Billiard Balls and Momentum

[spooked911]

Judy Wood's "Billiard Ball Example" is a strong proof that the WTC towers were brought down by abnormal means and were not gravity-driven collapses.
http://janedoe0911.tripod.com/BilliardBalls.html

Her basic point is that in a progressive collapse, it will take a fair amount of time for each floor to drop to the next and keep the collapse going.

Using an ideal model where each floor drops at free-fall speed to the next, but then pauses as it breaks the next floor, and then this floor falls at free-fall speed until it reaches the next floor, etc, she calculates a minimal collapse time of 97 seconds.

In reality, this model under-estimates the time, as each floor is NOT going to drop through the columns of the floor below at free-fall speed in a vacuum, but should go slower.

The big issue many people have, including me when I first saw her billiard ball piece, is MOMENTUM. Intuitively, it is natural to think that there should be some momentum transferred from floor to floor during a progressive collapse-- and that should speed up collapse time. The natural reaction is to think of a huge weight gaining so much speed that is smashes down through all lower floors, in a "pile-driver" type of reaction.

If you read down to the appendices of the Billiard Ball Example piece, Wood explains the logic of how momentum shouldn't be transferred during a floor collapse, and how floors coming down and bashing the lower floor will lead to the upper floors pausing as they knock loose the lower floor. These upper floors will then have to start falling again, which is what slows the collapse.

Is Wood wrong about momentum transfer? While there may be something out there refuting her, I can't see any high-profile clear refutation of Wood's analysis-- nothing turns up on Google, anyway. There are discussion board refutations of her model -- but I haven't seen a rigorous debunking. The reubuttals are more of an appeal to "common sense". Such as, 'come on, you KNOW momentum has to be transferred during a collision.'


So, I thought I would deal with the MOMENTUM issue a diffeent way.

I wondered if I could model the collapses where there was some degree of momentum transfer at each floor collision.

To do this, we need to use the following standard equations:

v = at and v (2) = v (1) + at

where v = velocity in feet per seconds, a = acceleration in feet (f) per second (s) per second, t = time in seconds, v(1) is initial velocity and v(2) is final velocity over a period of time t at acceleration rate a.

For these calculations, a is the force of gravity, 32 feet per second per second.

Thus,

v (f/s) = 32 (f/s/s) t (s)

and

v (2) = v (1) + 32(f/s/s) t ( s)

Also we need this equation
x = 1/2 at^2,
where x = distance travelled = 1/2 time t at acceleration a (squared).



Simply plugging in the height of one WTC tower, 1360 feet, and a as 32 f/s^2, we can easily solve for t and get a free-fall time of 9.2 seconds.

We will also need this equation:
x(2) = x(1) + v(1)t + 1/2 at^2
which tells us the distance x (2) travelled for a certain amount of time and certain acceleration, when there is an initial volecity v(1) starting at distance x(1).

So how do we work MOMENTUM into this system?

Momentum is mass times velocity. To start with, we will assume mass is constant for the mass falling at a certain velocity, meaning momentum is essentially velocity.

We will assume that there is free-fall between floors (this fast falling time, that assumes no impedances, greatly favors the official story) and that each floor is 12 feet in height. Also, we will assume that when one floor reaches the lower floor, its velocity is decreased by a set amount each time-- but that some velocity (essentially "momentum") is transmitted between floors to speed up the subsequent fall time between floors.

We will assume in this model that the only energy cost for destroying a floor is the loss of some degree of velocity at each floor collision.

The first set of calculations will be assuming that 50% of velocity is transferred at each collision of floors.

For the first floor, we need to calculate how long it took to fall to calculate its final velocity.

This can be done easily for the first floor using
x = 1/2 at^2
where x = 12 f
giving 0.87 s

Plugging 0.87 s into v (f/s) = 32(f/s/s) t(s), we see that the velocity after falling one floor is 27.8 f/s.

Now it gets more complicated for the second floor.

First, we assume that after bashing against the lower floor, that the two floors are going 50% of the original velocity -- in this case 13.9 f/s.

Now we need to solve for time it takes to fall the next twelve floors, and we need this equation which takes into account the velocity the floors are already going:

x (2) = x (1) + v (1)t + 1/2 at^2

In our situation, x (1) = 0 and x (2) = 12 f, v (1) = 13.9 f/s and 1/2 at^2 = 16 (f/s/s) times t squared.

In other words--
12 = 0 + 13.9t + 16t^2

Now how on earth do we solve that?

Actaully if we re-arrange it into 16t^2 + 13.9t - 12 = 0, it is a quadratic equation-- and we can solve for t easily with a quadratic equation calculator (available online).

Now we get a time of 0.53 s for the 2nd floor collapse at free-fall speed and 50% loss of momentum. Now we can calculate the final velocity after this floor falls 12 f ---> 30.9 f/s.

For the next floor collapse, the floor will start moving at 50% of this speed, at 15.5 f/s.

Going through the iterations for each floor, what happens is that after a few floors, a sort of terminal velocity is reached, where there is 0.5 seconds for each floor to drop.

If we assume that there is free-fall between floors and a 50% loss of velocity (momentum) used up by each floor/structural column collapse, the minimal time for collapse is 55 seconds. This is FAR longer than the maximal observed collapse time of 15 seconds per tower.

We can extend these calculations and test what happens if there is free-fall between floors and each floor/structural column collapse only slows velocity (momentum) by 25%. The calculated time is 36 seconds. This still is FAR longer than the maximal observed collapse time of 15 seconds per tower.

Lastly, we can extend these calculations and test what happens if there is free-fall between floors and each floor/structural column collapse slows velocity (momentum) by a mere 10%. This means again, there is pure free-fall speed between floors (which is highly unlikely) and only a tiny loss of velocity (momentum) when a floor is destroyed by the mass falling from above (extremely unlikely).

In this case, the calculated time is 23 seconds.

This time still is significantly longer than the maximal observed collapse time of 15 seconds per tower, even though it assumes the lower structure offered very little resistance to the falling mass.

One could go on, but it gets even more ridiculous. One could say the structure only slowed the falling mass by 1% at each floor collapse, and get close to the observed collapse times, but this defies physics and is an insult to engineers
who design strong buildings.

The bottom line is that even IF you take momentum transfer into account, the observed collapse times are far too short.

---------------

A somewhat different issue someone might raise is that a progressive collapse could gain momentum (mass times velocity) with time-- as the upper floors pile up, producing more mass to fall on lower floors.

The answer to that is two-fold.

First, the lower framework of any tower is always much stronger at the bottom than at the top, as the lower structure needs to support the upper weight. Thus, accumulating mass should be balanced out by the increased strength of the lower floors.

Second, what we saw on 9/11 was the upper floors disintegrating and turning to dust, with concrete being pulverized at each floor-- such that there really was relatively little of a "piledriver" effect.

Lastly, one reason I built a model of the WTC, was to try to see if I could induce any sort of progressive collapse and try to observe how it proceeded. Unfortunately, because of scaling issues, the model was too strong to undergo ANY collapse. But I still would love to see a physical model of a stable structure (i.e. not a tower of blocks) that undergoes a progressive collapse!

Addendums --

1) If my calculations are incorrect, someone please tell me. The calculations aren't hard but I still may have made a mistake somewhere.

