Tower Collapse Questions for Critical Thinkers

[psikeyhackr]

However the analogy quickly breaks down given that in a complex piece of equipment several ciruits fed from the same power supply will have different curents than others. If the electrons were required to flow in the path of least resistance then current would be flowing in only one of those circuits.

It would suck for any parallel circuitry:D
.
So the most current takes the path of least resistance in a parallel circuit. But structural engineering doesn't deal with things as small and fast as electrons. The falling material can't make 90 degree turns at 90% of light speed.

psik

[funk de fino]

.
So the most current takes the path of least resistance in a parallel circuit. But structural engineering doesn't deal with things as small and fast as electrons. The falling material can't make 90 degree turns at 90% of light speed.

psik

Then why do your lot bring it up then?

[PixyMisa]

It is the energy applied by the dropping mass that may break the glass. If the glass breaks, energy has been used, and one result is that the dropping mass decelerates (it has lost kinetic energy).
Then there is real need to investigate further, e.g. how much energy was used to break the glass, how much energy is still avalable to break further glass, etc.
With regard to WTC 1 the dropping mass, let's call it C, could only apply say 1.2 GJ of energy at impact with mass at rest, let's call it A, and as C and A are virtually identical structures at contact interface (no bowling ball C contacting glass A), the energy is applied 50/50 to A and C ... and the energy will start deforming elements in both C and A, which may cause some elements in C and A to break. Evidently the weaker elements break first in contact with stronger elements, e.g. columns will break floors, and then energy applied is transformed into heat.
And that's what should have happened with WTC 1 - only the bottom floor of C and the top floor of A would get damaged.
No. Completely wrong. (And completely absurd.)

Take that tower of glass tables example. Let's say each table weighs twenty pounds. The glass surface weighs ten pounds and can support twenty pounds in weight, total, so it holds itself up just fine. The legs of the table weigh another ten pounds in total, and are solid steel, so they can support two thousand pounds in weight.

You can stack fifty of these tables up so long as you carefully position them so that the legs of each table are directly above the legs of the one below. And you can add up to ten pounds of weight to each and every one of the tables and it will still stay up.

But if you put a twenty-pound weight on one of the tables, it will break, and drop thirty pounds of weight on the table below (more if the legs fall inwards) which will break and drop forty pounds of weight on the table below that. Stack fifty tables up and you have a nice, solid, secure tower. Take the top table - weighing only twenty pounds - turn it at an angle, and drop it from even one inch, and the entire structure, easily capable of holding five hundred pounds of weight, disintegrates.

[Architect]

LOL.

I just outline the basics of structural damage analyzis. It seems the real lying frauds are at NIST!

No, you are: I refer you to your spurious claims regarding Ronan Point.

[Justin39640]

.
So the most current takes the path of least resistance in a parallel circuit. But structural engineering doesn't deal with things as small and fast as electrons. The falling material can't make 90 degree turns at 90% of light speed.

psik

structural engineering never ever deals with the crystalline structure of metal and its atomic make-up? hmmmm :rolleyes:

the circuit draws as much current as it needs
hence why your lightbulbs dont explode every time you turn them on lol
just cause you have a power supply that can deliver 500 amps doesnt mean that youre gonna draw all 500 through the different paths of the circuit
IIRC when youre trying to understand how many amps it will draw the power formula comes into play along with ohm's law (if youre trying to size your supply)

IDK a whole lot about this stuff (and im sure im not 100% correct), just enough to fix it
but from what i understand the flow of a valance electron from one atom to the next is kind of a smooth transition not a 90 degree angle
and seeing even on the tiniest of printed circuit tracks its still thousands (modest) of atoms wide i dont think electrons take too many hard lefts like youre implying

so i take it then that youre saying thew towers should have fell strait down like they did
thanks

[BasqueArch]

......
And that's what should have happened with WTC 1 - only the bottom floor of C and the top floor of A would get damaged.
But as you need much more than 1.2GJ to damage these floors, the destruction due to a drop would stop at once!! Only local failures to the two floors in contact (and adjacent columns) would take place.

Evidently you do not see that on videos of the 911 WTC destructions. First you see upper mass C being blown apart (only debris of C is then falling) and then lower mass A is blown apart, step by step, from top down creating a fountain of debris, concrete dust (the floors are blown apart), big perimeter wall panel sections 10 floors high are blown away sideways, and smoke.

Sorry, dropping little C on big A cannot possibly create such a destruction! So the WTC 911 destructions are some sort of controlled demolitions using energy other than that of gravity acting on dropping mass(es).


And you propose these enormous forces created by a handful of 1kg charges placed at the core columns:


Heiwa
Well, say you need an average 1 kg powerful energetic device to cut apart an outer core column and that you have to cut 24 outer core columns to initiate the destruction - upper part moving down a little by gravity producing local structural failures elsewhere in, e.g. outer walls - then you only need 24 kgs of powerful energetic devices on one floor to start the show. Hm, it can be carried in one or two bags or one box! Easy to carry.

Say you find that you have the prepare every third floor in a similar way to produce a top down controlled demolition and that you rig total 30 floors to carry out the destruction then, lets see; 30 times 24 is 720.

So it seems 720 kgs of energetic devices are required.

Salma Hayek's unanswered response

Salma: “That’s better, I was beginning to think your friends were interested in my superficial temporal shell only, not my brains! Hand me the calculator sweetie I have some questions...

One. *Click, click, click ...* ( 208 perimeter feet x 4sides x 12 feet high per story x 110 stories / 1584#explosives = 1# explosives per 693 sf of perimeter columns area 35 to 60 feet away. And, 4.7MM sf floor area / 1584# explosives = 1# explosives per 2,967 sf of concrete floor area 18 vertical and 35 to 60 horizontal feet away, ) . And don't shaped charges concentrate their force in a small area and in one direction only?

So the mariner then agrees that 1kg of explosives could not have caused 4 ton perimeter columns to have been propelled horizontally 600 feet like the physics teacher claims, nor the complete pulverization of 4.7 million sf of concrete floors like many others claim. Does the mariner know that?

Two: And don’t recorded video facts show, in places, exterior core columns intact 40 and 60 stories high? Then explosives could not have been placed there!

Three: And wouldn't the exterior columns have been pulled in towards the core of the building and not toppled outwards, unattached to floors, like the recorded video facts show? Then explosives could not have been placed there!"

You can run away from Salma but you'll only die tired.


-----------------------------------------------------------------------
You can't reason someone out of something they were never resoned into

[kylebisme]

A principle that does not apply to collisions or collapses.
Perhaps you have seen others argue that the principle of least resistance applies to collisions and collapses in some way which it has doesn't, and seen such people thoroughly refuted. I am not any of those people though, and I am not making any such arguments here. I am talking about a well established principle which applies to all matter in all situations. To address the case of collisions specifically, I'll quote a doctor describing how this principle is observed in the fracturing of bones (http://www.mmortho.com/library/upper5.shtml):


And as we all remember from high school physics, force takes the path of least resistance, which in this case means the fracture is most likely to occur through the growing part of the bone.

To speak in far more general terms, I'll quote a physicist discussing how the path of least resistance confirms Einstein's General Relativity as providing a more accurate representation of observable reality than Newtonian physics (http://understandingscience.ucc.ie/naturalworld/Einstein_general_theory_relativity.pdf):

This is the modern model for the force of gravity. Objects follow a path of least resistance through space-time, and the path is curved when space-time is distorted.

So, please, do not conflate what I have been saying here with the absurd Idea that the top of the towers should have simply slipped off the side without crushing anything. I have not, and would not, make any such claim; and miss assuming such arguments upon me to dismiss what I have said by dying well established an consistently demontarted principles of physics does nothing to further the course of rational discussion.


Or you could read the Wiki "current divider" article (http://en.wikipedia.org/wiki/Current_divider), which correctly lays out the math.
As the Wiki article you link states:


This is because in current dividers, total energy expended is minimized, resulting in currents that go through paths of least impedance, therefore the inverse relationship with impedance.

Of course you could have also looked up path of least resistance (http://en.wikipedia.org/wiki/Path_of_least_resistance), which metions how the principle applies to both mass and electricty, as I have been saying here:


In physics, the path of least resistance is always taken by objects moving through a system. For example, water flowing downhill follows the path of least resistance as it is pulled downward by gravity. Electricity flowing through a circuit behaves similarly; while every available path has some current flowing through it, the amount of current through each path is inversely proportional to its electrical resistance.
While you may have semantic dispute with my phrasing, I hope you realise that I am talking about the behavior of electricity as represented in Ohm's Law.


Simply put, the ratio of the currents in two parallel circuit branches will be equal to the inverse of the ratio of their individual impedances.

Simply put; assuming two paths of different impedance, though which path does the majority of the current flow? I am guessing you can answer that question correctly, but as at loss as to why you refuse to see that I am using the phrase "the path of least resistance" to refer to that answer.

[funk de fino]

While you may have semantic dispute with my phrasing, I hope you realise that I am talking about the behavior of electricity as represented in Ohm's Law..

Nope, you are not

[HeyLeroy]

Typical Truther thread.

Truther asks leading, semi-incoherent question.

I try to figure out what is being asked and provide answers.

Argument continues, unabated. I have no idea what is being asked now, or where it's going. If the question that's really behind this is "why didn't the upper block topple off," it's because it can't. The maximum rotation seen at any point of collapse was about 26 degrees, and most of this happened as a free body, rotating around its center of gravity. The dimensions of the upper block are such that it would have taken almost 40 degrees of rotation before becoming a free body to move its center of gravity outside the footprint. In reality, it only rotated about ten degrees before coming loose. After it's loose, it cannot experience a "fulcrum"-like behavior, because there is no fulcrum. At that point, there is actually a restoring force exerted by the lower structure, not a continued torque towards rotating and toppling off.

Draw a free-body diagram if you don't believe me.


I covered this in great depth in my whitepaper (http://www.911myths.com/drg_nist_review_2_1.pdf), pp. 104-105 and 250-255. It's been out in the current draft for sixteen months or so.

The problem with the Truth Movement, as always, is that when it "asks questions and demands answers," the questions it asks are leading questions, and it is not intelligent enough to comprehend the answers.

And the VERY NEXT POST:


OMG, intelligent questions. I feel faint. :D

This presents the problem of relating what should have happened to what did happen.

I think Richard Gage said the top tilted at 22 degrees at his show I attended in 2008. I recently saw some site that said 23 degrees. It certainly looks like more than 15 to me.

http://cdn.vidilife.com/image/2006/10/10/946639/1747248L.gif

As to what should have happened. More weight should have been put on one side of the building and greatly overloaded that side crushing it more quickly which would then have caused the top to tilt more until the center of gravity was beyond the edge of the building. It then should have fallen down the side.

Evidence? References?


The fact that what did happen was so different from what should have happened demonstrates that other forces were involved in removing the resistance of the lower portion of the building.

(snip)

psik

I'll wait for your evidence before agreeing with you.

.
You call this VERY SLOW?

http://www.youtube.com/watch?v=9SSS0DDqfm0



Between five and six seconds into the video you can see the restoring force of which R.Mackey spoke. Pay attention to the columns toward the right of the screen, before they're enveloped in smoke. The counter-clockwise rotation stops, and the columns exhibit (for a second before they're obscured) a clockwise rotation.

[Heiwa]

No. Completely wrong. (And completely absurd.)

Take that tower of glass tables example. Let's say each table weighs twenty pounds. The glass surface weighs ten pounds and can support twenty pounds in weight, total, so it holds itself up just fine. The legs of the table weigh another ten pounds in total, and are solid steel, so they can support two thousand pounds in weight.

You can stack fifty of these tables up so long as you carefully position them so that the legs of each table are directly above the legs of the one below. And you can add up to ten pounds of weight to each and every one of the tables and it will still stay up.

But if you put a twenty-pound weight on one of the tables, it will break, and drop thirty pounds of weight on the table below (more if the legs fall inwards) which will break and drop forty pounds of weight on the table below that. Stack fifty tables up and you have a nice, solid, secure tower. Take the top table - weighing only twenty pounds - turn it at an angle, and drop it from even one inch, and the entire structure, easily capable of holding five hundred pounds of weight, disintegrates.

LOL! Original structure was 80 tables - not 50 - stacked on top of each other and each table had very strong legs as you point out. They could carry 2000 lb.

But this table tower (legs/glass tops) is very easy to topple as the tables are not really connected with one another. Just stacked on top of each other. Lateral strength of table tower is zero.

So result would be 80 broken glass tops and all table legs, strong, intact. No table leg will be broken. Like a house of cards! The cards are not broken. Just displaced.

You really don't know anything about structural damage analysis, I am sorry to conclude.

[Justin39640]

LOL! Original structure was 80 tables - not 50 - stacked on top of each other and each table had very strong legs as you point out. They could carry 2000 lb.

But this table tower (legs/glass tops) is very easy to topple as the tables are not really connected with one another. Just stacked on top of each other. Lateral strength of table tower is zero.

So result would be 80 broken glass tops and all table legs, strong, intact. No table leg will be broken. Like a house of cards! The cards are not broken. Just displaced.

You really don't know anything about structural damage analysis, I am sorry to conclude.

ok again im no engineer but

i think the glass table analogy works when youre talking about the trade center if you think of the glass as the supports for the legs and vise versa (the legs are bolted to the glass no cross members) when youre thinking about the connections from the tower's cores to the outer tubes

now heiwa
what happens when you drop the ball in this scenario?

[BasqueArch]

LOL! ....

...
don't know anything about structural damage analysis, I am sorry to conclude.



Salma agrees. Admit your explosives CD hypothesis is wrong.

[A W Smith]

LOL.

I just outline the basics of structural damage analyzis. It seems the real lying frauds are at NIST!


So hows that answer to Bazant coming along Anders? Figure out how e-mail attachments yet? "Engineer'?

:dl:

[kylebisme]

The division by 3 is not at all arbitrary; it is, in fact, a pretty good representation of the actual Tower.
I Made no claim that it was abitary, and I understand that it is a reasonable aporimxation of the disturbation of mass in the tower. I have never made a claim to the contrary here, and would aprecacte it if you would could resist your complusion to assume such nonsense on me, and stick to adressing the arguments I do make.


Anyway, what we learn from this is that you cannot follow even a simple potential energy calculation, even when all the work is shown for you and dumbed down to a high school sophomore level.
Rather, I know better than to think a simple potential energy calculation has any relevance to a complex system of interconnected mass.

A Newton is a unit of force. Structural integrity is not equivalent to a force.

Structural integrity is how much force a given mass or system of mass can take in a given situation.

As I said, the structural integrity [B]is not a well defined quantity.
Not that I ever claimed it was. I simply pointed that the lack of being a well defined quality is no excuse to ignore a physical reality, as struclrial integrity is a physical reality.

The videos with which you are not familiar describe a particular type of demolition, in which a single floor's worth of supports is suddenly destroyed through cables and hydraulics. This leaves an upper section to fall upon the lower portion, which is frequently much larger than the upper part. The entire structure is destroyed, despite no weakening at all being applied to the lower portion.
Do you agree that Newton's third law of motion in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o)? If so, would you please be so kind as to describe what effect it has on such a collapse?

[Reactor drone]

Do you agree that Newton's third law of motion in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o)? If so, would you please be so kind as to describe what effect it has on such a collapse?

Newton's third law-For every action, there is an equal and opposite reaction.

In the case of the towers collapse the action of the buildings top section falling on the lower section causes damage to both sections.Since tha damaged lower section cannot now hold itself up against gravity it falls and a higher mass impacts the next floor causing damage to both sections but due to the difference in mass more damage is caused to the bottom than the top.

You might think of it as a newtons cradle,the first impact is 1 ball hitting 1 ball,the second impact is 2 balls hitting 1 ball,the third impact is 3 balls hitting 1 ball etc and with each impact the effect on the speed of the larger mass is reduced.

[Newtons Bit]

For those who are wondering, there's no such measurement called "structural integrity" in any code book I've ever used. I've never heard it used that way before either. There are a number of chapters in various different material codes on structural integrity, however. For example:

In ACI318, the reinforced concrete spec referenced by all major building codes in the USA, requires that a minimum number of bars must be continuous across the entire slab or beam system and either have a high strength lap splice or be butt-welded. This is to prevent the entire system from failing from one column failure (thanks for that, Timothy McVeigh). There's never any units attached to it.

Moreover, the only really real way to measure a buildings strength is as a function of its capacity. In other words, one could state that under an extreme load event, the building is at 0.99 of its maximum capacity. This is a unit less measurement.

kylebisme is yet another truther that just makes things up as he goes along to justify his belief.

Edit: I should also point out that saying the "building is at 0.99" capacity is kind of a misnomer as well. There's no way to measure that, you have to go on the basic assumption that the building will fail when the first major structural element fails.

[R.Mackey]

I Made no claim that it was abitary, and I understand that it is a reasonable aporimxation of the disturbation of mass in the tower. I have never made a claim to the contrary here, and would aprecacte it if you would could resist your complusion to assume such nonsense on me, and stick to adressing the arguments I do make.

Oh, my god.

The factor of three comes from the integral. It is not an approximation of the distribution of mass, it is a consequence thereof. An "integral" is a mathematical concept you don't follow at all, just like "inertia."

Rather, I know better than to think a simple potential energy calculation has any relevance to a complex system of interconnected mass.

Absolutely 100% dead wrong. If you knew what an integral was, you would know that potential energy is an aggregate calculation, and can therefore be applied to any arbitrarily large or complex assortment of objects.

Seriously, this is award-winning nonsense you are writing.

