Why a one-way Crush down is not possible

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Andrew, relative to your post 763

No need to have "brittle" steel : connections between columns and floors are destroyed in at last two floors, so "buckling resistance" (sorry I don't know how to translate exactly "résistance au flambement") is divided by 9, if you add loss of strength due to heat, figure what happens !
 


No sorry but steelwork is not "super brittle" with "no heat" during a "smashing" impact. If it were it would not gradually crush during a vehicle impact to decelerate the occupants of the car. If steelwork were brittle it would disintegrate like a toughened bit of glass and the car occupants would hit the thing they were going to hit a lot harder and faster.

Holy strawman. Those were your words, not mine.

FYI- You guys need to take a closer look at controlled demolitions.The dust cloud is ejected by the collapse, not the explosives.
 
Jim Hoffman (October 16th, 2003) actually calculated that:
* 111,000 KWH is generated by the collapse of each tower.
* 135,000 KWH is needed to crush the concrete.

That figure is highly sensitive to the starting assumptions about how finely crushed the concrete was, and can vary by several orders of magnitude either way. Hoffman assumed that all the concrete was crushed to a particle size of 140µm, based on the samples of wind-borne dust collected half a mile from the WTC, and ignored the fact (since highlighted by, of all people, Steven Jones) that a very large proportion of the dust was in fact found in much larger fragments, typically several centimetres in size. Re-calculate Hoffman's numbers with a larger particle size distribution, based on what was actually observed rather than a biased guess, and this energy requirement becomes much more negligible.

* 2,682,000 KWH is needed to create the dust cloud (this assumes a sufficient source of water or this figure increases dramatically).

This is based on the completely unsupportable assumption that the dust clouds cannot have exceeded the original volume of the towers by any means other than thermal expansion or vapourisation of water from some unknown source. In fact, if the possibility is considered that the dust cloud could have expanded by mixing with air outside the towers, a process Hoffman has never advanced an argument against, other than the strange assertion that the dust cloud appeared to have a well-defined boundary and hence could not have mixed with ambient air, then this energy requirement becomes zero.

But let's imagine that Hoffman's numbers were correct; how much explosive (or thermite; the energy content is about the same) would be needed to release this amount of energy? You're arguing that an additional energy of 2,700,000kWh is needed. Converting that into sensible units at 1kWh=3.6MJ, we need an additional 9700GJ of energy. Thermite and most explosives have an energy density of around 4-5MJ/kg; let's assume 100% efficient energy release and the upper limit, so we need 1940000kg of explosive to supply the energy Hoffman claims was released.

That's TWO KILOTONS of high explosive.

I'll say that again.

TWO KILOTONS.

Your claim is therefore that two kilotons of explosives was packed into the Twin Towers, and exploded in the course of their collapses.

I'm going to stop there, because nobody sane could view the videos of the events, listen to the soundtracks, and read the accounts of the witnesses, and believe that the limited-scale explosions heard by firefighters and the small dust ejections obsessed over by truthers were caused by two kilotons of high explosive going off.

Really. Two kilotons. That's what you're asking us to believe.

Dave
 
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Jim Hoffman (October 16th, 2003) actually calculated that:
* 111,000 KWH is generated by the collapse of each tower.
* 135,000 KWH is needed to crush the concrete.
* 2,682,000 KWH is needed to create the dust cloud (this assumes a sufficient source of water or this figure increases dramatically).
This means that 122% of the total gravitational collapse energy available was necessary just to pulverise the concrete (let alone create the dust cloud), that is, more energy was needed just to pulverise the concrete than was generated by the collapse. This, of course, means that explosives, thermite or some other energy source must have supplied the extra energy.

I theorise that since WTC 1 and 2 were open plan office spaces they would have had raised technical services metal square flooring. In open plan office spaces you need to be able to wire the office services (electricity, telephone, Ethernet etc.) to a spot underneath each workstation desk. This means that you need raised removable square-panel technical flooring (and normally cosmetic decoration square carpet tiles on that) which leaves a gap above the concrete floor slab, beneath your feet, where the wires can run. This convenient technical services space would be a good place in which to spread your hypothetical nano-thermite compound, during out of office-hours periods (nights, weekends and public days-off work festivals like Christmas etc.) Such building (sophisticated First World militaristic) sabotage efforts would of course be completely invisible to the office workers using the office space, if carried out during the weeks before the extravagant 9/11 terrorist "shock and awe" event.

Wouldn't all those workers packing explosives under the floor interfere with those who are installing the 2 million explosive tiles?
 


