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Inside Job—9/11 Truth and other 9/11 Discussion (Merged)
Posted: 16 November 2008 10:06 AM   [ Ignore ]   [ # 301 ]
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psikeyhackr, the first link you provide concerning the calculation of the heat effects of the burning fuel is certainly far more detailed than the one I carried out. I acknowledge that I overestimated the fuel load of the aircraft, and that this lowers my estimate of temperature. I carried out a quickie calculation to demonstrate that the fire could have softened the steel enough to cause the collapse. So now let’s look more closely at the issue.

Let’s note that the two calculations make different estimates, that lean one way and the other. I estimated 5,000,000 kg of steel; they estimated 500,000 kg of steel—a difference of a factor of ten. I estimated 80,000 kg of fuel, they estimated 10,000 kg—a difference of a factor of eight. Of course, their lower estimate of the amount of fuel was based on the assumption that 10,000 kg of fuel were consumed in the initial fireball—and that none of the heat of the initial fireball remained in the building! That assumption of theirs immediately lowers the effective temperature by a factor of two.

The big difference in calculations, however, is their assumption that 1.4 million kg of concrete must also be heated to the same temperature as the steel. This assumption raises a great many questions, because the thermal conductivity of concrete is less than 1 W/mK. Depending upon the conformation of the concrete, much of it would have been insulated from the fire and would not have heated much.

But the real killer argument is that you don’t need to heat all the steel to the softening point—if just one section of steel softens, you can lose the entire structure. So instead of thinking in terms of a single mass of high-temperature material all at the same average temperature, we have to think in terms of hotter areas and cooler areas, and guarantee that none of the hotter areas exceed that critical temperature. By the way, I looked that up, and the building codes specify that structural steel be able to withstand temperatures up to 540C. Thus, if we can be certain that no portion of the structure exceeded 540C, then we can be certain that the structure would not have failed due to heating. But if the temperature at any point in the steel structure exceeded a mere 540C, then we have a reasonable basis for concluding that the steel at that location failed.

Let me also remind you of a basic point in mechanical engineering: the difference between force and torque. A standard rectilinear structure can withstand enormous amounts of force, but far less torque. That’s because the compression strength of materials is almost always much greater than the shear strength. Thus, a steel structure can withstand enormous vertical loads, but if that structure is bent even slightly, the gravitational load becomes a torque, and the strength of the structure depends upon the shear strength of the steel, not its compressive strength. Thus, a tall building must be strong enough to remain vertical in the strongest possible winds; if it flexes by more than some critical angle, it will collapse. That’s why even a slight weakening of a structural element can lead to collapse; if that structural element softens and sags, it pulls the rest of the structure and twists it—leading to catastrophic torque. Indeed, it is theoretically possible to bring a structure down without any steel softening. If the temperature of the structural steel on one side of the building is significantly higher than the temperature on the other side, then the hotter side will expand more from the heat, bending the building. It could bend the building past its critical angle, in which case the building would collapse. It all depends on the concentration and distribution of the heat in the structure.

Your central point seems to be summarized in this statement:

So how does a lighter portion overcome the inertia of the heavier portion to collapse in less than 18 seconds?

Perhaps you have forgotten the old story about Galileo dropping a lead shot and a cannonball from the top of the tower of Pisa and observing that the two hit the ground at the same time. Heavier objects fall just as fast as light ones. Yes, there was a diminution of speed arising from the collision of upper floors with lower floors. But that diminution of speed appears in the results as the fact that the building did NOT collapse at the speed of free fall—it took a few seconds longer. You seem to be flipping back and forth between arguing that the mass of the lower levels slowed the fall and that the structural strength of the building impeded the fall. Would you please make up your mind and argue these two issues separately? I have already given you the equations you need to carry out the calculation in the first case, and you have not reported any results. That says a lot.

I have lost patience with your confrontational style. It appears to me that you have no interest in discussing the physics of the collapse of the WTC buildings. Your primary interest appears to be in arguing. You have frequently indulged in denigratory comments. You seem to be more interested in proving that I am a dummy than in considering the physics of the WTC collapse. I will happily stipulate that I am in fact a dummy, but I have no interest in evaluating my intellectual strengths and weaknesses, nor do I care about your own. I have expended far too much time explaining in good faith the underlying physics, only to be countered with confrontational arguments made in bad faith. For this reason, I am terminating my participation in this discussion. I suggest that you take this matter up with Bryan. The two of you are well-suited to each other and I’m sure that you’ll have a delightful time communing in your preferred fashion.

