Apologies to wrs - thanks for the help solving the WTC collapse !

[Halophyte]

wrs - You are proving yourself more ignorant each time you type. First of all let's just consider the North Tower and the top 20 floors. Whatever their mass, when they finally do crush the 90th floor and cause it to begin falling, they only add 5% to the total mass since the top 21 floors are probably all close to the same mass. Now when you add the next floor, the 88th floor you have only added 4.76% to the falling mass. By the time you get down to the 80th floor you are only adding 3% to the total mass. So Halophyte, how is it that you can be so stupid? The incremental addition of mass to the falling mass at each floor is dropping not increasing.



Yes, you’re correct. My bad.


1) - The amount of mass added to the total mass in motion decreases as it falls but its static weight increases (mass at rest).

2) - Each floor offers resistance to the falling mass using up some of the kinetic energy as it falls – converting some of it back into static weight (mass at rest).

3) - That resistance is the same for all floors because the area impacted remains the same.

4) - It’s a matter of kinetic energy converted to static weight, then applied to the same floor varea as it falls.

5) - Each floor is rated at a maximum static load measured in units of weight per units of area.

6) - Therefore, the pressures applied per unit of area increase as it falls by adding static weight to each floor.


At the beginning of the collapse, the kinetic energy (mass in motion) is the greatest - at the bottom of its fall, the static weight (mass at rest) is greatest.

Duh, I should have known better.



The towers collapsed by simple structural overload of each floor as kinetic energy is converted to static weight overloading each floor in succession.

It was right under our noses and we didn't notice !


YOU JUST MADE THE PANCAKE COLLAPSE THEORY !!!



Kewl Dude !


Sorry if I was so ........ uh ...... "STUPID".


.

[Halophyte]

One other little diddy. From just eyeballing the floor plans I see about 70% floor area with no vertical support columns.

Makes for one hell of a catcher's mitt for all that weight eh ? :D

.

[gpond]

Have another one, Halo.

[Halophyte]

Nah, Let's remove kinetic energy/mass in motion from the equation.



I'll just stack the weight of about 20 floors on top of a single floor and see if it holds it ....

Then I'll stack the weight of about 21 floors on top of a single floor and see if it holds it ....

Then I'll stack the weight of about 22 floors on top of ....

See the deal here, I'm not stacking the weight on the support columns - I'm stacking it on the floor trusses.

That's what's initially catching the weight.



wrs concentrated on energy/mass conversion and losses while he forgets about static weight limits !

He thinks mass at rest decreases as it falls - that's a big no, no, no ! Only kinetic energy decreases - potential energy increases !

I need a real expert.

Where's Nailbender when you need him ?


.

[gpond]

Originally Posted by Halophyte

See the deal here, I'm not stacking the weight on the support columns - I'm stacking it on the floor trusses.

That's what's initially catching the weight.

Hmmmm.... The phrase "initially catching the weight" sounds interesting. Sounds time consuming.

[Halophyte]

No sir, potential energy (same as mass at rest) increases as it falls !

But it cannot stop falling because the potential energy of static weight overloads the trusses !


Yeeehaaaa !!!!

I think, I will have that drink now


wrs you're a great lab assistant, here's to you

.

[gpond]

Originally Posted by Halophyte

I think I'll have that drink now

That's what I thought.

Physics by jingoism.

[Halophyte]

To understand the structure is to understand the collapse.

While he's busy counting kinetic energy losses he forgets potential energy's increase and it's effect on the trusses.

Static weight IS potential energy.

Potential energy is measured in this (case) as pounds per square foot applied to the total floor area.

And this doesn't even take in consideration momentum of falling mass.

That means the potential energy goes parabolic as it falls !

Adding the initial kinetic energy of impact from the top 20 floors garantees a velocity close too freefall !




I'm being nice.


.

[gpond]

Originally Posted by Halophyte

No sir, potential energy (same as mass at rest) increases as it falls !

Potential energy decreases the closer it gets to the ground. (Look it up.)

But it sounded good when you said it.

[Halophyte]

Originally Posted by gpond

Potential energy decreases the closer it gets to the ground. (Look it up.)

But it sounded good when you said it.

Doesn't matter if its 1000 feet above ground or 1 foot above ground, static weight is the same.

But in this case it increases as it falls.

Static pressures applied to each floor increase as it falls.

The ratio of resistance (a constant) decreases vs static weight increasing as it falls.

