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Author Topic: 9/11 debate - enter at your own risk!  (Read 968814 times)

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Also I understand there was a real corrosion problem with the aluminum fascia that covered the steel beams. Some say the fascia sections would routinely fall off due to corrosion between the dissimilar metals and the humidity from the harbor.


 Could this be the source for all the red and gray flakes that are somewhat similar to thermite in the WTC dust?

Thermite is aluminum and iron oxide (rust) combined.


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Sulfur and the World Trade Center Disaster
 
Very interesting.
   
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Could this be the source for all the red and gray flakes that are somewhat similar to thermite in the WTC dust?

Thermite is aluminum and iron oxide (rust) combined.

I don't have a chemistry or metallurgical background so I will defer to someone who does. From my own experience, I will say that aluminum oxide builds up into quite thick layers once it starts (if humidity is present) , and may be able to form a reaction with the iron oxide if a high temperature is available to ignite it. Maybe the Prof can shed some light on this.

It is an excellent point to be considered.


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[ This does require that essentially NO MASS be in the way of the falling upper portion of the building -- for OVER 100 FEET, that is, 8-floors-worth of mass had to be moved.  

Can you dispense with the hot red text, please.

"In Stage 2, the north face descended at gravitational acceleration, as the buckled columns provided negligible support to the upper portion of the north face. This free fall drop continued for approximately 8 stories or 32.0 m (105 ft), the distance traveled between times t = 1.75 s and t = 4.0 s."

Big whoopee. If you read the final report, the why of that 8 or so floors of missing 'mass' is not a mystery. Columns buckling from fire, and the floors giving way en masse, all collapsing on the inside, leaving the shell to fall at gravity speed, mimics implosion. Does not mean it happened.


Whenever I read the fringe stuff regarding 9/11, I go off looking for evidence to support their views, and like some 9/11 Romero Device, come away lacking. So, after seeing Mr. Implosion vids 1-3, I think, ok, maybe Silverstein had it detonated for insurance money (something much more likely than any gubment anything). But then I read up on what's required. I read up on the sounds that need to be there, which are missing. I read the evidence for a non-conspiratorial cause, including most all of the official final report, which answers, rationally, many of the questions posed here on this forum, yet I cannot see that it was actually imploded.

I can see that the process mimicked it, and (some) people need to say that it was imploded, thusly.

It's kind of like having somebody come around after a fire which lightning started though, and calling it arson, because they found a point of origin which fit the criteria.


   

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I don't have a chemistry or metallurgical background so I will defer to someone who does. From my own experience, I will say that aluminum oxide builds up into quite thick layers once it starts (if humidity is present) , and may be able to form a reaction with the iron oxide if a high temperature is available to ignite it. Maybe the Prof can shed some light on this.

It is an excellent point to be considered.

I don't mean that it exploded, I just mean that a lot of this red and gray dust could easily have been created by the collapse of the buildings.  Aluminum with its layer of aluminum oxide, which is corundum or saphire and is used on sand paper, grinding down with the collapse, the rust on the steel beams.  I would think a lot of dust comprising aluminum and iron oxide would be created, which may be the stuff Physics Prof has studied and wrote his papers on.  


---------------------------
"Whatever our resources of primary energy may be in the future, we must, to be rational, obtain it without consumption of any material"  Nicola Tesla

"When bad men combine, the good must associate; else they will fall one by one, an unpitied sacrifice in a contemptible struggle."  Edmund Burke
   
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Also I understand there was a real corrosion problem with the aluminum fascia that covered the steel beams. Some say the fascia sections would routinely fall off due to corrosion between the dissimilar metals and the humidity from the harbor.

I'm interested in what Chet was told on this issue. It was fairly common in and around Lower Manhattan. I designed and assisted in the installation of many of the backup Diesel/Gas electric power plants in those buildings for about 20 years, including the twins & building 7. We also had issues when using aluminum.

