Truthers...what is your best piece of evidence ?

[SabreTruthTiger]

You're claiming that it's intuitively obvious that the collapses violated the law of conservation of momentum, then. Please present your intuitively obvious reasoning that led you to this conclusion. Note that the collapses took significantly longer (in the range 12-16 seconds) than a freefall collapse (about 9 seconds), so we're looking for an intuitively obvious reason why the law of conservation of momentum predicts a 3-7 second slowing of the collapse times. I've yet to see one, but you may be the first.

Dave

The collapse was too linear, i.e. it started at high speed immediately without time to gather enough mass, so the collapse should have been even slower. Also and this is a biggy, even symmetric collapse is impossible without controlled demolition as structural inequality is accumulative and would lead to uneven and partial collapse.
No modern building has ever collapsed evenly and symmetrically into it's footprint without controlled demolition EVER!!!!

 

[lapman]

Number one 25000 tons is ridiculous, the kinetic energy was minimal as it collapsed from almost zero height or the height of a floor and would not multiply the building's mass by a factor of 25!!!! i.e. designed to hold 5 ton static load which is 5 times the load it actually supports, so it's 1000 tonnes times 25? That's wrong. Also the pancaking theory has been debunked, you cannot treat it floor by floor as the entire lower section has distributed load bearing

If I took an SUV and dropped it from 12 feet above you, would you be able to slow it down at all? IIRC, 25,000 tons is the calculated wieght of the upper floors on WTC 2. Now, since you seem to know so much about physics, what is the dynamic load put on the floor below it after that section fell 12 feet?

 

[lapman]

The collapse was too linear, i.e. it started at high speed immediately without time to gather enough mass, so the collapse should have been even slower. Also and this is a biggy, even symmetric collapse is impossible without controlled demolition as structural inequality is accumulative and would lead to uneven and partial collapse.
No modern building has ever collapsed evenly and symmetrically into it's footprint without controlled demolition EVER!!!!

Own footprint? Then how did it crush WTC 3 and severely damage the surrounding buildings hundreds of feet away?

 

[SabreTruthTiger]

Great, start with office fires being between 1100 and 1400 degrees and you keep ignoring that and talking about how hot kerosene burns. You must have missed the Natgeo special where jet fuel burned over 2000 degrees.

Jet fuel or kerosine, in an optimal fuel/air mix can reach temperatures of 1800 degrees, possibly higher which is no doubt what NatGeo referenced, after all in a jet engine the fuel/air mix would have to be optimised. In a 'dirty burn' or uncontrolled circumstances in a building with other standard materials it only burns to about 700F

 

[Disbelief]

In all the vintage 2006-era discussions of the "speed of collapse violates conservation of momentum" issue, was it ever pointed out that demolition explosions would not affect the overall momentum of the system? So that, if a top-down collapse taking X number seconds were impossible without explosives, it would also be impossible with explosives?

The exception would be, if the explosives propelled a large mass of debris rapidly in the opposite direction -- which, to accelerate the downward collapse, would require propelling debris upward. But no significant mass being propelled rapidly upward was observed.

This shows, in layman's terms and with no calculations required, the intuitively obvious fact that conservation of momentum arguments cannot provide evidence for explosive demolition nor any other demolition device. The only logically consistent conclusions are then that either conservation of momentum was not actually violated, or that the collapses were impossible by any means whatsoever within the known laws of physics.

Pick one:

- The collapses did not violate conservation of momentum.
- The collapses happened as they did because of phenomena unknown to science, e.g. magic.
- The collapses did not happen.

Respectfully,
Myriad

I did ask Greening what the collapse time for a normal CD would be, and he had a study showing the information. It was in one of his long threads, and I do not feel like looking for it in regards to our current poster. If you would like me to see if I can find it, I can take a stab at locating it.