Structural integrity is how much force a given mass or system of mass can take in a given situation.

No, it is not. Because, again, that answer varies wildly depending on how that force is delivered. It is a mere figure of speech. It also does not have inertia as a component, as you claimed previously.

Not that I ever claimed it was. I simply pointed that the lack of being a well defined quality is no excuse to ignore a physical reality, as struclrial integrity is a physical reality.

Total babble.

Do you agree that Newton's third law of motion in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o)? If so, would you please be so kind as to describe what effect it has on such a collapse?

Newton's Third Law applies universally and at all times. In particular, it applies during the verinage demolition technique -- those crafty Frenchmen have not developed a magical way to suddenly turn it off, because if they had, instead of making a decent living demolishing buildings they could rapidly become masters of Earth and space. So, what this proves is that even though Newton's Third Law is in full effect, it is nonetheless possible for a small portion of structure to trigger a cascading failure and totally destroy an entire structure, including crushing a much larger lower portion.

There's a reason for this. Newton's Third Law says that forces are equal and opposite, at any point in time. It does not imply that damage is equal and opposite, particularly when totalled over a complex evolution. That's one of the little details that you and many other Truther ignorati simply cannot understand, having no practical scientific knowledge.

Like I said, I'm done with you. You go on my Ignore list, effective immediately. Unless you get the proper education, starting practically at zero, I don't see how I can discuss these topics with you without feeling like a bully, and that's really not what I'm trying to do here. I would try to educate you but I can't do that without your participation -- no one can. So, good luck to you, hope you get it someday. See here (http://forums.randi.org/showthread.php?postid=4461706#post4461706) if you have any further questions.

[kylebisme]

Nope, you are not
I most certainly am referring to the behavior represented in Ohm's Law when I speak of "the path of least resistance" in regard to electricity, and a quick Google search finds nearly two thousand hits using the phrase while mentioning Ohm's Law (http://www.google.com/search?source=ig&hl=en&rlz=&q=%22ohm%27s+law%22+%22path+of+least+resistance%22&aq=f&oq=&aqi=). Here one example in a worksheet covering Ohm's Law (http://www.allaboutcircuits.com/worksheets/ohm_law.html):

A common saying about electricity is that ït always takes the path of least resistance." Explain how this proverb relates to the following circuit, where electric current from the battery encounters two alternate paths, one being less resistive than the other:
Granted, in the answer to that question, they go on to note the semantic I suggested your argument might be based in:

As an instructor, I was very surprised to hear many beginning students claim that all current would go through the lesser resistor, and none through the greater resistor! The proverb about "takes the path of least resistance" really should be understood as "proportionately taking paths of lesser resistance."
Like the instructor, I'm surprised the phrase is missunderstood, I certainly never meant to imply what he reports his students take from it. I also respect his suggestion on rephrasing, but I'm at a loss as to what ground you think you might have to deny the use of the phrase as I did. Based on your lack of being able to formulate more than a hollow dismissal, I'm left to concluded you don't have any such ground to stand on.

[PixyMisa]

LOL! Original structure was 80 tables - not 50 - stacked on top of each other and each table had very strong legs as you point out. They could carry 2000 lb.
So?

But this table tower (legs/glass tops) is very easy to topple as the tables are not really connected with one another. Just stacked on top of each other. Lateral strength of table tower is zero.
No, wrong. Lateral strength would be limited by the friction of feet of one table on the surface of the one below. With hundreds of pounds of weight, that could be pretty high.

So result would be 80 broken glass tops and all table legs, strong, intact. No table leg will be broken. Like a house of cards! The cards are not broken. Just displaced.
So you have a pile of rubble with some components intact. My analogy is not perfect, that's true. But your claims are entirely absurd.

You really don't know anything about structural damage analysis, I am sorry to conclude.
I'm not the one claiming that it's impossible for a building ever to collapse.

[JimBenArm]

>develops serious man-crush on RMackey<

[kylebisme]

Newton's third law-For every action, there is an equal and opposite reaction.

Precisely.

Now, can you describe where this law of motion is observed in the reaction of the top sections of the buildings hitting the lower section in these verinage demolitions (http://www.youtube.com/watch?v=NwFHEoiUZ7o)?

This is an open question for all.

[Newtons Bit]

Precisely.

Now, can you describe where this law of motion is observed in the reaction of the top sections of the buildings hitting the lower section in these verinage demolitions (http://www.youtube.com/watch?v=NwFHEoiUZ7o)?

This is an open question for all.

In.
Every.
Single.
Frame.

[WildCat]

This is a wildly inaccurate recount of the observable phenomena (http://www.youtube.com/watch?v=9SSS0DDqfm0).
It's exactly that. What do you think that video shows?
kyle? What do you think that video shows?

[tsig]

For those who are wondering, there's no such measurement called "structural integrity" in any code book I've ever used. I've never heard it used that way before either. There are a number of chapters in various different material codes on structural integrity, however. For example:

In ACI318, the reinforced concrete spec referenced by all major building codes in the USA, requires that a minimum number of bars must be continuous across the entire slab or beam system and either have a high strength lap splice or be butt-welded. This is to prevent the entire system from failing from one column failure (thanks for that, Timothy McVeigh). There's never any units attached to it.

Moreover, the only really real way to measure a buildings strength is as a function of its capacity. In other words, one could state that under an extreme load event, the building is at 0.99 of its maximum capacity. This is a unit less measurement.

kylebisme is yet another truther that just makes things up as he goes along to justify his belief.

Edit: I should also point out that saying the "building is at 0.99" capacity is kind of a misnomer as well. There's no way to measure that, you have to go on the basic assumption that the building will fail when the first major structural element fails.

Actually it was the loss on moral integrity that caused the problem. The building were touted as the tallest in the world and that led to the sin of pride and we all know that pride goeth before the fall.

[tsig]

>develops serious man-crush on RMackey<

Been on them pigboats too long.

[R.Mackey]

Actually it was the loss on moral integrity that caused the problem. The building were touted as the tallest in the world and that led to the sin of pride and we all know that pride goeth before the fall.
That's pretty funny, actually. :alc:

[tsig]

That's pretty funny, actually. :alc:

Tnx.

[Grizzly Bear]

In.
Every.
Single.
Frame.

Every time they intercourse that law I can only assume these people can't grasp the idea that materials have a breaking point...

[kylebisme]

kyle? What do you think that video shows?
My bad, I had meant to respond to your request last night, but was distracted by company. Anyway, the video (http://www.youtube.com/watch?v=9SSS0DDqfm0) shows the top portion tipping sideways as the lower portion crumbles away, with the corner pushing though the debris cloud just before falling behind a larger one highlighted in this pic here (http://img10.imageshack.us/img10/5206/cornerk.jpg) (taken from around the 8s mark).

[beachnut]

Oh, my god.

The factor of three comes from the integral. It is not an approximation of the distribution of mass, it is a consequence thereof. An "integral" is a mathematical concept you don't follow at all, just like "inertia."

...
That was funny and sad to see someone proving their ignorance in math and physics without a clue.

[Reactor drone]

My bad, I had meant to respond to your request last night, but was distracted by company. Anyway, the video (http://www.youtube.com/watch?v=9SSS0DDqfm0) shows the top portion tipping sideways as the lower portion crumbles away, with the corner pushing though the debris cloud just before falling behind a larger one highlighted in this pic here (http://img10.imageshack.us/img10/5206/cornerk.jpg) (taken from around the 8s mark).

I wonder if you might expand upon the point you're trying to make here.I'm not sure exactly what your point is and what you think this video shows compared to what you think should be happening.

[kylebisme]

In.
Every.
Single.
Frame.
Would you please describe where Newton's third law can be observed in the reaction of the top sections of the buildings hitting the lower section in these verinage demolitions (http://www.youtube.com/watch?v=NwFHEoiUZ7o)?

Every time they intercourse that law I can only assume these people can't grasp the idea that materials have a breaking point...
That isn't an issue here by any means. The breaking materials is essential to what I'm hopping you all might be willing to discuss at some point.

[kylebisme]

I wonder if you might expand upon the point you're trying to make here.
I'd really prefer someone else describe the observable effects of Newton's third law in the verinage demolitions first, so that it comes from someone whom others here are more inclined to believe.

[kylebisme]

That was funny and sad to see someone proving their ignorance in math and physics without a clue.
Ask Mackey to try his calculations on a given spring falling from a given hight, and then drop it to see how how far off he is.

[Newtons Bit]

Would you please describe where Newton's third law can be observed in the reaction of the top sections of the buildings hitting the lower section in these verinage demolitions (http://www.youtube.com/watch?v=NwFHEoiUZ7o)?

Would you please point out how you think the laws of physics are being broken in those demolitions? Otherwise, I will reiterate my previous statement:

Newton's Third Law can be seen in every frame.

Do you have a point you are trying to make?

[Newtons Bit]

I'd really prefer someone else describe the observable effects of Newton's third law in the verinage demolitions first, so that it comes from someone whom others here are more inclined to believe.

The debris falling from the impact has a greater velocity and acceleration than that of the upper block. This means that there is resistance from the lower block acting on the upper block. This resistance can be measured as force. Those forces, by definition, are equal in magnitude to both the upper block and lower block. Thus the lower block and the upper block both suffer damage as seen in the videos. The location and magnitude of said damage depends on a number of factors to numerous to go into detail here: I really don't want to waste that much time on you.

[LashL]

Ask Mackey to...


You know, when you have been patiently and thoroughly schooled, as you have been here by R.Mackey (and others), you should at least try to learn from it.

[kylebisme]

The debris falling from the impact has a greater velocity and acceleration than that of the upper block.
Sure enough, debris falling from the impact have greater velocity and acceleration because they they are meeting less opposing force. But what I'm hopping you might here is how Newton's third law applies to the upper block itself. What what can be observed as the reaction to that upper block crushing the lower one in terms of change in velocity and acceleration?

I do thank you kindly for continuing to humor me here, as I feel you answering the above question will go well better than me doing so.

[beachnut]

Sure enough, debris falling from the impact have greater velocity and acceleration because they they are meeting less opposing force. But what I'm hopping you might here is how Newton's third law applies to the upper block itself. What what can be observed as the reaction to that upper block crushing the lower one in terms of change in velocity and acceleration?

I do thank you kindly for continuing to humor me here, as I feel you answering the above question will go well better than me doing so.
After proving you have no skills in math, physics or engineering to answer this or understand what happen on 911. Let me guess after someone posts the answer you will wave your hands and say wrong in a delusional manner and post some gibberish about springs. What is your major now?

[sylvan8798]

I have not, and would not, make any such claim; and miss assuming such arguments upon me to dismiss what I have said by dying well established an consistently demontarted principles of physics does nothing to further the course of rational discussion.


Is this a sentence? It's hard to have a rational discussion with a sentence like that.

Those demon tarts. They go straight to my thighs.:mad:

[kylebisme]

Spellchecking sometimes leaves me with with absurd grammatical errors due to my dyslexia, but surely it shouldn't be too hard to make sense of what I was going for there? Would you deny rational discussion with a deaf person due to poor enunciation?

[sylvan8798]

Enunciate how your concept of "path of least resistance" would or should have affected the falling mass of WTC 2, kyleb.

[Matthew Cline]

... as I feel you answering the above question will go well better than me doing so.

You could answer it yourself and then let others with experience in physics and engineering either confirm or correct your answer, rather than attempting to formulate the correct question to get the answer you're looking for.

[kylebisme]

Enunciate how your concept of "path of least resistance" would or should have affected the falling mass of WTC 2, kyleb.
As I explained previously (http://forums.randi.org/showpost.php?p=5108979&postcount=257), the path of least resistance is not a conceptualization of mine, but rather a widely understood principle. Also, as I explained to apathoid when he brought up the principle up:


Or is this a "path of least resistance" type of argument?
Path of least resistance, distribution weight, and ever other relevant principle of physics.
So, put simply, the path of least resistance affected the falling mass of WTC 2 exactly how it did. Why people are are attempting to assume on me some strange argument around fixating that principle that I never made, and trying to demean me for using the phrase in response to a question about it, all while pretending it isn't a long established principle, is for others to explain. Lacking psychic abilities, I can't rightly see in what goes on inside anyone's head but my own.
You could answer it yourself and then let others with experience in physics and engineering either confirm or correct your answer, rather than attempting to formulate the correct question to get the answer you're looking for.
Matthew, I respect how you have been reasonable with me throughout my few days here, but I hope might you understand how many others haven't been by any stretch. The whole path of least resistance nonsense, people accusing me of believing the jet fuel fire couldn't have deformed steel, and a whole host of other experience, has left me feeling it would be better someone else explains the physics my question refers to. Besides I was branded as failing physics by multiple people here with no one to suggest otherwise. With such circumstances considered, I hope you might respect my intent in letting someone who is considered more credible here explain the physics in question.

[Architect]

Solution: State simply, and clearly, exactly what you think the collapse pattern should have been including (for example) discussion of load paths during the event and why, therefore (and assuming you believe this to be the case) mass should have been significantly deflected/arrested/subject to rotation (delete as applicable).

[funk de fino]

I most certainly am referring to the behavior represented in Ohm's Law when I speak of "the path of least resistance" in regard to electricity, and a quick Google search finds nearly two thousand hits using the phrase while mentioning Ohm's Law (http://www.google.com/search?source=ig&hl=en&rlz=&q=%22ohm%27s+law%22+%22path+of+least+resistance%22&aq=f&oq=&aqi=). Here one example in a worksheet covering Ohm's Law (http://www.allaboutcircuits.com/worksheets/ohm_law.html):


Granted, in the answer to that question, they go on to note the semantic I suggested your argument might be based in:


Like the instructor, I'm surprised the phrase is missunderstood, I certainly never meant to imply what he reports his students take from it. I also respect his suggestion on rephrasing, but I'm at a loss as to what ground you think you might have to deny the use of the phrase as I did. Based on your lack of being able to formulate more than a hollow dismissal, I'm left to concluded you don't have any such ground to stand on.

I am an electrical and electronic engineer. I instruct on this stuff now. You made up laws. Ohms law is not applicable to anything we are discussing yet you brought it up. Ohms law does not mention "path of least resistance"

Current following paths can be worked out using Ohms law.

[dtugg]

Why are twoofers always pretending that they know what they are talking about when it is completely obvious that they don't have a clue?

[Mr.D]

Besides I was branded as failing physics by multiple people here with no one to suggest otherwise.

If you're really interested in learning, may I suggest starting a new thread with an apology and some straightforward statements about what it is you're confused or unsure about regarding the WTC collapses.

Then DROP THE ATTITUDE and politely ask some questions. You'll find some very knowledgeable people here with clear and highly readable writing styles.

[kylebisme]

I am an electrical and electronic engineer. I instruct on this stuff now.
Cool.
Ohms law does not mention "path of least resistance"
It doesn't mention the path of least resistance specifically, but that phrase is a commonly understood way of referring to the flow of current which Ohm's Law describes, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).

Ohms law is not applicable to anything we are discussing yet you brought it up.
I only referred to it as a side point, in response to denial of the path of least resistance having anything to do with physics, which can be found here (http://forums.randi.org/showpost.php?p=5105460&postcount=175). I did not attempt to construct any argument out of it.

Current following paths can be worked out using Ohms law.
Sure enough, and from among multiple paths of varying resistance; through which path does the most go though?

[MRC_Hans]

Sure enough, and from among multiple paths of varying resistance; through which path does the most go though?You cannot equate DC electrical laws with dynamic mechanical functions.

I haven't bothered to read, but I assume it is ye olde, why didn't the falling building follow the path of least resistance nonsense.

According to that argument, anything collapsing, for whatever reason, should spread itself thinly across the surrounding landscape. Which is obviously never the case for solid structures.

However, if you take dynamics into account, you will find that a building collapsing straight down does in fact follow the path of least resistance. At the speed (close to free fall) of such a collapse, diverting the falling mass to one side requires a force that is similar to the mass of the falling mass.

Hans

[stateofgrace]

Cool.

It doesn't mention the path of least resistance specifically, but that phrase is a commonly understood way of referring to the flow of current which Ohm's Law describes, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).



Really ? So this crap you wrote earlier

Yet I never said anything to suggest the path of least resistance is a law of physics. That said, it is wrong to claim otherwise in such general terms. As Arus mentioned, the path of least resistance is a law of the physics of electricity, commonly known as Ohm's Law. Of course we are not talking about electricity, here but rather mass, and in the case of mass the path of least resistance is a principle of physics.

Originally Posted by kylebisme
That means that voltage favors the path of least resistance.

is just that, crap. I have a BSc in it pal and have worked for the last twenty odd years on the stuff. Maybe the next you start quoting laws, especially electrical ones try and at least understand them. Ohms law does not state anything about the path of least resistance, end of.

And yes you did try and construct an argument from it and no I have no intention of being tolerant to somebody like you, who tries to twist laws you clearly don't understand in order to promote your agenda.

[Dave Rogers]

For those who are wondering, there's no such measurement called "structural integrity" in any code book I've ever used.

On the other hand, it turns up in just about every series of Star Trek, so it must be Real Science. Like all debunkers, you're making the mistake of concentrating on non-fiction to prove your point. As somebody said recently, "you guys are so caught up in the way the world is, you distant yourselves from truth and reality."

Dave

[Dave Rogers]

So, put simply, the path of least resistance affected the falling mass of WTC 2 exactly how it did. Why people are are attempting to assume on me some strange argument around fixating that principle that I never made, and trying to demean me for using the phrase in response to a question about it, all while pretending it isn't a long established principle, is for others to explain. Lacking psychic abilities, I can't rightly see in what goes on inside anyone's head but my own.

