Goodbye, Mr Roberts

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Whether the rifle but is pointed or not has little to do with it.

The area over which the force is applied certainly does matter. Why do you think people wear bullet "proof" vests? It is to spread out the force.

Chandler doesn't consider area explicitly in his calculations. This would be a critical omission if there was any plausible way (in the official story) that the cross section area of the lower collapsing/crushed floors was less than that of the same lower floors which minutes earlier supported the building.

My point was that basing analysis on a simple force diagram is too idealized to tell you anything useful about the event.

It may or may not be too idealized to generate useful results. All models of any non-trivial event might have that problem. So far in this discussion, I have presented reasons and observations why Chandler's model is sufficient. Hypotheticals of other situations in which it is not sufficient make for interesting mental experiments, but don't discredit what I've presented.

If we want our model to be an accurate representation then we need to account for things like this otherwise it becomes less useful for predicting outcomes or learning about past events.

One cannot dismiss a model because it is imperfect. They all are. One has to argue the specifics of the case at hand.

So far as I can tell (being a bit of a cynical cow at heart) the primary reason that Chandler's model is being dismissed is because it gets the "wrong" result, not because any evidence or observations show it unsuitable for use in this case.

As a side note. It is completely possible to bring down a large building like that without explosives or thermite.

I am not denying that it's plausible for a building to be brought down without explosives.

Chandler and I are saying that the falling upper portion did not crush floors on the lower portion. I know this because the upper floors did not decelerate enough. If the upper floors had crushed the lower floors, then (given that the supposedly undamaged lower floors were able right until the last minute to support the weight of the upper floors) the upper floors would have had to apply more force than just their weight, not less. But they applied considerably less, as evidenced by their substantial positive downward acceleration through a time period of impact and floor destruction. Q.E.D.

[Ghent12]

Re: Goodbye, Mr Roberts

P.P.S. -- Those were iron spheroids, not steel. This material did not come from the steel in the building. Something formed small, hot, melted globs of iron and ejected it into the air so that it could form round liquid balls and solidify while still in the air. One possible source of small molten iron globs is thermite explosions. I've seen no other possible source suggested in my readings so far.

Unless you can explain to me in exact detail the constituent elements of steel and how they are individually affected by a multi-Megajoule environment, you are unqualified to make any statement on the presence or absence of iron.

Further, unless you can eliminate all sources of iron save one, you cannot conclude anything about the origins of it. You say you've seen no other possible source, but that's only because you haven't even tried to look. You simply seek out things to reinforce your view. This makes your 'facts' to be 'opinions' using modern lexicon.

Kinda like how you believe energy doesn't matter when analyzing physics, you don't acknowledge that steel is mostly iron, that the presence of iron is what causes steel to rust, that iron spheres can be found in ink cartridges and created when salvage teams cut steel columns at 45 degree angles (which, if I'm not mistaken, you previously attributed to your super quiet very high yield nano-thermite, although that seems to be in contradiction to your ceiling-tiles-were-the-nano-thermite theory, but I digress).

[c1ue]

Re: Goodbye, Mr Roberts

So are F = ma, ft = mv and vē = 2as wrong, because they do not mention energy? The absurdity of that claim should open your mind to the realization that you have been irrationally denying something here.

They are wrong if used to describe the capability to break the lower towers. F = ma is fine for understanding the Forces involved at rest, but doesn't help once the collapse begins.

Chandler attempts to both say that because the lower structure was able to withstand the F=mg of the upper stories intact, that it could not possible have been destroyed by the mgh of the falling upper stories. He also attempts to say that since the lower stories can withstand the F of the upper stories at rest, that somehow even damaged the lower WTC could still withstand the F of the upper stories because of the overdesign factor - this is cribbed from the prior paper.

The prior paper states that there was a 3x to 5x net Force withstanding capacity in the overall steel structure, but fails to note that an ideal 3x to 5x Force capacity - which was reduced to 4x on an average day - is itself assuming an even load distribution. The reason there is overdesign is because load will shift due to winds, etc thus a 1.0x or even 2.0x Force withstanding capacity is insufficient.

Given this, and that the impact-severed columns were definitely all on one side, already there is an inconsistency due to the 'holes' in the load network.

It is entirely conceivable that between the severed core columns on one side and the likely fires starting in the same location that the next set of core columns experienced more than the normal F distribution even as they were being weakened by annealing (fire). The amount of F at some point thus could very conceivably have been greater than even the (3x - annealing = 1.5x?) design load asserted. The tipping of the roof tower is consistent with this.

The fact that the first paper fails to examine this possibility and disprove it shows the bias and/or lack of knowledge on the part of the first paper's author.

ft = mv is irrelevant. We're not talking about momentum, we're talking about energy. These aren't billiard balls, plus V is constantly increasing due to gravitic acceleration. Also note that mv is used to denote when all other forces are basically equalized to understand velocity of each object after impact. But the energy transfer is still 1/2 mass times relative velocity squared.

vē = 2as is used simply to arrive at kinetic energy so itself is not the key.