 

[Dave Rogers]

Number one 25000 tons is ridiculous, the kinetic energy was minimal as it collapsed from almost zero height or the height of a floor and would not multiply the building's mass by a factor of 25!!!! i.e. designed to hold 5 ton static load which is 5 times the load it actually supports, so it's 1000 tonnes times 25? That's wrong. Also the pancaking theory has been debunked, you cannot treat it floor by floor as the entire lower section has distributed load bearing

I'm not sure why you're throwing random numbers about, but let me point out that you haven't actually supported your assertion that the WTC towers were designed to a safety factor of x5. Can you please post a credible source to substantiate this? The total mass of each WTC tower was somewhere in the region of 280,000 tons, so the upper section of each was in excess of 25,000 tons. The kinetic energy of the upper block has been calculated, and found to exceed the energy absorption capacity of the lower block, so your assertion that it was minimal is, in this context, incorrect.

Also, can you please explain what you mean by "the pancake theory has been debunked" when it's well known to everyone here that it's the pancake initiation theory that has been superseded, not any theory of collapse progression?

Dave

 

[SabreTruthTiger]

Had to preserve this for a physics teacher to see; since you have never seen a physics teacher teach physics. Take this statement to your nearest physics teacher and tell her, or him, your ideas on 911. Too chicken?

Maybe I am wrong, show us your work. The equations you used. The numbers.

Why do you get 12.08 seconds if you do the momentum calculations for the collapse of the WTC using the top 12 floors? You failed to do the work. You failed to present but your own special physics, your own common sense approach that brings up the physics observation on your own failure.
This is the only relation you have with physics, being identified by Einstein.

Once again an insult but no refutation just the usual appeal to authority.

 

[beachnut]

The collapse was too linear, i.e. it started at high speed immediately without time to gather enough mass, so the collapse should have been even slower. Also and this is a biggy, even symmetric collapse is impossible without controlled demolition as structural inequality is accumulative and would lead to uneven and partial collapse.
No modern building has ever collapsed evenly and symmetrically into it's footprint without controlled demolition EVER!!!!

Your post is proof you have not done the calculation which show with momentum alone the times seen on 911 are exactly what a gravity collapse would be. Do the work and stop making moronic statements.

You never took physics; why? BTW, the collapse was not symmetric.

 

[Newtons Bit]

Also the pancaking theory has been debunked, you cannot treat it floor by floor as the entire lower section has distributed load bearing

Cite? Evidence? Proof?

 

[SabreTruthTiger]

If I took an SUV and dropped it from 12 feet above you, would you be able to slow it down at all? IIRC, 25,000 tons is the calculated wieght of the upper floors on WTC 2. Now, since you seem to know so much about physics, what is the dynamic load put on the floor below it after that section fell 12 feet?

Number 1 I wouldn't be able to support the static load of an SUV anyway, lol!

NIST were forced to acknowledge the weakness of the pancake theory when they tested steel samples from the World Trade Center.

"The results established that this type of assembly was capable of sustaining a large gravity load, without collapsing for a substantial period of time relative to the duration of the fires in any given location on September 11th," concluded NIST in their Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Towers.

 

[Dave Rogers]

The collapse was too linear, i.e. it started at high speed immediately without time to gather enough mass, so the collapse should have been even slower.

What you're doing here is a classic conspiracy theorist technique that I coined the term "unevaluated inequality fallacy" to describe. You're claiming that there was a particular velocity profile that the collapse should have followed. You're not working out, or demonstrating, what that velocity profile should have been. Nor are you working out, or demonstrating, what the velocity profile of the collapse actually was. From your standpoint of complete ignorance of these two sets of quantities, you are then going on to make the assertion that they are different. Since you don't appear to know how fast the building should have collapsed, nor do you seem to know how fast it did collapse, there is no way you can possibly make that claim with any credibility. And the more often you repeat it and refuse to justify it, the less credible you become.

How fast should it have fallen? How fast did it fall?

Also and this is a biggy, even symmetric collapse is impossible without controlled demolition as structural inequality is accumulative and would lead to uneven and partial collapse.
No modern building has ever collapsed evenly and symmetrically into it's footprint without controlled demolition EVER!!!!

This is simply parroting of well-rehearsed cult dogma. None of the collapses on 9/11 were into their own footprint, and none were symmetrical. Therefore, your comments are irrelevant. How many times do you plan to ignore this being pointed out to you?

Dave

 

[WildCat]

Also the pancaking theory has been debunked, you cannot treat it floor by floor as the entire lower section has distributed load bearing

Really? Every single video I've seen of the collapse shows it proceeding floor by floor. Can you link to the video showing the collapse happening all at once?