Perhaps you'd like to tell us all what conclusions you've reached about the falling mass of WTC2 based on your application of the principle of the path of least resistance, then. And, perhaps, outline the reasoning that leads you to those conclusions. As long as all you describe are your premises, then we don't have recourse to much else but our non-existent psychic abilities, because for us to know what's going on in your head, you have to tell us.

Alternatively, explain to me how the principle of the path of least resistance should be applied to the specific case of a brick falling on an egg. That way, you'll at least have demonstrated that your premises and reasoning can lead to a correct prediction of at least one real-world situation.

Analysis of the brick-on-egg problem that doesn't rely at any point on the principle of the path of least resistance will, of course, be rather a strong point of evidence that the principle is not of relevance to the description of a stationary object being crushed by another object falling on it. So make sure you use the principle in your reasoning.

And, of course, if you choose not to analyse the brick-on-egg problem based on the principle of the path of least resistance, you'll be presumed to be unable to do so.

Let me remind you of the problem:

Consider an egg lying on a horizontal hard surface, and a brick suspended a foot above it. If the brick is released, what path does it follow, and what happens to the egg?

Dave

[TruthersLie]

Sorry, dropping little C on big A cannot possibly create such a destruction! So the WTC 911 destructions are some sort of controlled demolitions using energy other than that of gravity acting on dropping mass(es).

Have you told that to the french demolitions companies who do EXACTLY that? who drop "little C on big A" and completely and utterly crush the building.

What have they told you about your claim that it is impossible? Huh?

[TruthersLie]

Nope, you are not

But he really does like to try to handwave away his mistakes and bs as "semantic" differences.

I"m still waiting to see how something can crumble down to its footprint...

[TruthersLie]

Actually it was the loss on moral integrity that caused the problem. The building were touted as the tallest in the world and that led to the sin of pride and we all know that pride goeth before the fall.

No no no.

MOTHRA

[TruthersLie]

Perhaps you'd like to tell us all what conclusions you've reached about the falling mass of WTC2 based on your application of the principle of the path of least resistance, then. And, perhaps, outline the reasoning that leads you to those conclusions. As long as all you describe are your premises, then we don't have recourse to much else but our non-existent psychic abilities, because for us to know what's going on in your head, you have to tell us.

Alternatively, explain to me how the principle of the path of least resistance should be applied to the specific case of a brick falling on an egg. That way, you'll at least have demonstrated that your premises and reasoning can lead to a correct prediction of at least one real-world situation.

Analysis of the brick-on-egg problem that doesn't rely at any point on the principle of the path of least resistance will, of course, be rather a strong point of evidence that the principle is not of relevance to the description of a stationary object being crushed by another object falling on it. So make sure you use the principle in your reasoning.

And, of course, if you choose not to analyse the brick-on-egg problem based on the principle of the path of least resistance, you'll be presumed to be unable to do so.

Let me remind you of the problem:

Consider an egg lying on a horizontal hard surface, and a brick suspended a foot above it. If the brick is released, what path does it follow, and what happens to the egg?

Dave

[smartassery on]
can I boil the egg?
Can I have an ostrich egg?
how about a boiled ostrich egg?
or can i have a BUNCH of eggs?
[smartassery off]


Mothra eggs will bounce bricks
:)

[kylebisme]

Perhaps you'd like to tell us all what conclusions you've reached about the falling mass of WTC2 based on your application of the principle of the path of least resistance, then.
I would if I had ever done anything of the sort. However, having not done so, and having never suggested otherwise, I'm not rightly in a position to answer your request.

That said, any chance you might be able to answer a question for me? I am wanting someone who is considered more credible here to explain the affects of Newton's third law of motion as observable in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Specifically, in each instance, what can be observed as the reaction to the upper block crushing the lower one in terms of change in velocity?

[dafydd]

Why are twoofers always pretending that they know what they are talking about when it is completely obvious that they don't have a clue?

And the less they know the more certain they are that they are right.Odd,isn't it?

[TruthersLie]

I would if I had ever done anything of the sort. However, having not done so, and having never suggested otherwise, I'm not rightly in a position to answer your request.

That said, any chance you might be able to answer a question for me? I am wanting someone who is considered more credible here to explain the affects of Newton's third law of motion as observable in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Specifically, in each instance, what can be observed as the reaction to the upper block crushing the lower one in terms of change in velocity?


What rather funny is that had you shown EVEN the slightest bit of abilities with math, physics or engineering there would be at least a half dozen really decent strutural engineers and physicists who might be willing to explain that to you...

[kylebisme]

What I find funny here is that I've know the answer to the question I'm asking since elementary school, while I get the strong impression that the many constantly attacking my intellect here couldn't answer the question to save their lives.

[Hokulele]

What I find funny here is that I've know the answer to the question I'm asking since elementary school...


Please post your answer.

[~enigma~]

which can be found here (http://forums.randi.org/showpost.php?p=5105460&postcount=175).
And it isn't a law nor was it ever a law. Stop imitating a moronic truther.

[kylebisme]

Please post your answer.
It isn't a matter of my answer, it's a matter of the answer, as the same laws of physics would apply regardless of my own existence. And again, as I've been branded as failing in my understanding of physics by many here, I'm figuring at least someone would be willing to demonstrate his/her own intellect by answering a simple question of Newtonian physics.
And it isn't a law nor was it ever a law.
It is a common way of describing a law of the physics of electricity, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).

[~enigma~]

It is a common way of describing a law of the physics of electricity, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).
Yet it isn't a law in spite of what you and your obvious pea brain believe. You are now going on ignore for wasting my oxygen.

[stateofgrace]

It is a common way of describing a law of the physics of electricity, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).

You are contradicting yourself, remember you wrote this , not so long ago ?


It doesn't mention the path of least resistance specifically, but that phrase is a commonly understood way of referring to the flow of current which Ohm's Law describes, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).



Did you even bother to read any of the links from your search ? No, I thought not.

Here is your search.

http://www.google.com/search?source=ig&hl=en&rlz=&q=%22ohm%27s+law%22+%22path+of+least+resistance%22&aq=f&oq=&aqi=

Here is mine.

http://www.google.com/search?hl=en&rlz=1G1GGLQ_ENUK308&ei=_rmwSrXQL8Ke4gbL0fTiCw&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=%22OHM%27S+LAW+PATH+OF+LEAST+RESISTANCE%22&spell=1

Notice the differance ?

Here is Ohms law.

Ohm's law states that the current (http://en.wikipedia.org/wiki/Electric_current) through a conductor between two points is directly proportional (http://en.wikipedia.org/wiki/Proportionality_%28mathematics%29) to the potential difference (http://en.wikipedia.org/wiki/Potential_difference) or voltage (http://en.wikipedia.org/wiki/Voltage) across the two points, and inversely proportional to the resistance (http://en.wikipedia.org/wiki/Electrical_resistance) between them.[1] (http://en.wikipedia.org/wiki/Ohm%27s_law#cite_note-0)
It does not mention the path of least resistance. You substantiated nothing, other than you are a liar, and know you are lying. Stop it before you embarrass yourself further.

ETA. This the final time I respond to this nonsense. Ohms law does not state anything about the path of least resistance. You have lied in order to claim you have substantiated it does.

[Reactor drone]

Originally Posted by kylebisme
What I find funny here is that I've know the answer to the question I'm asking since elementary school...


Please post your answer.

Or even post your question.All you've done so far is make vague comments about forces and laws without ever stating what you believe to be happening.

Please,clearly state your case just once.

[Matthew Cline]

But what I'm hopping you might here is how Newton's third law applies to the upper block itself. What what can be observed as the reaction to that upper block crushing the lower one in terms of change in velocity and acceleration?

1) The forces exerted on the upper block would damage the upper block.

1b) The forces exerted on the upper block would damage the upper block to the exact same extent that the forces exerted on the lower block damaged the lower block.

2) Something else.

[kimota]

There's something that's been weighing on my mind about the physics of falling objects and since this thread is turning into a physics smorgasbord, I'd like to throw it out and let it get picked over.

Consider dropping an aerodynamcally uniform object, like a blank bowling ball from an airplane. Air resistance acts upon its descent, until it reaches terminal velocity. So, until that point, the air resistance is reducing only the rate of acceleration; the bowling ball still experiences downward acceleration and is increasing in velocity. When it reaches terminal velocity, the downward acceleration is zero, but the velocity and the kinetic energy that that entails is still there. And the air resistance doesn't affect the velocity after terminal velocity is achieved.

Now, a building collapsing on itself is not going to offer uniform resistance; the floors are going to resist more than the spaces between floors, but would the principal be the same or, at least, similar? That resistance would have to overcome the force from acceleration due to gravity before it can overcome the kinetic energy due to the velocity of the falling object in order to completely stop it from falling?

[Dave Rogers]

I would if I had ever done anything of the sort. However, having not done so, and having never suggested otherwise, I'm not rightly in a position to answer your request.

So can I take it that you have formed no conclusions from the collapse of WTC2? If so, I may be able to offer you some evidence to consider.

That said, any chance you might be able to answer a question for me? I am wanting someone who is considered more credible here to explain the affects of Newton's third law of motion as observable in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Specifically, in each instance, what can be observed as the reaction to the upper block crushing the lower one in terms of change in velocity?

As the upper block impacts the lower, there is a distinct and measurable upward acceleration imparted to it by the force exerted on it by the lower block. At the time of impact, let's define our terms such that the upper block is moving downwards with a velocity -V, where positive is defined as upwards, and accelerating with an acceleration -A, which is close to gravitational acceleration. The upward force F exerted on the upper block results in an acceleration +A1, which varies with time. This adds to the acceleration due to gravity to give a total acceleration A1-A. Since the lower block is able to support the static weight of the upper block, then the maximum value of A1 is expected to be greater than that of A, resulting in an overall deceleration for a short period of time.

The velocity of the upper block increases, therefore, up to the impact, then decreases very briefly while the impact takes place. Once the next set of floor supports has been destroyed, the upper block then accelerates with acceleration -A until it hits the next floor of the lower block. The velocity will be observed to increase up to the point of impact, decrease briefly, then increase further up to the point of impact of the next floor (which takes place at a greater velocity), and so on. Averaged over the entire collapse, there is a net acceleration. This has been verified by measurements of the Balzac-Vitry collapse.

One important point about this, though, is that it relies on there being a single, well-defined impact between the upper and the lower block, which in turn relies upon the upper block remaining level as it falls. This is not too difficult to achieve in a demolition where the initiation is controlled by a precisely timed means such as explosives or hydraulic jacks. If the initiation is not precisely timed - indicative of an uncontrolled initiation - then the upper block wil initially lose support asymmetrically, and will fall at an angle. It's perfectly simple geometry (though some of the truth movement's leading engineers are unable to visualise it) that an upper block, falling at an angle, will not make a single, well-defined impact with the lower block. Instead, one corner will impact first, locally overloading a part of the structure and collapsing it; the impact will then propagate across the structure to the opposite corner, collapsing individual elements as it goes. For the WTC towers, it is again trivial geometry to show that, if the angle of the upper block is greater than about four degrees, then the impact on any given floor is still in progress when the impact on the next floor begins. The result of this is to average out the large variations in acceleration seen in the verinage demolitions; rather than accelerating at close to 1g, decelerating abruptly, then accelerating again at close to 1G, the expected behaviour of the upper block is to exhibit an acceleration varying only slightly about an average negative value.

This is the effect referred to by Graeme McQueen and Tony Szamboti as "the missing jolt". What they fail to understand is that the absence of the jolt is a very strong piece of evidence that the collapse was not a carefully controlled, sequential pancaking, as would be expected from a controlled demolition, but a chaotic and asymmetric one, as would be expected from the uncontrolled and randomly ordered collapse of the main structural members due to progressive weakening. In other words, the missing jolt is a strong piece of evidence that the WTC collapses were not initated by controlled means such as explosives.

Dave

[Dave Rogers]

Now, a building collapsing on itself is not going to offer uniform resistance; the floors are going to resist more than the spaces between floors, but would the principal be the same or, at least, similar? That resistance would have to overcome the force from acceleration due to gravity before it can overcome the kinetic energy due to the velocity of the falling object in order to completely stop it from falling?

Yes, the principal is similar, but not exactly the same. However, your main point is correct; if the resistive force exerted by the building exactly balances the downward force at all times, then that won't stop the collapse, but will only result in it progressing at constant speed. The entire kinetic energy of the falling mass, or rather the part of it that doesn't fall off the sides, needs to be absorbed by the structure before the collapse can stop.

However, there are two additional factors in a building collapse. One is that the structural strength of the building increases lower down, so the resistance will increase. The other is that the debris from the collapse is added to the falling mass, so the downward force also increases. It depends on the details of the building which of these predominates. Calculations of the structure of the twin towers make it clear that the downward force exceeds the resistive force by a very large margin throughout the collapse, however, so the collapse not only never stopped; it accelerated, all the way to the ground.

Dave

[funk de fino]

Cool.

It doesn't mention the path of least resistance specifically, but that phrase is a commonly understood way of referring to the flow of current which Ohm's Law describes, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).

I only referred to it as a side point, in response to denial of the path of least resistance having anything to do with physics, which can be found here (http://forums.randi.org/showpost.php?p=5105460&postcount=175). I did not attempt to construct any argument out of it.

Sure enough, and from among multiple paths of varying resistance; through which path does the most go though?

Stubbornly ignorant rather than just ignorant then.

I will give you another posters thoughts on this as it is blatantly obvious to everyone reading.

ETA. This the final time I respond to this nonsense. Ohms law does not state anything about the path of least resistance. You have lied in order to claim you have substantiated it does.

[BigAl]

Originally Posted by kylebisme

It is a common way of describing a law of the physics of electricity, as I substantiated here.

It doesn't mention the path of least resistance specifically, but that phrase is a commonly understood way of referring to the flow of current which Ohm's Law describes, as I substantiated here.


I was away for a day and I see that K remains uninformed about "path of least resistance" and electric current. Lets do a little Gedanken experiment. K, as an attendee of the Great Architects School and the Great Physicists School should be comfortable here.

Take a square metal plate. For this purpose, the dimensions are irrelevant.

Attach wires on opposite corners and apply voltage.

Think about where the current flows across the plate. The "Shortest path" would be across the diagonal. Is that were all the current goes?

If you cut metal away from un-wired corners towards the center, the current will decrease, indicting that current was passing through all places on the plate in proportion to the voltage difference across any two points on the plate.

"Path of least resistance" has damn little application in any formal or practical physics I can think of. Maybe water flowing it downhill is the only case. Free-slowing water is not a model of current flow.

I did my time in EE at University but it was mumble decades ago and I never used it. I can no longer solve this problem by equation. It's been a long time.

[bill smith]

Dang....has RM raised his shields already ? I wanted to put something to him. He said the following:-

' There's a reason for this. Newton's Third Law says that forces are equal and opposite, at any point in time. It does not imply that damage is equal and opposite, particularly when totalled over a complex evolution.'

I just wanted to know, given that the structural components in the ' upper block ' (part C) of WTC1 were lighter than the elements they impacted in the 'lower block ' (part A) what effect that would have when applied to 'Smith's Law' ?

Smith's first Law of WTC1:
''Whatever downwards force the moving body exerts on the stationary body of identical construction fixed in the ground is reciprocated by the stationary body equally and oppositely. After that it depends which body is rendered non-viable by mutual erosion first.''

[twinstead]

Dang....has RM raised his shields already ? I wanted to put something to him. He said the following:-

' There's a reason for this. Newton's Third Law says that forces are equal and opposite, at any point in time. It does not imply that damage is equal and opposite, particularly when totalled over a complex evolution.'

I just wanted to know, given that the structural components in the ' upper block ' (part C) of WTC1 were lighter than the elements they impacted in the 'lower block ' (part A) what effect that would have when applied to 'Smith's Law' ?

Smith's first Law of WTC1:
''Whatever downwards force the moving body exerts on the stationary body of identical construction fixed in the ground is reciprocated by the stationary body equally and oppositely. After that it depends which body is rendered non-viable by mutual erosion first.''

Jesus, Bill. Smith's Law?!? At least I have the courtesy to stay out of a discussion that I am wholly unqualified to comment upon. Can't say that stops you though.

[bill smith]

Jesus, Bill. Smith's Law?!? At least I have the courtesy to stay out of a discussion that I am wholly unqualified to comment upon. Can't say that stops you though.

Why don't you or one of your people write up a 'Debunker's first Law of WTC1' so we can compare the two laws and see which one makes the most sense ?

[JimBenArm]

Okay, here it is.
Debunker's first law: Before you hit "Post", reread your missive to ensure it complies with known physical laws, is logical, and is spelled and punctuated correctly. Otherwise, we will laugh at you.

[Newtons Bit]

Sure enough, debris falling from the impact have greater velocity and acceleration because they they are meeting less opposing force. But what I'm hopping you might here is how Newton's third law applies to the upper block itself. What what can be observed as the reaction to that upper block crushing the lower one in terms of change in velocity and acceleration?

I do thank you kindly for continuing to humor me here, as I feel you answering the above question will go well better than me doing so.

I.
Already.
Did.
Answer.
Your.
Stupid.
Question.
Stop.
Dodging.

[alienentity]

I would if I had ever done anything of the sort. However, having not done so, and having never suggested otherwise, I'm not rightly in a position to answer your request.

That said, any chance you might be able to answer a question for me? I am wanting someone who is considered more credible here to explain the affects of Newton's third law of motion as observable in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Specifically, in each instance, what can be observed as the reaction to the upper block crushing the lower one in terms of change in velocity?

