Hardfire: Szamboti / Chandler / Mackey

I hope this is still on topic, but further to Dave's last post, I also fail to see how the two main truther arguments can coexist:

1) That any collapse very close to freefall speed indicates explosive demolition
2) That when the collapse proceeds significantly slower than freefall speed (Tony's 70% figure, for example, and Chandler's 64%), this also indicates explosive demolition!!

I can't imagine these arguments would fool many wise observers, but I suppose they get the job done when foisted on the gullible and uninformed.
 
alienentity said:
I hope this is still on topic, but further to Dave's last post, I also fail to see how the two main truther arguments can coexist:

1) That any collapse very close to freefall speed indicates explosive demolition
2) That when the collapse proceeds significantly slower than freefall speed (Tony's 70% figure, for example, and Chandler's 64%), this also indicates explosive demolition!!

I can't imagine these arguments would fool many wise observers, but I suppose they get the job done when foisted on the gullible and uninformed.
Click to expand...

Alien
I would have said you must be crazy mistaken, but here it is:
Can anyone make sense of this

"Downward Acceleration of the North Tower
The roofline of WTC1 (The North Tower) begins dropping with sudden onset and accelerates uniformly downward at about 64% of the acceleration of gravity (g) until it disappears into the dust. This means it is meeting resistance equal to about 36% of its weight. The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section. This is much less than the force it would exert if it were at rest. The acceleration data thus prove that the falling top section of the building cannot be responsible for the destruction of the lower section of the building.
[I want to acknowledge the work of Graeme MacQueen and Tony Szamboti who have been engaged in similar measurements by other means and have reached similar conclusions.]
David Chandler

http://www.911speakout.org/ (near bottom of page)
 
This is a persistent delusion of the Truth Movement. I address this in Appendix B in my whitepaper. The first known sightings of this brand of stupidity are from Hoffman and Heikki Kurttila.

What they fail to understand is that the strength of the structure, the opposing force, is not a constant as the structure is destroyed. Work = Force times Distance. For some of that distance, possibly, the force is equal to the strength, but for most of the distance pieces are broken or buckled or not in contact, and the force drops to zero.

Initially I never would have guessed that the Truth Movement really is this stupid, but that's what the evidence supports.
 
BasqueArch said:
Alien
I would have said you must be crazy mistaken, but here it is:
Can anyone make sense of this

"Downward Acceleration of the North Tower
The roofline of WTC1 (The North Tower) begins dropping with sudden onset and accelerates uniformly downward at about 64% of the acceleration of gravity (g) until it disappears into the dust. This means it is meeting resistance equal to about 36% of its weight. The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section. This is much less than the force it would exert if it were at rest. The acceleration data thus prove that the falling top section of the building cannot be responsible for the destruction of the lower section of the building.
[I want to acknowledge the work of Graeme MacQueen and Tony Szamboti who have been engaged in similar measurements by other means and have reached similar conclusions.]
David Chandler

http://www.911speakout.org/ (near bottom of page)
Click to expand...

The truly bizarre thing about Chandler's statement is that, if taken at face value, it states that no building can ever collapse from its own weight ever. We already know this to be false: see Ronan's Point or Bailey's Crossroads. Both of those buildings collapses at a rate somewhere between 0g and 1g. Which means that the average force exerted on the lower structure is somewhere between 0% and 100% of the at rest weight.

What I think he, and other truthers miss, is that this is a measurement of average force, not of peak force. It is more probable that the resisting elements near the collapse are at near peak static capacity for brief periods of time, and then break and resist nothing at all. And given the fact that the vertical force resisting elements aren't all loaded at the same time, as the upper block is tilted and the damage in the upper block is unequal, it is equally probable that this force does actually appear as an average rather than a jolt (Tony Szamboti's problem).

It is also worth pointing out that the once the load paths change, and the columns aren't axially loading the columns below and instead are impact floors slabs, all bets are off.

Feel free to change more words of "more probable" with "almost definitely so".
 
BasqueArch said:
Can anyone make sense of this

"Downward Acceleration of the North Tower
The roofline of WTC1 (The North Tower) begins dropping with sudden onset and accelerates uniformly downward at about 64% of the acceleration of gravity (g) until it disappears into the dust. This means it is meeting resistance equal to about 36% of its weight. The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section. This is much less than the force it would exert if it were at rest. The acceleration data thus prove that the falling top section of the building cannot be responsible for the destruction of the lower section of the building.
[I want to acknowledge the work of Graeme MacQueen and Tony Szamboti who have been engaged in similar measurements by other means and have reached similar conclusions.]
David Chandler
Click to expand...