2) The method I used for calculating times gives a very different result than if you assume that there is constant acceleration during the progressive collapse, but that the acceleration is lower due to the resistance of the building. For instance if you assume that gravity can only pull down at 16 f/s/s (rather than 32 f/s/s) because the lower building structure offers even resistance, you get a fall time of 13 seconds for 1360 feet. But in real life, there would never be such even resistance-- rather there would be a significant slowing at each floor.

3) In real life, if we assume a progressive collapse occurred for the towers, it would probably affect the calculations this way:
a) fall time between floors would be slower than free-fall speed due to column resistance and walls and various building components
b) the first collision would probably consume all or most of whatever momentum there was from the dropping floor-- it is not clear at all that the first floor collapse would even break down the next floor to continue the collapse-- but let's say the collision consumes 90% of the momentum of the top block of floors. If the next floor could then break away from the collision, then one might retain somewhat more momentum from the added weight, so there might be less and less momentum consumed at each floor collision. Thus one could try to model the timings with increasing momentum at each collapse. But overall, the timing would certainly well above the observed collapse times.

4) As far as I can tell from NIST, their explanation for the rapid collapse times is:

BUILDING HEAVY, GRAVITY STRONG. They have NOT offered any serious explanation for the rapid collapses.

5) If we assume, by the official story, that a 15 story top chunk of tower (for WTC1) broke away from the lower structure due to a combination of plane damage, fire weakening and subsequent column stress, it is almost impossible that this chunk of building would gain significant momentum to break through the undamaged lower structure. The upper section of building is not going to suddenly break away and drop all at once at free-fall speed. Rather, it would start by the fire causing sagging on one side and the undamaged columns should take up the stress and eventually buckle and fail completely. But this process is not going to cause the upper section of building to plop down at free-fall speed-- which is really what is needed to gain enough momentum for a progressive collapse.

6) In reality, for asymmetric damage there should have been more of an asymmetric collapse. Witness, what happened to WTC5 and WTC6, which underwent severe asymmetric collapse without undergoing global collapse. For WTC1 or WTC2, there should have been more of a local evidence of collapse before the global collapse was initiated.

7) In terms of 9/11 reality, of course the towers exploded into dense clouds of dust, the bulk of the concrete was pulverized, the whole structure fell apart at near free-fall speeds, and the debris pile was remarkably small-- all signs of high-energy demolition.

8) In terms of academic analysis, the huge height of a WTC tower with 110 floors really makes it very attractive for mathematical modeling, and there are a lot of different approaches one could try. While mathematical models are nice to have, physical models are in fact the most useful and informative if done properly.

[Bolo Boffin]

1. You are not adequated accomadating for the mass of the upper section. n/t

Plug an velocity loss of 14.25% in.

[dailykoff]

3. Roger that.

:crazy:

[spooked911]

5. I did 10% loss and the time is too long for the observed time

[dailykoff]

2. Not to mention that pancaking was physically impossible. (n/t)

[spooked911]

4. well, yeah-- but how else do you explain the official story?

in a progressive collapse, there has to be some degree of pancaking

[dailykoff]

13. You can't without some kind of engineered destruction,

i.e. demolition. But I see your point--the progressive pancake fantasy is physcially impossible for several reasons including this one.

[William Seger]

15. This should be good

So tell me, what are these reasons that "the progressive pancake fantasy is physcially impossible?"

[spooked911]

17. the timing was too fast

[William Seger]

26. Sez who?

Judy Wood? No sale.

[dailykoff]

28. It is good.

I see you've been napping for the last five years. You've got some catching up to do. I'd start by figuring out what we've been talking about for the last 500 threads or so.

[William Seger]

35. That's what I suspected

What you and I have been mainly talking about lately is your willful ignorance and imaginary substitutes for things like physics and structural engineering. That's why I expect your reasons for thinking "the progressive pancake fantasy is physcially impossible" to be highly entertaining, and it's getting boring around here. Please do share your thoughts on these weighty matters.

[dailykoff]

37. Evidently the NIST doesn't think it possible either

or they would have explained how it supposedly occurred three times, or even once.

[William Seger]

44. You're not going to "explain" your assertion?

What a disappointment...

Well, anyway, you are wrong; NIST certainly thought it was possible, and they summed up the explanation very succinctly and accurately as: "The release of potential energy due to the downward movement of the building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure." You're not happy with that because it doesn't go into detail about what that means? Well, that's a disingenuous criticism, since you are also unsatisfied with the several analyses by qualified people that did go into detail about what that means. If those analyses had been included in the NIST report, would you be happy? Of course not.

But what I'm waiting for now, please, is your learned explanation of why that's "physically impossible."

[dailykoff]

50. It is impossible for a steel frame to behave like unreinforced masonry,

wood, or concrete. Yet that is ridiculous nonsense that you in your innocence are clinging to. Why, I have no idea.

[William Seger]

52. Fascinating. I what way did it "behave like unreinforced masonry, wood, or concrete"?

[dailykoff]

122. Concrete and masonry are brittle. Wood is weak.

Steel is ductile and orders of magnitude stronger than any of them and a high-strength steel frame could not shatter into a pile of rubble without the assistance of explosives and/or other destructive device(s).

[hack89]

123. But it didn't "shatter" ..

the joints failed - I don't see a lot of steel beams that were shattered.

[dailykoff]

125. See for yourself:

?click

Now how do think those two big towers turned into a heap of shards?

[hack89]

126. Do you have a close up?

How big would you expect a steel beam to look from that height?

[dailykoff]

127. The point is that they're disconnected, like bricks.

But steel isn't masonry and steel buildings don't shatter into shards.

More specifically, tremendous force had to be used to slice up all that steel and/or shear all those welded connections, and it sure as hell didn't come from jet fuel, gravity or "KE," dynamic or otherwise.

[AZCat]

6. Judy Wood clearly doesn't know what she is talking about.

Her model is significantly flawed. It's been discussed here already IIRC.

[DoYouEverWonder]

7. So are the NIST models

and they never were able to make the models work has I recall.

[AZCat]

8. We have discussed that before...

and I hope I have made my opinion of the NIST models (and the general idea of modelling such an event) clear.

[spooked911]

18. Yes, and you've read her whole paper and know the exact flaws, right?

so what are the flaws?

[AZCat]

48. I don't have to.

Anyone who omits conservation of momentum from calculations such as these is an idiot.

[DoYouEverWonder]

9. You mention the 'piledriver' effect

'Second, what we saw on 9/11 was the upper floors disintegrating and turning to dust, with concrete being pulverized at each floor-- such that there really was relatively little of a "piledriver" effect.'

That's right the floors apparently were pulverized and did not slam down on top of each other.

However, the collapses were designed to take advantage of existing objects, in order to create this piledriver effect. I believe this is why WTC 1 was hit at a higher point, then WTC 2. WTC 1 had the antenna and so they had to take this out first along with the hat truss that it sat on. This heavy object had no were else to go but down the center of the building. Then they blew out the first set of mechanical floors, then the 2nd set and then the core. Using the plumes of debris to cover up the sequenced blow outs on the way down.