OK, thanks everybody for deconstructing this troll. Comparing his various statements regarding 'Ohms law' and the 'path of least resistance' shows him to be a complete intellectual fraud.

I'm putting him on ignore. Good riddance to bad rubbish.

nb - truthers apparently operate according to the law of 'Path of Most Resistance'; that is, when placed between two logical points, they will resist one or more of those points using and equal and opposite 'Denial Force', (related to Newton's 3rd law), then if the Truther Intellectual Tension (TIT) crosses Boundary Sum (BS) level, a Deflection Force (a) intervenes and the truther escapes the logical points entirely, using the Path of Least Resistance.

I'm pretty sure that both Newton's 3rd law and the Law of 'Path of Least Resistance' are well established. kylebisme himself invoked both such laws, in exactly those words earlier on, so they must be true.:D

[jaydeehess]

No. Completely wrong. (And completely absurd.)

Take that tower of glass tables example. Let's say each table weighs twenty pounds. The glass surface weighs ten pounds and can support twenty pounds in weight, total, so it holds itself up just fine. The legs of the table weigh another ten pounds in total, and are solid steel, so they can support two thousand pounds in weight.

You can stack fifty of these tables up so long as you carefully position them so that the legs of each table are directly above the legs of the one below. And you can add up to ten pounds of weight to each and every one of the tables and it will still stay up.

But if you put a twenty-pound weight on one of the tables, it will break, and drop thirty pounds of weight on the table below (more if the legs fall inwards) which will break and drop forty pounds of weight on the table below that. Stack fifty tables up and you have a nice, solid, secure tower. Take the top table - weighing only twenty pounds - turn it at an angle, and drop it from even one inch, and the entire structure, easily capable of holding five hundred pounds of weight, disintegrates.

Nicely put. The only difference between the stacked tables and what I was considering is that I had the 4 legs as continuous columns with seats to bolt the glass 'floors' to. In this case if you load the top 'floor' with more than it can sustain it breaks and sends that mass plus the mass of glass debris down to the next floor.

Heiwa is ignoring completely that the falling mass will accellerate (in this analogy) between 'floors'. The only way for the collapse to arrest is for the decelleration of the falling mass that fails the first 'floor' exceeding the accelleration between floors by a substantial margin. Such decceration would have to negate the contribution of the added mass and the dynamic loading of that extra mass(it having gained velocity in the fall between floors as well), and reduce the velocity of the original mass such that its dynamic load plus gravitational load is less than the load that any one floor can sustain.

Now, if the original mass was dropped from a height equal to that of the distance between floors and that alone was sufficient to fail the 'floor' then even if that mass comes to a full stop as it fails that 'floor' its next drop will be exactly the same distance as its original drop. It will be joined by the mass of the failed 'floor'. In this case the only way for arrest the collapse would be for it to encounter a much more robustly built floor and it will have to do so soon since with every 'floor' failure more mass gets added.

In addition, and this could be somewhat minor in this scaled down analogy, with every floor failure the leg columns lose lateral support and will be prone to more sway or even buckling which would make the structure more susceptible to the effects of the mass falling down.


This analogy is a fairly basic first approximation of the WTC towers. Heiwa then wants to add detail such as the fact that the columns will hit first, punching through the floor pans, followed by the falling floor pan hitting the next lower one.



Well in this case you have an already violently damaged floor(columns having punched through) becoming loaded with the mass of an entire floor. So you have the case of a floor being suddenly loaded with approx twice the mass load at a time when its load carrying capacity will have been at least somewhat compromised given that its structural integrity has been compromised.( note to NB: this is qualitative phraseing in which I mean that the floor is no longer fully intact) Add to this mass loading the fact of the huge dynamic load.

(Now in the case of tower 2 the columns struck the floor at what angle? Punching not straight through. )

If this is not enough to immediatly fail a floor it is being followed by yet another floor.
Heiwa states that the falling floor will also become detached from the columns. True and in doing so it will not be robbing the rest of the upper section of a lot of velocity. Why? The truss seats are designed to hold a load acting in the other direction so the only thing holding a floor from moving upward(relative to the columns and truss seats, which are themselves moving downward wrt to the ground) are a few bolts. The first falling floor will be experincing a force that would be moving it upward wrt to the truss seat. That first floor will impact down on the yet-to-be-failed floor.

Heiwa states that the energy required to fail the lower section floor will equal that required to fail the first dropping floor, but since their failure modes are in opposite directions whereas the structure was designed for forces acting in only one of those directions, his contention is not true.

The next floor coming the way of the yet-to-be-failed floor will still be adding a large dynamic load as well as yet another floorspace's mass. It will do this well before the yet-to-be-failed floor springs back from the first impact meaning that the dynamic load of this next floor is impacting something already heavily deformed.

What would one see?
(start with WTC 1 as its upper section fell without a lot of tilt)
The perimeter columns of the upper section initially have no gravitational load on them at all. They are falling. They impact floor pans but the floor pans offer very little load compared to what they are capable of handling. However the floor pan of the first dropping floor tears away from its seats as it hits the first lower floor.
The upper section now has no connection between perimeter and core at that floor. However it does not require that lateral bracing since it has very little vertical loading. So initially we do not see the perimeter of the upper section come apart

No so for the lower section. Those perimeter columns are still experiencing weight, and they are unbraced for a two storey height, the top most floor having been violently torn from its seats.

[jaydeehess]

Sure enough, debris falling from the impact have greater velocity and acceleration because they they are meeting less opposing force. But what I'm hopping you might here is how Newton's third law applies to the upper block itself. What what can be observed as the reaction to that upper block crushing the lower one in terms of change in velocity and acceleration?

I do thank you kindly for continuing to humor me here, as I feel you answering the above question will go well better than me doing so.

You appear to be asking what the change in velocity of the lower block was.

Of course its velocity as a whole does not change measurably. Thi is because until the energy of collapse causes it to come apart it is still part of the mass we refer to as EARTH.

Take the case of both upper and lower blocks being solid objects dropped one on the other with the lower one sitting on the ground. The momentum of the impact is transmitted to the lower block mass PLUS the mass of the earth.

The change in velocity of the lower mass will be negligible.

Obviously that is not the whole story of what occured. The energy in the system caused both upper and lower sections to disintegrate (not to be confused as the inverse of the integration that Mackey has been trying to teach you).
Collisions occured between these pieces and the whole event was driven by one force acting in one direction, meaning that each individual piece experienced a downward force as it became detached from the structure as a whole.

clear now?

[jaydeehess]

Dang....has RM raised his shields already ? I wanted to put something to him. He said the following:-

' There's a reason for this. Newton's Third Law says that forces are equal and opposite, at any point in time. It does not imply that damage is equal and opposite, particularly when totalled over a complex evolution.'

I just wanted to know, given that the structural components in the ' upper block ' (part C) of WTC1 were lighter than the elements they impacted in the 'lower block ' (part A) what effect that would have when applied to 'Smith's Law' ?

Smith's first Law of WTC1:
''Whatever downwards force the moving body exerts on the stationary body of identical construction fixed in the ground is reciprocated by the stationary body equally and oppositely. After that it depends which body is rendered non-viable by mutual erosion first.''

What the H doesb "non-viable" mean?

It loses mass? Energy or momentum disappears?

Which weighs more bill, a pound of lead or a pound of feathers?

[firecoins]

can anyone prove explosives were in the building? The answer is NO. Thread over.

[tsig]

I would if I had ever done anything of the sort. However, having not done so, and having never suggested otherwise, I'm not rightly in a position to answer your request.

That said, any chance you might be able to answer a question for me? I am wanting someone who is considered more credible here to explain the affects of Newton's third law of motion as observable in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Specifically, in each instance, what can be observed as the reaction to the upper block crushing the lower one in terms of change in velocity?

The laws of physics are the same no matter who explains them.

Maybe you could explain what your problem is with them.

[tsig]

It isn't a matter of my answer, it's a matter of the answer, as the same laws of physics would apply regardless of my own existence. And again, as I've been branded as failing in my understanding of physics by many here, I'm figuring at least someone would be willing to demonstrate his/her own intellect by answering a simple question of Newtonian physics.

It is a common way of describing a law of the physics of electricity, as I substantiated here (http://forums.randi.org/showpost.php?p=5110090&postcount=268).

And there it is folks:

Proof by google.
That's the proof the troof loves.

[tsig]

OK, thanks everybody for deconstructing this troll. Comparing his various statements regarding 'Ohms law' and the 'path of least resistance' shows him to be a complete intellectual fraud.

I'm putting him on ignore. Good riddance to bad rubbish.

nb - truthers apparently operate according to the law of 'Path of Most Resistance'; that is, when placed between two logical points, they will resist one or more of those points using and equal and opposite 'Denial Force', (related to Newton's 3rd law), then if the Truther Intellectual Tension (TIT) crosses Boundary Sum (BS) level, a Deflection Force (a) intervenes and the truther escapes the logical points entirely, using the Path of Least Resistance.

I'm pretty sure that both Newton's 3rd law and the Law of 'Path of Least Resistance' are well established. kylebisme himself invoked both such laws, in exactly those words earlier on, so they must be true.:D

Perfect answer to Bill @326

[beachnut]

:boxedin:Ask Mackey to try his calculations on a given spring falling from a given hight, and then drop it to see how how far off he is.
You flunked physics; did I win?

[Hokulele]

It isn't a matter of my answer, it's a matter of the answer, as the same laws of physics would apply regardless of my own existence.


If your answer is net force=0, I am done with this.

[bill smith]

What the H doesb "non-viable" mean?

It loses mass? Energy or momentum disappears?

Which weighs more bill, a pound of lead or a pound of feathers?


Which body is eroded (worn away) by the attrition of the two bodies to the point of being non-viable (no longer of significance in terms of affecting the other body) first ? The 87 floors or the 13 floors ?

[jaydeehess]

Which body is eroded (worn away) by the attrition of the two bodies to the point of being non-viable (no longer of significance in terms of affecting the other body) first ? The 87 floors or the 13 floors ?

Oh, well now that you have completely failed at explaining the term it makes so much less sense.
Thank you.

What has more mass bill, an intact concrete floor or the same floor after being broken up? If in both cases the mass is moving which one has more momentum?

[jaydeehess]

bill has discovered anti-gravity. Just make an object "non-viable"

ETA: and it has the added cache of being a 'law'.

[sylvan8798]

Which body is eroded (worn away) by the attrition of the two bodies to the point of being non-viable (no longer of significance in terms of affecting the other body) first ? The 87 floors or the 13 floors ?

Now we're back to the idea that a giant pile of compacted rubble can't cause structural failures. By this reasoning, a giant pile of snow certainly could never have done this:

http://www.capretzer.com/images/forensics/snowLoadCollapse.jpg

or this:

http://images.google.com/imgres?imgurl=http://www.eilon-engineering.com/img/acc1.jpg&imgrefurl=http://www.eilon-engineering.com/code/accidents.html&usg=__eV1kZi5EnS_p9HKIjhf-n_PR2UQ=&h=468&w=700&sz=99&hl=en&start=1&um=1&tbnid=-ASBgD2dQbAEqM:&tbnh=94&tbnw=140&prev=/images%3Fq%3Droof%2Bcollapse%2Bsnow%26hl%3Den%26cl ient%3Dsafari%26rls%3Den%26um%3D1

or this:

http://images.google.com/imgres?imgurl=http://blog.mlive.com/chronicle/2008/01/02Collapse.jpg&imgrefurl=http://blog.mlive.com/chronicle/2008/01/roof_collapse_closes_bingo_hal.html&usg=__jlLo0PkVSECYTm2h15s3iwduJYU=&h=752&w=1135&sz=361&hl=en&start=2&um=1&tbnid=kYipce7dCTDeFM:&tbnh=99&tbnw=150&prev=/images%3Fq%3Droof%2Bcollapse%2Bsnow%26hl%3Den%26cl ient%3Dsafari%26rls%3Den%26um%3D1

...
...
...

[HeyLeroy]

What I find funny here is that I've know the answer to the question I'm asking since elementary school, while I get the strong impression that the many constantly attacking my intellect here couldn't answer the question to save their lives.

Please post your answer.

It isn't a matter of my answer, it's a matter of the answer, as the same laws of physics would apply regardless of my own existence. And again, as I've been branded as failing in my understanding of physics by many here, I'm figuring at least someone would be willing to demonstrate his/her own intellect by answering a simple question of Newtonian physics.

kylebisme, can you understand why people here have lost patience with you? Could it be your smug, arrogant, condescending attitude?

Instead of dancing around the issue, state your case in a clear, concise manner, present your evidence, and be prepared to defend it.

You have done none of these things (except the dancing-between-the-raindrops act). It is no wonder that people here regard your behaviour as trollish.

[bill smith]

Oh, well now that you have completely failed at explaining the term it makes so much less sense.
Thank you.

What has more mass bill, an intact concrete floor or the same floor after being broken up? If in both cases the mass is moving which one has more momentum?

Well the broken floor is not really one mass. It is many small masses. These small masses will strike the lower solid intact floor independently as small masses. The small masses will also interaact with each other while falling, losing some energy in the process.

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.

[HeyLeroy]

Stundielicious!

[jaydeehess]

Well the broken floor is not really one mass. It is many small masses. There small masses will strike the lower solid intact floor independently as small masses. The small masses will also interaact with each other while falling, losing some energy in the process.

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.

bill, which has more mass the intact floor or the broken floor?

How many broken floor masses can be supported by one unbroken floor?

[beachnut]

Well the broken floor is not really one mass. It is many small masses. There small masses will strike the lower solid intact floor independently as small masses. The small masses will also interaact with each other while falling, losing some energy in the process.

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.
Like a shot gun filled with small shot? Oops it make a big hole. Darn, you and physics are still strangers.

I have seen water cut metal; darn your delusions on 911 are based on failed science.

[bill smith]

bill, which has more mass the intact floor or the broken floor?

How many broken floor masses can be supported by one unbroken floor?

Well obviously they would not have the same sudden shattering impact as the impact that a solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

[HeyLeroy]

(snip) maybe (snip)

:solved1

[Mancman]

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.

Yeah, but even the loose sand would instantly collapse the floors and the columns would topple over due to loss of lateral bracing, so you fail again.

[GlennB]

The small masses will also interaact with each other while falling, losing some energy in the process.



<giggle>

[bill smith]

<giggle>

When a man giggles Glenn I always think that the white dinner jacket that buckles in the back is not far away.

[beachnut]

Well obviously they would not have the same shattering impact as the impact of solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

What are you trying to say? Your lack of understanding of the physical world is due to what?

You are saying a shotgun blast from buck shot, small buck shot is not as effective as a single shotgun slug. The buck shot will flow around my body like water. I can see why you support Heiwa's delusions, you have no practical knowledge or experience in science.

[SpitfireIX]

The small masses will also interaact with each other while falling, losing some energy in the process.


You really shouldn't try to learn physics from Heiwa.

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.


Which would have absolutely no effect on the failure of the floors.

[GlennB]

so in broken pieces maybe six or eight floors could be supported by one.

ha ha ha ha

Next time I think I'm overweight I'll put my hands on the bathroom scales too. Should reduce my weight by half.
If I'm losing weight, I'll stand on one foot to sort it out. Dramatically.

(Is Bill going for a Stundifiability record?)

[TruthersLie]

can anyone prove explosives were in the building? The answer is NO. Thread over.

I have told you before.

MOTHRA.

invisi super hush-a-wings mothra

[jaydeehess]

Well obviously they would not have the same sudden shattering impact as the impact that a solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

So in your mind it all comes down to how quickly the mass is impigned upon the floor?

Did you see anything happening in slow motion on 9/11?

Furthermore just how many floors did you see above the collapse zone in each case?

Yes, extending the time of momentum transfer lessens impulse force but in this case no matter how slow the upper mass comes down it will eventually see the mass of essentially the entire upper block being impinged upon the next lower floor. (and this then includes sections of the core columns, not just the floors. Column sections would remain pretty much as solid objects throughout the collapse)

[jaydeehess]

ha ha ha ha

Next time I think I'm overweight I'll put my hands on the bathroom scales too. Should reduce my weight by half.
If I'm losing weight, I'll stand on one foot to sort it out. Dramatically.

(Is Bill going for a Stundifiability record?)

Just sneak up on the scale slowly it will not 'know' you are even there.


Wile. E. Coyote just heard a beep-beep.

[alienentity]

Well obviously they would not have the same sudden shattering impact as the impact that a solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

Next time there's a tsunami, we won't need to worry. Bill's new discovery proves it.
Water is not a solid, it'll just splash a few things and drain away, right?:D

[Grizzly Bear]

Next time there's a tsunami, we won't need to worry. Bill's new discovery proves it.
Water is not a solid, it'll just splash a few things and drain away, right?:D

An avalanche wouldn't hurt to try either on my next skiing trip

[bill smith]

So in your mind it all comes down to how quickly the mass is impigned upon the floor?

Did you see anything happening in slow motion on 9/11?

Furthermore just how many floors did you see above the collapse zone in each case?

Yes, extending the time of momentum transfer lessens impulse force but in this case no matter how slow the upper mass comes down it will eventually see the mass of essentially the entire upper block being impinged upon the next lower floor. (and this then includes sections of the core columns, not just the floors. Column sections would remain pretty much as solid objects throughout the collapse)

Don't you really mean that one floor hits one floor ? After all A snd C are either two ' blocks ' or they are two assemblies of floors .

[nicepants]

Well obviously they would not have the same sudden shattering impact as the impact that a solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

What data are you basing this on?