Yes, there was (perhaps) enough energy. By your analysis, the official story is plausible.

No, there was not enough impulse (ft). By Chandler's analysis, the official story is not plausible.

You are objecting that he's not looking at it using the same tools as you are, therefore he's wrong. That is a totally indefensible position. That someone of your demonstrated mental abilities would insist on holding to such a position is prima facia evidence that their own mind is part of the 9/11 coverup.

Please consider my Styrofoam brick and sledgehammer example. It is I believe my most accessible example yet demonstrating the classic physics analysis of impulse, momentum, force, mass, position, velocity and acceleration is (as it has been since Isaac Newton) a valid approach in a situation rather similar in its essential ways to the WTC tower collapses we're discussing.

Both Chandler's and your methods of analysis are valid. One shows the official story to be plausible (there might be enough energy); one shows the official story to be implausible (but there is not enough impulse (ft).) Therefore the official story is implausible.

The brick and styrofoam example is not useful because it is F much much greater than the F withstanding capacity of the styrofoam.

Secondly the analogy is poor because you are again talking about small objects. Large objects matter because

1) There is noticeable propagation time along the WTC y-axis, something which for the nail effectively is zero.
2) Similar to the cube square law in animals, the sheer size and mass of the WTC buildings mean there are fundamentally different effects at play due to the relative material strengths vs. the forces involved. Also known as the "why ants are the strongest proportional lifters in existence".

If I were to take your hammer/nail/styrofoam analogy, but scale every thing up 1 billion times, would the interaction be the same?

The answer is no. Because even if everything else were identically scaled (force of swing scaled up 1 billion times, decreased drag effect of air compensated for, etc etc), swinging the hammer would pulverize the top surface of the nail. More relative energy would go towards the mechanical work of pulverizing the nail head than driving the entire nail into the styrofoam because the material strength of the nail stays the same in either case (F capacity per unit area). And in the 1 billionX case, the localized F is much much greater than the F capacity. To extend this further, if the hammer were to rest on the nail (gently), the effect would be the same.

Here's another example, this one focused on the matter of considering multiple models. If I analyze the driving time from where I am (North Texas) to say New York, I might determine that driving at the speed limit (say 60 MPH) for the distance involved (say 1600 miles) I can drive from here to New York in three days, including time for two night's rest. That's certainly plausible. But if I then look at my gas guage and realize I'm almost out of gas, and if look in my wallet and realize I have no money for gas, and if I know I have no other source of money, then I can determine that I cannot drive to New York, because I lack sufficient "energy" (gas.) You see? There's two valid ways to analyze something, one of which shows it could happen, the other of which says "no way." Therefore I can conclude it's not going to happen, given these particulars.

Again, the problem here is you're still trying to use momentum to denote energy.

A conclusion of implausible in any of multiple valid methods of analyzing a situation demonstrates that it's implausible, even if the other methods of analysis are inconclusive.

Wake up, c1ue! Take the Red Pill!

Sorry, but your, Chandler's, and what's his face's papers still lack many key details as well as some fundamental misunderstanding.

If this momentum theory were correct, then buildings should never collapse of their own weight. All modern buildings are built with steel frames, and most have both fire suppression systems and fireproof cladding of the frames. They also are always overdesigned to compensate for earthquakes, high winds, or several floors of inhabitants doing the Macarena.

Had one or more of these papers shown in detail that the forces or energy involved were impossibly disparate, then I would take the conclusion more to heart.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

They [F = ma, ft = mv and vē = 2as] are wrong if used to describe the capability to break the lower towers.

No. Newton's Laws of Mechanics do not have exemptions for lower WTC towers.

F = ma is fine for understanding the Forces involved at rest, but doesn't help once the collapse begins.

Wrong. I now know with certainty that you do not understand certain basic physics.

Outside of some extreme situations, such as sub-atomic physics (where quantum mechanics might be more useful) or physics at high speeds and large gravitational fields (where special or general relativity might be more useful), the force on an object is equal to (within a high degree of precision) its mass times its acceleration, where both force and acceleration are vector (directional) quantities. Note for instance that by 'a' I do not mean just 'g' (gravity.) Rather 'a' refers to acceleration, which is the rate of change of velocity, which in turn is the rate of change of position.

Perhaps you could benefit from a study of Newton's laws of motion, though I will admit I rather doubt you would find it useful, at least at this time. Before one can learn, one must realize that one doesn't yet know.

Chandler attempts to both say (A) that because the lower structure was able to withstand the F=mg of the upper stories intact, that (B) it could not possible have been destroyed by the mgh of the falling upper stories.

He does say (A), yes. I don't know what "mgh" is, so I cannot comment usefully on whatever confusion lies behind your claim (B).

He also attempts to say (C) that since the lower stories can withstand the F₁ of the upper stories at rest, that (D) somehow even damaged the lower WTC could still withstand the F₂ of the upper stories (E) because of the overdesign factor - this is cribbed from the prior paper. (subscripts added to the F terms by the Cow.)