No sorry but steelwork is not "super brittle" with "no heat" during a "smashing" impact. If it were it would not gradually crush during a vehicle impact to decelerate the occupants of the car. If steelwork were brittle it would disintegrate like a toughened bit of glass and the car occupants would hit the thing they were going to hit a lot harder and faster.

Obviously, you know nothing about cars either. You do realize that they are engineered to crumple in a certain way for passenger safety. You should also realize that many of the components do shear to accommodate this crumpling.

Comparing steel used in the WTC to steel in cars is laughable.
 
....I theorise that since WTC 1 and 2 were open plan office spaces they would have had raised technical services metal square flooring. In open plan office spaces you need to be able to wire the office services (electricity, telephone, Ethernet etc.) to a spot underneath each workstation desk. This means that you need raised removable square-panel technical flooring (and normally cosmetic decoration square carpet tiles on that) which leaves a gap above the concrete floor slab, beneath your feet, where the wires can run. This convenient technical services space would be a good place in which to spread your hypothetical nano-thermite compound, during out of office-hours periods (nights, weekends and public days-off work festivals like Christmas etc.) Such building (sophisticated First World militaristic) sabotage efforts would of course be completely invisible to the office workers using the office space, if carried out during the weeks before the extravagant 9/11 terrorist "shock and awe" event.

That is certainly a novel way to demolish a building. By attacking the concrete floor decks.

And it gets around all the difficulties associated with conventional explosives with their need to contact/close proximity to steel they are to cut AND "det cord wiring" which has to remain invisible.

Yes the idea needs a special place in the ranking of "truther demolition schemes".


:D
 


Jim Hoffman (October 16th, 2003) actually calculated that:
* 111,000 KWH is generated by the collapse of each tower.
* 135,000 KWH is needed to crush the concrete.
* 2,682,000 KWH is needed to create the dust cloud (this assumes a sufficient source of water or this figure increases dramatically).
This means that 122% of the total gravitational collapse energy available was necessary just to pulverise the concrete (let alone create the dust cloud), that is, more energy was needed just to pulverise the concrete than was generated by the collapse. This, of course, means that explosives, thermite or some other energy source must have supplied the extra energy.

I theorise that since WTC 1 and 2 were open plan office spaces they would have had raised technical services metal square flooring. In open plan office spaces you need to be able to wire the office services (electricity, telephone, Ethernet etc.) to a spot underneath each workstation desk. This means that you need raised removable square-panel technical flooring (and normally cosmetic decoration square carpet tiles on that) which leaves a gap above the concrete floor slab, beneath your feet, where the wires can run. This convenient technical services space would be a good place in which to spread your hypothetical nano-thermite compound, during out of office-hours periods (nights, weekends and public days-off work festivals like Christmas etc.) Such building (sophisticated First World militaristic) sabotage efforts would of course be completely invisible to the office workers using the office space, if carried out during the weeks before the extravagant 9/11 terrorist "shock and awe" event.

Do you not think that he stuff would have to be inside the concrete to do such a uniform job of the pulverisation ? And to vapourise all the reinforcing mats of steel mesh ? If the heat had been applied from only one side I get the impression we would see as much fragmentation as pulverisation.And where are the floor pans ?
 
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Jim Hoffman (October 16th, 2003) actually calculated that:
* 111,000 KWH is generated by the collapse of each tower.
* 135,000 KWH is needed to crush the concrete.
* 2,682,000 KWH is needed to create the dust cloud (this assumes a sufficient source of water or this figure increases dramatically).
This means that 122% of the total gravitational collapse energy available was necessary just to pulverise the concrete (let alone create the dust cloud), that is, more energy was needed just to pulverise the concrete than was generated by the collapse. This, of course, means that explosives, thermite or some other energy source must have supplied the extra energy.

Hoffman withdrew these theories/calculations years ago
 
Hoffman withdrew these theories/calculations years ago

Well, no, he didn't, exactly. He announced that he was working on a revision to account for the two minor problems with his theory; namely, that the dust cloud wasn't hot enough that anyone caught within it was instantly boiled to death, and that even if the concrete in the floors had somehow been still wet from pouring over thirty years earlier it still would have a few orders of magnitude too little water in it. As far as anyone can tell, he's still working on that revision, but version 3 is still available online as a trap for those unable to assess the sanity of its conclusions.

Dave
 
Do you not think that he stuff would have to be inside the concrete to do such a uniform job of the pulverisation ? And to vapourise all the reinforcing mats of steel mesh ? If the heat had been applied from only one side I get the impression we would see as much fragmentation as pulverisation.And where are the floor pans ?


http://911research.wtc7.net/wtc/evidence/plans/table.html

Just google let your fingers do the walking.
 