In WTC 2, they didn't have this natural 'piledriver' so they needed to use just the elevator hoists that were on the 81st floor, so they had to start the collapse at the floor below, in order to take out these 24-ton weights first and then from there the same sequence of event occurred has in WTC1.

[spooked911]

16. Interesting idea, but since they blew the towers to kingdome come

I'm not sure why they needed a piledriver at all

[DoYouEverWonder]

47. They might not have needed a piledriver,

but they did have to drop these objects in such a way has to take full advantage of their weight and extra bracing. Once that bracing was knocked out the floors below didn't stand a chance.

That's probably why it looks like the antenna starts to fall before the rest of the building. The collapse was designed for that to happen. Just like they dropped the Penthouse in WTC 7 first.

Besides, did you see the thread I posted about the antenna? It seems the pulverization that occured inside the building, did not have any effect on objects outside of the building, ie the antenna.

[DoYouEverWonder]

49. Actually, I'd like to modify the above post a bit

The antenna may have been a problem, rather then an asset. That may be why they had to take down the 1st section closer to the top of the building, which was not the optimum place and complicated the process. That may be why WTC1 took longer and was a bit sloppier.

The optimum place to take down the top section of the buildings was down near the 75th and 76th mechanical floors. These were the floors that didn't have staggered columns. The columns were all the same level, creating a seam around the building. Also, the mechanical floors had no windows. That made it much harder to tell from the outside, if there was fire activity or explosions on those floors.

The 81st floor carried 288 tons worth of elevator hoists. If you blew out the 80th floor first, that would have released the weight from all that tonnage above and could use the weight coming down to help knock out the mechanical floors below that had beams instead of trusses. Then the regular floors underneath, with the trusses, would start a domino effect at least until the next set of mechanical floors, and then the columns in the basement.

[William Seger]

42. "Apparently"

> > 'Second, what we saw on 9/11 was the upper floors disintegrating and turning to dust, with concrete being pulverized at each floor-- such that there really was relatively little of a "piledriver" effect.'

> That's right the floors apparently were pulverized and did not slam down on top of each other.

"Apparent" to whom, please? That's both ridiculously illogical and unsupported by any evidence. If Spook911 really thinks that what he "saw on 9/11 was the upper floors disintegrating and turning to dust" then he totally discredits himself as an observer, and he has created a scenario that he will find totally impossible to explain by any means that doesn't involve science fiction. How far do you expect to get with conclusions drawn from such ludicrous misperceptions?

[DoYouEverWonder]

53. Just look at the pictures

The east wall falls away in one piece and there is nothing of substance behind it. The interior of the building is already pulverized.

[William Seger]

59. Appearances can be deceiving

> The east wall falls away in one piece and there is nothing of substance behind it. The interior of the building is already pulverized.

It appears sorta like that... in that picture. Other pictures clearly show the whole top section tilting:

[DoYouEverWonder]

60. The picture you've posted

shows the east and north walls falling away from the building still attached to each other. It is an assumption that they are still attached to the floors or the core at that point. Remember the antenna fell first. That means the core failed before the perimeter walls did. For such a large section of perimeter wall to pull away from the building in one piece, indicates that all the floors above the impact zone failed almost simultaneously. The floors did not fall down on top of each other because the top of the building was blow up, it did not collapse.

[William Seger]

61. Again, appearances can be deceiving

First, take another look at your pic, with a little enhancement to compensate for the underexposure:



The east wall is not falling away "in one piece" "with nothing of substance behind it." The south wall is falling with it.

Here's another pic of the north and east walls, from father north:



Again, these walls are not "falling away from the building." That is the building.

So, yes, based on the pictures showing the entire top section falling together in the same direction, I would assume "that they are still attached to the floors or the core at that point." Assuming anything else would require some explanation, and I'm personally not interested in explanations that involve science fiction, and I'm not interested in any hypotheses not based on evidence.

> Remember the antenna fell first. That means the core failed before the perimeter walls did.

The antenna was on the north tower, of course, but as NIST reported:

An earlier building performance study, performed by a private-public sector team with funding support from the Federal Emergency Management Agency (FEMA), concluded that the core failed first in WTC 1 based on vertical movement of the antenna observed in a video recording from due north that did not capture the antenna tilt due to the angle from which the video was shot.

NIST found that the north tower rotated 3 to 4 degrees toward the south before the full collapse began, so the video shot from the north made it appear that the antenna dropped first, but actually it was just rotating away from the camera. So the initial assumption that the core failed first was discarded. Again, appearances can be deceiving.

> For such a large section of perimeter wall to pull away from the building in one piece, indicates that all the floors above the impact zone failed almost simultaneously.

Except the walls didn't "pull away from the building," so there's no reason for that conclusion.

[DoYouEverWonder]

73. If the top third of the building

feel in one piece, then why did the debris come down pretty evenly around the whole building?



WTC 1 from across the Hudson.

[William Seger]

84. "Pretty evenly" compared to what?

That picture is WTC1, so it wasn't the top third; it was only about 15 floors. Anyway, the top of that tower only tilted about 3 or 4 degrees toward the south before it started falling straight down. Looking at your picture, the debris on the south side is ahead of the north side, so the debris could seems to still have some evidence of that tilted beginning.

WTC 2 shows pretty much the same thing:



Also, I seem to recall a thread a couple weeks ago about how "strange" it was that some of the exterior walls were left standing, but I would take that to simply mean that it wasn't all that even.

[tenseconds]

124. Your photograph

Your photo shows the very onset of the collapse. The previous photo...?


Therefore not a valid comparison.

[greyl]

62. Do you remember the photos of Condi's stockings? nt

[DoYouEverWonder]

71. So?

The thread was meant has a joke because she looked so weird.

I thought she was wearing some weird pattern stockings, making some sort of Michael Jackson fashion statement.

It turned it was the shadows from the crappy lighting. Big deal.

Come on. I've got 1000's of posts under my belt. I'm sure I've made a few bigger mistakes then that one along the way.

OMG, I'm not infallible. How could that even be possible?

(Do I need to put in the sarcasm smilie?)

[greyl]

80. I like that example because it shows that you can change your mind

eventually when evidence presents itself and not be embarassed in proclaiming that you've learned something. Maybe this is one of those times, but we just haven't waited long enough?

[LARED]

10. Consider this

In your observation about momentum the mass does not stay the same. It would be considered an inelastic collision between the floors above and the floor below so the mass increases as the collapse progresses (meaning the mass combines after collision; (m1v1 +m2v2= (m1+m2)*vfinal). In your iterations you may want to consider increasing the mass each time by some factor. Of course all the mass does not pile up in the collapsing floors as some spills over the sides, but there is considerably more than one floors mass shorty after the collapse started.

Also you may want to reconsider your view that a 10% levels of "energy" transfer at each impact is meager. The total mass of the floors have tremendous stored energy as it falls. I think 5 or 10 percent of the energy used solely to break the floor free from it supports below is quite conservative. it could be considerably less.

Good luck, you are creeping ever closer to the truth.

[spooked911]

19. you act as though the lower supporting structure was paper mache

in fact it was incredibly strong. It is NOT as though any set of upper floors was dropping free-fall for 50 feet onto the floor below. Even then it's not clear that would cause that floor to break down. What you seem to neglect is the strength of the lower building, not to mention the dozen other telltale signs of demolition.