I now know with certainty that you do not understand Chandler. That is a massively confused and incorrect representation of what he says. We know that the force F₂ is less than F₁ because the mass is accelerating downward. No over design is necessary whatsoever. If the lower portion could (even just barely) support the upper at rest, then it could (if not otherwise damaged) support the upper while the upper is accelerating downward.

Yes, I realize that the immediately preceding sentence looks quite wrong to you.

You have chosen the blue pill.

ft = mv is irrelevant. We're not talking about momentum, we're talking about energy.

No. ft = mv is relevant, as is F = ma. Both of these are classical mechanics principles which are accurate to an extremely high degree of precision in the ordinary world that we're discussing here.

No. We are not talking about momentum. Chandler and I are.

No. We are not talking about energy here. You are.

Your energy analysis that a collapse was plausible just given the impact damage and fire does not discredit Chandler's analysis that the collapse that actually did happen (as measured by the change in position over time of the upper portion) required something else (other than the impact of the upper portion) to first substantially (WTC1) or entirely (WTC7) remove such load bearing capacity of the lower portion as it had just had prior to the collapse.

Yes, I realize the immediately preceding sentence is too long for there to be any chance that you will understand it, given that you do not yet understand Newton's Laws of Mechanics or Chandler's analysis of this matter.

vē = 2as is used simply to arrive at kinetic energy so itself is not the key.

Good grief. That equation does not even have a 'kinetic energy' term. It was used to solve for velocity 'v' or acceleration 'a', given the other. Your mind has you confused beyond my capacity to have an intelligent conversation with you on this matter.

The brick and styrofoam example is not useful because it is F much much greater than the F withstanding capacity of the styrofoam.

I was wondering how you were going to talk yourself out of understanding the usefulness of that example. I'd suggest variations on that example, such as balsa wood and a smaller hammer, but I've already convinced myself that, so far as the present topic is concerned, I'm conversing with a fool. So I won't bother.

Secondly the analogy is poor because you are again talking about small objects. Large objects matter because

Newton's Laws of Mechanics apply with extreme accuracy to objects of any of the sizes being considered here.

If I were to take your hammer/nail/styrofoam analogy, but scale every thing up 1 billion times, would the interaction be the same?

The essential interactions would still be the same. One could still determine whether the humongous hammer hit a Mont Blanc made of Styrofoam or of granite if one could accurately measure the position, hence velocity and acceleration, of the humongous hammer while it was impacting the mountain.

Again, the problem here is you're still trying to use momentum to denote energy.

No. I am not trying to do that. It is you who insists on only considering energy and discrediting or confusing everything else.

Sorry, but your, Chandler's, and what's his face's papers still lack many key details as well as some fundamental misunderstanding.

Sorry, but the fundamental misunderstanding is yours.

If this momentum theory were correct, then buildings should never collapse of their own weight.

No. We already went around that one a while back. I suppose you can find it if you look.

Had one or more of these papers shown in detail that the forces or energy involved were impossibly disparate, then I would take the conclusion more to heart.

I suspect that if these papers had reached conclusions that did not require you to completely rethink the events of 9/11, then you might have taken them more to heart.

Let me know when you have completed an introductory college physics course. Then I will decide whether you earned that passing grade, or your professor deserves a failing grade. If you've already passed such a course, then I already know my decision.

[c1ue]

Re: Goodbye, Mr Roberts

Outside of some extreme situations, such as sub-atomic physics (where quantum mechanics might be more useful) or physics at high speeds and large gravitational fields (where special or general relativity might be more useful), the force on an object is equal to (within a high degree of precision) its mass times its acceleration, where both force and acceleration are vector (directional) quantities. Note for instance that by 'a' I do not mean just 'g' (gravity.) Rather 'a' refers to acceleration, which is the rate of change of velocity, which in turn is the rate of change of position.

Sorry bubba, but you are wrong. Force is merely force. It doesn't become energy until it is exerted over a distance.

According to your theory, an object exerting force due to gravity has energy. It does not.

You're still not getting it.

Until the object with force moves, there is no energy. There may be potential energy, but potential energy is just that: potential. Not energy.

He does say (A), yes. I don't know what "mgh" is, so I cannot comment usefully on whatever confusion lies behind your claim (B).

mgh = gravitic potential energy.

I now know with certainty that you do not understand Chandler. That is a massively confused and incorrect representation of what he says. We know that the force F₂ is less than F₁ because the mass is accelerating downward. No over design is necessary whatsoever. If the lower portion could (even just barely) support the upper at rest, then it could (if not otherwise damaged) support the upper while the upper is accelerating downward.

Yes, I realize that the immediately preceding sentence looks quite wrong to you.

You have chosen the blue pill.

Again, you are confused. The force exerted by the upper stories above the break point NEVER CHANGES. That force is constant as it is due to gravity which DOES NOT CHANGE. Technically the mass of the upper stories changes slightly as some of it burns, but that can be ignored for this purpose.

The force withstanding capacity at the break point did change. F1 is irrelevant as it is merely a proxy for the force withstanding capacity of the structure. When said capacity is greater than the Force load, then the opposing forces are equal (i.e. Force load = opposing WTC lower structure force resistance). When said capacity falls below the force loading, then a collapse ensues.

