Hardfire: Physics of 9/11

[bill smith]

 

[Heiwa]

By "see", I mean observe naturally.

The first one that comes to mind has to do with deep beams. Beams 4'-0" or more in depth do not behave as a uniform section like smaller shapes do (such as what is commonly used in steel construction). You have to analyze it with a method such as "strut-and-tie" to address local tension and compression failures at nodes within the beam.

By normal design, the shape might have enough shear and moment capacity, but still fail.

Yes, a 4'-0" deep beam does behave as a 4'-0" plate with some other plates/flanges at the ends and not like a 4" beam. The plate/web shear buckles! We have plenty of those in shipbuilding. And we stiffen the web plate to avoid that problem. But maybe the end plate/flanges carry the load anyway? What has this to do with tiny scale? And normal design?

 

[Newtons Bit]

Yes, a 4'-0" deep beam does behave as a 4'-0" plate with some other plates/flanges at the ends and not like a 4" beam. The plate/web shear buckles! We have plenty of those in shipbuilding. And we stiffen the web plate to avoid that problem. But maybe the end plate/flanges carry the load anyway? What has this to do with tiny scale? And normal design?

No Heiwa, your ignorance is showing again. This occurs in members that are compact. In fact, it also occurs in solid concrete beams that don't even have any flanges.

 

[Newtons Bit]

Are you saying that the standard spaghetti model as suggested does not work beause it is improperly scaled ?

Why don't you apply what RMackey has shown you in his video and find out for yourself!

Get out a piece of paper and a pencil and do some work!

 

[Toke]

Newton/makey,

I am wondering about the simple description/model where the falling floors meet one intact floor and overcome its full carying capacity through impact.

In reality, the collums were stagered over 3 floors and bent, the floors were there for bracing not to take any vertical weight, an unbraced collum have little strengt left, etc...

Have any engineers dared making guesses at the real margin for stopping the collapse?

 

[Toke]

The washer toothpick model got me wondering.
It does show the deceleration at each floor, but looks completely irrelevant for actual collapse.
Floors are not equal to toothpicks, as they do not carry the building.

 

[psikeyhackr]

The washer toothpick model got me wondering.
It does show the deceleration at each floor, but looks completely irrelevant for actual collapse.
Floors are not equal to toothpicks, as they do not carry the building.

.
Suppose I had put ball bearings in a clear plastic tube and dropped a cylindrical slug from the top. Would you be so quick to compare them to FLOORS?

It is about falling mass hitting stationary mass. The shape is incidental. Ball bearings and a clear tube would have cost more and been more difficult to work with. Wire should work better than toothpicks.

The two problems with the current model are the way the washers tilt on the toothpicks and no noticeable reduction in fall occurred as mass was increased. They might be related.

I think using wire instead could solve the problem. I could drill two perpendicular holes and use two wires at right angles to hold the washers level. This would mean considerable testing with wire gauges to determine the energy requirements to bend the various thicknesses of wire.

I was expecting the mass to stop in significantly shorter distance with two washer than with one and even shorter with four. There was not a significant change. Considering how inconsistent the toothpicks were I would not trust them to give reliable results of that fine a distinction over such a small number of tests. Wire would be better because it should have much greater precision than chopped down toothpicks. I didn't think of using wire until I was nearly finished.

psik

 

[Toke]

It is about falling mass hitting stationary mass.

Yes. Your model show a slowdown at each floor.

but looks completely irrelevant for actual collapse.
Floors are not equal to toothpicks, as they do not carry the building.

Do you understand why your model is irrelevant for collapse mecanism?

Floors are not intended to carry weight and will fail instantly, that will remove the horisontal support from the collums, and with that most of their strength.
Your toothpicks/wire does not model that.

 

[Furcifer]

.
It is about falling mass hitting stationary mass.

"On a steeek"

What was your point of making that video anyway? Even as a demonstration of inertia it's flawed (for reasons you have already admitted to)

 

[psikeyhackr]

"On a steeek"

What was your point of making that video anyway? Even as a demonstration of inertia it's flawed (for reasons you have already admitted to)

.
To see what kind of moronic comments I could collect about it. I knew some people would make a BIG DEAL about WASHERS.

psik

 

[Furcifer]

.
To see what kind of moronic comments I could collect about it. I knew some people would make a BIG DEAL about WASHERS.

psik

You admitted they are a big deal. They get jammed on your "core".

Don't feel bad though, Mackey made a video and all he has collected is moronic comments. Some moron couldn't make a mental substitution of "hundreds" instead of "thousands"! They went on and on about it like it meant something, instead of treating it like the simple mistake it was.

 

[Homeland Insurgency]

I liked part three especially when the camera went to Ron with the confused look on his face and then later when Ron chimed in about Gage and his cardboard model for lack of anything else. That was it for me.

