IS Forum
Forum Index Register Members List Events Search Today's Posts Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Conspiracies and Conspiracy Theories » 9/11 Conspiracy Theories
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Tags ae911truth , richard gage , wtc 7 , wtc 7 report

Reply
Old 27th March 2011, 01:08 PM   #161
DGM
Skeptic not Atheist
 
DGM's Avatar
 
Join Date: May 2007
Location: West of Northshore MA
Posts: 24,748
Originally Posted by NoahFence View Post
The surface temp. of the pile was over 1,300 degrees? Why didn't the first responders melt or die from severe burns?

First responders were there within a matter of minutes and if I recall correctly, stayed for months.
He's referring to the AVIRIS study. No, it's not indicative of actual surface temperature.

http://pubs.usgs.gov/of/2001/ofr-01-...ermal.r09.html
__________________
"Remember that the goal of conspiracy rhetoric is to bog down the discussion, not to make progress toward a solution" Jay Windley

"How many leaves on the seventh branch of the fourth tree?" is meaningless when you are in the wrong forest: ozeco41
DGM is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 01:21 PM   #162
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by NoahFence View Post
The surface temp. of the pile was over 1,300 degrees? Why didn't the first responders melt or die from severe burns?

First responders were there within a matter of minutes and if I recall correctly, stayed for months.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 01:30 PM   #163
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by DGM View Post
He's referring to the AVIRIS study. No, it's not indicative of actual surface temperature.

http://pubs.usgs.gov/of/2001/ofr-01-...ermal.r09.html
Quite the contrary, those are measurements of the surface temperatures.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 02:01 PM   #164
DGM
Skeptic not Atheist
 
DGM's Avatar
 
Join Date: May 2007
Location: West of Northshore MA
Posts: 24,748
Originally Posted by Christopher7 View Post
Quite the contrary, those are measurements of the surface temperatures.
So how many pixels (how big is that in real life at 6,500 and 12,500 feet altitude) in the study image showed temps of 1300 degrees? You didn't read the study, did you?
__________________
"Remember that the goal of conspiracy rhetoric is to bog down the discussion, not to make progress toward a solution" Jay Windley

"How many leaves on the seventh branch of the fourth tree?" is meaningless when you are in the wrong forest: ozeco41
DGM is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 02:33 PM   #165
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by chrismohr View Post
CHRIS COMMENT: I suggested in the debate that the iron microspheres probably came from the 1972-73 welders. In welding the steel parts of the building together, the workers brought the steel up to very high temperatures with their torches and white-hot steel sprayed all over the place. Thus, microspheres everywhere.
Chris,

A few days ago I noted that your comment is just speculation but that post has been buried in the discussion so I am posting the comment again with my rebuttal and asking you for a response.

It is not known how many microspheres are created by welding or how many would be left after cleanup.

The RJ Lee Group said the iron spheres were created during the collapse.

RJ Lee 2003 report pg 17 [pdf pg 21]
"Various metals (most notably iron and lead) were melted during the WTC event, producing spherical metallic particles.
http://www.nyenvirolaw.org/WTC/130%2...logy.Final.pdf


Do you have any comment on my rebuttal?
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 02:45 PM   #166
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by DGM View Post
So how many pixels (how big is that in real life at 6,500 and 12,500 feet altitude) in the study image showed temps of 1300 degrees? You didn't read the study, did you?
Strange question. I could not know what the surface temperatures were without the study.

The point is: Even if the cars in the basement levels caught on fire, those fires would not burn long enough to heat the entire mass of eight or nine stories of debris and raise the surface temperature of the debris pile to 1376oF [747oC]

Last edited by Christopher7; 27th March 2011 at 02:47 PM.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 02:48 PM   #167
DGM
Skeptic not Atheist
 
DGM's Avatar
 
Join Date: May 2007
Location: West of Northshore MA
Posts: 24,748
Originally Posted by Christopher7 View Post
The point is: Even if the cars in the basement levels caught on fire, those fires would not burn long enough to heat the entire mass of eight or nine stories of debris and raise the surface temperature of the debris pile to 1376oF [747oC]
So what would?
__________________
"Remember that the goal of conspiracy rhetoric is to bog down the discussion, not to make progress toward a solution" Jay Windley

"How many leaves on the seventh branch of the fourth tree?" is meaningless when you are in the wrong forest: ozeco41

Last edited by DGM; 27th March 2011 at 02:49 PM.
DGM is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 03:44 PM   #168
Carlos
Critical Thinker
 
Carlos's Avatar
 
Join Date: Aug 2009
Posts: 285
Originally Posted by Christopher7 View Post
Strange question. I could not know what the surface temperatures were without the study.