The force withstanding capacity changed when the 767 severed some core columns.

The force withstanding capacity changed when the fires weakened the remaining core columns.

Just because at some point in time the structure at the break point was able to withstand the force of the upper stories does not mean it always can.

Chandler's argument is wrong. Your belief in it is also wrong. And you continue to compound your error.

No. ft = mv is relevant, as is F = ma. Both of these are classical mechanics principles which are accurate to an extremely high degree of precision in the ordinary world that we're discussing here.

No. We are not talking about momentum. Chandler and I are.

No. We are not talking about energy here. You are.

Your energy analysis that a collapse was plausible just given the impact damage and fire does not discredit Chandler's analysis that the collapse that actually did happen (as measured by the change in position over time of the upper portion) required something else (other than the impact of the upper portion) to first substantially (WTC1) or entirely (WTC7) remove such load bearing capacity of the lower portion as it had just had prior to the collapse.

Yes, I realize the immediately preceding sentence is too long for there to be any chance that you will understand it, given that you do not yet understand Newton's Laws of Mechanics or Chandler's analysis of this matter.

Sorry, but you continue to treat the 2 sections of the WTC as free floating bodies.

They are not.

Your and Chandler's momentum model completely ignores the loading capacity (or lack thereof) of the structure. As I said before and say again: if you do so then no buildings should EVER fall down since F1 = F2 in all such instances.

Good grief. That equation does not even have a 'kinetic energy' term. It was used to solve for velocity 'v' or acceleration 'a', given the other. Your mind has you confused beyond my capacity to have an intelligent conversation with you on this matter.

Again, what it is used for is exactly what I stated: to calculate the velocity after a given falling distance. The velocity is then used to determine kinetic energy.

Quote:

Originally Posted by c1ue vē = 2as is used simply to arrive at kinetic energy so itself is not the key.

Good grief. That equation does not even have a 'kinetic energy' term. It was used to solve for velocity 'v' or acceleration 'a', given the other. Your mind has you confused beyond my capacity to have an intelligent conversation with you on this matter.


Quote:

Originally Posted by c1ue The brick and styrofoam example is not useful because it is F much much greater than the F withstanding capacity of the styrofoam.

I was wondering how you were going to talk yourself out of understanding the usefulness of that example. I'd suggest variations on that example, such as balsa wood and a smaller hammer, but I've already convinced myself that, so far as the present topic is concerned, I'm conversing with a fool. So I won't bother.

You may insult all you want, but the reality is you still don't understand that huge masses like the WTC towers behave fundamentally different than small coherent objects.

Scaling the hammer/nail/styrofoam analogy is how I attempted to illustrate this to you, but in turn you refuse to acknowledge that there are differences due to the different material's intrinsic strength.

Returning again to an analogy used before: why is it that a horse and a cat falling off a cliff behave differently upon striking the ground?

Some of the difference is due to terminal velocity, but the real difference is that flesh has a specific intrinsic strength. A larger animal when falling exerts more force hence greater kinetic energy over its impact footprint - even though both animals may be falling with energy exactly proportional to their weights.

Quote:

Originally Posted by c1ue Again, the problem here is you're still trying to use momentum to denote energy.

No. I am not trying to do that. It is you who insists on only considering energy and discrediting or confusing everything else.

I've already noted that Chandler and company leave out many possible outcomes in their 'analysis'.

I've also noted that even Chandler's analysis as is fails to show why a collapse is impossible; all it purports to do is attempt a simplistic force equalization without at all analyzing the fundamentals behind these forces.

You're welcome to think what you want, but I've shown quite clearly that:

1) The energy of the falling WTC upper floors could easily have damaged and/or collapsed the lower structure

2) The unchanging force of the weight of the upper floors was being supported by a structure which was damaged in at least 2 different ways: by 767 impact and then again by annealing due to fire.

Chandler fails to analyze any of this.

A 'real' analysis would then look at the load distribution in a given floor and model how removal of 10 core columns would redistribute the still identical upper floor load onto the remaining columns, and how even this distribution is.

This same 'real' analysis would then examine what the actual horizontal and lateral load capacity of the core columns is at spec. The analysis could then give some idea as to how likely a progressive but rapid collapse in the core columns would be given the redistributed force loads and different temperature annealing profiles.

NIST doesn't seem to do this, true.

But then Chandler doesn't do this either.

Then again NIST isn't trying to demonstrate that the WTC towers could never have fallen. Their premise is that since it happened, obviously it could.

Chandler as one who disputes this above statement has the burden of proof to clearly demonstrate differently.

He has failed to do so.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

The force exerted by the upper stories above the break point NEVER CHANGES. That force is constant as it is due to gravity which DOES NOT CHANGE

The force due to gravity does not change, given of course we stay near the earth's surface. But when I say force, I mean force, not just the force due to gravity or some potential energy.

The total force applied by, and thus being applied to, a mass can change. The net force applied to a mass causes that mass to accelerate in the direction and in proportion to the magnitude of that force. Because the masses in question (the upper portions of WTC1 and WTC7) were accelerating downward, therefore the upward force on them was less than the force which earlier had supported the upper portions as a static load.

