Merged Continuation - 9/11 CT subforum General Discussion Thread

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jaydeehess said:
Close enough.

For the edification of tempesta
the angular momentum will be conserved by ROTATING the object about its center of mass. The direction that the center of mass is going? Straight down!

The center of mass of the upper block was still very much over the lower structure, having shifted maybe 10 -15 feet IIRC, from a point centered on the original structure. Only a small portion of the upper block then would be moving in a direction that would have it not fall onto the lower section.
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I don't know how you could possibly know how much the center of mass shifted. And how does a small portion of the upper block move in one direction and the rest in another? It's a single mass.

Even still, that shift should have been more evident the further down it collapsed, yet the entire lower structure was destroyed. The upper block still fell straight through the lower.
 
twinstead said:
No, the fact you are arguing from simple incredulity is NOT an ad hom.
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You're not stating a fact. That a falling mass will experience a decrease in its rate of acceleration when encountering increased resistance is a fact. Good. Now you know what a fact is.
 
Once the front had passed the first few floors, there wouldl have been an additional action occurring as the multi-story panels of exterior columns are pushed outward by the debris which was forced to move laterally because the floors would not get out of the way. This would be amplified by the increasing mass of rubble as collapse advanced.

No noticeable deceleration was likely. The energy available was constantly increasing.
 
tempesta29 said:
That's one of the definitions of deceleration. Look it up.



How it looked? I'm talking about what was measured. Chandler did an analysis and there was no measurable decrease in the upper section's acceleration.
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Darn, Chandler's work is claptrap (with respect to his conclusion of an inside job) which can't be published. We can see how the WTC fell, and the floors collapsing match a momentum transfer. What engineering journal published Chandler's work? The fact is the WTC fell at less acceleration than g, thus Chandler missed the "deceleration", and so did you. You should try some math next time.

I see you failed to support your path of least resistance the building should jump over into air and avoid the lower section.

Physics, which you failed to do will cure your jumping on the 911 truth failed physics train. Now how does the building jump to the air? You should revisit physics, or take a course as soon as possible.

Watergate, exposing Watergate was done in less than 2 years, it earned a Pulitzer Prize. The only thing 9 truth and Chandler have done with 10 years is expose ignorance and the ability to fool those who have no clue what physics is.
 
beachnut said:
Darn, Chandler's work is claptrap (with respect to his conclusion of an inside job) which can't be published. We can see how the WTC fell, and the floors collapsing match a momentum transfer. What engineering journal published Chandler's work? The fact is the WTC fell at less acceleration than g, thus Chandler missed the "deceleration", and so did you. You should try some math next time.
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Why do you people keep telling me that the upper sections fell at less than g when that isn't even relevant to the argument I'm making? I'm referring to these masses' rate of acceleration remaining unchanged through the crash zones. Are you dodging or simply unable to comprehend when you read?

It's as if you can't read, but I know the truth is that you're simply desperate.
 
tempesta29 said:
Wasn't likely? It's guaranteed. That's physics.
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Go to any university. Find a real physicist. Tell him the collapse of the twin towers was impossible without CD. Wait for him to stop laughing. Lather. Rinse. Repeat.

Keep thinking that you know something the rest of the world doesn't. Obviously it IS possible for the rate of acceleration to remain unchanged, especially if the resistance isn't enough to change it in any real way. We saw it happen!
 
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tempesta29 said:
It's not really that curious at all, especially since that tower didn't tilt toward its damaged corner. Regardless, it isn't falling in that direction. It's still falling straight down through the lower structure. It's really only rotating through its collapse path, not toppling.
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So you are expecting it to fall like a tree?
 
twinstead said:
Go to any university. Find a real physicist. Tell him the collapse of the twin towers was impossible without CD. Wait for him to stop laughing. Lather. Rinse. Repeat.

Keep thinking that you know something the rest of the world doesn't. Obviously it IS possible for the rate of acceleration to remain unchanged, especially if the resistance isn't enough to change it in any real way. We saw it happen!
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LOL.

"We saw it happen." That's absolutely hilarious.

Any physicist in the world will tell you that if you increase resistance to a falling mass the rate of acceleration of that mass will decrease.
 
tempesta29 said:
LOL.

"We saw it happen." That's absolutely hilarious.

Any physicist in the world will tell you that if you increase resistance to a falling mass the rate of acceleration of that mass will decrease.
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So where's the mass of papers in scientific journals indicating that the collapse of the WTC were physically impossible without active assistance from explosives or whatever you're trying to argue?