No. It makes no sense.

It makes sense until "The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section." It looks to me as though Chandler is trying to apply Newton's third law by reasoning that (1) the falling section is meeting resistance equal to 36% of its own weight, so (2) the falling section must be exerting a downward force equal to 36% of its own weight.

That's an accounting mistake. Gravity didn't go away, so the falling section always exerts a downward force equal to 100% of its weight. The question is how much of that force is resisted (36%, according to Chandler) and how much goes into acceleration (64%, also according to Chandler). The rest of Chandler's statement is a non sequitur.

Will
 
W.D.Clinger said:
No. It makes no sense.

It makes sense until "The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section." It looks to me as though Chandler is trying to apply Newton's third law by reasoning that (1) the falling section is meeting resistance equal to 36% of its own weight, so (2) the falling section must be exerting a downward force equal to 36% of its own weight.

That's an accounting mistake. Gravity didn't go away, so the falling section always exerts a downward force equal to 100% of its weight. The question is how much of that force is resisted (36%, according to Chandler) and how much goes into acceleration (64%, also according to Chandler). The rest of Chandler's statement is a non sequitur.

Will
Click to expand...
The whole thing is nonsense. A falling object generates a whole hell of a lot more FORCE than the same object under static conditions.
These guys use energy and force interchangeably.
Stress is a function of FORCE. Failure occurs because of the APPLIED FORCE exceeding the FORCE CAPABILITY of a structure
Energy is FORCE at WORK. Time is involved
 
rwguinn said:
The whole thing is nonsense. A falling object generates a whole hell of a lot more FORCE than the same object under static conditions.
These guys use energy and force interchangeably.
Stress is a function of FORCE. Failure occurs because of the APPLIED FORCE exceeding the FORCE CAPABILITY of a structure
Energy is FORCE at WORK. Time is involved
Click to expand...

I think you're confusing energy with force.

A falling object acquires kinetic energy. When it hits a static object, that object must either give way or exert a tremendous force (far greater than the weight of the falling object) to arrest the downward motion of the falling object within a very short time and very small deflection.

The falling object doesn't exert that tremendous force. The static object does, else it becomes ex-static. (No pun intended.)

Will
 
W.D.Clinger said:
The falling object doesn't exert that tremendous force. The static object does, else it becomes ex-static. (No pun intended.)

Will
Click to expand...

"For every action there is an equal and opposite reaction." I think someone important said that.

In any event, we're starting to get off topic.
 
W.D.Clinger said:
I think you're confusing energy with force.

A falling object acquires kinetic energy. When it hits a static object, that object must either give way or exert a tremendous force (far greater than the weight of the falling object) to arrest the downward motion of the falling object within a very short time and very small deflection.

The falling object doesn't exert that tremendous force. The static object does, else it becomes ex-static. (No pun intended.)

Will
Click to expand...
Bull's-eye.
The twufers don't see that connection.
 
Newtons Bit said:
"For every action there is an equal and opposite reaction." I think someone important said that.
Click to expand...

I stand corrected. What I should have said is that the falling object doesn't exert that tremendous force until it encounters the static object. The magnitude of the force exerted by the falling object is determined by the force exerted by the static object, which depends in turn on its stiffness, hardness, et cetera, and by whether it has enough strength to absorb the full impact before failing. In this case, it didn't.

In any event, we're starting to get off topic.
Click to expand...

Sorry about that. I was just speculating as to how someone with Chandler's education could have written such nonsense.

Will
 
alienentity said:
I hope this is still on topic, but further to Dave's last post, I also fail to see how the two main truther arguments can coexist:

1) That any collapse very close to freefall speed indicates explosive demolition
2) That when the collapse proceeds significantly slower than freefall speed (Tony's 70% figure, for example, and Chandler's 64%), this also indicates explosive demolition!!
Click to expand...

Elementary propositional logic: false -> true is a true statement, true -> true is a true statement. CD, "the towers where destroyed by explosive demolition," is a true statement because it is an axiom. Therefore, not("free fall") -> CD and "free fall" -> CD both are true statements.


QED.

;):D:boxedin:
 
Last edited:
W.D.Clinger said:
No. It makes no sense.

It makes sense until "The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section." It looks to me as though Chandler is trying to apply Newton's third law by reasoning that (1) the falling section is meeting resistance equal to 36% of its own weight, so (2) the falling section must be exerting a downward force equal to 36% of its own weight.