Liberty & Ellis Islands use my switchgear and control systems (sorry, no whoop dee do emoticon)
   

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I just posted a report on "Sulfur and the World Trade Center Disaster"

Quote
Appendix C of the well-known FEMA Report on the collapse of buildings at the WTC on September 11th,
2001, focuses on two samples of badly corroded structural steel removed from the WTC debris field, /See
Ref 1/. The authors of Appendix C, namely J. Barnett, R.R. Biederman and R.D. Sisson Jr., describe
metallographic sectioning and EDS (X-ray fluorescence) analyses of two samples and show that iron
sulfide, FeS, surface deposits are associated with the severe corrosion of the steel.
In an interview
published in the Spring 2002 issue of WPI Transformations, Barnett et al. speculate how the steel was
sulfided in the manner observed, but note that:
"The important questions are how much sulfur do you need, and where did it come from? The answer
could be as simple--and this is scary- as acid rain…… We may have just the inherent conditions in the
atmosphere so that a lot of water on a burning building will form sulfuric acid, hydrogen sulfide or
hydroxides, and start the eutectic process as the steel heats up,"
Barnett et al. note that the sulfur could also have come from the contents of the burning buildings, such as
rubber or plastics, or ocean salts, such as sodium sulfate, which is known to catalyze sulfidation reactions
on turbine blades of jet engines. However, at the time of writing, (Feb, 2006), Barnett et al. have not
published any additional information on the sulfidation of steel at the WTC.


So, corroded aluminum, rusty steel, and sulfur combine to cook the crap out of the steel structure.  Did they even need to bother planting explosives?  That building may have been "ready to go" at any time.  Hell, they may have discovered the "problems" when they inspected the building after the bombing in the garage.  
   

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Buy me some coffee
Wrong thread really but i thought i would mention it, I have a friend who is MD in a company that designs, builds and installs High power switch gear for the UK railways, I asked him if he has ever seen or heard of any anomalies, his response was, the most important thing that can go wrong is the earthing system, if the earths are not good then he said the metal in nearby buildings structures migrates, i then responded migrates, surely you mean oxidizes, he said he does not know but the industry say it migrates.  C.C

So the building has a steel structure the next check it doesn't  :o

I know in the UK years ago, they used blocks of magnesium electrically connected to underground cast iron gas pipes, to stop the iron rusting.
Aluminum normally does not oxidise that easily as it forms a layer of oxide that protects the rest of the metal inside from oxidizing.
   

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Here is a picture of the south tower under construction in 1969:

Quote
1969 view of the original WTC bathtub looking northeast. The frame of the south tower is on the left. PATH eastbound tunnel F can be seen in the center, penetrating the slurry wall on its way up Cortlandt Street to Hudson Terminal. (Remnants of this tunnel can still be seen today.) The slurry wall runs along the west side of Greenwich Street. The IRT subway tunnel runs below the street (behind the slurry wall).

That's a lot of steel.  Nice coat of rust too.  Nice cross-bracing at the bottom.

So, we see how the building is contructed.

Then the impact zone in the north tower. 

Does that look right?
   

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here is an interesting forum discussion of the WTC collapse.  Steel columns with no concrete or fire-proofing.  Probably weakened by years of corrosion and fatigue.  

http://www.politicalforum.com/9-11/132842-what-temperature-does-fire-protected-structural-steel-fail-24.html

The shit-starters that control the world have succeeded in blurring the line of truth with a fine mix of fact and our imaginations.  They leave out the details in their lies and we gladly fill in the blanks, but we never know the real truth because we blow right past it.

They got this condemned building to get rid of and a need to control Mid-East reserves.  So, they sit around with a few drinks and cook up a plan.  Works every time.  Look at the hours, days, weeks, and years of work they have forced you into.  With just a few little lies, the taxed you into slavery and you gladly paid with your time.  Stupid part is that you are still paying and they are long past this issue and tightening the noose around our necks.

We all know Iran is next, then our sovereign asses.  You smart gentlemen going to try to figure out the plan and interfere or wait for the fan to spray it in our faces and trry to clean up the mess?

EDIT:
Analysis: U.S. ramps up warnings on Iran strike risks
http://www.reuters.com/article/2011/12/05/us-iran-us-idUSTRE7B427I20111205
   
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Where are the people on those flights that never took off on 9/11?   :-\

http://letsrollforums.com/happened-passengers-4-flights-t20496.html


Dick Cheney is a crook!  He did it, I'm sure.    >:(

http://www.democraticunderground.com/articles/04/08/06_resume.html
   
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... surely you mean oxidizes, he said he does not know but the industry say it migrates...