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Posted: 16 November 2008 11:16 AM   [ Ignore ]   [ # 302 ]
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Mr.Crawford,I will come right out and say it.I believe it was already mentioned in this thread about a thousand pages ago.Some believe that there is an emotional/psychological response by people when confronted with mass catastrophies.It could be possible that this individual is still stultified by the occurences of 9-11.Some of the manifestations/or symptoms of this psychological reaction include denial and/or the creation of grand conspiracy theories.

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Posted: 16 November 2008 04:25 PM   [ Ignore ]   [ # 303 ]
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Thanks for bringing that up, Vyazma. Yes, major catastrophes tend to bring out the nutcases.

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Posted: 16 November 2008 06:25 PM   [ Ignore ]   [ # 304 ]
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While we may all disagree with Psi, and realize he’s impervious to contradicting data, we do have to refrain from ad hominum attacks such as suggesting psychological problems or suggesting obliquely that he may be a nutcase.  -  Occam

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Posted: 16 November 2008 06:40 PM   [ Ignore ]   [ # 305 ]
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I apologize, Occam. One reason I terminated the discussion was that I was finding myself starting to have an emotional reaction to psi. If I had ended it at that, I would have been fine, but I couldn’t resist one last Parthian shot.

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Posted: 19 November 2008 05:12 PM   [ Ignore ]   [ # 306 ]
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Occam - 16 November 2008 06:25 PM

While we may all disagree with Psi, and realize he’s impervious to contradicting data, we do have to refrain from ad hominum attacks such as suggesting psychological problems or suggesting obliquely that he may be a nutcase.  -  Occam

ROFLMAO

What contradicting data?

I am pointing out that the speed of the collapse CONTRADICTS the conservation of momentum but the official sources of information don’t tell us the steel on every level and create a 10,000 page report that doesn’t tell us the total amount of concrete.

Maybe this country has gotten to the point that understanding physics requires being a nutcase.  LOL

Chris Crawford - 16 November 2008 10:06 AM

psikeyhackr, the first link you provide concerning the calculation of the heat effects of the burning fuel is certainly far more detailed than the one I carried out. I acknowledge that I overestimated the fuel load of the aircraft, and that this lowers my estimate of temperature.

You admit to a mistake and then proceed to make another one.  The quantity of fuel does not change the temperature.  That is determined by the fuel and the efficiency of the burn.  The quantity of fuel can affect the length of tiem or the size of the area or both BUT NOT THE TEMPERATURE.

Chris Crawford - 11 October 2008 09:51 AM

The aircraft struck the building at about 2/3 of the way up from the ground. Thus, when the structural steel at that point softened, the entire upper third of the building began to fall.

Chris Crawford - 12 October 2008 06:22 PM

I stand corrected on the height at which the planes hit the building. That point, however, does not alter the basic reasoning used here.

You don’t get your information correct about where the planes struck on either of the buildings and then want to claim it doesn’t matter.  The higher up it struck the less mass to fall and crush that below and the more mass below that had to be crushed but to you it doesn’t matter.  So if you BELIEVE you don’t need to think.

Your calculation also errs in treating the material as having a fixed velocity. The velocity of all the material is increasing as it falls.

You either did not read what I wrote or you didn’t understand it.  This is the speed line for Case #2:

Case 2    1 ton       2            3            4
speed       0       32 10.67  33.74 16.87  36.17 21.70 38.66 ft
/sec 

In this case a 1 ton weight at 64 feet falls and hits a 2 ton weight at 48 feet.  then the combined 3 tons falls and hits the 3 tons at 32 feet and that 6 tons continues falling to hit 4 tons at 16 feet.

So the ZERO on the speed line is the starting velocity for the 1 ton weight.  It is traveling at 32 ft/sec the instant before it hits the 2 tons.  The conservation of momentum changes their combined velocities to 10.67 ft/sec.  Obviously the mass tripled so the velocity became 1/3rd.  The combined mass continued falling accelerating from 10.67 to 33.74 ft/sec.  Then 3 tons hit the stationary 3 tons and velocity was cut in half to 16.87.  The 6 tons then accelerated to 36.17 ft/sec and then hitting 4 tons resulting in a velocity of 21.7 ft/sec. The 10 tons then fell the remaining 16 feet to the ground impacting at 38.66 ft/sec.