The collapse should increase in velocity as it falls.


.

[gpond]

All the potential energy that the building ever was to have was created when it was built (and furnished). Falling does not increase the potential energy. It expends the potential energy.

This is not complicated.

[gpond]

Originally Posted by Halophyte

That means the potential energy goes parabolic as it falls !

That is a ridiculous statement.

wrs is right.

[gpond]

Originally Posted by Halophyte

Doesn't matter if its 1000 feet above ground or 1 foot above ground, static weight is the same.

But in this case it increases as it falls.

.

Huh? Try again tomorrow. You have ceased making sense.

[gpond]

Ok. That was less than gracious on my part. I apologize.

[Halophyte]

Okay gpond, does this make sense ?


Doesn't matter if its 1000 feet above ground or 1 foot above ground, static weight is the same.

But in this case it increases as it falls.

Static pressures applied to each floor increase as it falls.

The ratio of resistance (a constant) < static weight (increasing) as it falls from floor to floor.

The collapse should increase in velocity as it falls.


.

[bigjon]

PEgrav = m * g * h

In the above equation, m represents the mass of the object, h represents the height of the object and g represents the acceleration of gravity (approximately 10 m/s/s on Earth).

[gpond]

Originally Posted by Halophyte

It should easily overcome the resistance (a constant) for each floor impact.

PS. But while you are busy editing your posts removing the errors that I have pointed out, you might want to take a look at this one.

It implies that there is some constant resistance which would tend to slow the building's overall collapse. That might screw with your free-fall timing theory. The assumption of a constant resistance might tend to slow the building's time of descent, thus complicating things a bit for you.

I think you still have time to edit that out, though.

[Halophyte]

PS. But while you are busy editing your posts removing the errors that I have pointed out, you might want to take a look at this one.

Chill gpond I'm working it out.

Leave out the energy conversions just look at load limits - just for a minute, believe me it's not a con ...


Agreed BJ.. But in this case, static load is increasing as it falls.

Static loads limits remain the same per floor vs the static weight applied to each floor as it falls.

Static pressures increase because the area remains the same.

Each succeeding floor load limit is easier and easier to overcome as it collapses.

See what I mean ?


.

[gpond]

Originally Posted by Halophyte

Doesn't matter if its 1000 feet above ground or 1 foot above ground, static weight is the same.

But in this case it increases as it falls.

OK. Nice mode engaged again. It's hard to tell when to engage it.

I agree, static weight is the same. You said PE went exponential as it was falling. I could not agree with that.

Kinetic energy does increase, if I'm understanding correctly, as it falls. The idea is that 20 floors falls upon 1 floor and when the resistance is overcome (which takes time!) then we have 21 floors falling, etc. etc.

There is an arithmetic -- not exponential -- accumulation of falling mass.

I do not disagree with that.

So, if I'm understanding correctly, the kinetic energy does increase during the fall (not potential energy) -- NOT exponentially, but arithmetically -- one floor is added to the falling mass each time the RESISTANCE of that one floor is overcome. Then they begin travelling down together. But the equation for free-fall can not apply to this situation due to the cumulative resistance of each floor in kind. (boom, boom, boom, boom) I'm pretty sure you are bright enough to understand this, so I do not understand why you are ignoring the resistance (boom) -- and subsequent temporary loss of acceleration required to overcome the RESISTANCE of collapsing each intact floor. The overcoming of resistance of each floor should take SOME time, no? Especially when cumulatively there are at least 80-90 floors to overcome?

Come on, man. You know what I and wrs are talking about? Don't you?

It is perfectly obvious.

[Ponce Cuba]

To me this is nothing more than the old comedy routine by Abbot and Costello about "Who's on First?"......

[bigjon]

Yes G it is perfectly obvious that halo et al want to obfuscate the obvious with as much bs as they can throw at the wall, hoping some will stick.

[gpond]

Originally Posted by Ponce Cuba

To me this is nothing more than the old comedy routine by Abbot and Costello about "Who's on First?"......

I cannot disagree. But I am sure that you understand the meaning of (boom, boom, boom, boom, boom, boom, boom, boom, boom, 100 times...).

Heh, heh.. I know I don't have to ask.