Think of the electroplating process. All you need is a complete circuit. Just another reason to use A.C. for building power. If the situation is right you can have D.C. cross currents. Not a good thing in this context.

Quote
Aluminum normally does not oxidise that easily as it forms a layer of oxide that protects the rest of the metal inside from oxidizing.

Aluminum oxidizing isn't the big problem in a salt air environment where differential charges abide.

In an offshore oil platform generator application aluminum is forbidden unless there are no other options. When it is used it must be coated with a special multilayer epoxy system, no electrical connections are allowed and if at all possible it must be in a controlled environment (no salt in the air).

The reason is it will crystallize from within, become brittle at the least stress point and fracture.

I'm no metallurgist either but I remember having to send a very experienced painter to school so he was allowed to apply that special coating.
   
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Professor:

Quote
Yes, EXCEPT that we got NIST to admit to not just "Near free-fall speeds" as you repeatedly say -- but rather,
AT "PRECISELY FREE-FALL ACCELERATION,"   g= 32.2 feet/sec**2. 

You are back in your Spin Zone again.  "PRECISELY FREE-FALL ACCELERATION."  Really?  Look at the graph, the data points are above and below the red line and they are doing curve fitting and linear regression.  You are contradicting yourself with respect to the NIST data that you yourself posted!  That data probably comes from one camera view and it looks like they probably didn't do sub-pixel interpolation on the video frames to get a more accurate measurement of the displacement.



One more time ArtistGuy beat me to the punch.  WTC7 had to have at least six subbasements or more so just like WTC1 and WTC2, and most of the building collapsed into it's own subbasement.

There is no need for explosions to "get mass out of the way."  We have all seen demolitions of tall buildings using the bottom compaction zone technique and quite often they appear to be falling at free-fall speed also.  How do you use bombs like giant directed charges to expel mass out horizontally timed perfectly with the disintegrating building?  It makes no sense, it just doesn't fit.  No controlled demolition companies in the world have ever considered what you are talking about.

I don't believe that you have made a single substantial comment about my description of the compaction zone destruction process.  Nor have you made any comments about how the energy needed to crush the falling mass of building floor by floor in the compaction zone would be negligible compared to the energy inherent in the falling structure of the building itself.  That is very revealing.

The building fell at a near-free-fall rate that was not detectible as being different from true free fall by the ordinary video cameras in use at the time.  Again, just look at the irregularity in the data points on the NIST graph relative to the red line of constant acceleration.

Quote
This does require that essentially NO MASS be in the way of the falling upper portion of the building -- for OVER 100 FEET, that is, 8-floors-worth of mass had to be moved.  If you understand Newton's third law or, equivalently, the law of conservation of momentum PROPERLY.

No it doesn't require that NO MASS be in the way of the falling upper portion of the building.  Your sense of proportion and scale is out of whack and your mechanical/physical intuition is not there.  Let's assume the simplified model of a lower compaction zone and an integral mass of falling building.  Let's say mid way through the four-second free fall, how fast is the building falling at that point and how much mass is there left in the disintegrating structure?  Those numbers could be easily determined.  Then you could easily calculate how much 1/2 M v-squared kinetic energy is in the falling building at that point in time.  Then compare that to the amount of energy it takes to crush a floor in the compaction zone.  That will give you your negative delta-v for the falling building.  I can assure you that negative delta-v is negligible compared to the instantaneous velocity of the building at that point in time.

You crunch the numbers and do it PROPERLY.  You will see that the building can easily fall at what appears to be free-fall speed for several seconds and the difference from true free fall is beyond the ability of the mediocre quality video frames to measure without doing any fancy sub-pixel interpolation.

MileHigh
   

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OK, you have proved that the buildings did, indeed, collapse...
   
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Okay, so to respond to Ion and others as to why I think WTC7 collapsed in what looked like a controlled demolition.  Of course I am certainly not an expert and I am just expressing my opinion.