The steel used in constructing skyscrapers is not brittle, but ductile, and very strong indeed in compression and tension. That is why skyscrapers around the world do not shatter, explosively, as frequently as they did on 9/11 in New York. It would be extraordinarily dangerous to build skyscrapers out of brittle steel and since they could not move, flex and sway in winds or earthquakes, I expect we would have all witnessed the folly of using brittle steel in skyscrapers many times, a long time ago.

My point is that brittle is a relative variable.

So is your contention (I am detecting "no-planer" territory here) that the planes could not have passed through the outer frame of the building because the steel columns were ductile?

TAM:)
 
Well, no, he didn't, exactly. He announced that he was working on a revision to account for the two minor problems with his theory; namely, that the dust cloud wasn't hot enough that anyone caught within it was instantly boiled to death, and that even if the concrete in the floors had somehow been still wet from pouring over thirty years earlier it still would have a few orders of magnitude too little water in it. As far as anyone can tell, he's still working on that revision, but version 3 is still available online as a trap for those unable to assess the sanity of its conclusions.

Dave

Yeah, that rings a bell now. Thanks.

Didn't Hoffman originally use the Lioy et al 60micron average particle size and extrapolate it right back to the entire concrete contents of WTC, thus calculating an insane amount of energy sunk into concrete dustification? Is that the same Hoffman that Andrew quotes?

Andrew ... perhaps you can clear this up?
 
Off topic but the Nose Out theory complains that the UA175 aircraft (theoretically assumed CGI artefact) passed through the building and the nose popped out amazingly unharmed and with no loss of momentum.

Who on earth would be so stupid as to think that the lightweight (carbon fibre?) nose cone would be the object seen as the first item exiting WTC2? Had to be an engine, landing gear or - conceivably - some dense object from within WTC2 itself.

eta: are you Andrew Johnson, once of the UK 9/11 forum?
 
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Who on earth would be so stupid as to think that the lightweight (carbon fibre?) nose cone would be the object seen as the first item exiting WTC2? Had to be an engine, landing gear or - conceivably - some dense object from within WTC2 itself.

Looking at the shadows and the way that it all turned to flame when they kept the video running, I would say it was just a thin layer of jet fuel expelled from one floor only, caught edge-on by the camera.
 
Folks, I'm getting tired of moving blocks of posts to AAH . I hate handing out infractions for Rule 11 but you are making it difficult to do anything else.

So instead, consider this a strongly worded mod directive:

  1. Stay on topic (even if someone else has started the derail).
  2. Stop bickering
Ignoring this mod directive may result in infractions or more severe penalties.

I don't know how to make this any more clear.
Replying to this modbox in thread will be off topic  Posted By: Tricky
 
Yesterday I posted the statement below thinking that it paraphrased Newton's similar law. 'Every action has an equal and opposite reaction'. However several posters came back and told me that my statement is in fact incorrect. So thinking as I still do that it is applicable and immutable let it henceforth be known as 'Smith's Law'

Smith's Law
''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 is used up first.''

Smith's Nightmare
For every simple aspect of reality supported by conclusive evidence there is an overwhelmingly complicated explanation supported by paranoid self-deluding conjecture
 
Andrew; said:
Off topic but the Nose Out theory complains that the UA175 aircraft (theoretically assumed CGI artefact) passed through the building and the nose popped out amazingly unharmed and with no loss of momentum.

GlennB; said:
Who on earth would be so stupid as to think that the lightweight (carbon fibre?) nose cone would be the object seen as the first item exiting WTC2?
I will try to drag this detour that I did not invite back on topic (not easy, but read on). Nobody thought that, nobody thought that the lightweight (carbon fibre?) nose cone could do that, which is precisely why it became a "theoretically assumed CGI artefact". The problem is that most people naively, automatically, apparently will assume that "TV is reality", but as the fictional "Wag the Dog" movie warned us, that is not necessarily so.

GlennB; said:
Had to be an engine, landing gear or - conceivably - some dense object from within WTC2 itself.
A UA175 designated engine turned up at Church and Murray, some people claimed that it was from a smaller aircraft than the one advertised in the official narrative. Quite why that should be the case, if this size issue is a genuinely valid criticism, escapes me, since it sounds like a grotesquely careless and stupid "military deception" operational error; unless it was not an error at all, but a political Hegelian Dialectical "Easter Egg". The wingspan entry wound was also apparently not wide enough, for the aircraft that was advertised in the official narrative.