Until you understand this much, then I should take the honorable course of not further offering you the opportunity to embarrass yourself on this topic.

I will not put you on my ignore list, because I value your posts elsewhere, and even here, you have honorably and clearly presented your thoughts. Unfortunately the thoughts you present here on this topic are being played with by your unspoken assumptions, as a cat plays with a mouse.

(Yet one more example, if you would like to continue to challenge your understanding. I cannot resist - sorry. Consider (but best not to respond here regarding) how we train astronauts for zero-gravity by flying them in cargo planes that fly a parabolic arc such as a stone would take if tossed in the air and freely allowed to fall back. Someone sitting in that plane at that time will feel the pressure of the seat on their backside lessen and go to roughly zero. This means that the seat is "falling away" from their backsides at roughly 9.8 m/secē. If, exactly while that was happening, either the seat or their backside was being crushed to the point of destruction, then it would not be the impact of the "free falling" backside of our astronaut in training that was causing the crushing, for that backside was pressing far less than normal on the seat, as could be demonstrated if the measurements of the position of said backside over that period of time showed it to also be accelerating downward at roughly 9.8 m/secē.)

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Back on the original topic of this thread, PAUL CRAIG ROBERTS has granted Alex Jones an "exit interview". You can hear Mr. Roberts follow up on the original article that started this thread, at: Alex's Farewell Interview with Dr. Paul Craig Roberts on The Alex Jones Show 1/5 :

[skyson]

Re: Goodbye, Mr Roberts

Until the object with force moves, there is no energy. There may be potential energy, but potential energy is just that: potential. Not energy.

I would agree with COW at this one. You can use different approaches in solving problems. In this case, Chandler attempts to use fumdamental physics to demonstrate that the total collapse of WTC could not be achieved by gravity alone.

If his analysis is sound, I don't see your logic to invalidate his conclusion by accusing him not analysing the energy involved.

Again, you are confused. The force exerted by the upper stories above the break point NEVER CHANGES. That force is constant as it is due to gravity which DOES NOT CHANGE. Technically the mass of the upper stories changes slightly as some of it burns, but that can be ignored for this purpose.

The force withstanding capacity at the break point did change. F1 is irrelevant as it is merely a proxy for the force withstanding capacity of the structure. When said capacity is greater than the Force load, then the opposing forces are equal (i.e. Force load = opposing WTC lower structure force resistance). When said capacity falls below the force loading, then a collapse ensues.

The force withstanding capacity changed when the 767 severed some core columns.

The force withstanding capacity changed when the fires weakened the remaining core columns.

Just because at some point in time the structure at the break point was able to withstand the force of the upper stories does not mean it always can.

Chandler's argument is wrong. Your belief in it is also wrong. And you continue to compound your error.

OK, think more carefully about your statement. Lets take your example:

At break point:
1. when t=-1, F1 = F2 = 1000.
2. when t=1, F1= 1000, F2 = 300.
3. now upper section falling, lets say acceleration = 5 m/second.

Pass break point, and upper section impacts the undamaged lower section:
F1 = 1000
F2 = 1000
then, acceleration suppose to be 0 m/second, yet Chandler observe that acceleration is still 5 m/second. Does that tell you that the supposedly intact lower structure is not that "intact" after all?

As I pointed out many times, "initiation of collapse" != "global collapse ensued" - even the upper structure started to fall due to extensive damages at floor 95 and 96 floors of WTC1, it should not be assumed by NIST that total collapse must be the end result without backing it up with any evidence and analysis.

Why NIST chose to be so lame in their job?

Sorry, but you continue to treat the 2 sections of the WTC as free floating bodies.

They are not.

Your and Chandler's momentum model completely ignores the loading capacity (or lack thereof) of the structure. As I said before and say again: if you do so then no buildings should EVER fall down since F1 = F2 in all such instances.

Sorry, again as COW pointed out: you have no understanding in basic physics. Newton Third Law dictates that F1 is always equal to F2, but opposite in direction.

But that does not mean "no buildings should EVER fall down". Whether the building would fall down dictated by the ability of the structure at impact point to sustain the force(F1 and F2) without breaking. If F1/F2 overwhelms the capacity of 95/96 floor structure, then collapse would occur, otherwise the structure would stand. (* in above statement you said F1 NEVER change, I guess you don't differentiate dynamic load and static load?)

Newton Third Law is true even in the case of a iron ball falling in air.

F(iron ball) = 1000.
F(iron ball against air) = 0.1
F(air against iron ball) = 0.1

See, the spared F(iron ball) is very large, and that is why it falls down in air with an acceleration of almost "g".

Contrary to your various statements before, basic physics laws applied to all kind of objects, regardless of their size, their composition, or speed(well, between 0 and light speed).

That is how genius Newton is. Our high school physics DO help us solve a lot of problems.

Returning again to an analogy used before: why is it that a horse and a cat falling off a cliff behave differently upon striking the ground?