Let's start off with a simple thought experiment and my numbers are just hypothetical for illustrative purposes.  Imagine a 30-story concrete structure that's just a 10 x 10 matrix of non-reinforced concrete pillars with normal strength horizontal connections for each "floor."  It looks like a tall thin concrete tower.  Suppose that each concrete pillar can support the weight of 10,000 tons.  Suppose that at 30 stories high, each pillar is supporting the weight of 9,800 tons.

Don't forget, that we are dealing with pure concrete, no metal reinforcing bars inside the pillars.  So what would happen if you took out let's say four of the pillars in one section with cannon fire (or whatever).  What would happen?  The intact pillars closest to the four destroyed pillars would then have more than a 10,000 ton load and be overloaded and therefore they would explode.  This would quickly set off a cascade chain reaction and before you knew it, all 96 remaining pillars would explode because they were overloaded.  It might only take 30 seconds.

Meanwhile, when this happened, the 30 story concrete structure would still be standing more or less straight up, because it's so huge and has massive inertia to overcome.  In fact, you can imagine that it's center of gravity would still be within the square perimeter of the base.  So yes it can fall over eventually, but it takes time because it's so huge and heavy and has a massive moment of inertia.

So think of that model in the context of WTC7.  The context is that "all of the materials cost has been sucked out of modern buildings."  That means the main support pillars were as thin as the computer modeling and building codes would allow.  In other words, a modern skyscraper can be viewed as a structure that is "just strong enough to remain standing and no more," because the architects and the builders try to reduce cost as much as possible, and the way to do that is to reduce your materials cost, all the way down to how much metal you use in your main vertical support pillars.

My pet theory was that when WTC1 and WTC2 fell, they caused two very localized intense earthquakes.  Because of the huge momentum of the WTC7 building, in effect many of the main vertical support pillars were somewhat damaged because of the jarring.  The ground moved but the building refused to move, so the "ankles" of the vertical support pillars were damaged.  Since the structural integrity of the vertical support pillars was compromised, they slowly continued to bend and deform over the period of seven hours right at the base of the building.

Eventually one of the damaged and deformed "ankles" snapped, and then a few others in the immediate vicinity snapped, and then before you knew it they all failed.  At that point the building was still standing straight up with it's center of gravity within the outer perimeter.  But of course all of the vertical support members became spaghetti curlicues and the building went down.

That was my initial theory.

In looking at the NIST clip, I was a bit surprised that they reported that the fire inside the building was much larger than I think most people thought, up to 10 stories in total vertical displacement.  So with the heat buildup, eventually a few of the interior vertical columns failed and the same process took place as described above.  There was a cascade failure in the inner rectangle of vertical columns after only a few of them failed because all of the extra strength had been sucked out of the building design to reduce cost.  Once the inner rectangle of vertical columns failed then the outer main support wall columns then failed for the very same reason, they were all overloaded at roughly the same time and then the outer part of the building went down.

In thinking about the outer and inner rectangle of support columns (okay the outer "rectangle" was actually a trapezoid) it makes sense that the inner rectangle of columns was probably significantly weaker than the outer rectangle by design.  My guess for that reason is that the inner rectangle was much less stressed due to wind forces as compared to the outer rectangle.   Since the designers of the inner rectangle did not have to worry that much about compression stress due to wind pressure, they really went on the cheap when it came to the strength of the inner rectangle.

So you combine a weak inner rectangle of support columns with a fire that burns for hours and hours with no sprinkler system working and the building came down.

I haven't read any reports, I am just thinking about my original idea and watching the NIST clip for the first time a few days ago and telling you what I think.   You basically had a "perfect storm" for WTC7 and the building came down.

MileHigh
   
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Grumpy,

those pictures you posted of the WTC make it look so sturdy and strong!   amazing!     Now you got me thinking. 

Why didn't the WTC South and North towers after the attacks, just topple over or fall a few floors down and then STOP?    All those steel beams!  Maybe the explosive theory has some merit?  :-\


@ All,

Check out the pilots for 9/11 truth website, very good reading.   http://pilotsfor911truth.org/


   

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Structural engineers think the angle clips for the floor joist failed.  Very likely with the burn scenario.

http://www.tms.org/pubs/journals/jom/0112/eagar/eagar-0112.html

The more interesting questions are why and how the crashes occurred.