Now maybe I'm getting this wrong but apparently according to Mackey 20% or less of any structure is more capable of crushing the other 80% or more if it's really big.

So? What do I need to equate to 9/11. Is it really not scalable? It happened didn't it?

There must be a way.

Like how can I set up a 8 inch paper bag to hold up a 2 inch brick forever just as long as the weight is evenly distributed but then just shift that upper weight a little bit to easily crush the paper bag?

Maybe that's overkill. Let's just start with something lighter holding up something much heavier and massive as long as it's weight is evenly distributed.

Apparently we can't scale 80% of any kind of structure to hold up 20% of the same thing and then have that 20% crush the other 80% because we just can't go that big. The towers were 110 stories. Can we do it at five? Twenty? fifty? At what point does a high-rise become dangerous to support it's own weight? At what point are towers too tall for safety?

So in a model how much does the upper 20% need to be up-scaled in weight and mass to the point where the lower portion can hold it up as long as the weight is evenly distributed but as soon as the upper 20% is put at the right angle it will crush the lower 80%?

Can that be scaled?

 

[R.Mackey]

In reality, the collums were stagered over 3 floors and bent, the floors were there for bracing not to take any vertical weight, an unbraced collum have little strengt left, etc...

Have any engineers dared making guesses at the real margin for stopping the collapse?

You even left out the most important factors against survival -- fracture, and the significant tilt of the upper structures.

As far as I know, there have been no attempts to estimate the real margin needed. Some estimates are sharper than others. Bazant & Zhou is pretty darn conservative when you get down to it, and they estimated about 8:1. Taking these other factors into account, I'd eyeball it at no less than 20:1.

There are also papers on how to built structures that resist collapse, such as Newland and Cebon, but it's critically important to resist the impact and the fires such that the initial collapse is at least mitigated, hopefully prevented entirely. Once structures start to move, they're not very predictable anymore, and without accurate prediction of loads, structural engineering is a guess. Unless you want to build something armored like a tank, or blocky like a pyramid.

Don't feel bad though, Mackey made a video and all he has collected is moronic comments. Some moron couldn't make a mental substitution of "hundreds" instead of "thousands"! They went on and on about it like it meant something, instead of treating it like the simple mistake it was.

I've gotten a few good comments from folks, but not from the Truth Movement. Still nothing but drivel in my mailbox. Nobody has even attempted my "challenge," which is nothing more than asking them to explain themselves properly.

 

[psikeyhackr]

So? What do I need to equate to 9/11. Is it really not scalable? It happened didn't it?

There must be a way.

Like how can I set up a 8 inch paper bag to hold up a 2 inch brick forever just as long as the weight is evenly distributed but then just shift that upper weight a little bit to easily crush the paper bag?

Maybe that's overkill. Let's just start with something lighter holding up something much heavier and massive as long as it's weight is evenly distributed.

Apparently we can't scale 80% of any kind of structure to hold up 20% of the same thing and then have that 20% crush the other 80% because we just can't go that big. The towers were 110 stories. Can we do it at five? Twenty? fifty? At what point does a high-rise become dangerous to support it's own weight? At what point are towers too tall for safety?

So in a model how much does the upper 20% need to be up-scaled in weight and mass to the point where the lower portion can hold it up as long as the weight is evenly distributed but as soon as the upper 20% is put at the right angle it will crush the lower 80%?

Can that be scaled?

.
I thought of another model design, it would be more realistic in some ways. But it would also present the possibility of the top falling down the side which is what the south tower should have done.

Use 3 1/2" hard drives for your weights. Dead drives should be plentiful and cheap. They are relatively dense objects. Take the cardboard tubes from toilet rolls and cut them into 1" lengths to use as columns. So the strength can be varied by changing the number of cardboard cylinders under the drives. So if you use 22 drives then the tubes on the bottom must be strong enough to support all 22. The strength can be tapered going up as Mackey's scaling would require.

A problem with my toothpicks compared to the WTC is that the strength was the same all of the way down. But in the real building the strength had to increase all of the way. But that means that my toothpicks should have been LESS LIKELY to stop the falling mass than the WTC would have been. You can see what happened.

So if Mackey concedes that a model is properly scaled and it will not collapse I will be laughing my ass off. What do you bet the response will be, "It didn't collapse, it can't be valid." The point of my demonstration is that the stationary masses slow things down therefore it makes no sense not to know the distribution of that stationary mass in the WTC towers. You can't make a scaled model without that info.

psik

 

[R.Mackey]

.So if Mackey concedes that a model is properly scaled and it will not collapse I will be laughing my ass off. What do you bet the response will be, "It didn't collapse, it can't be valid."

As I stated quite clearly in the show itself, this is a result I would find very interesting. However, for me to "concede" that it's scaled properly, you have to scale it properly. For the third time, follow these guidelines, and if you do this, we can have a productive conversation. Thus far you don't seem interested in doing your homework.

