Do you believe in One Way Crushing?

[Shrinker]

One-way crushing seems to be a popular topic with a certain poster. It's the idea that the upper, falling parts of WTCs 1&2, crushed the lower portions, while remaining intact throughout the descent. Despite his revelation that the concept is not indexed by Google even once, he's determined to debunk it by collapsing everything he can get his hands on. Just out of interest, is he wasting his time? Let's have a poll...

The reason I ask is that I find these debates very perplexing. I am under the impression that option 1 is correct, but despite the fact it is a very succinct answer to the numerous challenges and accusations, I don't believe I've ever noticed anyone come out and say it. Perhaps I understand wrongly?

[Horatius]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

[Marquis de Carabas]

Is this the unrequited love thread?

[ElMondoHummus]

Is this the unrequited love thread?

That depends... does your definition of love involve being wet, sticky, and oh-so-disgusting, or does it actually include such nebulousness as emotion?

;):D

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

Yes, folks, this is right. Conspiracy peddlers all too often reel off reams of complaints about Bazant & Zhou's work, but until any one of them includes the concept of "boundary" (or "bounding) case in their analysis, none of them understand what B&Z (and later, Bazant, Le, Greening and Benson) were trying to say with their models.

[Shrinker]

Is this the unrequited love thread?

Tea and biscuits at the end. Tissues on the table, don't be afraid to cry...

[rwguinn]

Gee.
I wonder who the single option 4 responder could possibly be?

[tsig]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

Yes some posters have built entire theories and axioms using this straw man.

N. B. Isn't an axiom an unproven assumption?

" 1. A self-evident or universally recognized truth; a maxim: “It is an economic axiom as old as the hills that goods and services can be paid for only with goods and services” (Albert Jay Nock).
2. An established rule, principle, or law.
3. A self-evident principle or one that is accepted as true without proof as the basis for argument; a postulate."
http://www.answers.com/topic/axiom

[GlennB]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."



I think you're dead right. I suppose option 1) would be closest .

[jaydeehess]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

Bingo

[Lennart Hyland]

I dont even know what a one way crushing...

[Hokulele]

Now why did I think this was going to be another thread complaining about forum management...

[ElMondoHummus]

Now why did I think this was going to be another thread complaining about forum management...

Because you think Tricky has a crush on you and you refuse to return the favor??

:duck:

[bill smith]

Is Bazant considered an 'official' scientist for the purposes of this poll ?

[Shrinker]

Is Bazant considered an 'official' scientist for the purposes of this poll ?

Yes.

[tsig]

One-way crushing seems to be a popular topic with a certain poster. It's the idea that the upper, falling parts of WTCs 1&2, crushed the lower portions, while remaining intact throughout the descent. Despite his revelation that the concept is not indexed by Google even once, he's determined to debunk it by collapsing everything he can get his hands on. Just out of interest, is he wasting his time? Let's have a poll...

The reason I ask is that I find these debates very perplexing. I am under the impression that option 1 is correct, but despite the fact it is a very succinct answer to the numerous challenges and accusations, I don't believe I've ever noticed anyone come out and say it. Perhaps I understand wrongly?

need the planet X option.

[bill smith]

Yes.

Thanks

[Hokulele]

Because you think Tricky has a crush on you and you refuse to return the favor??


Well, I was thinking more along the lines of "Help, help! I am being oppressed!"

[GregoryUrich]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

I vote for this option.

[Architect]

I agree with Gregory

[3bodyproblem]

I vote for this option.

Because it's the most correct :)

[UNLoVedRebel]

A more correct answer would be, "It didn't happen on 9/11 but some scientists used it as a mathematical simplification in an early paper that was only intended to discuss the energy requirements of the collapse, not propose an actual collapse mechanism, but Certain Posters have latched onto this simplifying assumption in order to appear erudite and insightful, when, in actuality, they're just attacking a straw man."

But that's probably too long for a poll option.

:thanks

[Toke]

I pick number 1.

The intact upper part is just a model for the energies involved.

[bill smith]

Is it fair to say that Bazant's hypothesis is not in fact a graphic representation of what he thinks happened.literally ? If that is so then we can dispense with Bazant because debunking him is not debunking anything.

But does that mean that there is no official collapse theory other than a general statement of 'the buildings fell down from damage and fire' ?

[3bodyproblem]

Is it fair to ay that Bazant's hypothesis is not in fact a graphic representation of what he thinks happened.literally ? If that is so then we can dispense with Bazant because debunking him is not debunking anything.

But does that mean that there is no official collapse theory other than a general satement of 'the buildng fell down from damage and fire' ?


Man you guys are dense. Debunk it for what it is if you will, but don't try to debunk it for what it isn't.

[Myriad]

Is it fair to say that Bazant's hypothesis is not in fact a graphic representation of what he thinks happened.literally ? If that is so then we can dispense with Bazant because debunking him is not debunking anything.


Actually that's way overstating the issue. Crush-down followed by crush-up is in fact a reasonable hypothesis that fits to a reasonable approximation with the observed behavior and also with the expected physical behavior. Call it crush-primarily-down followed by crush-up to be more precise, but don't dismiss crush-down followed by crush-up as a completely arbitrary assumption made only to simplify the math.