More to come:

The slur campaign against Iran started years ago.  They provided 100's of millions of support to terrorist.  A logical JayZee action is to set off a few tactical nukes in the USA. 

You get rid of the gun-toting red-necks and activist, blame the terrorist, fallout is minimal, you kick off on Iran, install a government that sells you oil and natural gas.  China gets pissed and attacks, over half of the world population gets destroyed, now there are less people to control.  Sweet!

You could even hit other countries and let Iran take the rap for it.  Who would believe that Iran did not attack Israel if we tracked the missile leaving their country?  The deviousness of those bastards has no boundaries.  We are probably leaking nuke secrets to Iran while condemning them for building reactors at the same time.  Sweet! Playing both sides!

There is the China connection too.   China trades a little how-too nuke info for gas/oil - sweet...
   

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Quote from: MileHigh
...

Of course I am certainly not an expert and I am just expressing my opinion.
...

My pet theory was that when WTC1 and WTC2 fell, they caused two very localized intense earthquakes...
...

That was my initial theory.
...

I haven't read any reports, I am just thinking about my original idea and watching the NIST clip for the first time a few days ago and telling you what I think.   You basically had a "perfect storm" for WTC7 and the building came down.

MileHigh

In view of the candid "qualifiers," would
your opinions then be within the realm
of speculative fantasy?

Or, would you consider your opinions to
be scientific contribution to the "debate?"

There must be some reason for avoidance
of documented evidence, documented expert
opinions and published reports.

Pray tell, what might the reasons be MH?



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For there is nothing hidden that will not be disclosed, and nothing concealed that will not be known or brought out into the open.
   
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OK, you have proved that the buildings did, indeed, collapse...


Grumpy,

Don't tell me you've fallen for that B.S.  :-[

I'll bet you I can Google a web site with authenticated, documented and scientific<?> proof the buildings never fell and all is a ruse to gather free pizza, beer and a boost for the NYSE in hopes arm sales will skyrocket.


I am glad the link to pilotsfor911truth was posted. I fly commercial quite often. I'll be asking the crew members if they are a member of that group. If so, I'll just grab a bus or a boat. Talk about a furnace feeding its own flames....


   
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It's turtles all the way down
I'll try to respond to  MH

From MH:

Quote
Let's start off with a simple thought experiment and my numbers are just hypothetical for illustrative purposes.  Imagine a 30-story concrete structure that's just a 10 x 10 matrix of non-reinforced concrete pillars with normal strength horizontal connections for each "floor."  It looks like a tall thin concrete tower.  Suppose that each concrete pillar can support the weight of 10,000 tons.  Suppose that at 30 stories high, each pillar is supporting the weight of 9,800 tons.

Don't forget, that we are dealing with pure concrete, no metal reinforcing bars inside the pillars.  So what would happen if you took out let's say four of the pillars in one section with cannon fire (or whatever).  What would happen?  The intact pillars closest to the four destroyed pillars would then have more than a 10,000 ton load and be overloaded and therefore they would explode.  This would quickly set off a cascade chain reaction and before you knew it, all 96 remaining pillars would explode because they were overloaded.  It might only take 30 seconds.

What you are describing here is similar to a fast blow semiconductor fuse composed of many strands of fine silver wire in parallel. When the current is exceeded in one of the strands, usually the weakest or the one that is hogging a little  more current will fail and set of a chain reaction where the rest of the strands quickly blow. Quick blow semiconductor fuses blow in milliseconds. Here you admit that it is only a thought experiment, a fantasy, as there is no rebar in the mix as you stated. But wait......

Quote
So think of that model in the context of WTC7.  The context is that "all of the materials cost has been sucked out of modern buildings."  That means the main support pillars were as thin as the computer modeling and building codes would allow.  In other words, a modern skyscraper can be viewed as a structure that is "just strong enough to remain standing and no more," because the architects and the builders try to reduce cost as much as possible, and the way to do that is to reduce your materials cost, all the way down to how much metal you use in your main vertical support pillars.

