OK, so how do thermite demolitions work again?

[tempesta29]

The falling upper 12 stories did not crush the 98 stories below it. The falling upper 12 stories crushed the 1 story below it.

And then the resisting 97 stories crushed one story above it. See how physics work?

 

[Dog Town]

and the bonus to it all is: The core structure gets larger and stronger as the collapse progresses.

I.e, there is nothing to suggest this collapsing mass is growing more powerful as it falls.

stundied!

 

[Dave Rogers]

And then the resisting 97 stories crushed one story above it. See how physics work?

And then you had 11 storeys and two storeys' worth of rubble, falling on 97 storeys below. What happened next, (a) or (b)?

(a) The two storeys' worth of rubble impacted the 97 storeys at a large relative velocity, damaging them severely. The 11 storeys, however, were falling at the same speed as the rubble, and so did not suffer anywhere near as damaging an impact.

(b) Two storeys' worth of rubble suddenly turned a right angle in mid-air, jumped 100 feet sideways, and got out of the way of the 11 storeys so it could fall unimpeded on the 97 storeys.

Incidentally, this is yet another classically amusing truther contradiction. They claim that debris from the Twin Towers couldn't be thrown 300 feet sideways in a drop of 1,000 feet to hit another building unless there were explosives involved, yet at the same time they claim that debris must inevitably be thrown 100 feet sideways in a drop of only 12 feet if there were no explosives.

Bizarre.

Dave

 

[twinstead]

And then the resisting 97 stories crushed one story above it. See how physics work?

LOL

 

[ozeco41]

....They claim that debris from the Twin Towers couldn't be thrown 300 feet sideways in a drop of 1,000 feet to hit another building unless there were explosives involved,...

The question I have often asked of truthers is "How do you get explosives to throw large pieces of steel hundreds of feet?"

Remember that the claim that explosives threw the steel comes in the form of an alleged truther 'proof' that steel cutting explosives were used to cut steel....

....and cutting explosives are not the best 'throwers' of big lumps of anything.

 

[GlennB]

Negative. Mass is not necessarily stacking up. Mass in the Twin Towers is being blown laterally with incredible force. If anything, mass is decreasing. Since we both understand Newton's Third, we know that the upper section is being destroyed in virtually the same way as the lower section of each tower. Mass is essentially being blown outward; it isn't stacking up like pancakes. It's being broken up and dispersed and its force decreasing as collapse progresses.

The 'meteorites' show us that the debris was stacking up like pancakes.

Meanwhile the bolded section gives the lie to the following:

Straw man. I never suggested debris didn't accumulate at all, but there is nothing to suggest that this mass is some growing entity. It isn't.

Which by itself is also a bizarre statement. Maybe it is accumulating but it isn't necessarily growing?? That makes no sense.

 

[DGM]

LOL

I wonder if Dave will finally "understand physics" (Is that like hearing Jimi)?

 

[dafydd]

Straw man. I never suggested debris didn't accumulate at all, but there is nothing to suggest that this mass is some growing entity. It isn't. Not only is mass going in all directions out of the path of collapse, but this upper section itself is being destroyed and losing some of its ability to exert force downward. We can't quantify how much mass is being added to this collapse, but we know three things: a lot of mass is being lost by these ejections, the upper section is losing ability to exert downward force as its destroyed, the upper section loses momentum every time it creates this new falling mass. And the bonus to it all is: the core structure gets larger and stronger as the collapse progresses.

I.e, there is nothing to suggest this collapsing mass is growing more powerful as it falls.

Are you skipping all the physics lessons in school? Priceless,and well worthy of a stundie.

 

[WildCat]

And then the resisting 97 stories crushed one story above it. See how physics work?

Do you see the bolded word?

How does gravity factor into your physics?

 

[WildCat]

stundied!

That one is a beauty!

 

[jaydeehess]

Originally Posted by jaydeehess
How about some calculations to back that up? How about some facts and figures, such as the tonnage of material from the towers that ebded up not within the footprint versus the amount that did. .

The videos are our only evidence at this point. The videos indicate tremendous energy and tremendous lateral debris ejections. The mass of the upper section is most definitely not increasing or gathering.

Still no facts ot figures, just your own personal estimation?
As pointed out above the dense debris that was ejected should be ahead of the dustfall and IF your contention is correct then we should have seen a vast number of such heavy debris pieces falling past the collapse zone. We do not and thus your contentiuon fails on the evidence YOU choose to put forth. The videos.

If the lower sections are producing lateral ejections then the upper section must also be ridding its mass laterally, so this is very far from being a collapsing mass that is growing. Not to mention that the steel and concrete core grew tapered larger as it progressed down the structure, providing more resistance approaching ground level.