The objection raised by Heiwa and others, that the damage done by "A" (the still-intact portion of the floors above the initial collapse zone) on "C" (the still-intact portion of the floors below the initial collapse zone), must be equal to the damage done by C to A (or less, because the lower parts of C are built more strongly), due to Newton's law of equal and opposite forces, is invalid. Because after the initial instants of the collapse, A and C are no longer acting directly on one another.

Any parts of A and C that are crushed in those initial moments, except for the portion that was ejected out the side (which didn't appear to include any of the acre-size floors flying horizontally out of there like frisbees), becomes part of B, the rubble mass of the collapse front.

A presses down on B, B presses equally and oppositely upward on A. B presses down on C, and C presses equally and oppositely upward on B. But this does not mean that the A-B force and the B-C force are equal to one another. In in fact, they could not possibly have been, once the mass of B exceeded zero.

As a test case for comparison, let's suppose that the collapse front does not accelerate downward. Suppose, instead, B falls at a steady velocity. In that case, A would press down on B (and B upward on A) with a mean net force equal to A's full weight, m(A)*g. In order for B not to be accelerating, it must be experiencing balanced forces, so the mean net force of C acting upward on B must be equal to B's weight plus the downward force of A on B; that is, A and B's combined weight, (m(A) + m(B)) * g.

Clearly, once m(B) > 0, m(A) < m(A) + m(B). The more destruction of A -- which reduces m(A) and increases m(B) -- happens early in the collapse, the greater the difference between the force of B-C's interaction and that of A-B's interaction.

(Anticipating a spurious counter-argument: remember that B in no way resembles a loose shower of free-falling chunks of debris. It's a dense mass of debris that's being compressed between two other large colliding masses A and C.)

But in fact, the collapse front did not move at a steady velocity. It accelerated downward at a rate greater than zero (which would have been constant-velocity fall) and less than g (which would have been free fall). Call that rate d.

The mean net force between A and B is then m(A) * (g - d).

The mean net force between B and C is then (m(A) + m(B)) * (g - d).

As before, the mean net A-B force can only decrease during the collapse, while the B-C force increases as more of C's mass (and a smaller portion of A's) becomes entrained into B.

Even this highly simplified argument based on mean net forces shows that crush-down will diverge from and exceed crush-up, after an initial phase of starting out about equal. Of course, the mean net force doesn't tell the whole story in a collision. The peak dynamic forces are important too -- and the dynamic forces depend largely on relative velocities. With a downward accelerating collapse front, the relative velocity of B and C steadily increases while the relative velocity of A and B remains small until B hits the ground.

As the Roadrunner and the Coyote both know, being on top of the falling rock is less painful than being underneath it.

Respectfully,
Myriad

[Dave Rogers]

Is Bazant considered an 'official' scientist for the purposes of this poll ?

This usage of the word "official" is purely an invention of the 9/11 truth movement. Since it has no basis in reality, perhaps you should take it to mean whatever you want it to mean, then tell the rest of us.

But does that mean that there is no official collapse theory other than a general statement of 'the buildings fell down from damage and fire' ?

It is fair to say that there is no "official collapse theory", or indeed official theory of anything. There's just a general understanding, supported by the overwhelming majority of informed people who have studied the collapse in any detail, that the collapse was initiated by some combination of damage and fire and propagated by the conversion of gravitational potential energy into kinetic energy and then into fracture energy of structural components. The truther use of the word "official" is a strawman argument to give the incorrect impression that this point of view originates from the higher levels of the Bush administration. Sorry, but this isn't the government line, it's the consensus of the scientists and engineers who've studied the evidence.

Dave

[Shrinker]

Is it fair to say that Bazant's hypothesis is not in fact a graphic representation of what he thinks happened.literally ?

That's right.

If that is so then we can dispense with Bazant because debunking him is not debunking anything.?

That's wrong.

You seem to be ignoring the fact that Bazant actually did present a conclusion. ie the towers were heavy enough to collapse under their own weight. If truthers could refute that, they'd be getting somewhere.

[Horatius]

I'd just like to thank Heiwa for providing us yet another example of his straw man posturing.

http://forums.randi.org/showthread.php?postid=4619021#post4619021

Just before I go report him for flooding.

[Shrinker]

As the Roadrunner and the Coyote both know, being on top of the falling rock is less painful than being underneath it.

Respectfully,
Myriad

Thank you Myriad. That's an interesting refinement of the discussion. Presumably though, you're closer to 1 than 3?

[Myriad]

Thank you Myriad. That's an interesting refinement of the discussion. Presumably though, you're closer to 1 than 3?


Impossible to say, which is why I posted an actual response. Perfect one-way crushing probably didn't happen; differential crushing strongly and increasingly favoring crush-down until the collapse front reached the ground probably did. And "crushing" may be a misleading term for some because they seem to think it implies that individual steel columns must have been deformed like "crushed" empty beer cans, and/or they are associating crushing entirely with the comminution of the concrete floors (most of which likely happened on impact with the ground) instead of with e.g. separation of the floor trusses from the columns that happened in earlier stages of the collapse.

1. I ate no hot dogs.

3. I ate several hot dogs.

Now, if I actually ate one kielbasa, am I closer to 1 or 3?

Respectfully,
Myriad