Weight of one floor = ?
Load limit of one floor = ?

[Reactor drone]

Don't you really mean that one floor hits one floor ? After all A snd C are either two ' blocks ' or they are two assemblies of floors .

If 1 floor will hold the weight of the floor above it you have two options,

1-the floor connections break and the next floor lands on the two stacked floors and this continues until the load exceeds the carrying capacity of the floor or

2-the floor connections survive and the momentum of the entire upper block gets transferred through the structure onto the floor until the load exceeds its carrying capacity.

In no situation will the upper floors magically float above the impact area taking no part in the collision.

[Arus808]

Water is not a solid, it'll just splash a few things and drain away, right?:D

Oh? tell that to the residents of Thailand...2004 earthquake, killed nearly 4000 people (http://en.wikipedia.org/wiki/Effect_of_the_2004_Indian_Ocean_earthquake_on_Thai land)


water...ever hit water when you're going 5 mph.. its like hitting a brick wall.

[DGM]

Kyle and Bill:
Does a controlled demolition alter or defy Newtons third law? I'm courious to know.

[jaydeehess]

Don't you really mean that one floor hits one floor ? After all A snd C are either two ' blocks ' or they are two assemblies of floors .

Don't you see that, as I explained above in another post, if the floor of the upper block does not get lifted from its seats then you now have the entire mass of the upper block on the first lower floor. If it does then the columns continue downward carrying to our as yet unfailed level, another floor, and another,,,(repeat up to at least ten times)

You are now reduced to argueing how many floor masses it would take to fail one floor. In addition there is of course, the dynamic loading which you are attemptinmg to minimize yet it is still there. Further, of course, if this is more than one floor we simply cannot expect that the perimeter and core columns are sliding straight down the same hole they opened up as they speared downward at the initiation of collapse. They are tearing away more of that originally impacted flooring not to mention that they weakened the floor pan when they punched through in the first place. They are also doing a number on floors lower down.

You, and your mentor, seem to believe that the floor pan can by some magical physics, support the entire upper block. Heiwa has attempted to say that the material will get wedged between the core and perimeter. B.$. pure and simple. How can that possibly transfer the mass load of the block to the columns and not push the perimeter columns outward, snapping their seats to the trusses?

[jaydeehess]

Oh? tell that to the residents of Thailand...2004 earthquake, killed nearly 4000 people (http://en.wikipedia.org/wiki/Effect_of_the_2004_Indian_Ocean_earthquake_on_Thai land)


water...ever hit water when you're going 5 mph.. its like hitting a brick wall.

Well to be fair, that was a mass of water in the billions of tons was it not?

[HeyLeroy]

Oh? tell that to the residents of Thailand...2004 earthquake, killed nearly 4000 people (http://en.wikipedia.org/wiki/Effect_of_the_2004_Indian_Ocean_earthquake_on_Thai land)


water...ever hit water when you're going 5 mph.. its like hitting a brick wall.

I think AE was being sarcastic...

[kylebisme]

So can I take it that you have formed no conclusions from the collapse of WTC2?
First off, I am very grateful for your response to my question, particularly as I was beginning to worry no one would. That said, my only conclusion on the collapse of the towers is that gravity was not the only force involved. However, I implore you to set aside our differences in conclusions there, without any regard to to other matters but these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o) which we all can agree were most certainly caused by gravity alone (aside from the initial push out force of course). So, on to that:


At the time of impact, let's define our terms such that the upper block is moving downwards with a velocity -V, where positive is defined as upwards, and accelerating with an acceleration -A, which is close to gravitational acceleration.
I am in agreement with you here, though if we actually go though the math I'd prefer to flip the convention, making down positive and up negative, just to keep it mostly positive.

The upward force F exerted on the upper block results in an acceleration +A1, which varies with time. This adds to the acceleration due to gravity to give a total acceleration A1-A.
Surely you mean the force F exerted by the lower block on the upper one subtracts from the acceleration of that upper block? Like if you jump down onto a gymnastics mat it subtracts from your acceleration, slowing your fall. We have two forces here, but only one acceleration. As for the effect of that force F on the acceleration A:

Since the lower block is able to support the static weight of the upper block, then the maximum value of A1 is expected to be greater than that of A, resulting in an overall deceleration...
Rather, the upward force of the lower block is expected to be greater than the weight of the upper block, the lower block having held that upper block in place prior to the section between the two being pushed out. It is this net upward force which results in the deceleration you mention. Agreed?

The velocity of the upper block increases, therefore, up to the impact, then decreases very briefly while the impact takes place. Once the next set of floor supports has been destroyed, the upper block then accelerates with acceleration -A until it hits the next floor of the lower block. The velocity will be observed to increase up to the point of impact, decrease briefly, then increase further up to the point of impact of the next floor (which takes place at a greater velocity), and so on. Averaged over the entire collapse, there is a net acceleration. This has been verified by measurements of the Balzac-Vitry collapse.
Now, from the bold is where I'm not following you at all. You are speaking of the floor supports being destroyed in instances, with periods of free fall between them. I'd like to see the measurements you refer too, but in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o) I've been speaking of, it is not just floors falling one on top of each other, but the whole structure being crushed down, concrete walls and all. There is no chance of freefall after the initial collision, as there is constantly mass acting as resistive force in the way. Also, I dug up video of this Balzac-Vitry collapse (http://www.youtube.com/watch?v=syzKBBB_THE) which I'm guessing might be the one you refer to, but surely you are not suggesting there is any free fall after the initial collision in that?

[beachnut]

...
... , concrete walls and all. There is no chance of freefall after the initial collision, as there is constantly mass acting as resistive force in the way. ...
Free-fall?; the towers took over 12.08 seconds to fall, not close to free-fall but very close to a momentum transfer. Can you do physics? Didn't think so. You also demonstrated no working knowledge of calculus. Need an example of where you messed up?

The concrete walls you were talking about were in another building not the WTC, right?

The use of modeling the floors of the WTC and then looking at momentum transfer or collapse theories is useful. As you can see on 911 the gravity collapse was a chaotic event. The massive top of the WTC did not have to destroy the entire lower section in 12.08 seconds, it had to destroy the initial surface of the tower below the falling top. In the first 0.87 seconds only 10 feet of lower structure (average) was destroyed by the much larger top section. This piece by piece destruction is all you have to account for to see the lower section is doomed when masses of the WTC seen on 911 start to fall. After 0.87 seconds the mass is now more, and in the next 0.397 seconds the next 10 feet of WTC are destroyed, and that mass is added as the collapse proceeds. Your lack of knowledge in physics and engineering is miss leading you.

If I was totally ignorant on 911 and found the failed ideas of the 911 truth people interesting I would check with the foremost authority on the WTC structure. I would ask Robertson what he thinks. He said - “the collapse mechanism of the trade center, is as we anticipated it would be, when we first designed it” This is what he said! He said the WTC towers failed as it would be after aircraft impacts and large out of control fires initiated the collapse. Go ask him, I have found all of this from google and checking the facts personally. What Robertson has said about the WTC, including designing the WTC for aircraft impacts of 180 mph have been verified by other engineers; you lost this debate and are debunked. You could debunk yourself when you gain the knowledge.

[Justin39640]

First off (snip)
:popcorn6

[kylebisme]

Free-fall?; the towers took over 12.08 seconds to fall, not close to free-fall but very close to a momentum transfer. Can you do physics? Didn't think so.
Yet the problem here is your inability to respect context. Dave and I were not discussing the towers, but rather these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Furthermore, I was not claiming any free fall beyond the initial collision, but rather refuting his claims of it.

[beachnut]

Yet the problem here is your inability to respect context. Dave and I were not discussing the towers, but rather these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o). Furthermore, I was not claiming any free fall beyond the initial collision, but rather refuting his claims of it.
Good to know you don't have the delusion the towers fell at free fall. I am only a pilot who flew heavy jets with an engineering degree and not too good at these very technical jargon loaded discussions. Sorry, I thought you support the idiotic controlled demolition delusion and were spewing some moronic free-fall ideas.

I was in a hurry making 4 margaritas and a trip to the hot tub; had a date and she like the margaritas! successful mission took 56 minutes to complete. Did you get help figuring out how you messed up the calculus problem?

[tsig]

When a man giggles Glenn I always think that the white dinner jacket that buckles in the back is not far away.

How about loling you do that a lot.

[triforcharity]

Well the broken floor is not really one mass. It is many small masses. These small masses will strike the lower solid intact floor independently as small masses. The small masses will also interaact with each other while falling, losing some energy in the process.

Like if you drop a box of sand on the Tower it will have more effect than the same amount of loose sand which will behave more like a liquid and flow over and around the massive upstanding core columns.


Isn't EVERYTHING just a grouping of small masses?? I mean, EVERYTHING that we KNOW to exist in the Solar System?? Isn't it??

Maybe I am confused.

[triforcharity]

Well obviously they would not have the same sudden shattering impact as the impact that a solid floor would, so in broken pieces maybe six or eight floors could be supported by one.

I am not en engineer, but I understand loads. Ie: My porch can support about 4,000 lbs spread over the entire floor. Now, if I take 5,000 lbs of rocks, and put in on my porch, my porch floor will collapse. It doesn't matter if its sand, or bowling balls, or toasters, it will still collapse.

Why is it that Bill et al do not understand this concept??



Am I wrong in my assumption??

[kylebisme]

Good to know you don't have the delusion the towers fell at free fall. I am only a pilot who flew heavy jets with an engineering degree and not too good at these very technical jargon loaded discussions. Sorry, I thought you support the idiotic controlled demolition delusion and were spewing some moronic free-fall ideas.
All good, and I thank you for the apology. I also respect your difficulty with technical jargon as I know many are not comfortable with such things. This is why I've been attempting to speak in common terms, not out of any trouble with the technical descriptions myself.

Did you get help figuring out how you messed up the calculus problem?
I didn't mess up any calculus, but rather was simply strawman as being incapable of comprehending calculus while having the argument I did make ignored. Again, find someone to try Mackey's calculations with a given spring dropped from a given height, or rather just ask someone who would know, and you will see how far off his conseptualisation is.

Anyway, in common terms hope you might look at this video (http://www.youtube.com/watch?v=syzKBBB_THE) and tell me if you see what I am hopping everyone here will. Specifically, when watching the movement of the roof, do you see how it speeds up until the two sections collide, and then it slows down from there?

[HeyLeroy]

(snip)

Rather, the upward force of the lower block is expected to be greater than the weight of the upper block, the lower block having held that upper block in place prior to the section between the two being pushed out. It is this net upward force which results in the deceleration you mention. Agreed?

(snip)

I'm not a physicist, nor do I play one on TV, but that doesn't make sense to me.

The lower section would not be exerting a force greater than the falling portion; the falling portion has momentum.

The only reason the lower portion held the upper portion (I refrain from using your term, "block"; this would seem to imply that the sections above and below the impacts were far more solid than they were. See picture below.) was that it was designed to carry a static load; the falling section was a dynamic load that completely overwhelmed the lower section.

Note in the Vérinage video the collapse that starts about 3:16 (dang; can't find the website that lets me link to a timepoint in a Youtube vid!). They drop the upper three floors onto the lower section. By about 3:26, the upper portion is almost completely destroyed, and the lower portion has hardly started its collapse by then, yet the lower portion is also completely destroyed by what's left!

Why? The lower portion had been holding the upper portion for (presumably) years. Ahh... it was a static load.

Yet the upper falling portion completely overwhelms the lower section. Why? The static load is transformed to a dynamic load.

Oh, and here's the picture I mentioned earlier; this is why I didn't want to refer to the upper portion as a 'block':

http://cdn.vidilife.com/image/2006/10/10/946639/1162750L.jpg

We're not playing Jenga.

[kylebisme]

I am not en engineer, but I understand loads. Ie: My porch can support about 4,000 lbs spread over the entire floor. Now, if I take 5,000 lbs of rocks, and put in on my porch, my porch floor will collapse. It doesn't matter if its sand, or bowling balls, or toasters, it will still collapse.
...
Am I wrong in my assumption??
You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

[triforcharity]

All good, and I thank you for the apology. I also respect your difficulty with technical jargon as I know many are not comfortable with such things. This is why I've been attempting to speak in common terms, not out of any trouble with the technical descriptions myself.




:eye-poppi:eye-poppi:eye-poppi:eye-poppi WHAT?? Have you JUST called EVERY SINGLE PERSON on this forum a COMPLETE IDIOT???

I am not often at a loss for words, but trying to describe what I think of this has gotten me speachless.

[triforcharity]

No, it DOESN'T MATTER if I drop it, or break it apart into tiny weights. The weight will still eventually be ON my porch, even if not all at once. I believe its called "static load", but I could be wrong. Like I said, I am not an engineer.

It doesn't matter. Either way, my porch WILL collapse.

[BigAl]

You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

To the degree you are correct, depending of the weight and the porch, the momentum can be sufficient to collapse your porch, anyway.

It was on 9/11.

[Reactor drone]

You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

Why exactly wouldn't they hit at the same time?If they're dropped from the same height and accelerate due to gravity everything should fall in the same amount of time regardless of whether it's a solid block or the same sized aggregate of particles.

[WildCat]

All good, and I thank you for the apology. I also respect your difficulty with technical jargon as I know many are not comfortable with such things. This is why I've been attempting to speak in common terms, not out of any trouble with the technical descriptions myself.
Trust me, you're not impressing anyone here with your technical knowledge. Quite the opposite actually.

[kylebisme]

The lower section would not be exerting a force greater than the falling portion; the falling portion has momentum.
momentum = mass x velocity.

force = mass x acceleration

The two are related, but not the same; mass doesn't doesn't gain force though momentum. (That really isn't quite true, but the increase is immeasurably small until coming very close to the speed of light, which isn't rightly relevant here.)


The only reason the lower portion held the upper portion (I refrain from using your term, "block...
Not that I was not commenting on the towers there, but rather the conversation you responded to was about these these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o).

[triforcharity]

I just spoke to the engineer who designed my overly simple porch, (my father) and I spoke to the builder (myself and my BIL, who is also a structurl engineer) and they have all agreed that it wouldn't matter if the weight was in pebbles, or toasters, it would still cause the catastrophic failure of my porch.

[rwguinn]

momentum = mass x velocity.

force = mass x acceleration

The two are related, but not the same; mass doesn't doesn't gain force though momentum. (That really isn't quite true, but the increase is immeasurably small until coming very close to the speed of light, which isn't rightly relevant here.)


Not that I was not commenting on the towers there, but rather the conversation you responded to was about these these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o).
What the Hell?

Mass and force are related only through acceleration.
a 1 kilogram mass(9.8 N at 1 g) can exert a force of 9800000 N quite easily.
take it up to 1000 m/second velocity, and stop it in 10 milliseconds

[kylebisme]

Have you JUST called EVERY SINGLE PERSON on this forum a COMPLETE IDIOT???
I did nothing of the sort. I believe we are all intelligent, but I know we all have different interests and many never found much use for studying physics. My comment was not even directed at forum members, but rather a comment on people in general.
No, it DOESN'T MATTER if I drop it, or break it apart into tiny weights. The weight will still eventually be ON my porch, even if not all at once. I believe its called "static load", but I could be wrong. Like I said, I am not an engineer.

It doesn't matter. Either way, my porch WILL collapse.
It does matter, for the reasons I explained above. Also, static load is the weight of the porch itself, dynamic load is what it is designed to hold beyond it's own weight.
Why exactly wouldn't they hit at the same time?
Because we broke them apart. Even if you could just neatly stack them all together tightly hovering in mid air to drop them from there, air resistance would cause them to push each other apart. Also, the pieces impacting on each other would absorb some of the force rather than transferring it to the deck below, acting like crude shock absorbers.

[kylebisme]

I just spoke to the engineer who designed my overly simple porch, (my father) and I spoke to the builder (myself and my BIL, who is also a structurl engineer) and they have all agreed that it wouldn't matter if the weight was in pebbles, or toasters, it would still cause the catastrophic failure of my porch.
Ask them to read what I wrote instead of presenting your interpration, as I get the strong impression you didn't compherend what said.
What the Hell?

Mass and force are related only through acceleration.

What the hell? I never claimed otherwise, and rather stated exactly that in other terms.

[WildCat]

Also, static load is the weight of the porch itself, dynamic load is what it is designed to hold beyond it's own weight.
No.

[dtugg]

Seriously, twoofer, stop pretending that you know what you are talking about. You obviously have no idea.

[triforcharity]

Ask them to read what I wrote instead of presenting your interpration, as I get the strong impression you didn't compherend what said.

I sent it to my dad in his office. I copied exactly what I said, and what you said.

He laughed.

So did my BIL. Actually, he said a few choice words about your intelligence, then laughed.

So, are they BOTH wrong?? I highly doubt that.

[Newtons Bit]

Because we broke them apart. Even if you could just neatly stack them all together tightly hovering in mid air to drop them from there, air resistance would cause them to push each other apart. Also, the pieces impacting on each other would absorb some of the force rather than transferring it to the deck below, acting like crude shock absorbers.

Loads don't just vanish instantly the moment after they are applied. This is easily modeled by the characteristic equation of vibration. This translates to something similar to a sinusoidal wave with an intial magnitude equal to the dynamic load effect of the force and decays down with each cycle.

The period of this sinusoidal wave in the WTC is measured in seconds.
The percent damping, or reduction in amplitude for every cycle is about 10% (which is exceptionally high for a building). This crude shock absorber you're talking about is insignificant.

The tower was doomed once the upper block began falling. Not only because of the forces from the debris impacts, but because the force in the lower block columns from the upper block hadn't unloaded before the upper block struck.