[LARED]

29. Consider this

The strength of the floor support was most likely fairly constant through the building, so the amount of energy to break a floor free will be about the same.

The strength of the columns increased approaching grade to handle the increasing weight of the building and column itself. What many CT'er fail to grasp is that without the floors providing lateral support, the column lose stability and will fail. In fact if you removed the practical need for floors as a work area, the WTC would still have required many dozen lateral supports structures to keep the columns stable. Also the perimeter columns failed largely at the bolted connection, at each column section as it was assembled, the weakest element of the columns. This would have been a weak point along the entire column assembly from top to bottom.

You also need to grasp a concept about the strength of the building. It was designed to handle gravity loads and wind load as a structural system. Once a collapse mechanism started this system was degraded and the load were highly dynamic; very different from design criteria.

[dailykoff]

31. Wind loads ARE dynamic.

Just thought I'd clear that one up for you. :)

[LARED]

36. I, of couse know that.

You know I know it, so why bother to post it?

[dailykoff]

39. Now you do. (n/t)

[spooked911]

65. my question is

how much do you get paid to spout this crap?

[LARED]

67. For a short time I was hopeful you were starting to figure it out

I was wrong

[DoYouEverWonder]

68. The strength of the floor support

was NOT fairly constant through the building. The mechanical floors didn't even have trusses.

[LARED]

72. You're missing the point

Yes, the mechanical floors (where there four?) were different than the other 105 or so floors. The point is on the non mechanical floors the connection between the columns and the floor joists were the most likely the same at each floor. So just because the column cross sections increased, the strength of the floor connection changed little regardless of the location in the structure.

Get it?

[DoYouEverWonder]

74. Floors 9, 41, 42, 75, 76, 77 and 107 - 110

were mechanical floors.

Also 81 had modifications to accomodate the weight of the elevator hoists.


In WTC 1, 43 and 67 also had modifications for the Port Authority.

[LARED]

118. OK, there were 6 mechanical floors below the impact, not 4.

What do you think of the point that non-mechanical floors were connected the same way regardless of position in the towers

[Make7]

78. There were actually eight mechanical floors. 7, 8, 41, 42, 75, 76, 108, and 109.

The floor above each pair of mechanical floors also used beam framed construction. As did the floor for the observation deck/restaurant (107), the roof, and also the floors below the lowest mechanical floors.

That gives us the following beam framed levels from top to bottom:

the roof
110
109
108
107
-
-
 77
 76
 75
-
-
 43
 42
 41
-
-
 9
 8
 7
-
-
 2
 1
 B1
 B2
 B3
 B4
 B5

I just wanted to clarify this information, even though it has nothing to do with your larger point.

- Make7

[LARED]

79. Thanks for the correction (n/t)

[MervinFerd]

11. "High energy demolition"???? HOW MUCH explosive are we talking?

Try making that calculation. If gravity doesn't supply enough energy to do the things you claim happened, HOW MUCH explosive would be needed to supply that energy? Do that calculation. Then get back to us.

[spooked911]

21. you seem to forget the building was incredibly strong steel welded

together. It was not a set of children's blocks waiting to be knocked over, for god's sake.

Buildings... don't... just... fall... apart.. completely.. from ... their.. own ...weight -- unless they are blown apart.

That is why they demolish buildings with explosives and don't set fires in one part of the building in hopes it will collapse.

[William Seger]

27. Buildings,,,

> ... don't... just... fall... apart.. completely.. from ... their.. own ...weight

I should hope not, but that's totally irrelevant. It fell apart from it's own weight falling -- a BIG difference. The gravitational energy available in the collapse was approximately the same as it would take to lift a tower half almost half it's own height -- lift about a half-million tons, maybe 600 feet or so in the air. What would you expect to happen if you did that and then dropped it? I realize that you don't yet understand why your bunny cage tower won't tell you anything about the collapse, but what you need to grasp is that your inability to understand this doesn't make it false.

[dailykoff]

32. So who lifted the buildings 600 feet in the air?

This should be good. :popcorn:

[William Seger]

34. Mostly, those construction cranes

... and then the elevators were used to lift the furnishings.

... and you forgot your "special" smiley.

[dailykoff]

38. I see.

This is very interesting. I missed the construction cranes in the 9/11 footage. Did Al Qaeda supply them or did Rudy?

[William Seger]

40. Answer the question, then we'll proceed with the argument

What would you expect to happen if you lifted the towers 600 feet and then dropped them? But never mind, let me assume that even you would know the obvious answer -- they would be completely destroyed. Then, the argument would be: well, that's only about twice the gravitational energy that was available when the towers were standing on the ground, because the cranes and elevators had already stored an equivalent amount of gravitational energy in the buildings. If you can easily understand why the towers would be completely destroyed if they were dropped from 600 feet, then you should be able to understand that the claim that they shouldn't have been destroyed by gravity alone is equivalent to saying that half the energy of a 600 foot fall shouldn't destroy them. Does that little thought experiment trigger any thought processes?

[dailykoff]

41. Answer: nobody lifted the towers 600 feet in the air. (n/t)

[William Seger]

43. So, your answer is...

... yes, the towers would be completely destroyed if they were lifted 600 in the air and dropped, but half that amount of energy would have no effect at all. Is that your answer?

[spooked911]

64. the question is

1) what toook out the lower supports of the building to make it fall so damn hard?

2) how much do you get paid to spout this nonsense?

[William Seger]

66. Answers

1) Gravity.

2) Beg your pardon, but did you mean how much do I get paid to refute nonsense? Nothing, but I do write it off my taxes as a charitable contribution.

[William Seger]

45. Oh, well, it was just a thought experiment

Maybe you could borrow the necessary equipment?

[DoYouEverWonder]

51. Zero according to the OCTers

So based on that concept, I suppose you wouldn't need much at all.

[AlienSpaceBat]

12. My take on this

was posted here some time ago, with data and graphs. I have looked over my data again, and cleaned it up a little.

What I did here was to assume that the top 30 floors collapsed as a block. When they hit the next floor, 25% of the energy was lost in destruction of supports, debris flying horizontally, pulverisation of structure etc.

On every floor following I assumed that the same amount of energy was lost in the collision.

On these assumptions my total time came out at 14.8 secs for the total collapse. If I used a loss of 50% of the first collision at every floor, I get a total collapse time of 21.6 secs.

I can't back this up with any evidence, but 25% of the initial collision energy (31 floors = many tens of thousands of tons moving at 28 ft/s) seems a large amount to lose overcoming the resistance of each floor - I would guess that the real amount lost is *much* smaller. If it was smaller, then the time taken falls again.

What impressed me when I first did this momentum including calculation was the overwhelming effect of the mass of the upper floors. It leads me to conclude that the collapse times are not significant - any collapse that started at floor 80 with all the weight above would be finished well before 20 secs. What is significant is the initiation of the collapse and what brought that about.

My data table and a chart are below - apologies for the number overload, but what can you do ? :)

[spooked911]

20. you act as though the lower supporting structure was paper mache

in fact it was incredibly strong. It is NOT as though any set of upper floors was dropping free-fall for 50 feet onto the floor below. Even then it's not clear that would cause that floor to break down. What you seem to neglect is the strength of the lower building, not to mention the dozen other telltale signs of demolition.