The point is: Even if the cars in the basement levels caught on fire, those fires would not burn long enough to heat the entire mass of eight or nine stories of debris and raise the surface temperature of the debris pile to 1376oF [747oC]

Was the entire mass of eight stories of debris heated to 1376oF? Are you sure?
__________________
In most cases debating with a 9/11 truther is rather like trying to play chess with a pigeon; it knocks the pieces over, craps on the board, and flies back to its flock to claim victory.

The customer with the knife is always right - Quohog, the bartender
Carlos is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 04:47 PM   #169
LashL
Goddess of Legaltainment™
 
LashL's Avatar
 
Join Date: Aug 2006
Posts: 36,472
Originally Posted by Christopher7 View Post
The RJ Lee Group said the iron spheres were created during the collapse.

RJ Lee 2003 report pg 17 [pdf pg 21]
"Various metals (most notably iron and lead) were melted during the WTC event, producing spherical metallic particles.
http://www.nyenvirolaw.org/WTC/130%2...logy.Final.pdf


Do you have any comment on my rebuttal?
Chris, take a look at page 2 of the Report (page 3 pdf), section 5.0 (1) and following. That makes it pretty clear that the WTC Event, as used in the report, includes the collapse and the subsequent fires, as does the last paragraph of page 9 (page 10 pdf) and many other sections and references throughout the report. But this belongs in one of the pre-existing threads on the minutiae of the dust particles and pulverization discussed in the R.J. Lee Report. See mod-box below.
LashL is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 04:47 PM   #170
LashL
Goddess of Legaltainment™
 
LashL's Avatar
 
Join Date: Aug 2006
Posts: 36,472
Mod WarningFolks, this seems to be getting far astray from the thread's subject. If you wish to discuss the minutiae of the dust and pulverized particles and the R.J. Lee Report, that should be done in one of the perfectly cromulent already-existing threads on that subject. This thread is about the latest Gage debate (and perhaps the next one, if there is a next one).
Responding to this modbox in thread will be off topic Posted By:LashL
LashL is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 05:42 PM   #171
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by LashL View Post
Chris, take a look at page 2 of the Report (page 3 pdf), section 5.0 (1) and following. That makes it pretty clear that the WTC Event, as used in the report, includes the collapse and the subsequent fires, as does the last paragraph of page 9 (page 10 pdf) and many other sections and references throughout the report. But this belongs in one of the pre-existing threads on the minutiae of the dust particles and pulverization discussed in the R.J. Lee Report. See mod-box below.
My question concerns Chris Mohr's suggestion during the debate that the iron spheres in the RJ Lee report were created by welder's torches during the construction.

You are right that the discussion about the dust in the debris pile is off topic but my question to Chris Mohr is specific to the debate.

The referral to;
RJ Lee 2003 report pg 17 [pdf pg 21]
"Various metals (most notably iron and lead) were melted during the WTC event, producing spherical metallic particles.

is in rebuttal to his explanation for the presence of the iron spheres.

Last edited by Christopher7; 27th March 2011 at 05:48 PM.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 05:51 PM   #172
LashL
Goddess of Legaltainment™
 
LashL's Avatar
 
Join Date: Aug 2006
Posts: 36,472
Originally Posted by Christopher7 View Post
My question concerns Chris Mohr's suggestion during the debate that the iron spheres in the RJ Lee report were created by welder's torches during the construction.

You are right that he stuff about the dust in the debris pile is off topic but my question to Chris Mohr is specific to the debate.

The referral to;
RJ Lee 2003 report pg 17 [pdf pg 21]
"Various metals (most notably iron and lead) were melted during the WTC event, producing spherical metallic particles.

is in rebuttal to his explanation for the presence of the iron spheres.

See the mod-box above. You raised that 60+ posts ago and it immediately led to a derail into the minutiae that is properly the subject matter of other existing threads, so please take it to one of those threads. The other member whom you're addressing can find it there and respond there as well.
LashL is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 06:01 PM   #173
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by LashL View Post
See the mod-box above. You raised that 60+ posts ago and it immediately led to a derail into the minutiae that is properly the subject matter of other existing threads, so please take it to one of those threads. The other member whom you're addressing can find it there and respond there as well.
10-4
The discussion about the debris pile has run its course so I will not respond to posts concerning that and wait for a response from Chris Mohr on my rebuttal to his explanation for the origin of the iron spheres.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th March 2011, 09:14 PM   #174
Justin39640
Illuminator
 
Justin39640's Avatar
 
Join Date: May 2009
Posts: 4,202
Originally Posted by Christopher7 View Post
Quite the contrary, those are measurements of the surface temperatures.
Um... Why would they need NASA's ARIVIS to take simple surface temperature readings? Surely there is faster and more economical ways to take the temperature of an area that's right in front of them? Just sayin...