[Infidel]

Originally Posted by gpond

So, if I'm understanding correctly, the kinetic energy does increase during the fall (not potential energy) -- NOT exponentially, but arithmetically -- one floor is added to the falling mass each time the RESISTANCE of that one floor is overcome. Then they begin travelling down together. But the equation for free-fall can not apply to this situation due to the cumulative resistance of each floor in kind. (boom, boom, boom, boom) I'm pretty sure you are bright enough to understand this, so I do not understand why you are ignoring the resistance (boom) -- and subsequent temporary loss of acceleration required to overcome the RESISTANCE of collapsing each intact floor. The overcoming of resistance of each floor should take SOME time, no? Especially when cumulatively there are at least 80-90 floors to overcome?

Gpond,

All this resistance does is converts the energy back from kinetic to potential minus heat slowing the fall down. This is the resistance in action, once the potential energy is greater than the force of resistance it needs to overcome it falls and starts converting to kinetic energy

http://st12.startlogic.com/~xenonpup/physics/

The most difficult feature of the collapses to account for is that the buildings fall
in almost exactly the time it would take for an object to reach the ground from
the height of the roof. Several careful analyses of the video evidence show that
the fall occurs in ~9 seconds, within measurement error of the free-fall time.

At the moment of collapse the building still has considerable resistance to vertical
compressive loads, even if a little local weakening exists at the level of the crash
and fire. The central core is still mostly intact (especially in the south tower,
where any significant heating would have been near the corner the plane struck,
and the core could not have been hit by major parts of the plane) and much of the
outer frame is still intact at this point. The energy to overcome this resistance
can only come from the gravitational potential energy of the building. The
dissipation of that potential by doing the mechanical work of crushing structural
materials must be subtracted from the force available to accelerate the upper
part of the building, and this must result in a significant slowing. One estimate
by a structural engineer at MIT article estimated 30% of the gravitational potential
being used to crush the building, probably a conservative estimate since it does not account for the energy needed to pulverize the concrete and eject powder and debris laterally at high speeds. For any this value of resistance consistent with the real-world strength of the columns there would have been a very observable slowing. Intuitively it's plain that the only way a building can fall at free-fall speed is for there to be no resistance at all... as if the whole building had suddenly liquefied, or if a wave of liquefaction (i.e. demolition wave) had traveled down at or above the rate of free fall.

[Halophyte]

Static pressures increase because the floor area remains the same.

Each succeeding floor load limit is easier and easier to overcome as it collapses.

Typical pancake collapse function.




For those who may think no one has written a peer reviewed paper on the collapse of the towers here it is...

http://www-math.mit.edu/~bazant/WTC/

Walter P. Murphy Professor of
Civil Engineering and Materials Science
Northwestern University

The towers of the World Trade Center were designed to withstand as a whole the horizontal impact of a large commercial aircraft. So why did a total collapse occur? The reason is the dynamic consequence of the prolonged heating of the steel columns to very high temperature. The heating caused creep buckling of the columns of the framed tube along the perimeter of the structure, which transmits the vertical load to the ground. The likely scenario of failure may be explained as follows...

http://www-math.mit.edu/~bazant/WTC/WTC-asce.pdf

The version linked above, to appear in the Journal of Engineering Mechanics (ASCE), was revised and extended (with Yong Zhou on September 22 and additional appendices on September 28) since the original text of September 13, which was immediately posted at various civil engineering web sites, e.g. University of Illinios. It also has been or soon will be published in a number of other journals, including Archives of Applied Mechanics, Studi i Ricerche, and SIAM News:

Z. P. Bazant and Y. Zhou, "Why Did the World Trade Center Collapse?", Society for Industrial and Applied Mathematics News, vol. 34, No. 8 (October, 2001).

That means it's not just a document, book, web site or calculation on a forum. It's had to pass critical review by other engineering Professors.

I know there are CT sites which attack this paper but not one person has yet to disprove it's hypothesis professionally. There are still people attacking the theory of evolution. Anyone can attack, not many can produce a paper to back it up. Just as there is no "Theory of intelligent design" except in christian web sites there are no alternatives to this paper other than in CT sites and books.

Below is the list of people who peer reviewed the only paper which passed the scrutiny of peer review regarding the WTC tragedy...