[AlienSpaceBat]

46. No I don't !!

What I have done is to say that 25% of the downward momentum of the top 30 floors was dissipated when they hit floor 80. Rather than treat the lower structure as papier mache I have made the same amount of momentum dissipate 79 times as each floor collapse takes place.

I haven't anywhere allowed anything to fall 50 feet - each floor falls 12.273 feet under gravity. It is then slowed by the dissipation of momentum in the collision with the next floor, and further slowed by the accretion of the mass of the next floor.

Even if I amend the calculation and say that every lower floor takes 2% more than the floor above, so the lowest floors dissipate ~250% of the energy that the first one did, the total time comes out at 18.4 secs.

I thought, overall, that I was saying much the same thing that you were, and I was just providing my calculation in support ??

Repeating myself, I originally thought that the collapse times being anywhere in the region of a free fall time was a smoking gun. After doing the calculation, and seeing the massive effect of the downward momentum of the top part of the towers, I have changed my mind. Because of this effect, a tower collapsing at floor 80 will inevitably collapse within 150% - 250% of the free fall time I think, so the collapse time would be similar whether the tower was deliberately brought down, or came down according to one of the OCT stories (take your pick ..!).

As a result, I think that what is more fruitful to look at is the method of the collapse initiation, and why the central core didn't remain standing etc. These things still appear wrong to me ... FWIW ...

[spooked911]

131. Okay, I understand. Here are my thoughts on the initiation of the destruction...

If the top of the south tower or north tower truly broke off as a chunk and tipped, one could imagine that this large weight would overwhelm the floor slabs on one side directly underneath and fall very rapidly with little slowing. But in that case, one would expect to see:
a) more of an assymetric collapse with the lower core and floors on the oppsite side of the tipping left relatively intact
b) this upper chunk start to progressively fall away from the lower floors and eventually completely fall away from the rest of the tower, leaving the lower portion of the tower intact

If the lower core below the collapse initiation needs to be taken out (as what happened on 9/11), that is going to offer huge resistance and slow things down much more.

So really, the timing very much depends on how the collapse proceeds. If it is complete symmetric collapse involving the core, it will be much slower than what was observed on 9/11.

[DoYouEverWonder]

69. Two questions

Did you take into account that the perimeter walls fell away from the building, they did not go straight down. Therefore weight was relieved, when the top of the building fell away?

Also, did you take into account that all of the mechanical floors had beams, instead of trusses?

[AlienSpaceBat]

119. No I didn't

My calculations are really glorified back of envelope stuff. I didn't have a reasonable idea of how much of the mass would have fallen outside the tower footprint at each floor collision, and I didn't include different strengths for the mechanical floors. I didn't go any further because I know these calculations are nowhere near sophisticated enough to provide accurate results - I do think though that they show the overwhelming nature of the mass driven collapse once it starts at floor 80.

[DoYouEverWonder]

120. Did you know that Floor 80 was special?

edit: Actually it was floor 81 that was really special, but you had to take out floor 80, to release the energy from the weight of the objects on the floor above.

[AlienSpaceBat]

121. I wasn't trying to factor in that kind of element

I know that I don't have detailed enough knowledge to make it meaningful. I was just trying to provide a better analysis of the central point - how much difference (approximately) would conservation of momentum make to the collapse time calculations ?

I was aware of the floors with mechanical equipment, if that's what you are referring to. As I say, I didn't specifically factor them in, and I must admit I thought that they were floors 75/76 anyway ..?

[William Seger]

14. Invalid assumption

Momentum is always conserved in collisions, whether elastic or inelastic. The difference between elastic and inelastic is that kinetic energy is also conserved in elastic collisions, whereas as in inelastic collisions some kinetic energy is lost by bending, breaking, compressing or otherwise permanently deforming stuff, and some is converted to other forms of energy such as heat and sound. But momentum is always conserved, which means that you can use momentum transfer analysis to determine velocities after the collision.

> The first set of calculations will be assuming that 50% of velocity is transferred at each collision of floors.

No, you can't make any such assumption about a constant "transfer of velocity." What you need to do is calculate how much momentum is transferred at each floor and then calculate a new velocity based on the remaining momentum. The amount of momentum transferred to each impacted floor is going to be approximately the same each time (if the mass and strength of the columms were the same, but you can include more accuracy if desired), but if the falling mass is gaining both mass and velocity, then it's also gaining momentum, so the amount transferred is going to be a different (decreasing) percentage of the momentum at each collision, so the loss of velocity is also going to be a decreasing percentage. The first floor impacted might transfer enough momentum that it would decrease the velocity of the falling block by 50%, but then both the combined mass and the velocity at the next impacted floor are going to be greater than the first impact, so the momentum is also going to be greater. Thus the percentage loss in velocity in the second collision is going to be less than the loss in the first. What happened in the collapse of the towers is that the momentum of the falling mass became so large that the amount transferred in each collision slowed the mass less and less, until the momentum transferred was such a small percentage of the total that the falling mass was slowed hardly at all -- "near" free fall.

See Dr. Greening's calculations for an example of one way to solve the problem (in particular, section 3, Momentum Transfer Theory of the WTC Collapse): http://www.911myths.com/WTCREPORT.pdf

Sorry, but the method you are trying to use is just not valid. On the other hand, it's somewhat closer than the method Judy Wood used, since she seems to think that momentum is not conserved in inelastic collisions.

[spooked911]

22. If I assume mass is constant, then momentum is proportional to velocity

As far as the method Judy Wood used, perhaps you could read the appendix to her article that deals with momentum and then maybe you can explain why it is flawed.

http://janedoe0911.tripod.com/BilliardBalls.html

"she seems to think that momentum is not conserved in inelastic collisions."

I don't think that is a fair characterization at all.

[William Seger]

24. Huh?

> If I assume mass is constant, then momentum is proportional to velocity.

Well, the mass wasn't constant, but the rest of the statement doesn't have anything to do with your invalid attempt to analyze the collapse as a constant 50% "transfer of velocity." There's no such thing going on. The percentage loss of velocity at each collision will decrease until it becomes virtually insignificant.

> "she seems to think that momentum is not conserved in inelastic collisions."

I don't think that is a fair characterization at all.

I think it was more than fair. "Bizarre" or "complete idiotic" might be a better characterizations. She apparently added the momentum bullshit at the end of her paper after it was pointed out that she apparently had never heard of the concept. But as nearly as I can make out in that disorganized mess, in order to pretend to be taking that into account without retracting her idiotic conclusion, she's claiming that the "pulverized" mass had a mass of 0, which is nonsense. (First, because only part of the concrete would have been pulverized in the collision -- and NONE of the steel was! -- and second because even then, the mass of the concrete doesn't change because it's pulverized; it stays exactly the same.) And then farther down, she's still claiming that the impacting mass "stopped momentarily" and then started accelerating from 0. In other words, according to Wood, there was NO momentum transferred, and that's just bullshit. College degree of no degree, she has no idea what she's talking about. Prove me wrong: try to find a single physicist who will agree with that nonsense.

