide can see that this reduces the value of F considerably. Small F equals less stable. In order to compensate, the area moment of inertia (i) needs to be increased as the slenderness ratio increases in order for the column to be stable. This can be accomplished with a lot more columns in the center, or it can be accomplished by increasing the distance of columns from the centroid of the shape. The latter requires less materials, and hence the need for outer walls.

 

It is only about physics. The math is only relevant to the extent that it is useful to understanding the physics.

A skyscraper with that slenderness ratio probably would not be economical, that does not mean it could not stand. The core was mostly elevators to lift people to the floorspace outside of the core. But no one is going to build a structure like the core just to see if it could stand. Its existence had to be justified, which required lots of floor space.

Why don't you just build a model and do the collapse and provide the details about the model? You and the engineering schools have had almost 12 years.

And were is this radio tower that collapsed straight down onto itself. Does your math explain that? If not, then what good is it but as a distraction to try to show that you are smart? But if it does not explain a straight down collapse then it is not too smart.

psik

 

oh so you are using applied forces again to prove I am correct and you are incorrect.

LMAO

 

How surprising...Yet another subject koko doesn't know d**k about

 

Blah blah blah. Why don't you do the math? Prove it with math rather than you're empty assertions.