So here you are basically saying that all modern skyscrapers are designed with no reasonable safety margins, and like a fast blow semiconductor fuse, you need only take out one or two pillars to start the chain reaction. You claim that all of the cost is sucked out and the designers of the buildings provide no safety margins as if they were designing a cheap toy. These things are ready to come down at the slightest earthquake. Whatever happened to building codes and safety margins. Was everyone "paid off"?  Are automobiles designed that way too? I better not drive anymore if they are. Now that sounds like a "conspiracy theory".

No, as a matter of fact buildings and automobiles are designed to standards for safety, just as automobile critical components like ball joints, steering rods, tires etc. need to meet federal safety standards with wide safety margins regarding shock loads etc. Buildings also need to meet fire and earthquake safety requirements so they are usually overdesigned. The cost of having to rebuild a building that  "just fell down 'cause it was marginally designed" would outstrip the cost of a little overdesign. So it is with automobile recalls. Not to mention the cost of the lawsuits that would occur.

Quote
My pet theory was that when WTC1 and WTC2 fell, they caused two very localized intense earthquakes.  Because of the huge momentum of the WTC7 building, in effect many of the main vertical support pillars were somewhat damaged because of the jarring.  The ground moved but the building refused to move, so the "ankles" of the vertical support pillars were damaged.  Since the structural integrity of the vertical support pillars was compromised, they slowly continued to bend and deform over the period of seven hours right at the base of the building.

Eventually one of the damaged and deformed "ankles" snapped, and then a few others in the immediate vicinity snapped, and then before you knew it they all failed.  At that point the building was still standing straight up with it's center of gravity within the outer perimeter.  But of course all of the vertical support members became spaghetti curlicues and the building went down.

Nice theory, but shouldn't those earthquakes have brought down a lot more buildings and reach pretty far out from ground zero in circular rings of intensity zones. Those seismic waves were pretty smart to  take down only the insured buildings. Larry Silverstein must have been praying hard at temple. Must be a lot of buildings around ground zero with "spaghetti curlicue legs" ready to blow to this day. I can't find anything on WTC7 but architects have often claimed that  WTC1 and 2 were overdesigned by a wide margin.

I'm glad you qualified this  as "only your opinion". How many "tokes" does it take for you to form such an opinion, it's really "out there", but I do enjoy reading it.
« Last Edit: 2011-12-06, 04:33:05 by ION »


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Several good points have come out, although the content of my last post has been missed by some it seems.   :'(
  (I like the Santa smiley's, poynt.)

Now Room raises the question I've seen before:

Quote
I don't mean that it exploded, I just mean that a lot of this red and gray dust could easily have been created by the collapse of the buildings.  Aluminum with its layer of aluminum oxide, which is corundum or saphire and is used on sand paper, grinding down with the collapse, the rust on the steel beams.  I would think a lot of dust comprising aluminum and iron oxide would be created, which may be the stuff Physics Prof has studied and wrote his papers on.  

Now, I would invite you to actually read our published peer-reviewed paper on the red/gray chips, here:

Find the April 2009 published article at this link.

Quote
http://www.bentham-open.org/pages/content.php?TOCPJ/2009/00000002/00000001/7TOCPJ.SGM
Deseret News article on the paper:
http://www.deseretnews.com/article/705295677/Trace-explosives-in-911-dust.html
I comment on the paper:
http://911blogger.com/news/2009-04-04/active-thermitic-material-discovered-dust-911-world-trade-center-catastrophe

As you read this paper carefully, you will notice that there is a significant ORGANIC content in the RED portion of these red/gray fragments (see photo in attachment) that we found and studied.  Attached find a Scanning Electron Microscope image of the red portion -- and note the comments regarding the UNIFORMITY of the thin (~40 nanometers thick) platelets containing the aluminum and PARTICULARLY THE ORGANIC MATRIX which holds the aluminum and the iron oxide.  

Quote
I would think a lot of dust comprising aluminum and iron oxide would be created, which may be the stuff Physics Prof has studied and wrote his papers on.

Ah -- but you have forgotten the significant organic matrix in which the THIN aluminum is embedded -- where did this come from?

@MH:   I have shown how the "compaction zone" model is NOT consistent with the observed free-fall acceleration at g=32.2 ft/s**2.