[BigAl]

It does matter [static and dynamic loads] , for the reasons I explained above. Also, static load is the weight of the porch itself, dynamic load is what it is designed to hold beyond it's own weight.

Because we broke them apart. Even if you could just neatly stack them all together tightly hovering in mid air to drop them from there, air resistance would cause them to push each other apart. Also, the pieces impacting on each other would absorb some of the force rather than transferring it to the deck below, acting like crude shock absorbers.

You post an empty hypothetical. Details matter.

On 9/11, the load was sufficient to collapse the tower.

I'm really not interested in the countless other buildings in the world, if only because no other buildings were constructed like WTC1 and 2 were in ways that are relevant to the way they collapsed.

You, Herrit, Jones, Gage et all are ignorant of that fact.

[Newtons Bit]

It does matter, for the reasons I explained above. Also, static load is the weight of the porch itself, dynamic load is what it is designed to hold beyond it's own weight.

Please quote the relevant passage from the IRC (or any building code) which talks about designing porches for a dynamic load.

Heh, I know you can't. It doesn't exist. The only dynamic loads any architecture structure is designed for is earthquakes. For a porch in a region of low snow-fall and non-hurricane region, the porch wouldn't need any capacity greater than a 20psf roof live load and 30psf wind uplift force.

Be careful with what you talk about on these forums. You can't just make up whatever you want. People here earn a living actually doing the things you can only lie about.

[triforcharity]

This paper, incidentally enough, explains dynamic VS static in relation to the WTC, and all I did was google, "Dynamic V static"

http://www.burtonsys.com/staticvdyn/

It even has PICTURES!! I love pictures!

[triforcharity]

Please quote the relevant passage from the IRC (or any building code) which talks about designing porches for a dynamic load.

Heh, I know you can't. It doesn't exist. The only dynamic loads any architecture structure is designed for is earthquakes. For a porch in a region of low snow-fall and non-hurricane region, the porch wouldn't need any capacity greater than a 20psf roof live load and 30psf wind uplift force.

Be careful with what you talk about on these forums. You can't just make up whatever you want. People here earn a living actually doing the things you can only lie about.

Newtons,

You must be psychic. I live in a NO snow-fall, high hurricane region (Florida) and I just looked at my drawings for my porch. Guess what?

My capacity is 25psf, and a 40 psf uplift. I wanted it stronger, as we do live where many hurricanes can occur in just 6 weeks (2004) I am somewhat anal like that.

[Newtons Bit]

Newtons,

You must be psychic. I live in a NO snow-fall, high hurricane region (Florida) and I just looked at my drawings for my porch. Guess what?

My capacity is 25psf, and a 40 psf uplift. I wanted it stronger, as we do live where many hurricanes can occur in just 6 weeks (2004) I am somewhat anal like that.

I'm not psychic, I just do this stuff for a loving. With things much much larger than porches. :D

[Lupie]

I can't believe that this "kylebisme" has managed to generate ten pages of responses to his completely ignorant, and uninformed theories. I guess it's ironic, that a little bit of stupid, can attract the attention of a whole lot of smart. When does it finally become a futile waste of time and words?

L.

[rwguinn]

Ask them to read what I wrote instead of presenting your interpration, as I get the strong impression you didn't compherend what said.
We did read, and it is pure pseudo-scientific gibberish

What the hell? I never claimed otherwise, and rather stated exactly that in other terms.

Yes. Yes you did claim mass=force...
...mass doesn't doesn't gain force though momentum...

Although to be painstakingly fair, bending over backwards, as it were, it is through change in momentum over time that "mass gains force", so from a purely pedantic POV, you are correct...

[kylebisme]

Although to be painstakingly fair, bending over backwards, as it were, it is through change in momentum over time that "mass gains force", so from a purely pedantic POV, you are correct...
It's not pedantic, it is the crucial difference between momentum and acceleration. Mass gains force though acceleration, not momentum. While the momentum changes as mass falls, the acceleration is the constant force of gravity.

As for dynamic load (http://www.strucalc.com/engineering-resources/the-most-used-engineering-terminology-defined/):
Dynamic Load
This type of load varies over time.
I'm curious to know; where are you all deriving a different definition from?

[Justin39640]

As for dynamic load (http://www.strucalc.com/engineering-resources/the-most-used-engineering-terminology-defined/):
Dynamic Load
This type of load varies over time.
I'm curious to know; where are you all deriving a different definition from?

do you understand that "time" can be a fraction of a second and the "variation" could be millions of pounds?

[rwguinn]

It's not pedantic, it is the crucial difference between momentum and acceleration. Mass gains force though acceleration, not momentum. While the momentum changes as mass falls, the acceleration is the constant force of gravity.
Mass doesn't change with velocity. You got that part right.
Force and velocity are related through changes in velocity. Momentum is a steady-state condition. It converts to a force when velocity changes.

As for dynamic load (http://www.strucalc.com/engineering-resources/the-most-used-engineering-terminology-defined/):

I'm curious to know; where are you all deriving a different definition from?Dynamic loading/ conditions are short-term (dT is small) Increases Changes over a time span > 1/wn (wn=Natural frequency) are not dynamic, but are considered static or quasi-static

[Hokulele]

You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

As for dynamic load (http://www.strucalc.com/engineering-resources/the-most-used-engineering-terminology-defined/):

Dynamic Load
This type of load varies over time.


:confused:

[kylebisme]

Dynamic loading/ conditions are short-term (dT is small) Increases Changes over a time span > 1/wn (wn=Natural frequency) are not dynamic, but are considered static or quasi-static
Ah, fair enough, my bad. It's been well over a decade since I used such terms regularly, and it seems I let live load and dynamic load blend together since then.

[WildCat]

:confused:
kyle thinks he hasn't dumbed it down enough for us. It simply doesn't occur to him that he has absolutely no idea what he is talking about.

The arrogance of truthers is astounding, isn't it?

[rwguinn]

Ah, fair enough, my bad. It's been well over a decade since I used such terms regularly, and it seems I let live load and dynamic load blend together since then.
Did you intentionally mis-quote?

[Grizzly Bear]

:confused:

If he wants to be more specific the dynamic load as defined in architectural text is one which is applied suddenly. In the context of the towers this load was applied in such a short time period that the disjointed nature of the debris they claim should have a lesser effect is negligible. Approximately the same mass is loading the floors within the span of a second or less (extremely conservative estimate) as if the mass was still intact. It wasn't exactly powder hitting those floors, many of those individual "pieces" were several to tens of tonnes each.

[kylebisme]

kyle thinks he hasn't dumbed it down enough for us. It simply doesn't occur to him that he has absolutely no idea what he is talking about.
I'm surprised no one was able to explain that I was confusing live load with dynamic load.
Did you intentionally mis-quote?
No, my bad. I fixed it now and added your correction.

[WildCat]

I'm surprised no one was able to explain that I was confusing live load with dynamic load.
And what do you think the design live load of the WTC floors was?

[Hokulele]

If he wants to be more specific the dynamic load as defined in architectural text is one which is applied suddenly. In the context of the towers this load was applied in such a short time period that the disjointed nature of the debris they claim should have a lesser effect is negligible. Approximately the same mass is loading the floors within the span of a second or less (extremely conservative estimate) as if the mass was still intact. It wasn't exactly powder hitting those floors, many of those individual "pieces" were several to tens of tonnes each.


Yep. The puzzled face was over why he thought it mattered whether or not the mass was intact or not. Overload is overload (in the static case of triforcharity's porch) and dynamic load is dynamic load (in the case of any of the collapses under discussion), regardless of the number of "pieces" it is in.

[kylebisme]

And what do you think the design live load of the WTC floors was?
I've had no reason to really look into it in detail, but while reading Makey's whitepaper I saw he suggested at least 500,000 tons, and and notes it was estimated to be carrying at least 2/3s of that at the time by NIST. Note of course that is the whole building, each floor has it's own limit too.

[kylebisme]

Yep. The puzzled face was over why he thought it mattered whether or not the mass was intact or not. Overload is overload (in the static case of triforcharity's porch) and dynamic load is dynamic load (in the case of any of the collapses under discussion), regardless of the number of "pieces" it is in.
Try dumping a bucket's worth of sand on a a cardboard box, and then sweep up all the sand, put it in a bag, and try again.

[BigAl]

Try dumping a bucket's worth of sand on a a cardboard box, and then sweep up all the sand, put it in a bag, and try again.

Huh?

Enough of you. You're on ignore.

[triforcharity]

You cannot compare a cardboard box to anything that is load bearing. The cardboard box gets its strength fromm it's sides, certainly not from the top.

Please, someone correct me if I am wrong.

Oh, and my dad is still laughing at you. He is now about to pee on himself.

[sylvan8798]

Well the broken floor is not really one mass. It is many small masses. These small masses will strike the lower solid intact floor independently as small masses. The small masses will also interaact with each other while falling, losing some energy in the process.


Do they make baby masses while they are at it?:cool:

[kylebisme]

You cannot compare a cardboard box to anything that is load bearing.
I'm comparing a bunch of loose mass to a solid one, the box is just for simplicity of the example. The same applies to a load bearing structure, but you'd need a lot more sand and and a much bigger bag.

[triforcharity]

Son, I think you just gave my dad a heart attack. I think most people here would agree, that a cardboard box is not the best anology. Either way, its still fail.

Wanna use a bucket and some water instead??

[sylvan8798]

You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

Why wouldn't they hit at the same time if you dropped them at the same time?

[Hokulele]

Try dumping a bucket's worth of sand on a a cardboard box, and then sweep up all the sand, put it in a bag, and try again.


That depends on how you dump it and how strong the box is. If you can dump it all at once, there will be essentially no difference. If the box cannot hold the weight of the sand, it doesn't matter how fast you pour it. Either way, you will have a crushed box.

[kylebisme]

If someone took a hacky sack and pelted you with it, would it hurt more than if he took the hacky sack apart and threw that separated mass at you?

[triforcharity]

how fast is said hackey-sack traveling?? What is the makeup of it's contents??

You're not very good at anologys are you??

[sylvan8798]

If someone took a hacky sack and pelted you with it, would it hurt more than if he took the hacky sack apart and threw that separated mass at you?

We're not talking about something being broken into sand-sized pieces here. The steel columns broke into sections ~30 feet long, and the slabs were being slammed over and over again as they fell, but as they first began to fall they would still have been LARGE pieces. Certainly large enough to cause failures on the next floor down. Stuff was being DRIVEN downward and compacted by the material still above it. Don't you get that?

You need better analogies. So far these are all fails. By a long shot.

[Audible Click]

If someone took a hacky sack and pelted you with it, would it hurt more than if he took the hacky sack apart and threw that separated mass at you?

We could call this the Zohan analogy! :D

[LashL]

I can't believe that this "kylebisme" has managed to generate ten pages of responses to his completely ignorant, and uninformed theories. I guess it's ironic, that a little bit of stupid, can attract the attention of a whole lot of smart. When does it finally become a futile waste of time and words?


Nine pages ago.

[kylebisme]

We're not talking about something being broken into sand-sized pieces here.
We are talking about the difference between a solid chunk of mass and the same mass broken into smaller pieces. The sand-sized pieces were simply to highlight that distinction for those who were attempting to deny it.


The steel columns broke into sections ~30 feet long, and the slabs were being slammed over and over again as they fell, but as they first began to fall they would still have been LARGE pieces. Certainly large enough to cause failures on the next floor down. Stuff was being DRIVEN downward and compacted by the material still above it. Don't you get that?

Surely you aren't suggesting the building just collapsed into its own footprint? If you are, how do you figure all this stuff wound up all over the place (http://www.noaanews.noaa.gov/wtc/images/wtc-photo.jpg)?

[TruthersLie]

You are correct, but you are missing Bill's point. You could take a giant 2,000 pound weight that covered the area of your porch and collapse it by dropping that weight from high enough. However, if your broke that weight into a bunch of pieces, they wouldn't hit at the same time, and hence would have to be dropped from far higher to collapse your porch.

you are so right.

this is just water drops... small parts that should break it up
Jp_C9YuqC_E

what happened to the car?

[sylvan8798]

Surely you aren't suggesting that everything that was broken fell OUTSIDE the footprint and that nothing was landing on the still-intact structure?

[TruthersLie]

momentum = mass x velocity.

force = mass x acceleration

The two are related, but not the same; mass doesn't doesn't gain force though momentum. (That really isn't quite true, but the increase is immeasurably small until coming very close to the speed of light, which isn't rightly relevant here.)


Not that I was not commenting on the towers there, but rather the conversation you responded to was about these these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o).

wow... you finally shifted from weight to mass. It seems like you are learning about technical jargon.

I'm still waiting for the measure of structural integrity... newtons was it? (roflmao).

still waiting for the citation for the body panels of a peugeot are steel... what are the brakes then? or was it 0 for brakes and 0 for fuel tank?

reading for comprehension is your friend.

[tsig]

Try dumping a bucket's worth of sand on a a cardboard box, and then sweep up all the sand, put it in a bag, and try again.

Why don't you try it?

[Lupie]

You know kylebisme, if you put this sort of effort into actually educating yourself about the subjects that you talk about, you might actually learn something. You come across as a total fool and pawn of the "truthers". If you were to put even half the effort into actually reading about what you are attempting to talk about, as you do into carrying the truther banner here, you might actually learn that there are only two versions of things. There is what has been proven as fact, and there is BS.

L.

[tsig]

Son, I think you just gave my dad a heart attack. I think most people here would agree, that a cardboard box is not the best anology. Either way, its still fail.

Wanna use a bucket and some water instead??

He'd have to poke a hole in the box, set it on fire and wait an hour to make it realistice.

[triforcharity]

We are talking about the difference between a solid chunk of mass and the same mass broken into smaller pieces. The sand-sized pieces were simply to highlight that distinction for those who were attempting to deny it.

It would still hurt, but it certainly wouldn't kill me, either way. You see, my body was designed to withstand impacts and loads from much smaller objects. A better anology would be (even though the fail is still the same)

Take a car, and set it on top of your body while prone=dead guy

Take same car, shread it up, and set it on top of you=still alive*


Surely you aren't suggesting the building just collapsed into its own footprint? If you are, how do you figure all this stuff wound up all over the place (http://www.noaanews.noaa.gov/wtc/images/wtc-photo.jpg)?

No, he is not. Not at all. He is explaining the collapse. Good strawman though.
BTW, nice job on using my photo that I pointed you to for demonstration of "Outside of footprint".

HE'S LEARNT ONE THING AT LEAST!! WOO HOOO!!!



*you would still be dead either way.

[triforcharity]

Tsig,

He would have to open the box. He wouldn't know where it went, or understand how it got there.

[kylebisme]

what happened to the car?
It was damaged a lot less that it would have been if it a bag full of the watter that hit it dropped on it instead, or even considerably less watter.

Surely you aren't suggesting that everything that was broken fell OUTSIDE the footprint and that nothing was landing on the still-intact structure?
No, I'm suggesting that what was landing on the structures wasn't anywhere close to enough to bring it the towers down. Furthermore, even if there had been enough, the collapse would have decelerated on the way down just like those seen here (http://www.youtube.com/watch?v=NwFHEoiUZ7o), or anywhere else one collection of mass crushes another under the force of gravity alone.

[triforcharity]

Your suggestion is obviously wrong.

How much weight do you think the floors of the WTC could hold??

[Matthew Cline]

That depends on how you dump it and how strong the box is. If you can dump it all at once, there will be essentially no difference.

To the extent that falling loose sand acts as a liquid, it might make a difference (I'm not a physicist or engineer). However, I rather doubt that the mass of rubble of the collapsing WTC buildings acted much like a liquid.

Loads don't just vanish instantly the moment after they are applied. This is easily modeled by the characteristic equation of vibration. This translates to something similar to a sinusoidal wave with an intial magnitude equal to the dynamic load effect of the force and decays down with each cycle.

The period of this sinusoidal wave in the WTC is measured in seconds.
The percent damping, or reduction in amplitude for every cycle is about 10% (which is exceptionally high for a building). This crude shock absorber you're talking about is insignificant.

What range of frequencies/periods might cardboard boxes have, and what range of damping percentages? I'm guessing that the period is very short and the damping percent very high, and if it was the same as for the WTC that it's likely a dumped bucket of sand would collapse the box.

[kylebisme]

Can anyone provide an example outside the events of 9/11 where one collection of mass crushes another under the force of gravity alone, without decelerating on the way down?

[Brainache]

Can anyone provide an example outside the events of 9/11 where one collection of mass crushes another under the force of gravity alone, without decelerating on the way down?

Did you try that "Brick and Egg" experiment that was suggested earlier?

[kylebisme]

Did you try that "Brick and Egg" experiment that was suggested earlier?
The brick decelerates when it hits the egg and starts accelerating again from there. Surely you aren't suggesting the bottom portions of each tower was like a giant egg?

[triforcharity]

The amount of deceleration is minimal at best. Maybe a few nano-seconds would be my guess.

And not, not the mass of the entire flors below it, just the one immeadiatly below the failure point.

That is 2 strawman arguments in one day. Kyle, you need to go to bed.

[kylebisme]

The amount of deceleration is minimal at best. Maybe a few nano-seconds would be my guess.
It is mostly instantaneous, but it is declaration regardless.


And not, not the mass of the entire flors below it, just the one immeadiatly below the failure point.

Yet when you add an egg for every floor, that deceleration adds up.

[triforcharity]

Ok, so total of a 1/10 of a second??

[Hokulele]

It is mostly instantaneous, but it is declaration regardless.