ETA: Sorry LashL.
__________________
"I joined this forum to learn about the people who think that 9/11 was an inside job. I've learned that they believe nutty things and are not very good at explaining them." - FineWine
"The agencies involved with studying the WTC collapse no more needed to consider explosives than the police need to consider brain cancer in a shooting death." - ElMondoHummus
Justin39640 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th March 2011, 08:20 AM   #175
Disbelief
Illuminator
 
Disbelief's Avatar
 
Join Date: Mar 2007
Posts: 3,306
Originally Posted by NoahFence View Post
Cars that are made of aluminum which can easily account for the "molten metal" at the scene. Since there were no reports of molten metal prior to the collapses, is this not a viable theory?
Just to nitpick, most cars are not made from aluminum (Audi having an exception). While the amount is increasing, it is still rare to find vehicles with more than 10% aluminum - usually engine blocks, rims and now front/rear bumpers.

However, there would be plenty of vehicles that would have caught fire (witnessed by pics) and the aluminum could easily have melted. A hundred punds per vehicle would still be a substantial amount of aluminum.
__________________
Zensmack (LastChild, Laughing Assassin, RazetheFlag, Wastrel, TruthbyDecree) - Working his way up the sock puppet chain, trying to overtake P'Doh. Or, are they the same?

Quote me where I said conspiracists use evidence. - mchapman
Disbelief is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 09:50 AM   #176
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
Gage Debate Update and Microspheres too

Hi Christopher7 and all,

Richard Gage and I have agreed to do two five-minute video "Epilogues" each, one each for the Twin Towers and Building 7. This will not be inserted into the debate, but will be a chance for each of us to do post-debate commentary and catch up on what we missed first time around.

Christopher7, your posts have been helpful. I take my time looking at things before jumping into rebuttal mode. Here are some things I've found in the RJ Lee report regarding the iron microspheres:

The conf lagrat ion a c t ivat ed proc e s s e s that caus ed ma t e r ial s to form into
sphe r i ca l pa r t i c l e s s u c h as me ta l s ( e .g. , Fe , Zn , Pb ) and sphe r i ca l o r ve s i cula r
s i l i cat e s or f ly ash.

Sorry for the spacing problems in this cut and paste, but they never said that normal office fires could not have produced temperatures high enough to cause this.

Further down, we read that

Pa r t i c l e s o f ma t e r ia l s tha t had b e en m od i f i ed by expo s u r e to h igh
t empe ratur e , such as spher i ca l pa r t i c l e s of i r on and s i l i cat e s , ar e common
in WTC Du s t be caus e of th e f i r e that ac compani ed t h e WTC Event.

Again, they quietly assume that normal office fire temperatures would have been able to produce these spheres. Next passage makes it explicit:

Cons ide r ing the high t emp e ratur e s r eached dur ing the de s t ruc t ion of
the WTC, the fol lowing thr e e type s of combus t i on produc t s would be
expe c t ed t o be pr e s ent in WTC Du s t . The s e produc t s a r e :
• Ve s i c u la r c a rbona c eous par t i c l e s pr ima r i l y f rom p las t i c s
• I ron - r i ch s phe r e s f rom i ron -bear ing bui lding compon ent s or con t ent s
• High t empe ratur e aluminos i l i cat e f rom bui lding mat e r ial s


You may be right that iron microspheres couldn't have been created by steel-melting acetelyne torches in 1972 (though I still think that is a reasonable hypothesis, with or without the RJ Lee study). But it sure looks to me like this study is awfully calm about the iron microspheres. The authors clearly expect iron microspheres to be a natural byproduct of this kind of office fire. Why is that? I would expect them to say, "Iron microspheres can only be created with 2800 degree temperatures, and the fires in the WTC buildings never got over 1800 degrees. WHAT THE HELL IS GOING ON HERE?" Or some scientific-sounding version of this.