Now I thought I had explained that with sufficient clarity in FALL OF PHYSICS without unnecessary verbosity but even with the changes in velocity listed you accused me of “errs in treating the material as having a fixed velocity”.

So with all of your blatant errors do you really think I give a damn about this:

I have lost patience with your confrontational style. It appears to me that you have no interest in discussing the physics of the collapse of the WTC buildings. Your primary interest appears to be in arguing. You have frequently indulged in denigratory comments. You seem to be more interested in proving that I am a dummy than in considering the physics of the WTC collapse. I will happily stipulate that I am in fact a dummy, but I have no interest in evaluating my intellectual strengths and weaknesses, nor do I care about your own. I have expended far too much time explaining in good faith the underlying physics, only to be countered with confrontational arguments made in bad faith.

You seem to be more interested in proving that I am a dummy than in considering the physics of the WTC collapse.

You don’t need any help from me on that score.  You just call something confrontational when it shows you are wrong and that you don’t even bother researching the subject.

You fell off the horse in your attempt to imitate the Parthians.

psik

[ Edited: 21 November 2008 08:24 AM by psikeyhackr ]
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Posted: 19 November 2008 05:48 PM   [ Ignore ]   [ # 307 ]
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PsiHack-could you tell me?Are you just trying to explain that the 2 towers were shoddily built,and all it took was for the 2 planes to bring them down?
Or are you saying that there were explosives planted inside the building,and the planes were just a decoy?
Are you saying that the 2 planes never were there.It was a David Copperfield illusion.
Are you saying that the 2 planes hit the building,but they shouldn’t have collapsed.But they did anyways,somehow.
There were additional explosives brought on board the planes to accellerate the collapse?
The buildings were purposefully built shoddily so as to facilitate a future terrorist action?
Have you ever once in this thread offered up your opinion as to what REALLY happened on 911?
The terrorist cell planted bombs inside the 2 towers to help the planes crush the buildings?
Missiles were fired at the buildings at the time of impact of the planes?
The engineers data on the material used for construction is being held from the public,so as not to make the architect liable for damages?
Are you not telling us the reasons,because you want us to figure out the conspiracy.You’re giving us hints,and we are getting “warmer” or “colder”?You know the cause,but you are paternalistically waiting for those who aren’t “in the know"to figure it out for ourselves?
With the 50 million or so words you’ve expended on this topic,I’m assuming you know the truth behind 911.What is it?

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Posted: 19 November 2008 11:21 PM   [ Ignore ]   [ # 308 ]
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VYAZMA - 19 November 2008 05:48 PM

PsiHack-could you tell me?Are you just trying to explain that the 2 towers were shoddily built,and all it took was for the 2 planes to bring them down?

Since that question demonstrates that you either can’t read, haven’t read or can’t understand what I have written so far I see no point in further response.

If you can’t understand the significance of FALL OF PSYSICS and don’t ask specific questions about it there is nothing for me to say to you.

Are you not telling us the reasons,because you want us to figure out the conspiracy.You’re giving us hints,and we are getting “warmer” or “colder”?

You can do a search and see what I have ever said about “CONSPIRACIES”.  Conspiracies are about the actions and motives of human beings.  Human beings cannot change the laws of physics.  That laws of physics do not give a damn about human beings.

The design of the WTC towers had to be based on the laws of physics.  The designers had to figure out how much steel and concrete to put where and it had to be documented to construct the buildings.  What would happen when the airliners struck the buildings would be affected by those distributions of steel and concrete.  It would not be affected by whether the plane was flown by Arab terrorists.  It would not be affected by whether the plane was flown by CIA agents with remote controls.  It would not be affected by whether the plane was flown by drunken Hell’s Angels snorting coke.  Therefore any conspiracy is totally irrelevant to what I am talking about and is therefore of no interest to me whatsoever.

If you want to know who or why you are welcomed to research it by whatever means you have at your disposal.  Do not talk to me about it.  I am not interested.  [11/30/08 21465]

psik

[ Edited: 30 November 2008 06:24 AM by psikeyhackr ]
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Posted: 21 March 2009 03:14 AM   [ Ignore ]   [ # 309 ]
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Finally!

http://www.youtube.com/watch?v=LXAerZUw4Wc

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Posted: 21 March 2009 08:03 PM   [ Ignore ]   [ # 310 ]
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psikeyhackr - 21 March 2009 03:14 AM

Finally!

http://www.youtube.com/watch?v=LXAerZUw4Wc

psik

Does it matter that the toothpicks do not effect each other? The momentum of the tower collapse is directly effecting the lower levels, and not just one at at time. The toothpicks do not effect one another, their relation is in if they fail or not to hold, or to what extent they slow down the weight. One toothpicks failure does not directly effect the integrity of the lower pick, they hold no direct physically interdependent relation.