 

[Crazytimes]

Jet fuel or kerosine, in an optimal fuel/air mix can reach temperatures of 1800 degrees, possibly higher which is no doubt what NatGeo referenced, after all in a jet engine the fuel/air mix would have to be optimised. In a 'dirty burn' or uncontrolled circumstances in a building with other standard materials it only burns to about 700F

Amazing.....

"Great, start with office fires being between 1100 and 1400 degrees and you keep ignoring that"

 

[Dave Rogers]

Once again an insult but no refutation just the usual appeal to authority.

You keep using that phrase. I do not think it means what you think it means.

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

What we're asking is for you to appeal to evidence, and that's what you're refusing to do.

Dave

 

[WildCat]

The collapse was too linear, i.e. it started at high speed immediately without time to gather enough mass,

Are you claiming that there were gigantic rockets engines secretly attached to the tops of the towers which fired up and drove the collapse downward? If not, please elaborate on a non-gravity explanation for your claimed observation.

 

[Dave Rogers]

"The results established that this type of assembly was capable of sustaining a large gravity load, without collapsing for a substantial period of time relative to the duration of the fires in any given location on September 11th," concluded NIST in their Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Towers.

Ah, quote mining. Are there any other common truther styles of lying you'd like to try out while you're here?

Dave

 

[SabreTruthTiger]

I'm not sure why you're throwing random numbers about, but let me point out that you haven't actually supported your assertion that the WTC towers were designed to a safety factor of x5. Can you please post a credible source to substantiate this? The total mass of each WTC tower was somewhere in the region of 280,000 tons, so the upper section of each was in excess of 25,000 tons. The kinetic energy of the upper block has been calculated, and found to exceed the energy absorption capacity of the lower block, so your assertion that it was minimal is, in this context, incorrect.

Also, can you please explain what you mean by "the pancake theory has been debunked" when it's well known to everyone here that it's the pancake initiation theory that has been superseded, not any theory of collapse progression?

Dave

The pancake progression was not even looked at by NIST because they knew they wouldn't be able to find a plausible explanation. The Structural steel beams would have provided ample resitance and if they remained stndng then the lack of resistance would have had more credibilty but somehow the main columns disintegrated.
NIST were forced to acknowledge the weakness of the pancake theory when they tested steel samples from the World Trade Center.

"The results established that this type of assembly was capable of sustaining a large gravity load, without collapsing for a substantial period of time relative to the duration of the fires in any given location on September 11th," concluded NIST in their Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Towers.

 

[beachnut]

Once again an insult but no refutation just the usual appeal to authority.

Once again you make no attempt at presenting your time of fall based on anything remotely associated with physics.

You present your own failed opinions and not a single piece of evidence to support your failed ideas you found on the Internet and you will not try to think for yourself or take your massive pile of BS to a physics teacher to learn the truth. You are the standard poster of lies on 911 and have not stopped to show me the simple physics you said you had.

... The physics are simple ...

Then show us the simple physics, super physics person. Show us.

I am waiting, my grandkids are waiting, my grandkids kids will be waiting. lol
Heal yourself, get an education

 

[dtugg]

Now you're just lying, twoofer.

 

[SabreTruthTiger]

What you're doing here is a classic conspiracy theorist technique that I coined the term "unevaluated inequality fallacy" to describe. You're claiming that there was a particular velocity profile that the collapse should have followed. You're not working out, or demonstrating, what that velocity profile should have been. Nor are you working out, or demonstrating, what the velocity profile of the collapse actually was. From your standpoint of complete ignorance of these two sets of quantities, you are then going on to make the assertion that they are different. Since you don't appear to know how fast the building should have collapsed, nor do you seem to know how fast it did collapse, there is no way you can possibly make that claim with any credibility. And the more often you repeat it and refuse to justify it, the less credible you become.

How fast should it have fallen? How fast did it fall?



This is simply parroting of well-rehearsed cult dogma. None of the collapses on 9/11 were into their own footprint, and none were symmetrical. Therefore, your comments are irrelevant. How many times do you plan to ignore this being pointed out to you?

Dave

Completely wrong. Reeeeeeally wrong wow! WTC7, try watching the video. the roof line fell evenly and symmetrically, impossible without demolition.