Some of the difference is due to terminal velocity, but the real difference is that flesh has a specific intrinsic strength. A larger animal when falling exerts more force hence greater kinetic energy over its impact footprint - even though both animals may be falling with energy exactly proportional to their weights.

No, if take away the effect of terminal velocity, there is NO difference between a falling small object and a large object, providing that their composition is similar. The damages to the cat and horse are proportional to their body weight, each will be like say: 50%.

1) The energy of the falling WTC upper floors could easily have damaged and/or collapsed the lower structure

2) The unchanging force of the weight of the upper floors was being supported by a structure which was damaged in at least 2 different ways: by 767 impact and then again by annealing due to fire.

Your statement is true only at the impact zone. What happen to the intact lower structures?

NIST doesn't seem to do this, true.

But then Chandler doesn't do this either.

Then again NIST isn't trying to demonstrate that the WTC towers could never have fallen. Their premise is that since it happened, obviously it could.

Chandler as one who disputes this above statement has the burden of proof to clearly demonstrate differently.

He has failed to do so.

"Their premise is that since it happened, obviously it could."? What a joke!!! Seriously, do you know what you are saying? How about this:"Since the earth looks flat, obviously it is". Put it another way, do you mean NIST catered their investigation to a pre-determined conclusion? :rolleyes:

No, Chandler has successfully demonstrated that a pure gravity induced collapse could not lead to total collapse. It is contradictory to the laws of basic physics.

The burden of proof is on the NIST to prove that a pure gravity could lead to total collapse. It is their duty, yet they refused to do so.

The force due to gravity does not change, given of course we stay near the earth's surface. But when I say force, I mean force, not just the force due to gravity or some potential energy.

The total force applied by, and thus being applied to, a mass can change. The net force applied to a mass causes that mass to accelerate in the direction and in proportion to the magnitude of that force. Because the masses in question (the upper portions of WTC1 and WTC7) were accelerating downward, therefore the upward force on them was less than the force which earlier had supported the upper portions as a static load.

Until you understand this much, then I should take the honorable course of not further offering you the opportunity to embarrass yourself on this topic.

It took me two hours just to read through your responses. Wow, THE COW certainly has great deal of patience.

Ghent12 and c1ue:

How come you guys did not respond to my challenge at post #170? Don't you want to see how I solve the WTC1 mystery with high school physics? ;)

[c1ue]

Re: Goodbye, Mr Roberts

The total force applied by, and thus being applied to, a mass can change. The net force applied to a mass causes that mass to accelerate in the direction and in proportion to the magnitude of that force. Because the masses in question (the upper portions of WTC1 and WTC7) were accelerating downward, therefore the upward force on them was less than the force which earlier had supported the upper portions as a static load.

Until you understand this much, then I should take the honorable course of not further offering you the opportunity to embarrass yourself on this topic.

I will not put you on my ignore list, because I value your posts elsewhere, and even here, you have honorably and clearly presented your thoughts. Unfortunately the thoughts you present here on this topic are being played with by your unspoken assumptions, as a cat plays with a mouse.

(Yet one more example, if you would like to continue to challenge your understanding. I cannot resist - sorry. Consider (but best not to respond here regarding) how we train astronauts for zero-gravity by flying them in cargo planes that fly a parabolic arc such as a stone would take if tossed in the air and freely allowed to fall back. Someone sitting in that plane at that time will feel the pressure of the seat on their backside lessen and go to roughly zero. This means that the seat is "falling away" from their backsides at roughly 9.8 m/secē. If, exactly while that was happening, either the seat or their backside was being crushed to the point of destruction, then it would not be the impact of the "free falling" backside of our astronaut in training that was causing the crushing, for that backside was pressing far less than normal on the seat, as could be demonstrated if the measurements of the position of said backside over that period of time showed it to also be accelerating downward at roughly 9.8 m/secē.)

You keep coming up with these examples where both objects are accelerating: 1 from gravity and the other from gravity + additional downward acceleration.

Perhaps this is the gap: where is the 2nd object with additional downward acceleration beyond gravity? The 1st object accelerating due to gravity's effect is clearly the WTC upper stories.

The free fall flight example you postulate isn't useful; it is the energy on the seat by the astronaut which matters and that is determined by the relative velocity. The total energy is higher, true, but only in reference to a zero movement point like the earth - which technically is moving also.

But in reference to the seat, the astronaut has a different kinetic energy than in reference to the earth.

So again I fail to see what your example was trying to show.

As for my unspoken assumptions: be clear on what those are.

If you are saying I am assuming that there was no demolition - then yes, this is true. For the exercises I went through, every one assumed the lower structure was not demolished by nano-thermite.

What I am trying to do is to show that the WTC tower's collapse CAN be due to natural causes, thus the assumption is valid.

[skyson]

Re: Goodbye, Mr Roberts

At the same time however, such mass delusions are common. Is the American contentment with the War on Terror any less destructive in the end than the cultural revolution?

It is hard to compare man made disasters.