Yet when you add an egg for every floor, that deceleration adds up.


Calculate how much deceleration you expect based on your claims and how that would affect the collapse times.

[kylebisme]

Ok, so total of a 1/10 of a second??
Perhaps if you drop the brick from high enough.

Of course the tops of the towers compared to the bottoms weren't like bricks compared to eggs. A better analogy would be a tube of 110 eggs, pull one towards the top out of the stack, and watch how quickly that decelerates. Besides, that isn't even considering the fact that the "eggs" at the bottom of the towers were much stronger than the ones at the top.

[kylebisme]

Calculate how much deceleration you expect based on your claims and how that would affect the collapse times.
I will tomorrow if you post the figures you want me to use. I'm off to bed for now.

[Hokulele]

I will tomorrow if you post the figures you want me to use. I'm off to bed for now.


Use the values for WTC 2.

[Brainache]

It is mostly instantaneous, but it is declaration regardless.


Yet when you add an egg for every floor, that deceleration adds up.

Don't forget that the falling mass is increasing with every floor that gets crushed.

We know that the debris that fell outside the towers was falling faster than the collapse front, therefore the collapse front did decelerate as it hit each subsequent floor, but it never came to rest until it reached the ground.


Just checking: Is this 2009, or did I just dream the last three years- like some Antipodean Bobby Ewing?

[GlennB]

Can anyone provide an example outside the events of 9/11 where one collection of mass crushes another under the force of gravity alone, without decelerating on the way down?

Dave Rogers explained this to you some pages ago. Tony Szamboti had it explained to him many times in the 'missing jolt' thread.

The collapse zones at WTC were tilted, eccentric. There were thousands if not millions of small decelerations in the impact areas as structural members and connections broke, but none of these - and no collection of these - was sufficient to lead to a measureable 'jolt' from the point of view of the roofline. All that was detectable was that the buildings came down at less than freefall. The deceleration was 'averaged out'.

The verinage CD's were very different in this respect. The upper sections fell fair and square on the lower, as was intended. What's more they were reinforced concrete buildings. The deceleration or 'jolt' was detectable.

Analogies involving sand and cardboard boxes will not help you understand anthing here. The scale, structure and materials involved are in the 'back yard' range of daily experience.

[Architect]

Indeed.

There is, of course, a reason why structural engineers require 4 years of university level study followed be several years of post graduate on-the-job training before they get to play with this kind of stuff.

Hint: it's not because it's easy and you can work it out with sand and carboard boxes.

[Dave Rogers]

Surely you mean the force F exerted by the lower block on the upper one subtracts from the acceleration of that upper block? Like if you jump down onto a gymnastics mat it subtracts from your acceleration, slowing your fall. We have two forces here, but only one acceleration.

The distinction is purely a matter of convention. Adding a positive number to a negative number is the same as subtracting a positive from a positive. It's more rigorous to talk in terms of vectors, but in this case all the forces act in one dimension so we can talk about addition and subtraction in a scalar sense. There is a resultant acceleration, and vector arithmetic can be done with acceleration as well as with forces (though doing it with forces is more correct).

Rather, the upward force of the lower block is expected to be greater than the weight of the upper block, the lower block having held that upper block in place prior to the section between the two being pushed out. It is this net upward force which results in the deceleration you mention. Agreed?

Agreed.

Now, from the bold is where I'm not following you at all. You are speaking of the floor supports being destroyed in instances, with periods of free fall between them. I'd like to see the measurements you refer too, but in these collapses (http://www.youtube.com/watch?v=NwFHEoiUZ7o) I've been speaking of, it is not just floors falling one on top of each other, but the whole structure being crushed down, concrete walls and all. There is no chance of freefall after the initial collision, as there is constantly mass acting as resistive force in the way. Also, I dug up video of this Balzac-Vitry collapse (http://www.youtube.com/watch?v=syzKBBB_THE) which I'm guessing might be the one you refer to, but surely you are not suggesting there is any free fall after the initial collision in that?

It's an approximation to treat the collapse as a series of discrete shocks, but in the case of the Balzac-Vitry demolition it's not a bad one. This is not argued from a theoretical approximation, but from the actual data; the Balzac-Vitry demolition shows a decrease in downward acceleration at the initial impact, then a greater acceleration as it falls through the height of the supporting walls, then another decrease as it hits the next floor. The conclusion to be drawn is that most of the resistance takes place as the floors collide, that a storey of supporting walls collapses and ceases to offer significant resistance, and that the upper block then falls, approximately in free fall, until it impacts on the next floor.

Again, this isn't theorising, it's observation. I'm not suggesting that there's near free-fall after the original collision; I'm observing it.

Dave

[Dave Rogers]

momentum = mass x velocity.

force = mass x acceleration

The two are related, but not the same; mass doesn't doesn't gain force though momentum. (That really isn't quite true, but the increase is immeasurably small until coming very close to the speed of light, which isn't rightly relevant here.)

Sorry, kylebisme, but that paragraph is so scientifically illiterate that it's almost painful to read it. Mass does not "gain force" through any means, as the two are dimensionally different. Mass increases close to the speed of light, but this is not "gain(ing) force". Mass, however, exerts force through changes in its momentum; force may be defined as the rate of change of momentum with time, and therefore the momentum of a mass may be used as a measure of its ability to exert force. The lower blocks of the WTC towers needed to exert sufficient force to counteract the effects of gravity on the upper block - which they were capable of doing, of course - but at the same time they had to exert sufficient force to reduce the momentum of the upper block to zero before being compressed to the point of failure. This they were not capable of doing, even in their undamaged state - which they were very far from at thhe moment the collapses began.

Dave

[dafydd]

Why wouldn't they hit at the same time if you dropped them at the same time?

Antigravity?

[Dave Rogers]

It's not pedantic, it is the crucial difference between momentum and acceleration. Mass gains force though acceleration, not momentum. While the momentum changes as mass falls, the acceleration is the constant force of gravity.

I really think you need to go back to school and learn some elementary physics. You're embarrassing yourself by posting this sort of word salad. "Mass gains force through acceleration, not momentum" is quite literally meaningless.

Dave

[dafydd]

I really think you need to go back to school and learn some elementary physics. You're embarrassing yourself by posting this sort of word salad. "Mass gains force through acceleration, not momentum" is quite literally meaningless.

Dave

I have only high school physics but I can see that is total nonsense.

[Dave Rogers]

The brick decelerates when it hits the egg and starts accelerating again from there.

Wrong. The acceleration of the brick decreases very slightly when it hits the egg, but is still downward. You will at no point see the downward velocity actually decrease (which is what is meant by the word "decelerate"). Therefore, this is a trivial example of "one collection of mass crush[ing] another under the force of gravity alone, without decelerating on the way down".

Surely you aren't suggesting the bottom portions of each tower was like a giant egg?

If truthers can use pizza boxes, chicken wire and filing trays...

Whether or not there are any relevant similarities, they follow the same laws of physics. I'm not using the brick-and-egg analogy to explain the collapses, I'm using it to try to teach you the physics involved.

Dave

[NutCracker]

The brick decelerates when it hits the egg and starts accelerating again from there. Surely you aren't suggesting the bottom portions of each tower was like a giant egg?

Look, it's pretty simple. The towers' tops should have fallen sideways because of "the law of path of least resistance," right? This "law", should also apply to a brick falling on an egg. I.e. the brick should go round the egg. In reallity that doesn't happen. Explain, please.

And now you are heading into '"the law of path of least resistance" apllies not to bricks and eggs, but does apply to WTC towers' territory. A rather predictable evasion. I saw it coming when the brick-egg challenge was posed.

[WildCat]

I've had no reason to really look into it in detail, but while reading Makey's whitepaper I saw he suggested at least 500,000 tons, and and notes it was estimated to be carrying at least 2/3s of that at the time by NIST. Note of course that is the whole building, each floor has it's own limit too.
I'm positive Ryan made no such claim, as it was nowhere near 500,000 tons. Typically a commercial office space would have floors capable of carrying 150 lbs/sq ft. At ~40,000 sq. ft. that means each floor could handle about 3000 tons evenly distributed. They certainly were not rated at 25,000 lb per sq. ft. And certainly nowhere near that much weight when it has velocity!

Now, what do you think the weight of the upper block was?

[WildCat]

the collapse would have decelerated on the way down just like those seen here (http://www.youtube.com/watch?v=NwFHEoiUZ7o),
Nothing of the sort is happening there.

[WildCat]

Calculate how much deceleration you expect based on your claims and how that would affect the collapse times.
It's a function of how fast a Republican can say "clunkety-clunk". Didn't you learn your truther fizziks?

[Ragnarok]

Uneven support, caused by the weakening of the structure on the side were the plane hit. There is nothing inherently dubious about that. The problem is the lack of the rotation of the block being reflected in the destruction bellow it.

However, that video does show an curious cloud of dust and debris rising from the upper section of the building after it tumbles off to the side, but before it has a chance to hit the ground.

It also shows a curious burst of fire off to the right hand side at 4 seconds in, but I suppose that was just oxygen being pushed into an already burning fire by the collapse? :rolleyes: The flame did seem particularly white though, if that means anything.

And if the weight of the building itself was crushing everything below it, rather than an artificial weakening of certain parts contributing to it, why was there still a big spike of the tower left upright momentarily?

[Dave Rogers]

It also shows a curious burst of fire off to the right hand side at 4 seconds in, but I suppose that was just oxygen being pushed into an already burning fire by the collapse? :rolleyes:

Most likely, yes, or the flame from an already-burning fire being redirected by air movement. Why would anyone think this was unlikely?

And if the weight of the building itself was crushing everything below it, rather than an artificial weakening of certain parts contributing to it, why was there still a big spike of the tower left upright momentarily?

Because it wasn't a homogeneous solid block. The most likely collapse scenario is that the debris from the crushing front was funnelled into the space between the core and the perimeter columns, and caused a progressive collapse of the floor pans which preceded the collapse of the perimeter columns and the core. Neither the core nor the perimeter columns could stand unbraced by the floors, as they exceeded the limit at which they could be self-supporting against buckling failure, so the perimeter columns peeled off after the internal collapse wave had passed. The core would have been badly damaged by collisions from debris, but appears to have failed last of all, leaving the well-known spires standing briefly at the end of the collapse. All this is entirely consistent with a gravity-driven collapse.

Dave

[TruthersLie]

It also shows a curious burst of fire off to the right hand side at 4 seconds in, but I suppose that was just oxygen being pushed into an already burning fire by the collapse? :rolleyes: The flame did seem particularly white though, if that means anything.

And if the weight of the building itself was crushing everything below it, rather than an artificial weakening of certain parts contributing to it, why was there still a big spike of the tower left upright momentarily?

Are you really that dense?

a big spike of tower would be because UNLIKE what Bazant discussed and the verinage videos shows, the towers did not come down uniformly and it was not filled with column on column collapses. It was a messy deformation, and that ment that parts of the interior of the bulding were still standing.

Though it is very funny.. since when you implode a building you destroy the CORE first and the building collapses... that big spike of the tower which was left was the CORE. wow... there goes the CD theory...

[paulheinze]

Though it is very funny.. since when you implode a building you destroy the CORE first and the building collapses... that big spike of the tower which was left was the CORE. wow... there goes the CD theory...

The spires left standing were only a part of the cores.
For WTC1 see
http://www.youtube.com/watch?v=nHxDdbdsCDY
at 15 seconds
Interestingly, the comprised of the weaker columns of the core whereas intuition would suggest that the stronger columns would survive.

[Ragnarok]

Most likely, yes, or the flame from an already-burning fire being redirected by air movement. Why would anyone think this was unlikely?
So, why no intense bursts from any of the fires nearer to the collapse, genius? There was a pretty large fire blazing right in the centre of the building, and that didn't rear up with the sudden rush of oxygen, or we'd have noticed it as clearly as the one on the far side from the collapse point.


Because it wasn't a homogeneous solid block. The most likely collapse scenario is that the debris from the crushing front was funnelled into the space between the core and the perimeter columns, and caused a progressive collapse of the floor pans which preceded the collapse of the perimeter columns and the core. Neither the core nor the perimeter columns could stand unbraced by the floors, as they exceeded the limit at which they could be self-supporting against buckling failure, so the perimeter columns peeled off after the internal collapse wave had passed. The core would have been badly damaged by collisions from debris, but appears to have failed last of all, leaving the well-known spires standing briefly at the end of the collapse. All this is entirely consistent with a gravity-driven collapse.

Dave

Go on, I'll take your word for all that. You obviously know what you are on about. Whereas NIST decided to not even bother going there, as it was all too complex and irrelevant.

[TruthersLie]

The spires left standing were only a part of the cores.
For WTC1 see
http://www.youtube.com/watch?v=nHxDdbdsCDY
at 15 seconds
Interestingly, the comprised of the weaker columns of the core whereas intuition would suggest that the stronger columns would survive.

ah hem.
Let me repeat.

when you do CD to implode a building (which is all of the truther lies about falling into own footprint) you blow up the CORE (all of it) and the building implodes. If any part of the core is still standing, guess what that tells you? It wasn't CD.

Based on your wonderful intutition you have conflated many issues from your hatred of GWB and the immorality of the war in Iraq to jump on the MIHOP bandwagon. So pardon me if your intution doesn't mean squat here.

And thought it may be counterintuitive to you, it isn't to me. Stronger doesn't mean it handles sheering forces better. Oak is stronger than a willow tree... which one survives hurricanes and tornadoes better? the willow.

[TruthersLie]

So, why no intense bursts from any of the fires nearer to the collapse, genius?

PMSLMAO.... how about something simple, the initial collapse was where the impacts were... what else was there? Oh massive open spaces, and no place for the air to compress into..

so at the initiation where the impacts were the air flowed out pretty freely... then compress the air down and guess what it does? (feeds the flames, and created those "squibs" you twoofs love so much)


Go on, I'll take your word for all that. You obviously know what you are on about.

definately knows a lot more than you... I'd bet he has forgotten more about physics than you have ever learned. Watching him school you (and Kyle, and paul) has been great fun

[TruthersLie]

Whereas NIST decided to not even bother going there, as it was all too complex and irrelevant.

Which is yet another twoof lie. Thank you for playing... we have some lovely twoofie kool aid for you. Drink up.

You may want to think about going back to school and finishing it... I know it is hard and scary, but it really is worth it.

[Ragnarok]

Which is yet another twoof lie. Thank you for playing... we have some lovely twoofie kool aid for you. Drink up.

You may want to think about going back to school and finishing it... I know it is hard and scary, but it really is worth it.

Welcome to ignore, troll.

Oh, I've been dying to use that favourite line of all you open-minded thinkers on here!

Consider yourself honoured; you are my first and will always be my favourite.

[paulheinze]

ah hem.
Let me repeat.

when you do CD to implode a building (which is all of the truther lies about falling into own footprint) you blow up the CORE (all of it) and the building implodes. If any part of the core is still standing, guess what that tells you? It wasn't CD.

Based on your wonderful intutition you have conflated many issues from your hatred of GWB and the immorality of the war in Iraq to jump on the MIHOP bandwagon. So pardon me if your intution doesn't mean squat here.

And thought it may be counterintuitive to you, it isn't to me. Stronger doesn't mean it handles sheering forces better. Oak is stronger than a willow tree... which one survives hurricanes and tornadoes better? the willow.

So you suggest, I should not point out a detail in order to enhance the quality of a discussion. Do you mean the observation is not correct? If not, what is your problem.
If you think I take my position because of hatred of GWB, does it mean that you defend the official theory because you love GWB?

[NutCracker]

So, why no intense bursts from any of the fires nearer to the collapse, genius? There was a pretty large fire blazing right in the centre of the building, and that didn't rear up with the sudden rush of oxygen, or we'd have noticed it as clearly as the one on the far side from the collapse point.



Go on, I'll take your word for all that. You obviously know what you are on about. Whereas NIST decided to not even bother going there, as it was all too complex and irrelevant.

OMG, the ignorant, delusional (Rule 10) doesn't understand some detail, or does pretend not to -> inside jobby-job.

[Grizzly Bear]

So you suggest, I should not point out a detail in order to enhance the quality of a discussion.
It's fine that you brought up the remnant core structure, however, it does nothing to support your assertion that the towers were "controlled demolitions." If you're arguing in favor of that you might want to choose a different piece of evidence.


Do you mean the observation is not correct? If not, what is your problem. If you think I take my position because of hatred of GWB, does it mean that you defend the official theory because you love GWB?
False dichotomy...

[paulheinze]

It's fine that you brought up the remnant core structure, however, it does nothing to support your assertion that the towers were "controlled demolitions." If you're arguing in favor of that you might want to choose a different piece of evidence.

I did not argue in favor of anything. You should be interested in precision of the arguments presented, too. You should try to stick the text written and not with "this-is-twoof-it must-be-wrong"-eyeglasses.

False dichotomy...
Wrong. I did not construct a dichotomy. You should recognize a rhethorical question when you read one.

[Ragnarok]

OMG, the ignorant, delusional (Rule 10) doesn't understand some detail, or does pretend not to -> inside jobby-job.

Or alternatively, I am pointing out something that has piqued my curiosity and would like to hear opinions on it - but that would be a far less glamorous thing to rail against, wouldn't it, fool?

[Ragnarok]

Btw, the "spike" you see here http://www.youtube.com/watch?v=9SSS0DDqfm0 at 10 seconds in, looks more like the outer walls of the tower than the core, which is even more surprising, since seconds before the whole thing was crumbling. But, I'm sure there's a reasonable explanation!

[BadBoy]

If truthers can use pizza boxes, chicken wire and filing trays...