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Posted: 21 March 2009 08:43 PM   [ Ignore ]   [ # 311 ]
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Robert Buhn - 21 March 2009 08:03 PM

Does it matter that the toothpicks do not effect each other? The momentum of the tower collapse is directly effecting the lower levels, and not just one at at time. The toothpicks do not effect one another, their relation is in if they fail or not to hold, or to what extent they slow down the weight. One toothpicks failure does not directly effect the integrity of the lower pick, they hold no direct physically interdependent relation.

True, but the strength of the toothpicks is more or less constant all of the way down.  The WTC had to get stronger and therefore heavier all of the way down.  That is why I have those questions about the steel and concrete on every level.

Also my stack of washers is an almost a solid mass.  It could support my entire 195 pounds if I could arrange a way to stand on them.  The top of the north tower was constructed the same as the mass below only lighter.  So the bottom of the falling portion should have been crushing itself while it crushed the top of the intact portion of the building.  That would result in an additional loss of energy causing it to slow down.

I think it would be damn near impossible to build a truly accurate small model demonstrating all that would happen in the WTC collapse.  So that video was just to demonstrate one IMPORTANT effect.  The distribution of mass would affect the collapse time just as I showed in FALL OF PHYSICS.  But that mathematical simulation did not include any physical support that had to be broken like the toothpicks so the mass alone could never stop the fall.

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Posted: 21 March 2009 09:27 PM   [ Ignore ]   [ # 312 ]
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psikeyhackr - 21 March 2009 08:43 PM

True, but the strength of the toothpicks is more or less constant all of the way down.  The WTC had to get stronger and therefore heavier all of the way down.  That is why I have those questions about the steel and concrete on every level.

Would it matter if the toothpicks are the same strength or any variation of intermittent strengths? The fact of the picks behaving within their individual capacity under the variable stresses, negates using the toothpick experiment as a model for a comparative illustration to the levels within the towers behaving in accordance to relationship dependent features. The toothpick illustration denotes only the shared instance of the effects of a top down physical force, though not related in terms of scale, or again, the dynamics of the structural system.

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Posted: 22 March 2009 10:17 AM   [ Ignore ]   [ # 313 ]
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Look for my upcoming video.In my video,I take a standard deck of playing cards and construct a tall tower out of them. Then I take a yardstick and briskly strike the top 1/3 of the Card tower. Watch in amazement as the card tower comes tumbling down!!

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Posted: 22 March 2009 11:23 AM   [ Ignore ]   [ # 314 ]
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VYAZMA - 22 March 2009 10:17 AM

In my video,I take a standard deck of playing cards and construct a tall tower out of them. Then I take a yardstick and briskly strike the top 1/3 of the Card tower.

Is the yardstick 1/2 of 1/10th of 1% the mass of the cards?

The planes were less than 200 tons the towers were more than 400,000 tons.

Don’t forget to pour at least a quart of kerosene on the cards before you start the fire.

psik

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Posted: 22 March 2009 11:47 AM   [ Ignore ]   [ # 315 ]
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Robert Buhn - 21 March 2009 09:27 PM

Would it matter if the toothpicks are the same strength or any variation of intermittent strengths? The fact of the picks behaving within their individual capacity under the variable stresses, negates using the toothpick experiment as a model for a comparative illustration to the levels within the towers behaving in accordance to relationship dependent features. The toothpick illustration denotes only the shared instance of the effects of a top down physical force, though not related in terms of scale, or again, the dynamics of the structural system.

It is because I knew there were significant variations in my chopped down toothpicks that I did multiple drops of each type.

The distance fallen by the mass in the video was reduced on average by 63% due to the stationary washers.  When dealing with multiple complex factors in a physical event the net result will be affected by some factors much more than others.  In FALL OF PHYSICS I demonstrated mathematically that mass alone could change the result by 20% without any physical resistance having to be broken. 

Now if you can come up with a mathematical exposition of the effects you are alluding to influencing the result by as much as 10% then I would be interested.  But if all you can come up with is rhetorical speculation then I am afraid that I do not see the point.

psik

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