Serious question. Surely you don't believe every physicist in the WHOLE WORLD is "in on it" or is "afraid of losing his job"?
 
uke2se said:
So where's the mass of papers in scientific journals indicating that the collapse of the WTC were physically impossible without active assistance from explosives or whatever you're trying to argue?

Serious question. Surely you don't believe every physicist in the WHOLE WORLD is "in on it" or is "afraid of losing his job"?
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I can't answer that question, nor is it relevant to my argument.

If you increase resistance to a falling mass the rate of acceleration of that mass will decrease. Do you disagree with this statement or not?
 
tempesta29 said:
dictionary.com
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You said earlier:
tempesta29 said:
Deceleration in this case means a decrease in the rate of acceleration of the falling mass
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dictionary.com says no such thing:
dictionary.com said:
de·cel·er·ate
1. to decrease the velocity of: He decelerates the bobsled when he nears a curve.
2. to slow the rate of increase of: efforts to decelerate inflation.
3. to slow down: The plane decelerated just before landing.
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"rate of increase" <> "rate of acceleration". Rate of increase is homologous to speed, not acceleration.


tempesta29 said:
Yes.

http://www.youtube.com/user/DavidChandler911#p/u/10/AJf7pWVyvIw
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I think you misunderstand something:
Chandler shows that the North Tower descended at an acceleration that is 64% of g.

This means that the acceleration of the falling mass is decreased by 36%, for the acceleration of falling masses is 100% of g.

This means further that there is resistance! The resistance adds -36% of g to the free fall acceleration of 100%g. In this sense, the acceleration is decreased. By resistance of the structure.

As I and others have told you already, this decrease by 36% is a fairly good match with theoretical expectation derived through several lines of reasoning (physics and engineering). This match is actually good evidence and supports the theory that the structure below the fire zone was sound and intact and not weakened by explosives or other means.
 
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tempesta29 said:
I can't answer that question, nor is it relevant to my argument.

If you increase resistance to a falling mass the rate of acceleration of that mass will decrease. Do you disagree with this statement or not?
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I disagree, after reading Oystein's post above.

We know that there was resistance in the towers. This is why they did not free fall to the ground.

(I know there's an old twoofer lie about the towers "falling at free fall speed" or whatever. However, this has been thoroughly debunked, so I hope for your credibility's sake that isn't what you are trying to argue.)
 
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tempesta29 said:
I can't answer that question, nor is it relevant to my argument.

If you increase resistance to a falling mass the rate of acceleration of that mass will decrease. Do you disagree with this statement or not?
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I disagree. Resistance should in fact increase as you move down on the tower (as the dimensions of the steel structure get larger, since it has to bear higher loads firther down), but at the same time, the amount of the falling mass also increases. These effects can be expected to largely cancel out.

What matters is the ratio between mass above collapse front and resistance (structural strength) just below the collapse front. This ratio remains fairly constant, as at any level, column dimensions are designed to carry 2-3 times the static load (mass) above.

Acceleration will be roughly constant at (100-X)% of g. X can be computed to be roughly 1/3, or 33%.
 
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tempesta29 said:
LOL.

"We saw it happen." That's absolutely hilarious.

Any physicist in the world will tell you that if you increase resistance to a falling mass the rate of acceleration of that mass will decrease.
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If we're going to talk physics, we should talk physics. Feel free to pick it to pieces. Let's start with

Sum Forces = ma.

Taking up as positive, on the forces side we have F(resistance) - mg, and on the negative side ma. Your claim is that F(resistance) changes, so we take some derivatives

dF/dt -m(dg/dt)-g(dm/dt)=m(da/dt)+a(dm/dt)

Now, we can take dg/dt = 0, since the change of g isn't much in the height of the WTC. You contention is that da/dt is also =0 since a is constant at some value less than g.

dF/dt = g(dm/dt) + a(dm/dt) = (g+a)(dm/dt)

Now a is known to be negative (lets call it A as our working value), since we took up as positive, and A is less than g, so we have

dF/dt = (g-A)(dm/dt)

Your contention is that an increase in F (positive dF/dt) HAS to result in an increase in A, however we see that if the mass is changing as it falls (dm/dt is not zero), then it is possible to have an increase in F with constant acceleration. Most of us think the falling mass increases as it progresses. How about you?
 
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