It's worth mentioning, too, that they identified all kinds of plastics, asbestos, other hazardous materials, iron microspheres etc, but they never suggested that they found any kinds of thermites, explosive residues, or anything that would offer solid support for a controlled demolition theory. Since they were especially sensitive about searching for environmentally hazardous materials, wouldn't one expect that they would have found such deadly things as thermates or nanothermitic dust, both of which would be extremely hazardous to breathe and therefore be of great interest to the authors of this study?

Help me out here buddy.
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 10:14 AM   #177
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
Playing Devil's Advocate

OK friends,

The weakest moment in my March 6 Mohr/Gage debate was explaining the 2.25 seconds of free-fall collapse in Building 7. It may have been a curtain-fall collapse of the outside perimeter, but those are most common in masonry walls. Since there were 58 steel perimeter columns offering structural support to the outside of Building 7, it doesn't seem logical to assert that the interior collapsed and therefore the perimeter walls had no support.

A collapse, yes, absolutely. Totally free fall for 8 or 9 stories with strong steel supports right in the perimeter walls? I'm searching for a short, simple narrative that can really nail this. NIST does not think it's important, they just studied the probable collapse sequence up to its start and then they say gravity took care of the actual collapse from there. The best help I've gotten so far has been from Ryan Mackey, who mentioned that one interior support column eight stories in length remained attached and helped actually drag the perimeter wall down during that 2.25 seconds.

The Chris Mohr 911 Prize will be awarded for the best explanation. I'll even mail you a $9.11 money order for your pains if you want. And I have to be 100% convinced myself. You have to account for the 58 perimeter support columns, especially on the north face where fire damage had not completely wiped out that side of the building. I am not too proud to say I don't have a fully satisfactory explanation if it comes to that.

Thanks all,
Chris
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 10:38 AM   #178
9/11 Chewy Defense
Banned
 
Join Date: Jul 2007
Posts: 3,593
That's the funny thing about Truthers talking about "2.25 seconds of free-fall". They claim that it was caused by "explosives", how freaking insane is that?

2.25 seconds of anything is the start of something massive (like a global collapse) and there's nothing on this Earh that can't stop it. Truthers aren't structural engineers nor fire investigators, they can't simply rule out fire.

If you take out 1 or 2 structural supports, the buildings integrity is comprimised. Fire can cause steel to soften & weaken the supports to cause collapse. What happened in WTC7 was fire induced, it involved no explosives.

BTW: If any Truthers are suggesting that they planted explosives before the collapse, they have to explain why ALL the explosives didn't go off when the building was on fire. Also why isn't there any reports from the FDNY saying they seen CD crews working while they evacuated WTC7?
9/11 Chewy Defense is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 12:06 PM   #179
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
"That's the funny thing about Truthers talking about "2.25 seconds of free-fall". They claim that it was caused by "explosives", how freaking insane is that?"

Thanks, but I am going to be more relentless here in my quest. I believe that in the Twin Towers, the strong structural steel slowed down the collapse by about 33%. I have all kinds of arguments AGAINST Controlled Demolition. I need to fully understand how 58 structural columns provided NO slowdown to the final perimeter collapse for those 2.25 seconds. I remain the Devil's Advocate because I need either a better answer than I have so far or an admission that I haven't found a 100% satisfactory answer. I'm Ok saying either in the debate epilogue.
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 12:14 PM   #180
DGM
Skeptic not Atheist
 
DGM's Avatar
 
Join Date: May 2007
Location: West of Northshore MA
Posts: 24,748
Originally Posted by chrismohr View Post
Thanks, but I am going to be more relentless here in my quest. I believe that in the Twin Towers, the strong structural steel slowed down the collapse by about 33%. I have all kinds of arguments AGAINST Controlled Demolition. I need to fully understand how 58 structural columns provided NO slowdown to the final perimeter collapse for those 2.25 seconds. I remain the Devil's Advocate because I need either a better answer than I have so far or an admission that I haven't found a 100% satisfactory answer. I'm Ok saying either in the debate epilogue.
You might have just answered your own question (bold). The collapse is only significant if you focus on the 2.25 seconds and ignore the rest. NIST does not do this.
__________________
"Remember that the goal of conspiracy rhetoric is to bog down the discussion, not to make progress toward a solution" Jay Windley

"How many leaves on the seventh branch of the fourth tree?" is meaningless when you are in the wrong forest: ozeco41
DGM is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 12:24 PM   #181
NoahFence
Banned
 
Join Date: Mar 2011
Location: Patriot Nation
Posts: 22,131
That this is still an ongoing debate is just outrageous.