As pointed out above there was a comapcted devris zone between upper and lower blocks. Yes both upper and lower blocks would be coming apart at approximately the same rate but all this does is make the debris zone larger and larger.
I cannot envision how you would think that I was sayiong that the upper block was getting heavier. I was saying that the amount of loose debris impacting lower floors was getting heavier and heavier with each destroyed floor.
,,,,and again,,,,,,, the size of the columns simply does not enter into it since the falling mass has no way of having its force transfered to those columns unless the floors are capable of doing so, and it is patently obvious that a floor was only designed to carry and transfer the forces that could normally be expected to impinge upon ONE floor, not the mass of a dozen floors.

Quote:
Pretty much except for the hat truss which would allow the upper bolck to remain relatively intact for a bit longer.
There are other differences as well. The floor pans of the uppersection are being taken off their truss seats upward(wrt to the seats themselves)while the lower floors were being pushed downward and had to bend those seats over. Not sure how much effect that might have had.

10 stories with a hat truss versus 100 stories and an enlarging core structure. Where would you put your money if you were a betting man?

Not on anything you designed that's for sure.
HOW DOES THE FORCE of the falling mass get transfered to, carried by, supported by, impinged upon the columns?

I have lost count on the number of times you have ignored or dodged this question.

Quote:
Its exiting out the sides in much the same way that a pile of gravel forms an inverted cone that widens as more get piled on. Except that in this case there is the constraint of the floor area and if something falls past it then its off into free air.

Nonsense. Gravel falls down when it is piled on. These ejections are symmetric around all sides of both buildings and are absolutely horizontal. There is no measurable downward angle. So no, they are nothing alike.

Ummm, you don't even grasp what I said do you? I said that gravel will fall and pile up into a cone shape that gets larger and in the case of debris in the towers if it piled such that he bottom of the pile was greater than the floor area it would be ejected off the sides. Its an analogy T, but you failed to grasp even this simple concept.

Quote:
So there is AT LEAST a minimum mass of falling debris that is always within the walls AND its velocity is increasing AND thus the momentum of that mass is increasing

.
A conclusion based on nothing introduced as evidence in this discussion. And what does "at least a minimum mass" mean? It sounds redundant.

whhoo boy,,,,
YOU said that the mass was being ejected and the only way for LESS mass to hit the second failed floor than hit the first failed floor would be for MORE mass to be ejected than was created by the destruction of that first floor. THIS is the only way for a collapse to be brought to a halt SINCE we already have that the falling massd that hit the first floor was sufficient to fail it.
I then supposed that it might , in some possible scheme of things, be that the falling mass did not change in quantity, that ejections equaled accumulation (of loose debris-material no longer connected to the structure) BUT even if that is so then it is also obvious that the velocity is increasing. YOU EVEN know this since the collapse acellerated. It does not matter that it did not become a lesser acelleration since if acelleration is greater than zero then velocity must increase over time. Increased velocity results in increased momentum/kinetic energy and if mass remains the same and was sufficient at velocity 'v', to fail a floor then that same mass at velocity 'v+delta v' will be more than sufficient to do so to the next floor.

Quote:
Is this the 'a pile of debris cannot exert the force of a solid object' strawman so favoured by 9/11 conspiracists?

First, I don't know why you call it a straw man. A straw man is a misrepresentation of an argument. That loose debris exerts less impact force than solid mass is a fact. These aren't metal washers being stacked up on pole; this is literally exploding mass being blown in all radial directions, so let's not pretend it's something it isn't. Not only is mass being blown outward with massive force, the falling mass is being destroyed and losing its prior ability to exert force downward.

Really? Mass of some quantity m exerts less force if it is a loose collection of particles than if its a solid?
What physics realm does this oddity take place in?

I explained why a falling loose collection of particles exerts less dynamic force than a solid. You did not read past the words 'straw man' did you?

Quote:
AND,,,,,, again,,,,,, the vast majority of this mass and impact force(dynamic load) is hitting the floor pans, NOT the axis of the columns. THEREFORE the floors fail. There may be some force due to pressurized air as well but I do not subscribe to that as having a significant effect.

No floors=no lateral support=column failure

Absolute unfounded hogwash. You have no clue what the vast majority of this mass is hitting.

Tell me how it would be possible foir the vast majority of the falling mass to hit axially on the columns and avoid the floors!

,,,,more later, going back to work

 

[ElMondoHummus]

This is always the way I have looked at it. A lot of truthers complain that the mass above should be stopped by the mass below, but the mass below was only one floor at a time; it could never have supported the mass above.