The paper... http://www-math.mit.edu/~bazant/WTC/WTC-asce.pdf

http://www.pubs.asce.org/journals/edem.html

Editor:
Ross B. Corotis, Ph.D., P.E., S.E., NAE, University of Colorado, Boulder
corotis@colorado.edu

Editorial Board:
Younane Abousleiman, Ph.D., University of Oklahoma
Ching S. Chang, Ph.D., P.E., University of Massachusetts
Joel P. Conte, Ph.D., P.E., University of California, San Diego
Henri Gavin, Duke University
Bojan B. Guzina, University of Minnesota
Christian Hellmich, Dr.Tech., Vienna University of Technology
Lambros Katafygiotis, Ph.D., Hong Kong University of Science and Technology
Nik Katopodes, Ph.D., University of Michigan
Nicos Makris, University of Patras
Robert J. Martinuzzi, P.E., University of Calgary
Arif Masud, Ph.D., University of Illinois, Chicago
Arvid Naess, Ph.D., Norwegian University of Science and Technology
Khaled W. Shahwan, Daimler Chrysler Corporation
George Voyiadjis, Ph.D., EIT, Louisiana State University
Yunping Xi, Ph.D., University of Colorado
Engineering Mechanics Division Executive Committee
Alexander D. Cheng, Ph.D., M.ASCE, Chair
James L. Beck, Ph.D., M.ASCE
Roger G. Ghanem, Ph.D., M.ASCE
Wilfred D. Iwan, M.ASCE
Chiang C. Mei, M.ASCE
Verna L. Jameson, ASCE Staff Contact

Engineering Mechanics Division Executive Committee
Alexander D. Cheng, Ph.D., M.ASCE, Chair
James L. Beck, Ph.D., M.ASCE
Roger G. Ghanem, Ph.D., M.ASCE
Wilfred D. Iwan, M.ASCE
Chiang C. Mei, M.ASCE
Verna L. Jameson, ASCE Staff Contact

Journal of Engineering Mechanics http://scitation.aip.org/emo/

Doc Jones didn't make the list ... he won't challenge it either....

.

[PatColo]

Originally Posted by Halophyte

blah blah

www.WTC7.net

@Halo,

Could you please remind the lurking masses why you don't put your Big League Engineering Skills (BS for short) to work in collecting your

MILLION BUCKS???


www.WTC7.net

Let's imagine that your concern with channeling your valuable engineering time towards more industrious use as outlined above, is due to your concern that Walters/reopen911.org may welch on their proposal (a scenario we have some experience with around here!).

Let's imagine you're fixated on defending the Official 911 Conspiracy Theory purely out of academic pride.

In this case, why don't you devote your labors to publicly critiquing such peer reviewed academic works as :

- Why Indeed Did the WTC Buildings Collapse?
by Steven E. Jones, Ph.D.

- The Destruction of the World Trade Center: Why the Official Account Cannot Be True
by David Ray Griffin, Ph.D.

- Thinking about "Conspiracy Theories": 9/11 and JFK
by James H. Fetzer, Ph.D.


www.WTC7.net

And lastly Halo,

I've noticed that your thorough & exhaustive assessment of the reason(s) for the abrupt, symetrical, free-fall-speed collapse of the 47 story steel-framed HOUSE OF SPOOKS, AKA WTC-7, on 9/11 afternoon, perfectly agrees with the similarly thorough & exhaustive assessment of WTC-7's collapse by the Zelikow 9/11 Whitewash Commission Report.

As we're all aware, the Zelilkow 9/11 Report duly gives taxpayers the fullest possible accounting of the events of 9/11. So the fact that your assessment of the strange collapse of the House Of Spooks (WTC-7) agrees so perfectly with the assessment of same by this utterly thorough, landmark/definitive gummit report on 9/11... is cause for kudos to you.


www.WTC7.net

But I must ask:

Did YOU get YOUR WTC-7 assessment directly from the Zelikow Commission Report, or did THEY get THEIR WTC-7 assessment directly from YOU??


www.WTC7.net

[gpond]

Originally Posted by zhukher

For any this value of resistance consistent with the real-world strength of the columns there would have been a very observable slowing. Intuitively it's plain that the only way a building can fall at free-fall speed is for there to be no resistance at all... as if the whole building had suddenly liquefied, or if a wave of liquefaction (i.e. demolition wave) had traveled down at or above the rate of free fall.

Yes. I see your point.

[gpond]

Halo,

You seem to be arguing for ZERO RESISTANCE.

True?

[Halophyte]

Originally Posted by PatColo

www.WTC7.net

@Halo,

Could you please remind the lurking masses why you don't put your Big League Engineering Skills (BS for short) to work in collecting your [b]

@Patty


Here, try a peer review instead ... but I'm sure they are all apart of your CONspiracy too.