Dave

What about blueberries. I tried droping 10 blueberries onto a stack of 100 blueberries...

and suurrrrprise... NO ONEWAY CRUSHDOWN!!

so, government blue up the towers. QED. (cant get away from my dimond edge logic hu)

I tried crushing them down by jumping off a chair my while only wearing my underpants eating 10 blueberries AND holding a box of SIX eggs AT THE SAME TIME to simulate adding additional force with gravitating momentum and they did crush down causing quite a mess. But thats not the same thing at all. (scientifically speaking)

I know I know, I should be wroking for JPL. They wouldnt pay me enough though so Im sticking to stacking shelves.

[Ragnarok]

Again, "structural integrity" is not a well defined term.

WHAT? You mean architects have been building structures for centuries upon end, and there is no real clue how they are standing up?

Explain yourself, man!

[Ragnarok]

What about blueberries. I tried droping 10 blueberries onto a stack of 100 blueberries...

and suurrrrprise... NO ONEWAY CRUSHDOWN!!

Yes, but I bet you'd have got a nice drink out of it, if you'd done it in a bowl.

[Dave Rogers]

So, why no intense bursts from any of the fires nearer to the collapse, genius?

Thanks for the recognition. Because chaotic processes produce chaotic results. We don't know any of the fine details enough to predict what should have happened, but it's simple enough to understand some of the details of what did happen.

Go on, I'll take your word for all that. You obviously know what you are on about. Whereas NIST decided to not even bother going there, as it was all too complex and irrelevant.

Exactly right. NIST would have been unable to offer more than a general description of the collapse due to the complexity of modelling it, and this would have added precisely nothing to their understanding of why the collapse began. Too complex, therefore, for anything other than a general account, and irrelevant to the vitally important question (to those with more than the most tenuous grip on reality) of what changes should be made to the way large buildings are constructed for safety.

This is borne out by what we saw, in fact, when NIST gave in to pressure from the delusional and incorporated a collapse model into the WTC7 report. As might be expected, the model didn't match the detailed features of the collapse particularly accurately, leading to the usual paranoid psychotic claims that they were somehow covering up for the impossibly vast conspiracy. I suspect that they regret ever bothering.

Dave

[NutCracker]

Or alternatively, I am pointing out something that has piqued my curiosity and would like to hear opinions on it - but that would be a far less glamorous thing to rail against, wouldn't it, fool?


Sure! Just curiousity! Just asking questions! Look, the intelligent are able make inferences from what and how you post.

Well, if the detail interests you, do some real research and report your conclusions and, above all, the logic that brought you to the latter.

[BadBoy]

Most likely, yes, or the flame from an already-burning fire being redirected by air movement. Why would anyone think this was unlikely?



Because it wasn't a homogeneous solid block. The most likely collapse scenario is that the debris from the crushing front was funnelled into the space between the core and the perimeter columns, and caused a progressive collapse of the floor pans which preceded the collapse of the perimeter columns and the core. Neither the core nor the perimeter columns could stand unbraced by the floors, as they exceeded the limit at which they could be self-supporting against buckling failure, so the perimeter columns peeled off after the internal collapse wave had passed. The core would have been badly damaged by collisions from debris, but appears to have failed last of all, leaving the well-known spires standing briefly at the end of the collapse. All this is entirely consistent with a gravity-driven collapse.

Dave

Hi Dave, I enjoy your posts.

I had a thought while reading this. "IF" a controlled demolition were required to bring down a building like the twin towers (legitimately), I wonder how they would go about it without having the sides peel off and affecting buildings in the surrounding area. I guess they would have to take out the external perimeter columns with explosives, maybe all the way down, to cause them to buckle inwards. I wouldn't have thought they would want a building that size to pancake.

Anway, I know the loons would just argue that they wouldnt need a nice controlled demolition. I just wonder if there is something in the way the building is shown to collapse which would negate the use of explosives. I mean if for argument sake (cant believe Im even saying this) a plan was hatched to finish the job with explosives, how would they do this in order to be sure the building collapse completely, and what would the buildings collapse look like in this scenario (apart from the obvious missing noise of explosives going off, the problems of planting the explosives and the missing evidence in the pile of rubble - though i know they argue this point), keeping in mind that they think pancaking (crush down) wouldnt work so they couldnt rely on it.

Just thinking its maybe possible to prove within reasonable doubt that to bring them down with explosives it would not be possible to create the same scenario we all witnessed.

However, I see that this is starting from the pov that explosives were used and then disproving it from there thus giving the crackpots far to much credit soo... probably bad idea. The burden of proof is on them.

The whole argument is pointless anyway. I just read this thread because Im interested in understanding how they fell. Its quite an interesting topic (unfortunately).

[Dave Rogers]

Btw, the "spike" you see here http://www.youtube.com/watch?v=9SSS0DDqfm0 at 10 seconds in, looks more like the outer walls of the tower than the core, which is even more surprising, since seconds before the whole thing was crumbling. But, I'm sure there's a reasonable explanation!

One reasonable explanation would be that the video you linked doesn't show the core spike, which lasted for a few seconds after the main collapse. It does show a section of perimeter column sticking up for a moment before collapsing, as you'd expect if the collapse followed the sequence I mentioned earlier.

But I'm sure that isn't a reasonable explanation in truther world. Two different things happening, that look a bit different - that's too far-fetched for anyone to believe, isn't it?

Dave

[Dave Rogers]

Hi Dave, I enjoy your posts.

Thank you.

I had a thought while reading this. "IF" a controlled demolition were required to bring down a building like the twin towers (legitimately), I wonder how they would go about it without having the sides peel off and affecting buildings in the surrounding area. I guess they would have to take out the external perimeter columns with explosives, maybe all the way down, to cause them to buckle inwards. I wouldn't have thought they would want a building that size to pancake.

Most likely the building would be dismantled rather than imploded, because of the dangers to surrounding buildings. But generally, with explosive demolitions, the collapse is initiated at the bottom rather than near the top. The whole structure falls close to vertically, and is only destroyed as it contacts the ground. As a result, nothing is ejected at height, and hence can't travel outwards so far before hitting the ground. The difference can be seen with WTC7, which collapsed from the bottom upwards and did much less damage to the buildings around it than WTC1 and WTC2. (Some truther is bound to jump on this and say "So you admit WTC7 looked like a CD then?" It's irrelevant. A goose looks like a duck.)

Disclaimer: I'm a physicist, not a demolition expert. The track record for physicists talking about controlled demolitions w.r.t. 9/11 is not exactly flawless.

Dave

[funk de fino]

Go on, I'll take your word for all that. You obviously know what you are on about. Whereas NIST decided to not even bother going there, as it was all too complex and irrelevant.

Yet they did explain the collapse propogation and gave calculations for it. You did know that right?

[jaydeehess]

Don't you see that, as I explained above in another post, if the floor of the upper block does not get lifted from its seats then you now have the entire mass of the upper block on the first lower floor. If it does then the columns continue downward carrying to our as yet unfailed level, another floor, and another,,,(repeat up to at least ten times)
You are now reduced to argueing how many floor masses it would take to fail one floor. In addition there is of course, the dynamic loading which you are attemptinmg to minimize yet it is still there. Further, of course, if this is more than one floor we simply cannot expect that the perimeter and core columns are sliding straight down the same hole they opened up as they speared downward at the initiation of collapse. They are tearing away more of that originally impacted flooring not to mention that they weakened the floor pan when they punched through in the first place. They are also doing a number on floors lower down.

You, and your mentor, seem to believe that the floor pan can by some magical physics, support the entire upper block. Heiwa has attempted to say that the material will get wedged between the core and perimeter. B.$. pure and simple. How can that possibly transfer the mass load of the block to the columns and not push the perimeter columns outward, snapping their seats to the trusses?

It is mostly instantaneous, but it is declaration regardless.

.

Any deccelleration that the falling mass experiences must, in order to arrest the collapse, reduce the impact at the next lower floor.

How can it do so. Well it cannot do so by reducing the velocity of the falling mass as that falling mass will again experience the same accelleration falling between the first failure floor and the next. Therefore even if velocity was reduced to zero before the first floor failed the falling mass would acheive that same impact velocity again when it hits the next lower floor.

Obviously in the case of the towers the initial impact did not reduce the velocity of the falling mass to zero and thus the velocity of the mass falling on the next lower floor was even greater than the first.

Yes, impact force is the transfer of momentum divided by the duration time of impact. That is why a container of sand produces greater impact that a slowly poured bucket of sand. The very first impact of floor on floor occured with largely intact floors so this is not a bucket of sand, rather it is a load of large rocks by analogy.

1) This is sufficient to snap or buckle the majority, if not all, of the truss seats on the lower block's floor and lift the upper block floor from its seats. Now the combined mass of the upper and lower block floors are heading downward and will impact the next lower floor at a higher velocity than the first impact due to the fact that the upper floor was already moving. The transfer of monentum would have seen the velocity of the combined mass of the two floors being less than a free fall object BUT the columns are still spearing downward through more floors AND the next intact upper block floor is coming down at the same acelleration of the rest of the upper block (which is what we see from outside). This next upper block floor would eventually catch up to the combined mass of the other two floors since it has yet to be involved in a transfer of momentum.
Thus you have a situation in which the collapse will not arrest as each floor gets hit by a mass of greater velocity and greater mass than the one above it. The slowing of the transfer of momentum by the break up of the debris is small compared to the gain in momentum due to the acceration due to gravity and the increse in falling mass.

2)The first impact is not sufficient to break the truss seats. It holds against the impact of the two floors and is hit half a second later by yet another floor of essentially equal mass but which has been falling for 30-50% longer and thus is moving even faster than the first impact. This floor is likely more intact and hitting as a solid object more so than the first impact. So we have less effect of a slowing of transfer of momentum.
It would be difficult to imagine that this lower block floor, significantly damaged by the spearing through of the columns of the upper block, would resist this second impact but even if it does it is followed by yet another one after a still shorter interval and at a yet higher velocity, and again ,, and again,,,,,
In this case the slowing of transfer of momentum by the break up of debris is less significant because each impact is occured at a faster velocity and with less of a time interval between impacts(which would disallow the resisting floor time to rebound). This floor will eventually succumb to the insults and the combined mass of however many floors you wish this to be will now impact the next lower floor followed quickly by yet another upper block floor. The rubble will at this time still contain large blocks rather than be 'sand'. It will also simply have a mass that would be a strain on one floor if it were all loaded onto a pristine intact WTC tower floorspace much less one that is already damaged (spearing columns)and loaded with this mass over a time of no more than three quarters of a second!

What is visible from the outside? Not the floor impacts, the dust and smoke expelled and the perimeter columns would obscure this. Instead all we can see is the perimeter columns above and below the dust/smoke cloud.
(note that we are speaking of the first few seconds here)

ETA(because I cannot resist): I do declare!

[rwguinn]

Anybody notice that after at least 2 of us pointed out the ignorance of equating mass and force was, and how momentum and force are related, we ind up with 3 pages of distractions to get that stuff out of the lime-light?
All this in 10 hours...

[Mancman]

It was damaged a lot less that it would have been if it a bag full of the watter that hit it dropped on it instead, or even considerably less watter.



Here's a bag of water being dropped on a car:
gNjU54UbDWo

They also drop small bags of water on an office desk (which is destroyed) and a concrete patio (which is shattered).

How does it feel to fail in every post you make?

[jaydeehess]

Here's a bag of water being dropped on a car:
gNjU54UbDWo

They also drop small bags of water on an office desk (which is destroyed) and a concrete patio (which is shattered).

How does it feel to fail in every post you make?

Back when we had to fend off dinosaurs to combat forest fires :D I was a forest firefighter. When the waterbombers came in we stood well back. The water coming down easily snapped large branched off trees and would just as easily snap a neck on a hapless soul who lingered too long on the fire lijne with a load of water coming in.

If one was caught you were to dive for the base of a tree and lay down and not look up!

[SpitfireIX]

I'm surprised no one was able to explain that I was confusing live load with dynamic load.


Wildcat did, in post #390. He just didn't elaborate. Fail.

[jaydeehess]

Anybody notice that after at least 2 of us pointed out the ignorance of equating mass and force was, and how momentum and force are related, we ind up with 3 pages of distractions to get that stuff out of the lime-light?
All this in 10 hours...

Happens every time.

I notice that even kyle and bill's mentor has vanished. One would think that the experienced engineer would be here helping out the junior engineer and the layman who are attempting to explain the senior one's contentions.

[jaydeehess]

Hmmm, thought of another senario to add to the ones in my above post.

In this case the impact does fail the truss seats on the lower block floor but does not fail the truss to column connections of the upper block floor. In this case the transfer of momentum is not just between two floors of near identical mass, it is between a floor and the entire upper block and thus the velocity of the faling mass changes very little. This results in the next impact lower down being at a much greater velocity, and if the upper block truss connections do fail it would be with twice the mass of one floor (this senario is very unlikely since the trusses seats were stronger for loads in the normal direction, down)

[Grizzly Bear]

Wrong. I did not construct a dichotomy. You should recognize a rhethorical question when you read one.
My mistake. I thought the Bush comment was serious. My apologies if that was incorrect.

I did not argue in favor of anything. You should be interested in precision of the arguments presented, too. You should try to stick the text written and not with "this-is-twoof-it must-be-wrong"-eyeglasses.
If you're not arguing in favor of anything then there's no reason for you to have been bothered by it. I said bringing it up was fine, however if using it entails supporting the demolition claim you'd be best using something else.

As per your original comment...
The spires left standing were only a part of the cores.
For WTC1 see
http://www.youtube.com/watch?v=nHxDdbdsCDY
at 15 seconds
Interestingly, the comprised of the weaker columns of the core whereas intuition would suggest that the stronger columns would survive.
Not really. If the assertion that what remained were the "weaker" columns is true then mostly likely they stood longer because the assembly was relatively intact after the main collapse progressed away from them. At those heights, without the floors providing any lateral support neither could support their own weight.

[jaydeehess]

I really think you need to go back to school and learn some elementary physics. You're embarrassing yourself by posting this sort of word salad. "Mass gains force through acceleration, not momentum" is quite literally meaningless.

Dave

Indeed I would have thought that this would have been made abundantly clear in his first year physics courses.

Force can increase due to an increase in the mass or accelleration of that mass.
A force can be generated by the transfer of momentum because the velocity changes ( which is a definition of accelleration). The shorter the duration of the impact the greater the force. This force deccellerates the impacting mass and accellerates the mass being impacted. (in an ideal collision, which is unconstrained such as by one mass being bound to the earth in which case the impacted mass would be the entire earth)

[jaydeehess]

Originally Posted by R.Mackey
Again, "structural integrity" is not a well defined term. WHAT? You mean architects have been building structures for centuries upon end, and there is no real clue how they are standing up?

Explain yourself, man!

He is saying that the term is a subjective, qualitative one rather than an objective, quantitative engineering term.

He is saying that there is no quantitative measure known as "structural integrity".

Here (http://www.msm.cam.ac.uk/phase-trans/2006/SI/SI.html) is a treatment of the assessment of structural integrity but in it you will find no term that is actually labeled "structural integrity" rather you will find such things as "Fatigue life assessment", and "Brittle fracture assessment".

[psikeyhackr]

Force can increase due to an increase in the mass or accelleration of that mass.
.
That is almost as bad as this:

"Mass gains force through acceleration, not momentum"
.
The momentum and kinetic increase as the velocity increases. How do you increase the mass without reducing the velocity unless you get the velocity of the added mass synchronized with the original mass? As long as we are talking about less than 10% of light speed. What force? It will impart more force if it hits something and take more force to stop but as long as it is moving what force are you talking about?

psik

[jaydeehess]

.Force can increase due to an increase in the mass or accelleration of that mass.
That is almost as bad as this:


.
The momentum and kinetic[energy] increase as the velocity increases. How do you increase the mass without reducing the velocity unless you get the velocity of the added mass synchronized with the original mass? As long as we are talking about less than 10% of light speed. What force? It will impart more force if it hits something and take more force to stop but as long as it is moving what force are you talking about?

psik
should have included one more word;
Force can increase due to an increase in either the mass or accelleration of that mass.

But if that wording is still bad;

The force on an object is proportional to the mass of the object and the accelleration of the object.
better?

I was not assuming a situation in which mass of an object magically increased. Adding mass to an object is collision between two or more objects,. I thought that was pretty clear.

[Ragnarok]

Sure! Just curiousity! Just asking questions! Look, the intelligent are able make inferences from what and how you post.

Surely you mean the blinkered and the jaded?

[Dave Rogers]

That is almost as bad as this:


Not really. It's not too well phrased, but it's instantly recognisable as Newton's Second Law.

Dave

[Heiwa]

Any deccelleration that the falling mass experiences must, in order to arrest the collapse, reduce the impact at the next lower floor.

How can it do so. Well it cannot do so by reducing the velocity of the falling mass as that falling mass will again experience the same accelleration falling between the first failure floor and the next. Therefore even if velocity was reduced to zero before the first floor failed the falling mass would acheive that same impact velocity again when it hits the next lower floor.



Yes, anything dropping on top of something is decelerated ... and if something doesn't fail at top, anything stops on top of something. If top on something fails, anyting may drop again on the next top of something ... and if something has 90 extra tops, anything must crush 90 top to destroy something.
So anything must be really solid to carry out this feat. If anything is weaker than something (which is the case of WTC 1), anything has no chance against something. Anything is destroyed in its bottom at impact to start with. Something is not destroyed ... just partially damaged.

[Architect]

But Heiwa, what about Ronan Point? You know, the one that you don't understand?