9-11 Presentation at NMSR, May 19 2010

[TheRedWorm]

I see an intact upper block crushing through some disabled floors. How is this a correct analogy?

How crushed were the upper portions of the WTC towers, and how do you conclude this?

 

[triforcharity]

Because the rubble is a loose and randomized collection of building fragments and tends to spill over the sides. Individual rubble pieces do not have sufficient mass to crush through intact building components.

Correct in that individual significant mass to cause damage. Correct!

However, you put MILLIONS of them together, Including things like desks, chairs, filing cabinets, copt machines, and thousands of tons of steel and concrete, and drop them on a single floor system, and you will excede the weight bearing capability of that floor. Now you have ADDED a WHOLE ENTIRE FLOORS WORTH of crap to the falling collection of rubble. Now, it hits the NEXT floor. and so on and so on.......

Sure, some will be sent off to the sides, and out of the area, HOWEVER, more than enough will remain to collapse the next floor.

Plain simple anology.

Your roof of your house can support X amount right? We will use a number, so, 100 lbs. (not realistic number)

Now, you can safely place 100 lbs of hurse crap on your roof. It will hold it, no problem. Can do this all day long, night and day.

Now, take the 100 lbs of horse crap, and drop it on your roof from a height of 12 feet. Can your roof hold it? No. Why you ask? Dynamic Vs. Static loading.

THis is simple really.

 

[ergo]

What we're discussing is impact force. Let us say that the top block falling down has a mass of 1000 kg (just for ease of calculating it). We'll use this nifty online calculator. Again, for ease of calculating, let's imagine the height being 10 meters. Total impact force with these parameters is 1,400,000 N.

1,000kg produces 140,000 N.

Now, let's say the top block is split up into 1000 1 kg pieces. Other parameters remain the same. The pieces fall on the bottom block, each impacting with 1400 N. This happens a thousand times, giving us 1000*1400 = 1,400,000 N, the same force as if we dropped a solid block.

1 kg gives 140 N.

Now, explain how this energy is deflected.

The 1,000 pieces hit the intact components differently. Force is applied differentially. As smaller discrete units, air friction and friction from other flying parts affects them differentially. The energy is deflected because a 1 kg object will not destroy the various building components. Damage perhaps, but not destruction. If the building part that the 1kg mass hits is not destroyed, the 1 kg object is deflected.

It's like if I drop a bowling ball on your head from a window above, I would probably kill you. Your skull would be crushed. If I drop the broken fragments of a bowling ball on your head from a window above, it would hurt you, you would sustain bruises, but your skull would not be crushed.

 

[pgimeno]

http://www.internationalskeptics.com/forums/showpost.php?p=6244034&postcount=132

Ok, sorry, it's me who missed it.

I see an intact upper block crushing through some disabled floors. How is this a correct analogy?

1. The layer between the falling section and the lower section is rubble.

2. The lower floors are not disabled in the sense that they can still bear the load of the upper section.

3. In fact, in some cases they are not disabled at all. Here's the text of the patent (EP 1,082,505) on that demolition technique (Google translation from the French original):

Moreover, this method is also safe for operators because it is not necessary to weaken the structure of the building.​

(Translated from http://www.freepatentsonline.com/EP1082505.html)

(ETA: Original text in french: "Par ailleurs, ce procédé est également sans danger pour les opérateurs étant donné qu'il n'est pas nécessaire de fragiliser la structure de l'immeuble")

 

[ergo]

Ok, sorry, it's me who missed it.

1. The layer between the falling section and the lower section is rubble.

Being driven by an intact upper block. I asked how rubble alone could crush the lower part of the building.

 

[Myriad]

Well, ergo is remaining unconvinced that the laws of physics as applied by physicists, engineers, investigators, historians, and even truck drivers, actually work the way the textbooks and equations say they do. What fortitude! What determination! What strength of character!

Unfortunately people who actually get to make decisions about engineering matters such as whether or not the issues covered in the NIST report should be re-investigated don't see it ergo's way. In fact, they seem to regard remaining unconvinced as not any sort of worthwhile accomplishment at all.

Which means ergo gets to stay wrong, and the rest of us get to stay uninterested in ergo's opinions (and less likely to accept his word or his reasoning on anything else, to boot). Amazing! Another day of accomplishment for the Truth Movement!

Respectfully,
Myriad

 

[TheRedWorm]

Being driven by an intact upper block. I asked how rubble alone could crush the lower part of the building.

To which I responded with:

How crushed were the upper portions of the WTC towers, and how do you conclude this?

 

[BigAl]

No, what we have here is a pile-on.

In all these posts not a single one of you has shown how rubble can crush through a building through gravity alone. Your ridiculous notion does not stand up to scrutiny. In your parlance, that's a "Fail".

Here we go.

"If you push something hard enough it will fall over."

- Fudd's First Law of Opposition​

 

[pgimeno]

Being driven by an intact upper block.

Interesting. So, are you saying that the upper section of each building remains intact until it reaches the floor?