Quote
NIST final on WTC 7:  “This acceleration was 32.2 ft/s2 (9.81 m/s2), equivalent to the acceleration of gravity g.”
“…This free fall drop continued for approximately 8 stories or 32.0 m (105 ft)…”
          NCSTAR_1A_p87

Note the accuracy of the fit to the data, to three significant digits.  If you understand normal data-scatter, you will understand why some of the individual velocity points do not lie exactly on the a = g = 32.2 ft/s2 (9.81 m/s2) line, even though the fit itself can indeed show the degree of accuracy which they give in their numerical fit (which however I would like to re-check/analyze with a data-fit of my own, as I stated in my previous post.)
   
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Structural engineers think the angle clips for the floor joist failed.  Very likely with the burn scenario.

http://www.tms.org/pubs/journals/jom/0112/eagar/eagar-0112.html

Good link. If one watches the NOVA show on the towers and their design, then the loss of fireproofing (blown off the steel supports by the initial impact), along with some interior support columns (one tower more than the other in particular), offers no surprises as to the outcomes.

Here's the link for the stage 2 section of the NIST report I quoted...

http://www.nist.gov/customcf/get_pdf.cfm?pub_id=861610


Column 79...the impetus for the collapse.

FAQ
http://www.nist.gov/el/disasterstudies/wtc/faqs_wtc7.cfm

Excerpt:

11. In a video, it appears that WTC 7 is descending in free fall, something that would not occur in the structural collapse that you describe. How can NIST ignore basic laws of physics?


In the draft WTC 7 report (released Aug. 21, 2008; available at http://www.nist.gov/el/disasterstudies/wtc/wtc_draftreports.cfm), NIST stated that the north face of the building descended 18 stories (the portion of the collapse visible in the video) in 5.4 seconds, based on video analysis of the building collapse. This time period is 40 percent longer than the 3.9 seconds this process would have taken if the north face of the building had descended solely under free fall conditions. During the public comment period on the draft report, NIST was asked to confirm this time difference and define the reasons for it in greater detail.

To further clarify the descent of the north face, NIST recorded the downward displacement of a point near the center of the roofline from first movement until the north face was no longer visible in the video. Numerical analyses were conducted to calculate the velocity and acceleration of the roofline point from the time-dependent displacement data. The instant at which vertical motion of the roofline first occurred was determined by tracking the numerical value of the brightness of a pixel (a single element in the video image) at the roofline. This pixel became brighter as the roofline began to descend because the color of the pixel started to change from that of the building façade to the lighter color of the sky.

   
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FAQ
http://www.nist.gov/el/disasterstudies/wtc/faqs_wtc7.cfm

Excerpt:
...
To further clarify the descent of the north face, NIST recorded the downward displacement of a point near the center of the roofline from first movement until the north face was no longer visible in the video. Numerical analyses were conducted to calculate the velocity and acceleration of the roofline point from the time-dependent displacement data.


Yes -- this is the work that physicist David Chandler and I insisted that NIST do, and they came up with the numerical result that the roofline indeed fell at g = 32.2 feet/s**2 as I have repeatedly cited in this thread.


@MH, I reply as a courtesy but remind you that you still have not addressed my straightforward questions,
1.  What is the Third-law pair force corresponding to your F = Mg?  If you don't understand enough to answer this simple question, I ask that you study up.
2.  How do you explain the SYMMETRY of the fall of the "outside shell" of WTC7, part of which was hit by debris from the Tower, after the inner-floors (According to NIST!) have already fallen?
   
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Dumped:

Quote
would your opinions then be within the realm of speculative fantasy?

Perhaps this is the opportune time to repost your "big reveal" posting, the most important announcement in the history of the world.  You know the one that nobody commented on.  Something about aliens from Cygnus Major coming to see us soon and everything was going to change. (or whatever)

Ion:

Quote
So here you are basically saying that all modern skyscrapers are designed with no reasonable safety margins, and like a fast blow semiconductor fuse, you need only take out one or two pillars to start the chain reaction.

No I am not saying that because that would be totally ridiculous.  What I am saying is that the designs are still trimmed to the bone to just respect the safety margins with as little material expense as possible.  That is probably a contributing factor to the collapse of WTC7.  You are fully aware of the fact that I am aware of the concept of safety margins in building design.  The rest of your posting is just gratuitous "styling" or "pimping" of your original statement.