While Twinstead is correct, there's something - two something's, actually - that absolutely must be made clear, and unfortunately answers only involving relative masses lead to a misapprehension by folks who aren't as familiar with the arguments.

The first thing is that the floors were never "load bearing" - i.e. being able to handle structural load - to begin with. They were only able to handle their own weight plus the incidental amount placed on them by the occupants and contents. Twinstead of course knows this, since he's been around here even longer than I have, but that may not be clear to others less familiar with the Towers construction. The columns were what bore the loads on the Tower's structure. But what ended up taking the majority of the falling mass? Not the top ends of the columns, but the floors themselves. Which almost certainly wouldn't have been strong enough to hold the mass of those floors had they been gently placed on one of them, nevermind dropped on top of them like they were. Heck, Bazant showed that the columns themselves weren't, so there's no way the floors would've been.

The second thing is that, once that first floor below the fire/impact zone in each tower failed, there was nothing left to hold the columns below upright. Truthers miss the fact that the greater mass below the top sections were dependent on their construction to keep things upright. But when a floor above goes missing, the next floor's columns suddenly become waaaaaaaaaaay short of being able to stand up straight, nevermind resist what's coming down on it. So even if one of those floors were normally able to bear the load of the upper section on its own, how could anyone reasonably expect it to when the perimeter columns are peelling off and the interior ones can't stay in place because of that? This is more than just a question of mass because the connections keeping that lower masses in place suddenly get compromised when the series of columns above become able to move side to side. So when that falling mass impacts, forget what the ideal strength is, the real strength of that floor - already insufficient - has in fact been further weakened.

At any rate, Twinstead is correct, but people not as familiar with how the Towers were built need to understand why he's right. And it's because the construction of the towers set up a situation to where the failure of those individual floors one-by-one mattered. Those one-by-one failures tore away column support, and that made the lower floors more vulnerable, nevermind the fact that the falling mass was already enough to overwhelm their maximum strength.

Does that make sense? Engineers and architectural types, feel free to correct what I may have gotten wrong or explained poorly. Or expound further.

 

[ozeco41]

...Does that make sense? Engineers and architectural types, feel free to correct what I may have gotten wrong or explained poorly. Or expound further.

A good enough explanation for this engineer.

 

[ElMondoHummus]

and the bonus to it all is: The core structure gets larger and stronger as the collapse progresses.

I.e, there is nothing to suggest this collapsing mass is growing more powerful as it falls.

stundied!

That one is a beauty!

OMG, that's a facepalmer.

Not only was it growing in size as it accumulated failed floors and their contents, it was also accelerating. That's what gravity does: It does move things at a constant speed, it accelerates them.

My God, that's just incredible, that error.

 

[ElMondoHummus]

Thanks!

A good enough explanation for this engineer.

 

[tempesta29]

Still no facts ot figures, just your own personal estimation?
As pointed out above the dense debris that was ejected should be ahead of the dustfall and IF your contention is correct then we should have seen a vast number of such heavy debris pieces falling past the collapse zone. We do not and thus your contentiuon fails on the evidence YOU choose to put forth. The videos.

It works both ways: you don't have data regarding how much debris "stacked up," as you're claiming. We have to use the available evidence.

As pointed out above there was a comapcted devris zone between upper and lower blocks. Yes both upper and lower blocks would be coming apart at approximately the same rate but all this does is make the debris zone larger and larger.
I cannot envision how you would think that I was sayiong that the upper block was getting heavier. I was saying that the amount of loose debris impacting lower floors was getting heavier and heavier with each destroyed floor.
,,,,and again,,,,,,, the size of the columns simply does not enter into it since the falling mass has no way of having its force transfered to those columns unless the floors are capable of doing so, and it is patently obvious that a floor was only designed to carry and transfer the forces that could normally be expected to impinge upon ONE floor, not the mass of a dozen floors.

Yet despite your theory, acceleration remains constant. If momentum were increasing exponentially then so would measurable acceleration.

Not on anything you designed that's for sure.
HOW DOES THE FORCE of the falling mass get transfered to, carried by, supported by, impinged upon the columns?

I have lost count on the number of times you have ignored or dodged this question.

That's because the question is so vague as to be incomprehensible. Keep asking it though; maybe it will just spontaneously make sense.

Ummm, you don't even grasp what I said do you? I said that gravel will fall and pile up into a cone shape that gets larger and in the case of debris in the towers if it piled such that he bottom of the pile was greater than the floor area it would be ejected off the sides. Its an analogy T, but you failed to grasp even this simple concept.