That's an accounting mistake. Gravity didn't go away, so the falling section always exerts a downward force equal to 100% of its weight. The question is how much of that force is resisted (36%, according to Chandler) and how much goes into acceleration (64%, also according to Chandler). The rest of Chandler's statement is a non sequitur.

Will
Click to expand...

That's my read of it as well. The statement 'This is much less than the force it would exert if it were at rest' is just mindbogglingly silly. Even worse is that truthers aren't calling him on this nonsense.
 
alienentity said:
I hope this is still on topic, but further to Dave's last post, I also fail to see how the two main truther arguments can coexist:

1) That any collapse very close to freefall speed indicates explosive demolition
2) That when the collapse proceeds significantly slower than freefall speed (Tony's 70% figure, for example, and Chandler's 64%), this also indicates explosive demolition!!

I can't imagine these arguments would fool many wise observers, but I suppose they get the job done when foisted on the gullible and uninformed.
Click to expand...

It's the "Twoofer Two-step". You'll see it quite often: Debris within the footprint? Evidence of deliberate demolition. Debris outside the footprint? Evidence of deliberate demolition.
 
BasqueArch said:
Alien
I would have said you must be crazy mistaken, but here it is:
Can anyone make sense of this

"Downward Acceleration of the North Tower
The roofline of WTC1 (The North Tower) begins dropping with sudden onset and accelerates uniformly downward at about 64% of the acceleration of gravity (g) until it disappears into the dust. This means it is meeting resistance equal to about 36% of its weight. The implication of this, however, is that the force it is exerting on the lower section of the building is also only 36% of the weight of the falling section. This is much less than the force it would exert if it were at rest. The acceleration data thus prove that the falling top section of the building cannot be responsible for the destruction of the lower section of the building.
[I want to acknowledge the work of Graeme MacQueen and Tony Szamboti who have been engaged in similar measurements by other means and have reached similar conclusions.]
David Chandler

http://www.911speakout.org/ (near bottom of page)
Click to expand...

The big problem here is he ignores the inertia force, which must be considered in any dynamic problem.

Once we add the inertia force, a free body diagram of the upper block (which chandler seems to try to do) can be drawn that actually makes sense. This is the case because once the inertia force is included the system can be said to be in equilibrium

For example considering downward positive, the sum of the gravity(mg, acting down), inertia(mass of the upper block times its acceleration, acting up by definition), and resistive forces from the lower structure (F acting up) looks like this:

mg - ma - F = 0
or
mg - F = ma
or
g- F/m = a

from this you can tell if F/m > g, a will be negative, meaning upward in this case. That means the upper block decelerates.

On the other hand if F/m < g, the upper block will accelerate.

If the deceleration caused by resistive force F is enough to arrest collapse can't be known without knowing the specific details about the columns(and considering energy quantities would be better anyway), but we can say that we know the resistive force will vary with the displacement of the column. Also since the columns were designed to hold the static force mg with a reasonable factor of safety, there is certainly a time when the upper block decelerates, followed by a time when it accelerates because a column loses almost all of its strength when it buckles.

In short, chandler showed that the lower structure will cause the upper portion to accelerate at an average rate less than the rate of gravitational acceleration. Which would be expected in a gravity driven collapse where the lower structure provides resistance.
 
Also the phrase "The acceleration data thus prove that the falling top section of the building cannot be responsible for the destruction of the lower section of the building"
is very vague but it seems to imply that the collapse should be halted abruptly upon contact of the upper and lower blocks.

Referring back to
g - F/m = a
or
g - F/m = DeltV/DeltT
you can see that if you want to change the velocity of the upper block from some finite number to zero instantaneously(i.e. with no time change), the acceleration will be infinite in magnitude acting up, which implies a resistive force that is also infinite.

Maybe thats not what chandler is arguing but it seems that way
 
TjW said:
It's the "Twoofer Two-step". You'll see it quite often: Debris within the footprint? Evidence of deliberate demolition. Debris outside the footprint? Evidence of deliberate demolition.
Click to expand...

I have a comic about this.

cdboth.png
 
Last edited:
Hey Ryan,

What do you think of Jim Hoffmans responce to your paper debunking Griffin?
 
You can download that paper here. We also had a discussion last year in this thread. But this is off-topic -- your question would have been better in a PM, or to find the original discussion.
 
You must log in or register to reply here.

Back
Top Bottom