The Cultural Revolution destroyed a whole generation(might be two) of Chinese, the traditional culture, social relationships, education system, and economic development.It was a total disaster, almost unparallel in modern world history.

That is why it is especially sad to witness another man made disaster at close range...

[skyson]

Re: Goodbye, Mr Roberts

Originally Posted by ThePythonicCow
The key is that by Chandler's analysis, one can measure how strong was the stationary target, when hit and penetrated or destroyed by an object in motion. One does this by observing the impact on the acceleration of the moving object. The greater the negative change to the moving objects acceleration, the more force was generated during the impact. This is simply an application of the classic vē = 2as, F = ma and ft = mv equations.

Wouldn't this imply that the fellow who shot the gun would end up with a huge hole in his shoulder.

hmmm...lets look at a simple example:

F(bullet) = M(bullet)xA(bullet)

where M(bullet) = 2.6 g.

F(rifle) = M(rifle)xA(rifle)

where M(rifle) = 4 kg.

since F(bullet) = F(rifle)
so M(rifle)xA(rifle) = M(bullet)xA(bullet)
4000g x A(rifle) = 2.6 g x A(bullet)

Now A(rifle) = A(bullet)/1538

If you do as the coach tells you to do: hold the rifle against your shoulder and hold it tight:

F(rifle+man) = M(rifle+man)xA(rifle+man)
so M(rifle+man)xA(rifle+man) = M(bullet)xA(bullet)
74000g x A(rifle+man) = M(bullet)xA(bullet)

Now A(rifle+man) = A(bullet)/28461

OK, next time I go on a hunting trip, I will be very confident that I am not committing suicide...

[skyson]

Re: Goodbye, Mr Roberts

Originally Posted by TPC
The total force applied by, and thus being applied to, a mass can change. The net force applied to a mass causes that mass to accelerate in the direction and in proportion to the magnitude of that force. Because the masses in question (the upper portions of WTC1 and WTC7) were accelerating downward, therefore the upward force on them was less than the force which earlier had supported the upper portions as a static load.

Until you understand this much, then I should take the honorable course of not further offering you the opportunity to embarrass yourself on this topic.

I will not put you on my ignore list, because I value your posts elsewhere, and even here, you have honorably and clearly presented your thoughts. Unfortunately the thoughts you present here on this topic are being played with by your unspoken assumptions, as a cat plays with a mouse.

(Yet one more example, if you would like to continue to challenge your understanding. I cannot resist - sorry. Consider (but best not to respond here regarding) how we train astronauts for zero-gravity by flying them in cargo planes that fly a parabolic arc such as a stone would take if tossed in the air and freely allowed to fall back. Someone sitting in that plane at that time will feel the pressure of the seat on their backside lessen and go to roughly zero. This means that the seat is "falling away" from their backsides at roughly 9.8 m/secē. If, exactly while that was happening, either the seat or their backside was being crushed to the point of destruction, then it would not be the impact of the "free falling" backside of our astronaut in training that was causing the crushing, for that backside was pressing far less than normal on the seat, as could be demonstrated if the measurements of the position of said backside over that period of time showed it to also be accelerating downward at roughly 9.8 m/secē.)

You keep coming up with these examples where both objects are accelerating: 1 from gravity and the other from gravity + additional downward acceleration.

Perhaps this is the gap: where is the 2nd object with additional downward acceleration beyond gravity? The 1st object accelerating due to gravity's effect is clearly the WTC upper stories.

There is NO additional downward acceleration!

COW is saying this: 1. a =< g, and g is the acceleration when something falling through vacuum(or air if ignore the slight difference). 2. if lower structure was intact, then would render a = 0. 3. since observable a > 0, so lower structure was not intact, and the closer the a is to g, the less intact the lower structure is.

How clear that would need to be before you could understand? Are you intentionally playing dumb, or what?

The free fall flight example you postulate isn't useful; it is the energy on the seat by the astronaut which matters and that is determined by the relative velocity. The total energy is higher, true, but only in reference to a zero movement point like the earth - which technically is moving also.

But in reference to the seat, the astronaut has a different kinetic energy than in reference to the earth.

Please re-read Chandler's article and COW's posts. Other than that, not much help.

[radon]

Re: Goodbye, Mr Roberts

hmmm...lets look at a simple example:

F(bullet) = M(bullet)xA(bullet)

where M(bullet) = 2.6 g.

F(rifle) = M(rifle)xA(rifle)

where M(rifle) = 4 kg.

since F(bullet) = F(rifle)
so M(rifle)xA(rifle) = M(bullet)xA(bullet)
4000g x A(rifle) = 2.6 g x A(bullet)

Now A(rifle) = A(bullet)/1538

If you do as the coach tells you to do: hold the rifle against your shoulder and hold it tight:

F(rifle+man) = M(rifle+man)xA(rifle+man)
so M(rifle+man)xA(rifle+man) = M(bullet)xA(bullet)
74000g x A(rifle+man) = M(bullet)xA(bullet)

Now A(rifle+man) = A(bullet)/28461

OK, next time I go on a hunting trip, I will be very confident that I am not committing suicide...