The bottom line is the building burned internally and apparently suffered a lot of internal damage and then collapsed.  Perhaps 10 or 20 or 30 of the support pillars in the internal rectangle were compromised from heat and failed before the collapse started.  The report focused on one critical corner beam.  I don't know and you don't know.  But the building did come down.

MileHigh
« Last Edit: 2011-12-06, 11:09:02 by MileHigh »
   
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Grumpy:

Quote
he shit-starters that control the world have succeeded in blurring the line of truth with a fine mix of fact and our imaginations.  They leave out the details in their lies and we gladly fill in the blanks, but we never know the real truth because we blow right past it.

They got this condemned building to get rid of and a need to control Mid-East reserves.  So, they sit around with a few drinks and cook up a plan.  Works every time.  Look at the hours, days, weeks, and years of work they have forced you into.  With just a few little lies, the taxed you into slavery and you gladly paid with your time.  Stupid part is that you are still paying and they are long past this issue and tightening the noose around our necks.

We all know Iran is next, then our sovereign asses.  You smart gentlemen going to try to figure out the plan and interfere or wait for the fan to spray it in our faces and trry to clean up the mess?

Yet "the powers that be" that have taxed you into slavery and have noose around your neck allow you to go to the supermarket and get food and go to the gas station and gas up your car so that you can sit at your desk in warm comfort and make postings on the Internet.  Without the whole mechanism of society working and without the oil flowing within three weeks you would be cooking grass roots in a pot heated by wood from the neighbourhood trees that people are hacking down for fuel in order to not starve to death.  Something to think about.

PhysicsProf:

Quote
Note the accuracy of the fit to the data, to three significant digits.  If you understand normal data-scatter, you will understand why some of the individual velocity points do not lie exactly on the a = g = 32.2 ft/s2 (9.81 m/s2) line, even though the fit itself can indeed show the degree of accuracy which they give in their numerical fit (which however I would like to re-check/analyze with a data-fit of my own, as I stated in my previous post.)

You can ignore my outline of the energy analysis all you want but the bottom line is that WTC7 fell at near-free-fall speeds in a very similar way to what happens when other similarly sized structures are demolished using the lower compaction zone technique.  The structural failures in WTC7 due to fire made it appear to be very similar to a controlled demolition.  You are obsessed with the near-free-fall speed when it means absolutely nothing.

Quote
What is the Third-law pair force corresponding to your F = Mg?  If you don't understand enough to answer this simple question, I ask that you study up.

Now, now, now, professor, I answered that question stating that Mg was the force downward and the inertia of the object resisting acceleration was the equal and opposite force.  You then responded by saying this is wrong because the force pairs cannot act on the same body.  I asked you to explain.  But if you want to play the game using phraseology like this, "If you don't understand enough to answer this simple question, I ask that you study up," then a strict school mistress is going to give you an over-the-knee spanking for entering this forum as a "physics professor" here to analyze a Joule Thief circuit only to quickly reveal to everyone that could tell that you had absolutely no idea what you were doing.  So you get a spanking for making false statements about your qualifications with respect to circuit analysis and I can tell you that a lot of people had high hopes that were quickly dashed.  It was already obvious that you were not qualified in electronics within less than 10 postings.   When you turned and asked Poynt what the "resistance" of a particular diode was the floor collapsed all around you.  Even though you had already lost your credibility by that time, it was still an absolute shock to see a "physics professor" ask that question, a shock!

So forget the pretense of the "schoolmaster" and "assigning tasks" with information conditional upon completion of those said tasks.  Just respond to your question now that I have tried to answer it.

Quote
How do you explain the SYMMETRY of the fall of the "outside shell" of WTC7, part of which was hit by debris from the Tower, after the inner-floors (According to NIST!) have already fallen?

That's easy to explain.  The horizontal connections in the outer shell structure were still pretty much intact while it descended into the compaction zone.  That plus the massive inertia of the outside shell itself resulted in a quite orderly descent into the compaction zone.

MileHigh
« Last Edit: 2011-12-06, 11:44:55 by MileHigh »
   
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