[freedom fighter jh]

23. How do you calculate the momentum transferred?

If marble A, moving, hits marble B, still, then marble B may start moving in the original direction of marble A, while marble A reverses course. Try the same thing with two gobs of playdough and they may stick together and move together. In both cases momentum is conserved, but the results of the two cases are very different.

Which of these two cases did the collapse of the towers resemble, or was that case somewhere in between? That is, when a higher floor, or a bunch of higher floors, fell into a lower floor, did the higher floors bounce, or did they merge with the lower floors? This is assuming, of course, that there was some real impact. I'm not sure there was since, as has been pointed out, the upper floors were pulverized, so that air resistance kicked in in a big way. But way there was impact. How can we know how momentum was transferred?

[William Seger]

25. It was inelastic, by definition

> If marble A, moving, hits marble B, still, then marble B may start moving in the original direction of marble A, while marble A reverses course.

That would be an example of an elastic collision (or nearly so, since a perfectly elastic collision is not really possible -- a tiny amount of kinetic energy will be converted to heat, and unless it's in a a vacuum, some to sound). Marble A would back up only if it had less mass than B. If they were the same mass and hit dead-on, then A would stop and B would move on at (almost) the original speed of B, and neither marble would be deformed. Both momentum and kinetic energy are conserved in an elastic collision.

> Try the same thing with two gobs of playdough and they may stick together and move together. In both cases momentum is conserved, but the results of the two cases are very different.

Correct, if the balls stick together, then that's a perfectly inelastic collision; momentum is still conserved but kinetic energy is not because some energy is used deforming the balls. If the balls were the same mass, then they both would continue on at half the speed of A.

The collapse would be an inelastic collision, by definition, because some of the kinetic energy would be lost in deforming steel columns and breaking concrete. To do a reasonably precise analysis of the collapse to determine if the collapse should continue or halt and the collapse time, then, you need to estimate how much kinetic energy was lost in breaking stuff, then proceed with how much was left. Again, see Greening's paper: http://www.911myths.com/WTCREPORT.pdf

> This is assuming, of course, that there was some real impact. I'm not sure there was since, as has been pointed out, the upper floors were pulverized, so that air resistance kicked in in a big way.

Sorry, but that's bullshit, no matter how many times it's "pointed out." First, no steel was pulverized at all; and second, some concrete (and only some) was obviously pulverized after the collision, not before, after which is was carried down in a dense layer with all the other debris. The concrete floors were thin slabs poured on top of steel decking, so that decking would mostly hold the pulverized concrete in place. With the decking below and the debris above, very little of it got free to float around -- a little bit of concrete can make a lot of dust, so you can't really say much by what the dust cloud outside the building looked like -- so most of even the finest dust that was still in the falling debris had mass and momentum.

[freedom fighter jh]

30. Right. You don't know just how elastic or inelastic the collisions were.

So you can't calculate a collapse time based on momentum. If you assume the collisions were perfectly elastic, then you are assuming no energy was lost in them. But that can't be the case, because if it were no energy would be available to pulverize the concrete, shatter the steel, create huge dust clouds, and project pieces of debris with such force that they embedded themselves into buildings across the street. If you assume they were somewhere in between elastic and inelastic -- but you have no idead of just where in between -- you've got no basis for calculations.

Oh, and watch your language. Calling someone else's assertion "bullshit" does nothing to advance the argument. Unless your idea of advancing the argument is to use profanity to distract from the fact that if debris was littered all over downtown Manhattan it was not available to be your piledriver.

[William Seger]

33. Bullshit

Yuck, yuck, I just said that to piss you off. Hey, I said I was sorry that your statement, "assuming, of course, that there was some real impact," was bullshit. But why do you assume I'm trying to "advance an argument" about that? Do you think there is really any serious argument about whether or not there was "some real impact?" Sorry again, but I don't, and when someone tries to "advance an argurment" that's absurd, I call bullshit on it. I suspect you'll get used to it. :)

> If you assume they were somewhere in between elastic and inelastic -- but you have no idead of just where in between -- you've got no basis for calculations.

"No basis?" The calculation will be as accurate as your estimate -- nothing particularly earth-shaking about that observation. How accurate do you want it to be? How would you know if you got it exactly right, when the collapse time that your comparing to is also just an estimate? You can't tell exactly how long it took, because it was obscured by dust. But, anyway, if you read Greening's paper, he observed that the collapse time is not particularly sensitive to that estimate of how much energy was "non-recoverable." He first did a simple calculation that assumed perfectly inelastic collisions, then when back and used a reasonable estimate for the energy lost, and there wasn't much difference. He then made a nice graph that showed the how the collapse time would vary for different estimates of the lost energy, to show how little difference it made. That chart shows, for example, "Thus, even if E₁ were twice as large as our estimated value of 0.6 x 10⁹ J, t_c would only increase by about 0.5 seconds." How can you say there is "no basis for calculations" when any reasonable estimate is more accurate than the time that's estimated from the videos?

> Unless your idea of advancing the argument is to use profanity to distract from the fact that if debris was littered all over downtown Manhattan it was not available to be your piledriver.

First, debris was certainly not "littered all over downtown Manhattan" during the collapse. That mainly happened after it all hit the ground! There was a huge amount of kinetic energy left over when it all hit the ground, and it had to go somewhere. Second, yes, of course the videos show debris falling outside the building during the collapse, but what percentage of the total mass is that? Are you suggesting that enough mass was ejected during the collapse that the collapse should have halted, or the collapse should have taken significantly longer? Please show me your calculations, since Greenings calculations using reasonable estimates for that loss over the side show very little difference. I would seriously doubt that any large percentage of the total mass could be ejected, since most of the debris was trapped in a falling pile that was over 200 feet wide, so the only stuff that could possibly be ejected was stuff near the edges. If you've got an argument that doesn't start with a ridiculous assumption that the tower was "pulverized" in mid-air before it could impact anything, and you've got calculations to back it up, then please "advance" your argument.

[DoYouEverWonder]

54. Why do you have to continue

to personally attack people and call everyone names?

Can't you respond without having to resort to this sort of thing in almost every post?

[William Seger]

57. Because I am your enemy

"Truth movement" my ass.

[greyl]

63. Your post is untrue.

Please, once and for all, learn what a personal attack(ad hominem) is. Bluntly stating that an argument is total fucking bullshit is not a personal attack, no matter how bad it makes someone feel.
If Seger's posts only consisted of curt statements, I could understand why you may want to encourage him to offer a better formed argument. However, I think the inability to counter his arguments led you to personally attack him. You might as well check the definition of hypocrisy while looking at ad hominem.

[DoYouEverWonder]

70. I will not discuss issues with people

who have to resort to insults and putdowns. And I will call people on it when they do it.

Maybe it's my background in early childhood ed, but I don't tolerate this behavior in 4 years olds, I refuse to tolerate it in adults.

[greyl]

81. You personally attacked him.

Do you also think George Carlin speaks on a 4 year old level?

[DoYouEverWonder]

83. Carlin doesn't

attack members of his audience.

There is a difference you know.

[greyl]

85. Yeah, Carlin does, but in this case, Seger did not. You did.

Ad Hominem (Argument To The Man){personal attack}:

...........
A variation (related to Argument By Generalization) is to attack a whole class of people. For example, "Evolutionary biology is a sinister tool of the materialistic, atheistic religion of Secular Humanism." Similarly, one notorious net.kook waved away a whole category of evidence by announcing "All the scientists were drunk."