However, the lack of a loss of momentum on the Nose Out video would still be a problem if the "nose" were something else from a genuinely video recorded "material object" aircraft, rather than the nose. The pixel shape was apparently of the "nose leaving the WTC2 north face unscathed", without slowing down inside the building, not of an engine which would have been behind the nose and should have exited the building later anyway. It looks to me rather like either a massively important video fraud happened on 9/11 itself, or a relatively minor video fraud has happened since 9/11, by some mischievous troublemakers. I do not know and I cannot know which theory is correct, because video is obviously not very reliable as a form of evidence.

Topic link. So we have the steel frame of the building behaving apparently rather strangely on 9/11, but in a somewhat consistent manner. When an apparent aircraft flies into the steel frame building it does not seem to decelerate inside the building. If the object that flew out the other side was not the nose (the nose was the apparent shape) but an engine, then the engine actually accelerated whilst inside the building.

Vertical crush down collapse topic. When the top load suddenly falls on the intact tower below (by whatever process, exploding pancake, tiredness, magic) it crushes down the building in an amazing low resistance manner. Even though the WTC2 top load disintegrated upwards faster than it could fall downwards and the top was more weakly constructed than the tower below that it was theoretically impacting. So, the "gathering snowball effect" theory is that 40% of the top load was ejected outside the tower footprint during the first couple of seconds of the collapse process when the top load disintegrated. This left 60% of the normal static weight (mass x gravity) of a loosely arranged "snowball of disassembled building components" falling as a dynamic "heavy rain" load on the intact, redundantly over-engineered and very robust tower below. Not falling as a contiguous robust "sledgehammer load", but as heavy rain. Not like as a "sandbag" dropped from the top of a building on the head of an unsuspecting person below, but as the contents of a sandbag dropped from the top of a building. What is the difference? An intact sandbag would kill you, break lots of bones in your body, but loose dry sand falling on you would put sand down the back of your neck and probably only irritate you.

So when the WTC2 tipped-over-top disintegrated upwards faster than it could fall down, it did so explosively, which is to say stuff flew in all directions at once, up, down and sideways. The ripple-down explosive collapse process below the exploding top, in the initial stages, was also faster than the now disassembled top-load components could keep up, as they fell out of the sky, 40% outside of the tower footprint. It is difficult for me to see how gravity alone could achieve all of these strange effects. The hypothesised gravity motivated "heavy rain snowball" was evidently not causing the ripple down explosive collapse process, or causing the apparently explosive (presumably mistimed) squibs even lower down the tower than the main rapidly descending demolition wave front. How did the hypothetical "heavy rain" break the lateral floor connections between the core columns and perimeter columns so easily? Or break out the "barrel banding effect" of the perimeter column tube, or crush down the core columns, or crush the concrete etc. in such an apparently effortless resistance-free manner in such a short time frame? I really do not know but I think that the distortion of space called "gravity" only really supplied the energy to get the already disassembled, by some other energy means, building down to the ground.

GlennB; said:
eta: are you Andrew Johnson, once of the UK 9/11 forum?
No.

leftysergeant; said:
Looking at the shadows and the way that it all turned to flame when they kept the video running, I would say it was just a thin layer of jet fuel expelled from one floor only, caught edge-on by the camera.
The quick "fade to black" part of the theory was that the video did not actually keep running, because the terrorists made a semi-live "Wag the Dog" type video error during the 17-second time delay. Which the terrorists, in charge of this "shock and awe media propaganda narrative", corrected by the quick fade-to-black, when they spotted the unfortunate SNAFU "nose out" problem developing.
 
Didn't Hoffman originally use the Lioy et al 60micron average particle size and extrapolate it right back to the entire concrete contents of WTC, thus calculating an insane amount of energy sunk into concrete dustification?

Yes, but that's a fairly common truther misconception. Kenneth Kuttler makes a similar assumption in his paper, and subtracts the required energy from the kinetic energy at each floor impact, so he's not even considering the possibility that concrete could have been pulverised by its final impact with the ground. Where Hoffman really clears the shark's fin by about 30,000 feet is in his assumption that the dust cloud couldn't have mixed with ambient air, and therefore could only have got bigger by thermal expansion or by the generation of steam from an unknown source of water. The concrete pulverisation argument only inflates the energy requirements to just a little more than the potential energy available, which no doubt wasn't enough for Hoffman's agenda; the dust cloud expansion argument gives him a requirement for about 10-20 times the potential energy, which would be rather harder to explain if it had the slightest basis in reality.

Is that the same Hoffman that Andrew quotes?

Yes, no possible doubt that it's the same one. The numbers and publication date are the same.

Dave
 
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