Even in the last building? Here's that one alone, again:

 

[ergo]

To which I responded with:How crushed were the upper portions of the WTC towers, and how do you conclude this?

I'm not sure how this matters. They were either half crushed or completely crushed. The posters here seem to have differing opinions on this. In my opinion, completely crushed. I conclude this by observing the absence of any visible upper block during the collapse progression. A photo of which I posted earlier in this thread.

 

[uke2se]

1,000kg produces 140,000 N.

Not when you factor in drop height. You should look at the link I provided.

1 kg gives 140 N.

Again, you forget drop height. However, it doesn't really matter.

The 1,000 pieces hit the intact components differently. Force is applied differentially. As smaller discrete units, air friction and friction from other flying parts affects them differentially.

Uhm... no.

The energy is deflected because a 1 kg object will not destroy the various building components. Damage perhaps, but not destruction. If the building part that the 1kg mass hits is not destroyed, the 1 kg object is deflected.

Uhm... no. You see, we are discussing total impact force and the sustainability of an object to said force. The total force is the same whether the objects falling are many or a single one with the same mass. You are simply wrong here, and I have demonstrated such.

It's like if I drop a bowling ball on your head from a window above, I would probably kill you. Your skull would be crushed. If I drop the broken fragments of a bowling ball on your head from a window above, it would hurt you, you would sustain bruises, but your skull would not be crushed.

If you could arrange it so that all the pieces of the ball struck me, the impact force on my head would be the same. Seriously, this is high school physics. Did you attend high school?

ETA: If you want to factor in air resistance and assert that that would provide a strong enough counter force, you need to show your math. Keeping with our example, what kind of air resistance would we expect with a 10m drop height. How much smaller would the total impact force be?

 

[TheRedWorm]

The collapse is obscured by dust, you can't say for sure the the upper block is completely crushed. Also, you seem to discount the effect of mass, without even realizing how big of a factor mass and velocity play in the event. I likened it to a shotgun shell and a cannon, do you understand why I chose such an analogy?

 

[Miragememories]

Seriously, this is high school physics. Did you attend high school?

Did you?

MM

 

[ergo]

Not when you factor in drop height. You should look at the link I provided.

Pretty sure I did. But, as you say, it doesn't matter for our purposes.

Uhm... no.

In logical argument, you can't just say "um, no" without explaining yourself. Well, you can, but no one will take you very seriously.

Uhm... no. You see, we are discussing total impact force and the sustainability of an object to said force. The total force is the same whether the objects falling are many or a single one with the same mass. You are simply wrong here, and I have demonstrated such.

You're just repeating your same false assertion. The total force is not the same when you have particles instead of a single solid mass.

If you could arrange it so that all the pieces of the ball struck me, the impact force on my head would be the same. Seriously, this is high school physics.

It would be close, but not the same. But it doesn't matter, does it? This isn't what happened in the WTC.

 

[BigAl]

Pretty sure I did. But, as you say, it doesn't matter for our purposes.



In logical argument, you can't just say "um, no" without explaining yourself. Well, you can, but no one will take you very seriously.



You're just repeating your same false assertion. The total force is not the same when you have particles instead of a single solid mass.

One more time.

"The linear momentum of a system of particles is the vector sum of the momenta of all the individual objects in the system"

http://en.wikipedia.org/wiki/Momentum

 

[uke2se]

Did you?

MM

Yes. You?

 

[uke2se]

Pretty sure I did. But, as you say, it doesn't matter for our purposes.

You didn't, but I'll let it slide.

In logical argument, you can't just say "um, no" without explaining yourself. Well, you can, but no one will take you very seriously.

Since I have gone out of my way to try to explain this to you and you get to simply handwave it away with unsupported assertions, an um, no is all you're going to get. Nobody takes you seriously as it is, so you'd do well to actually show some frigging math some time soon.

You're just repeating your same false assertion. The total force is not the same when you have particles instead of a single solid mass.

The total force is the same when you have particles instead of a single solid mass. If you believe otherwise, show me the math.

It would be close, but not the same. But it doesn't matter, does it? This isn't what happened in the WTC.

It isn't, so why did you bring it up?

 

[ergo]

Where have I seen that argument before? Ah yes!
http://www.internationalskeptics.com/forums/showthread.php?p=5266918#post5266918

I am extremely flattered to have my argument compared with that of Tony Szamboti's, and very pleased with myself that I could come to the same (albeit stupidly obvious) conclusions as he, considering his knowledge of physics is vastly superior to mine. Thank you. I know I'm on the right track.

 

[Miragememories]

Dropping a bag of sand onto a structure has the potential to focus more destructive force
than dumping the contents of the same bag onto the structure.

You have to talk to OCTers at a kindergarten level ergo or theydon't get it.

MM

 

[uke2se]

Dropping a bag of sand onto a structure has the potential focus more destructive force
than dumping the contents of the same bag onto the structure.

You have to talk to OCTers at a kindergarten level ergo or theydon't get it.

MM

Show your math. They don't teach math at kindergarten, but you could ask an adult to help you.