Another variation is attack by innuendo: "Why don't scientists tell us what they really know; are they afraid of public panic?"

There may be a pretense that the attack isn't happening: "In order to maintain a civil debate, I will not mention my opponent's drinking problem."*

*another example:

DoYouEverWonder: "I will not discuss issues with people who have to resort to insults and putdowns." - "Why do you have to continue to personally attack people and call everyone names?" - "Can't you respond without having to resort to this sort of thing in almost every post?"

Sometimes the attack is on intelligence. For example, "If you weren't so stupid you would have no problem seeing my point of view." Or, dismissing a comment with "Well, you're just smarter than the rest of us." (In Britain, that might be put as "too clever by half".) This is related to Not Invented Here, but perhaps it is more connected to Dismissal By Differentness and Changing The Subject.

Ad Hominem is not fallacious if the attack goes to the credibility of the argument. For instance, the argument may depend on its presenter's claim that he's an expert. (That is, there is an Argument From Authority.) Trial judges allow this category of attacks.
www.don-lindsay-archive.org/skeptic/arguments.html#hominem

Is the problem that you mistakenly believe that calling someones argument bullshit is a personal attack?

[Grateful for Hope]

86. Maybe you OCT'ers would be more respected

if you did not use such terms as "bullshit" to argue points, and, if each of you would fight your own battles. The "tag team" effort is particularly tiresome, in my opinion.

[Grateful for Hope]

88. Please see response # 87

Case in point.

:rofl:

[Name removed]

90. Deleted message

Message removed by moderator. Click here to review the message board rules.

[AZCat]

91. "Tag Team" effort? Please define this for me.

And I fail to see how profanity has anything to do with the quality of the points in an argument. If you have a problem with profanity, then this probably isn't the site for you. I'm sure there are internet forums where the administrators have banned profanity where you would be more comfortable.

[greyl]

93. You know, like post 86.

She provided an example of "Tag Team" effort in the very post she ridiculed its use, for our convenience.

[AZCat]

94. ?

Maybe I'm a little slow tonight, but there didn't seem to be any example in her thread.

:shrug:

[Bolo Boffin]

95. Hope 2006 "tag-teamed" when she was decrying "tag-teaming".

Her post 86 was a perfect example of tag-teaming. Was she involved in the conversation before post 86? No.

[AZCat]

96. Oh - duh.

That's tag-teaming? Jeez - what would internet forums be without people jumping in to discussions unbidden? I figured it had to be something else (what, I dunno).

[Bolo Boffin]

98. I guess that's tag-teaming.

Hope, could you be so good as to reply to this message of mine and explain what you meant by "tag-teaming"? Or if I've read you correctly, just reply with a Yes.

Thanks, and pet those pretty kitties on the head for me! :)

[greyl]

101. Well, we can't rule out that they define it differently than we do. ;)

It's a mystery for the ages, I guess.

[AZCat]

108. Hopefully not that long.

I hope the answer will soon be forthcoming.

[Kingshakabobo]

97. She jumped in the middle of an argument and took up sides....

.....Using: "you know you OCTers bla, bla bla".......

[greyl]

99. but provided zero persuasive argument. It was no help at all, and only changed the subject.

Maybe she thinks the interruption was necessary because she has a low opinion of debating ability of the person she interrupted? It amounted to a pro wrestler farting at the opposing team through the ropes. :)

[AZCat]

100. I must admit I've never seen that.

The farting part, I mean. Not that I wouldn't put it past them.

[greyl]

104. Neither have I.

It was the first fun analogy I came up with. ;)

[AZCat]

105. Well don't let Vince McMahon (sp?) see your post.

Professional wrestling doesn't need any more ideas...

[AZCat]

102. But we ALL do that!

I'm withholding my judgement until Hope2006 replies with a clarification.

[Kingshakabobo]

106. That's the point! We do, but we don't cry "tag team"........n/t

[AZCat]

107. No, we don't, but I'm waiting to see if that's the definition that Hope2006 uses.

It would have been nice if her post had been more clear, but perhaps she felt the definition was obvious (at least to her).

[Bolo Boffin]

112. Hope has responded!

Why she won't reply to my post (she's allowed to), I don't know.

Anyway, below, she says this:

Hope2006 Wed Jan-10-07 05:44 AM
Response to Reply #109
110. Exactly right

and, it has taken at least 6 OCt'ers in this thread alone to attack your point of view as well as mine.

Tag team effort -- this thread is an example.

She has obviously confused the idea of "pile-on" with "tag team". I reject either characterization of what's going on here, of course. And Hope, you still have not addressed the fact that you jump into conversations yourself, all the time - in support of people's positions. You act exactly the same way you deplore when manifested in other people.

[Grateful for Hope]

113. au contraire

I used to jump in, but, I disliked being ganged up on by five or six members so I pretty much stopped posting with some rare exceptions. This thread is an exception as I think the ganging up needed to be pointed out.

Stick with your point of view, and I'll stick with mine. You in no way convince me of anything.

[Bolo Boffin]

87. Maybe CTer's would be respected...

...if their arguments weren't bullshit.

Hope2006 Wed Jan-10-07 12:15 AM
Response to Reply #85
86. Maybe you OCT'ers would be more respected

if you did not use such terms as "bullshit" to argue points, and, if each of you would fight your own battles. The "tag team" effort is particularly tiresome, in my opinion.

[greyl]

89. That's the triple truth, Ruth.

What's with the prudish reaction to adult language? Oh right, lack of an argument that isn't bullshit.

[William Seger]

92. LMAO !

Poor sensitive Hope2006 has me blocked from replying to her, so thanks, tag team!

[Kingshakabobo]

103. There seems to be a lot of that going on around here......

If I didn't know better, I would think there is a conspiracy....


aaack! I said conspiracy!

[DoYouEverWonder]

109. For example, It is one thing to say

'No, you are wrong, the Towers did not have a concrete core, they were clearly made of steel' has opposed to saying, 'You're a liar, an idiot, or a jerk because you think the Tower had a concrete core and because of this you are a bad person who has no value or crediblity.'

Sometimes it's not what someone says, it's how they say it, that's the problem.

[Grateful for Hope]

110. Exactly right

and, it has taken at least 6 OCt'ers in this thread alone to attack your point of view as well as mine.

Tag team effort -- this thread is an example.

[greyl]

111. Not all examples are so obvious, but maybe we're getting somewhere.

Not personal attacks:

"No, you are definitely wrong, the Towers did not have a concrete core, they were clearly made of steel"

"No, the asinine claim that the Towers had a concrete core and were not made of steel is utter pathetic bullshit and belongs in a septic tank with rancid dead rats from hell."

Personal attacks:

"No, sir or ma'am, I'm sincerely dismayed that you must be so woefully lacking in cognitive ability to believe that the Towers did not have a concrete core and were clearly made of steel"

"No, only a bushco shill would repeat the claim that the Towers did not have a concrete core and were not made of steel."

Personal attacks are defined by what is said, not how something is said. Words have meaning.
Attacking attributes of a point of view, a statement, or an argument is fine.
Attacking attributes of a person who has the point of view is not.