This is partially what I was implying when I objected to that line of reasoning. In many cases the (rifle+man) experience no significant acceleration whatsoever, and yet a projectile goes flying out the barrel. By your own demonstration observing the impact of acceleration alone was not particularly useful, and would lead you to erroneous conclusion. The third law and F=ma in this case doesn't tell you anything at all about how the system evolves, what work is done, and who ends up with the lions share of the energy(it's not the rifleman).

Read my second post, number 225, where I describe it in detail with a slightly larger rifle. In that case the bullet from my favorite gun is traveling at about 1Km/s and has a KE of roughly 7KJ. In order to illustrate this better we could use an example of a larger round like the 50BMG that scales up to 20KJs.

How high would you have to raise a 10Kg weight in order to develop 20KJ, and what do you think would happen if it fell on you? Clearly my arm is take nothing like that strain, if it had I'd no longer be using it to shoot.

Think about F = d(mv)/dt and what that really means in the context you are using it. If you want to know what is wrong with Chandler's reasoning it might help to think of Zeno's paradox of the Achilles and the tortoise.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

That is why it is especially sad to witness another man made disaster at close range...

Yes .

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Think about F = d(mv)/dt and what that really means in the context you are using it. If you want to know what is wrong with Chandler's reasoning it might help to think of Zeno's paradox of the Achilles and the tortoise.

Could you be more explicit in your suggestion, radon? I missed your point.

In any case, here's one more attempt at explaining what I think is shown by Chandler's work.

Let's say that the official story is correct. In particular, the upper floors suffered critical damage from the plane impacts and subsequent fire, so started to collapse. This much even I could agree with. Whatever floor (80 or 100 or whatever) was most damaged would begin rapid failure. The floor above, already weakened itself by the rising fires, would come down and fail, and so forth, with catastrophic failure rapidly moving up from the point of initial failure, somewhere around the 80 or 100th floor, whatever it was.

So far, so good. Even I find that plausible.

Now what happens to the floors below the impact zone. So far as I understand from the official story, these stories, up until the moment of general collapse, were in pretty good shape. Some have argued that the steel in these lower floors could have been already heated to the point of significant weakening; that I strongly disagree with.

For the sake of discussion, allow me to assume for the rest of this post that the steel in the 80 or 100 floors below the impact zone was at pretty close to full strength and structural integrity, right up to the point of general collapse. If that assumption is wholly unacceptable to you, then you can skip the rest of this post ... oh well.

Ok, so what do we have at this point? We have the upper floors collapsing rapidly onto the lower floors. Now by the official story, if I understand it correctly, these falling and self-destructing upper floors essentially crushed the lower floors, top down, bang, bang, bang, one floor at a time, all the way to the ground. First the top of the building (above the impact zone) weighed too heavily on the severely damaged impact area, crushing it, and then all that stuff, including the still partially formed upper most floors and debris, came crushing down on the lower floors, top down, one floor at a time. Hopefully I am presenting the official story correctly here.

Ok let's ask what it would take to crush one of the heretofore undamaged lower floors. It would take pressing or impacting on it with more force than the normal static load of whatever was above it, right? Rather obviously, an undamaged floor N could support the full static weight of all floors N+1 up to the roof. The reason (by the official story) that floor N failed suddenly was that it rather suddenly got impacted with more than that amount of force, that is with more than the static weight of the floors above it. It got hit with the dynamic weight of those floors falling. Each floor below the original impact zone got hit with more force than the normal static load of those floors above it, right?

I claim that the following three statements are true for any (small, relative to the earth) object falling toward the earth (or other large mass):

• If the falling object is met with a force that's equal to the weight of that object, it continues to fall at constant velocity.
• If the falling object is met with a force that is greater than it's weight, it falls slower (decelerates.)
• If the falling object is met with a force that is less than it's weight, it falls faster (accelerates.)

The "small" and "large" are not essential to the mechanics involved, but are suggested by the common use of such words as "falling" and "weight". I may be bigger than the average human (most cows are ), but no one (to my face) speaks of the earth falling toward my mass .

Anyway, confirm for yourself if you will that the above three statements are true.

Chandler's observations demonstrate that the upper building was "falling faster". Upper WTC1 was accelerating downward at 6⁺ m/secē and upper WTC7 was accelerating downward at 9⁺ m/secē. Therefore, by the third statement above, upper WTC1 and WTC7 were each "met with a force ... less than it's weight."

So, for any floor X between 1 and the bottom of the impact zone (or whatever the equivalent was for WTC7?), we have that floor X was structurally sound and at roughly full strength, until suddenly, it was met with a force less than that which it had been supporting, causing it to collapse catastrophically.

Huh? That last sentence made no sense. If floor X could hold the weight of the floors above it, then why would it collapse under less force?

What I would have expected Chandler's measurements to find, if the official story was correct, is that the falling upper portion decelerated (slowed down) as it impacted the lower portion that was being crushed by reason of suddenly having more force down on it than the normal static load it bore. The falling portion would decelerate (fall slower), most likely losing all velocity before reaching the ground, leaving the remaining floors below that point still standing.