Yeah. Can't imagine how I misinterpreted the oft-cited "pile of gravel" analogy. Now that I understand it, it's even less clear. In fact, it may be the most ridiculous unsupported assertion I've seen yet: debris in the towers piled up like a pile of gravel rocks and ejected itself horizontally at up to 125 miles per hour.

You slay me.

whhoo boy,,,,
YOU said that the mass was being ejected and the only way for LESS mass to hit the second failed floor than hit the first failed floor would be for MORE mass to be ejected than was created by the destruction of that first floor. THIS is the only way for a collapse to be brought to a halt SINCE we already have that the falling massd that hit the first floor was sufficient to fail it.
I then supposed that it might , in some possible scheme of things, be that the falling mass did not change in quantity, that ejections equaled accumulation (of loose debris-material no longer connected to the structure)

Sure, some of the newly-destroyed structure is accelerating downward, no doubt. And?

On one hand we have the upper sections being destroyed by their lower counterparts. On another hand we have large quantities of debris, including massive steel girders being ejected laterally at high speeds. Furthermore we have a core structure that is growing larger and stronger further towards the base. What part of this, in your mind, equates to some constant increase in mass?

But that's neither here nor there at this point:

BUT even if that is so then it is also obvious that the velocity is increasing. YOU EVEN know this since the collapse acellerated. It does not matter that it did not become a lesser acelleration since if acelleration is greater than zero then velocity must increase over time. Increased velocity results in increased momentum/kinetic energy and if mass remains the same and was sufficient at velocity 'v', to fail a floor then that same mass at velocity 'v+delta v' will be more than sufficient to do so to the next floor.

You've created a grave error in logic. You attempt to reverse engineer your argument from available data, and you fail miserably. You claim that since velocity is increasing, according to our measurement of acceleration, that this means that this mass' momentum is increasing, which is undeniable. However what you fail to realize is that you have no proof that mass "was sufficient at velocity 'v' to fail" any floors. Your argument presupposes this. You can't use this to support your argument because it in and of itself is a theory that requires support (seeing as it cannot be proven absolutely).

I propose that the upper sections are not causing any structural failures to the lower sections, that, in fact, the upper sections are simply passing through debris as the lower structure is destroyed by controlled means. The constant rate of acceleration confirms this, both through the crash zone and as the upper section encounters greater resistance from the enlarging core, an upper section, mind you, that is being destroyed in the process, further limiting its ability to apply constant force to the lower structure.

Throughout all of this: acceleration remains constant. It simply doesn't fit your theory that the upper sections are destroying the lower, a theory which, we've just seen, you've used to support another theory.

Really? Mass of some quantity m exerts less force if it is a loose collection of particles than if its a solid?
What physics realm does this oddity take place in?
I explained why a falling loose collection of particles exerts less dynamic force than a solid. You did not read past the words 'straw man' did you?

We're talking about structural failure here. Time is incredibly important. Exerting a force over a period of time may not yield any failure but that same force exerted over a shorter period (impact force) may in fact yield failure. Mass in both instances is the same yet the results are different. Are you under the impression that this fact is irrelevant? I assure you it is just the opposite.

We're talking about a falling mass whose force allegedly overcame resistance of the structure below. The upper mass, however, is losing its ability to exert force as it descends because it is being broken up. Then add in the fact that the core structure is growing slightly larger further down. This factors do not allow for constant acceleration: both factors work against the collapsing mass' net force.

Tell me how it would be possible foir the vast majority of the falling mass to hit axially on the columns and avoid the floors!

,,,,more later, going back to work

I answered this with my response to your earlier question #3.

 

[tempesta29]

OMG, that's a facepalmer.

Not only was it growing in size as it accumulated failed floors and their contents, it was also accelerating. That's what gravity does: It does move things at a constant speed, it accelerates them.

This isn't a rubber ball falling through the air, nor is it a set of washers accumulating on a wire. You are aware there are other actions at play here, right?

My God, that's just incredible, that error.

So says the spectator/cheerleader with no actual counterargument whatsoever. If there is some error, then let's hear you argument. Or you could just pay attention and learn, because you clearly have no idea what you're talking about.

 

[twinstead]

You need to go on the academic lecture curciut, tempesta--I'm curious as to how many people you would need to tell you that you don't know what you are talking about before you actually start saying, "hmmmm"

 

[Thunder]

delete

 

[Thunder]

Not only is mass going in all directions out of the path of collapse, the upper section is losing ability to exert downward force as its destroyed,

And the bonus to it all is: the core structure gets larger and stronger as the collapse progresses.

I'm sorry..........WHAT????????????




...so as the upper section collapses it gets smaller & weaker...but it made the core from top to bottom get LARGER and STRONGER?

Einstein would find these new laws of Physics amazing.