[freedom fighter jh]

114. Speaking as the target of that attack . . .

. . . I can tell you it felt pretty personal.

I don't see that DYEW said it was "ad hominem." She said it was personal, and it was. When you respond to a statement with a word that aims at eliciting negative emotions, that's personal. Didn't he later say he'd said it just to make me mad? Oh, and if he was only kidding when he said that, then he said "bullshit" to express contempt about me so that what I said would be disrespected.

Thank you, DYEW, for stepping in.

[greyl]

115. You can't, because you weren't the target. Your statement was.

Personal attack = ad hominem.

If someone takes it personally when a statement of theirs on a discussion board is called bullshit, they may consider not making statements on discussion boards.

Sorry, but it looks to me like the "ruffled feathers" due to PG rated language is only an attempted distraction from the facts, evidence, and opinions being discussed. Check out Harry Frankfurt's book On Bullshit for more info.

edit: to recap, the following statements were total bullshit: "Why do you have to continue to personally attack people and call everyone names? Can't you respond without having to resort to this sort of thing in almost every post?"
They're bullshit because there was no personal attack, let alone continual personal attacks, and there was no name calling.

[William Seger]

117. Well, you misunderstood

My reply to your request that I "watch my language" was titled "Bullshit", and that was the one I said just to piss you off -- just my subtle way of letting you know that I am watching my language, thank you. The original post that you took such personal offense to was my reply to you saying this:

> This is assuming, of course, that there was some real impact. I'm not sure there was since, as has been pointed out, the upper floors were pulverized, so that air resistance kicked in in a big way.

I try to choose my words carefully to express myself as clearly as I can, and "bullshit" is a reply that I generally use only when I find a remark that's particularly insulting and offensive not just to my intelligence, but to what I take as ordinary common sense. That was bullshit, and I certainly wasn't joking to tell you so. If you had a "personal" "negative emotional" response to me telling you so, well, either stop posting bullshit or grow a thicker skin.

[DoYouEverWonder]

55. You once again prove

your logic is deeply flawed.

Some concrete (and only some) was obviously pulverized after the collision, not before

You've got to be kidding? The entire contents of the floors above the impact zone were pulverized before the building even started to collapse.

If you believe that 'the decking would mostly hold the pulverized concrete in place', then where are the pancakes of steel and concrete decking in the rubble pile?

Oh and the one piece they have at Hanger 17 is not two towers worth of pancakes.

[Bolo Boffin]

56. Which DoYouEverWonder post should we believe?

This one at Mon Jan-08-07 07:34 AM, where you claim, "The entire contents of the floors above the impact zone were pulverized before the building even started to collapse"...

Or this one at Mon Jan-08-07 05:45 AM, where you claim, "On the top section of each tower they just need to cut two of the four corners of the first floor they wanted to drop"?

I'd be interested in seeing you reconcile these two posts, that you made within two hours. What mechanism do you propose for the pulverization of the entire contents of the floors above the impact zone, if you only think thermite was used to cut two of the four corners on the first floor they wanted to drop?

You do understand that these positions are mutually exclusive of each other?

[DoYouEverWonder]

75. Well, if you want to take things out of context

and reconnect pieces, you can make up anything you want.

Why don't you post at least the whole paragraph or the first link, so that people can see that I was talking about two different things?

[Bolo Boffin]

76. I provided links to all necessary posts.

The other post in the other thread is linked. The post I was replying to is linked (through the Response to Reply # link in every DU post).

You are clearly talking about the top section of both towers. In one place, you say that the entire contents of the upper sections were pulverized. In another place, you say that the planners of this controlled demolition only had to knock out two of four columns.

Please explain this contradiction.

[DoYouEverWonder]

77. The comment about the corners

was in regards to the use of thermite. My point was that if there was any pre-cutting of beams to weaken the structure so that it would fall in a certain way, they just need to take out a few key points, not every beam.

The event that actually blew up the buildings, was another matter entirely and my theory is that some kind of gas or accelerant was used.

[Bolo Boffin]

82. The comment about the corners is your theory, too.

However, if my theory is correct and they only needed to take out two corners in the top section, then they would know that the planes aiming at the center of the buildings wouldn't have been a problem.

Which is your real theory?

[William Seger]

58. "Deeply flawed" logic?

Apparently, my eyesight is much better than yours, but if my logic is "deeply flawed," it should be trivial to point out the flaws.

> The entire contents of the floors above the impact zone were pulverized before the building even started to collapse.

Gosh, I know how sensitive you are, so I really hate to say this, but that appears to be similar to that stuff that falls out of a bull's butt. I certainly don't see any such thing going on from outside the building. Please show me some pictures from inside the building showing that the "entire contents of the floors above the impact zone were pulverized before the building even started to collapse."

> If you believe that 'the decking would mostly hold the pulverized concrete in place', then where are the pancakes of steel and concrete decking in the rubble pile?

Well, slight flaw in your logic there: I'm only referring to what would "logically" happen between the time when one floor got hit and when that floor hit the next floor below; other than some stuff near the edges, most of the pulverized concrete could not just blow away, so it would contribute to the momentum and kinetic energy hitting that floor. What happened after that, as it all continued to be ground up with columns in the falling debris pile, and especially when it all hit the ground with huge amounts of kinetic energy left over, that would be a different story.

[TheWraith]

116. The upper floors certainly wouldn't pause on each lower floor. That's just wrong.

The pile-driver analogy is more apt. While the lower floors would slow down the collapse, they would buckle long before they'd absorbed even a fraction of the momentum of the upper sections. They certainly wouldn't have brought the whole mass to a standstill for 1.5 seconds per floor, making the idea that the building should have taken 97 seconds to collapse just wrong. The safety margin for dynamic load wouldn't have been anywhere close to high enough for that.

[CB_Brooklyn]

128. Massive Energy Releases

Erupting Volcano: Massive Energy Release

Nuclear Blast: Massive Energy Release

World Trade Center: Massive Energy Release??

Fire/Impact Damage? Explosives? High Energy Exotic Weapon?

[spooked911]

129. Welcome to DU, CB!

[DoYouEverWonder]

130. Don't you know that skyscrapers made of steel

will do this if you fly a passenger jets into them? :sarcasm:

It took a massive amount of energy to do this to two 110 story steel buildings. However, I don't think they needed anything very 'exotic'. I think they had everything they needed already on site. There was lot's of fuel, chemistry, steam and the mechanical systems necessary to deliver it already there.

9-11 was an inside job, in more ways then one.

BTW: Welcome to the DUngeon :hi:

[William Seger]

132. Absolutely, yes, it was a "massive energy release"

It was equal to the energy required to lift almost a half-million tons for each tower about 600 feet in the air. The kinetic energy stored in each tower, due to lifting all that mass against the force of gravity, made the energy of each collapse approximately equal to 270 tons of TNT. That's like dropping 270 of the large 2000 lb "smart bombs," all directly on target. What would you expect 270 tons of TNT to do to that building, or any similar sized building?

(Edit to clarify that the calculation is for each tower.)

[CB_Brooklyn]

133. It turned to powder from the top down

How can a "gravity collapse" explain that?