Paranioa will destroy ya'





For those who may think no one has written a peer reviewed paper on the collapse of the towers here it is...

http://www-math.mit.edu/~bazant/WTC/

Walter P. Murphy Professor of
Civil Engineering and Materials Science
Northwestern University

The towers of the World Trade Center were designed to withstand as a whole the horizontal impact of a large commercial aircraft. So why did a total collapse occur? The reason is the dynamic consequence of the prolonged heating of the steel columns to very high temperature. The heating caused creep buckling of the columns of the framed tube along the perimeter of the structure, which transmits the vertical load to the ground. The likely scenario of failure may be explained as follows...

http://www-math.mit.edu/~bazant/WTC/WTC-asce.pdf

The version linked above, to appear in the Journal of Engineering Mechanics (ASCE), was revised and extended (with Yong Zhou on September 22 and additional appendices on September 28) since the original text of September 13, which was immediately posted at various civil engineering web sites, e.g. University of Illinios. It also has been or soon will be published in a number of other journals, including Archives of Applied Mechanics, Studi i Ricerche, and SIAM News:

Z. P. Bazant and Y. Zhou, "Why Did the World Trade Center Collapse?", Society for Industrial and Applied Mathematics News, vol. 34, No. 8 (October, 2001).

That means it's not just a document, book, web site or calculation on a forum. It's had to pass critical review by other engineering Professors.

I know there are CT sites which attack this paper but not one person has yet to disprove it's hypothesis professionally. There are still people attacking the theory of evolution. Anyone can attack, not many can produce a paper to back it up. Just as there is no "Theory of intelligent design" except in christian web sites there are no alternatives to this paper other than in CT sites and books.

Below is the list of people who peer reviewed the only paper which passed the scrutiny of peer review regarding the WTC tragedy...

The paper... http://www-math.mit.edu/~bazant/WTC/WTC-asce.pdf

http://www.pubs.asce.org/journals/edem.html

Editor:
Ross B. Corotis, Ph.D., P.E., S.E., NAE, University of Colorado, Boulder
corotis@colorado.edu

Editorial Board:
Younane Abousleiman, Ph.D., University of Oklahoma
Ching S. Chang, Ph.D., P.E., University of Massachusetts
Joel P. Conte, Ph.D., P.E., University of California, San Diego
Henri Gavin, Duke University
Bojan B. Guzina, University of Minnesota
Christian Hellmich, Dr.Tech., Vienna University of Technology
Lambros Katafygiotis, Ph.D., Hong Kong University of Science and Technology
Nik Katopodes, Ph.D., University of Michigan
Nicos Makris, University of Patras
Robert J. Martinuzzi, P.E., University of Calgary
Arif Masud, Ph.D., University of Illinois, Chicago
Arvid Naess, Ph.D., Norwegian University of Science and Technology
Khaled W. Shahwan, Daimler Chrysler Corporation
George Voyiadjis, Ph.D., EIT, Louisiana State University
Yunping Xi, Ph.D., University of Colorado
Engineering Mechanics Division Executive Committee
Alexander D. Cheng, Ph.D., M.ASCE, Chair
James L. Beck, Ph.D., M.ASCE
Roger G. Ghanem, Ph.D., M.ASCE
Wilfred D. Iwan, M.ASCE
Chiang C. Mei, M.ASCE
Verna L. Jameson, ASCE Staff Contact

Engineering Mechanics Division Executive Committee
Alexander D. Cheng, Ph.D., M.ASCE, Chair
James L. Beck, Ph.D., M.ASCE
Roger G. Ghanem, Ph.D., M.ASCE
Wilfred D. Iwan, M.ASCE
Chiang C. Mei, M.ASCE
Verna L. Jameson, ASCE Staff Contact

Journal of Engineering Mechanics http://scitation.aip.org/emo/


.

[gpond]

Originally Posted by zhukher

All this resistance does is converts the energy back from kinetic to potential minus heat slowing the fall down. This is the resistance in action, once the potential energy is greater than the force of resistance it needs to overcome it falls and starts converting to kinetic energy

Thank-you, zhukher. I understand your correction. The time involved interests me quite a lot.

[Infidel]

Halo please delete the repost in the post of yours directly above this one. You stated the same 4 posts above this one. this is akin to shouting with your hands over your ears

You can just reference a post like I am doing