The point of my demonstration is that the stationary masses slow things down

Nobody disputes this. Every paper has stated, and I have echoed, that the timing of collapse is driven by momentum transfer, not strength.

therefore it makes no sense not to know the distribution of that stationary mass in the WTC towers. You can't make a scaled model without that info.

Fortunately, this information is quite easy to come by.

 

[Homeland Insurgency]

.
I thought of another model design, it would be more realistic in some ways. But it would also present the possibility of the top falling down the side which is what the south tower should have done.

Use 3 1/2" hard drives for your weights. Dead drives should be plentiful and cheap. They are relatively dense objects. Take the cardboard tubes from toilet rolls and cut them into 1" lengths to use as columns. So the strength can be varied by changing the number of cardboard cylinders under the drives. So if you use 22 drives then the tubes on the bottom must be strong enough to support all 22. The strength can be tapered going up as Mackey's scaling would require.

A problem with my toothpicks compared to the WTC is that the strength was the same all of the way down. But in the real building the strength had to increase all of the way. But that means that my toothpicks should have been LESS LIKELY to stop the falling mass than the WTC would have been. You can see what happened.

So if Mackey concedes that a model is properly scaled and it will not collapse I will be laughing my ass off. What do you bet the response will be, "It didn't collapse, it can't be valid." The point of my demonstration is that the stationary masses slow things down therefore it makes no sense not to know the distribution of that stationary mass in the WTC towers. You can't make a scaled model without that info.

psik

I'm already laughing my ass off.

Supposedly it's not only that the buildings were huge but it's as if they were so tall the upper block (cough, gag, vomit) had more time to pick up velocity and power as it fell because it had so far to go. Yes, as if nothing were in it's way. Right?

Except that the very same thing the lower structure was made of so was the upper block. Except that there was much more of the lower structure and it wasn't hit by any impacts of anything and wasn't exposed to any fire that barbecued it for an hour.

And remember how fast that upper barbecued block (cough, gag, vomit) pile driver smashed through that lower not hit by a plane, undamaged, un-barbecued 80%?

But this is because of scale according to Mackey. Therefore it can't ever be accurately replicated because we can't afford it. Just go away nothing to see here because Mackey has spoken.

Wow. I never thought science was suppose to be this funny.

Surely Mr. Mackey can scale an upper 20% of anything to a lower 80% of anything else lighter and less massive where the lower 80% can support that upper 20% as long as the weight is evenly distributed.

Then just shift that upper weight and cause global collapse of the lower portion.

Is it really possible that the only way to replicate this is to build it 110 stories with the same materials?

How convenient for scientists these days.

 

[Furcifer]

Except that there was much more of the lower structure and it wasn't hit by any impacts of anything and wasn't exposed to any fire that barbecued it for an hour.

Given the number of people that died in the fires, the term "barbecued" is really in poor taste. I heard the term used in a similar manner in regards to the Holocaust as well. But I suspect you knew all of this.

Would it matter if there were much less of the lower section? If we imagined floors 1-85 never existed but the damage and the fires raged on in the upper section what would happen?

 

[psikeyhackr]

Nobody disputes this. Every paper has stated, and I have echoed, that the timing of collapse is driven by momentum transfer, not strength..

.
So you are saying that if I ran the tests using different gauges of wire to vary the strength in different tests or even at each level that that would not change the speed of the collapse?

psik

 

[R.Mackey]

Nope. But if the model is scaled properly, the wire strength would be a minor contributor.

You haven't addressed that "if."

 

[psikeyhackr]

I'm already laughing my ass off.

Supposedly it's not only that the buildings were huge but it's as if they were so tall the upper block (cough, gag, vomit) had more time to pick up velocity and power as it fell because it had so far to go. Yes, as if nothing were in it's way. Right?

Except that the very same thing the lower structure was made of so was the upper block. Except that there was much more of the lower structure and it wasn't hit by any impacts of anything and wasn't exposed to any fire that barbecued it for an hour.

And remember how fast that upper barbecued block (cough, gag, vomit) pile driver smashed through that lower not hit by a plane, undamaged, un-barbecued 80%?

But this is because of scale according to Mackey. Therefore it can't ever be accurately replicated because we can't afford it. Just go away nothing to see here because Mackey has spoken.

Wow. I never thought science was suppose to be this funny.

Surely Mr. Mackey can scale an upper 20% of anything to a lower 80% of anything else lighter and less massive where the lower 80% can support that upper 20% as long as the weight is evenly distributed.

Then just shift that upper weight and cause global collapse of the lower portion.

Is it really possible that the only way to replicate this is to build it 110 stories with the same materials?

How convenient for scientists these days.

.
Using my hard drive toilet roll model, 3 drives would be dropped on 19 drives. But those three drives could be separated by tubes also so they could be crushable. Another place for energy to be absorbed. Not like the solid starting mass in Mackey's diagram or my washer model.

psik