Why can't something we've never seen before result in something we wouldn't expect?

Its not as if we have reams of data on how a building should behave when struck by a 500mph massive jumbo-jet.

Lets say (God Forbid) something like this happens again? What if the next building collapses? Will truthers finally agree that maybe, just maybe an aircraft AND fires can knock down a building?
NoahFence is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 01:34 PM   #182
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
Outrageous or not, I'm new to JREF and somehow I ended up debating Richard Gage. I'll yank a good narrative out of someone yet. The part about focusing only on the 2.25 seconds (above) is a good start... as in, eight seconds from east penthouse collapse, then a couple seconds perimeter collapse slower than freefall, then freefall for 2.25 seconds which completely 100% overwhelms the 58 perimeter support columns because.... ??
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 01:50 PM   #183
NoahFence
Banned
 
Join Date: Mar 2011
Location: Patriot Nation
Posts: 22,131
I dunno.
Because the support columns aren't there anymore?

I'll go to my grave not knowing why 2.25 seconds of freefall means it had to be explosives/thermite.
NoahFence is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 02:35 PM   #184
twinstead
Penultimate Amazing
 
twinstead's Avatar
 
Join Date: Apr 2005
Posts: 12,374
Just like all these truthers will go to their graves without ever getting that "other investigation" they claim to want.
__________________
You are not entitled to your opinion. You are entitled to your INFORMED opinion. No one is entitled to be ignorant. -- Harlan Ellison
twinstead is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 02:48 PM   #185
Childlike Empress
Banned
 
Childlike Empress's Avatar
 
Join Date: Jun 2006
Location: Ivory Tower
Posts: 20,632
Originally Posted by chrismohr View Post
I'll yank a good narrative out of someone yet.

Won't happen. There is none. Prediction: Press Ryan Mackey on the issue and he'll put you "on ignore".
Childlike Empress is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 02:50 PM   #186
Oystein
Penultimate Amazing
 
Oystein's Avatar
 
Join Date: Dec 2009
Posts: 18,667
Chris, I do not know the answer to your tough question. Maybe it can be found by carefully reading the NIST report, or studying their collapse simulation. If not, I am afraid we can't give you an answer that will convince you "100%". The best will be answers that are many times more plausible than anything involving thermite or RDX.

So here is my educated speculation:
We already know that the core gave way before the perimeter did. This will imply some pulling in of the perimeter wall.
At some point, the first perimeter column(s) will buckle to a point where they offer practically zero resistance. This will immediately put meighboring columns under overload conditions and cause them to buckle/break. And so on. Buckling/breaking will progress horizontally. If this started around the 8th floor, that's your explanation why at some point in time after the beginning of north face collapse, the north face started free fall: All 58 columns gave way in very rapid progression after the first broke.
Alternatively, or additionally, if some quirk of the core collapse pulled the 8th floor more inward as an assembly than any other floor, that might have triggered an even faster progression at that height.

ETA:
Some such mechanism must have happened.
Two things that are not possible are:
- Severing all 58 simultaneously by explosive charges - no such 58 blast sounds occurring within milliseconds of one another were recorded by any device or reported by any of the many demolition crews nearby.
- Severing all 58 simultaneously by incendiaries like thermite - that method works too slow to allow for such synchronized attack.
At most a truther could speculate about thermite (or whatever) cutting one or few columns, and collapse propagating rapidly outward from there. Which of course is no different from my scenario, except that it isn't necessary at all to invoke such incendiaries, as we know for a fact that the building was collapsing already.

Last edited by Oystein; 30th March 2011 at 02:55 PM.
Oystein is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 03:29 PM   #187
NoahFence
Banned
 
Join Date: Mar 2011
Location: Patriot Nation
Posts: 22,131
Originally Posted by twinstead View Post
Just like all these truthers will go to their graves without ever getting that "other investigation" they claim to want.
You mean that other, other, other, other independent investigation.

There's only been like 5 of 'em.
NoahFence is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 04:17 PM   #188
ozeco41
Philosopher
 
ozeco41's Avatar
 
Join Date: Mar 2009
Location: Moss Vale, NSW, Australia
Posts: 7,617
Originally Posted by chrismohr View Post
"That's the funny thing about Truthers talking about "2.25 seconds of free-fall". They claim that it was caused by "explosives", how freaking insane is that?"

Thanks, but I am going to be more relentless here in my quest. I believe that in the Twin Towers, the strong structural steel slowed down the collapse by about 33%. I have all kinds of arguments AGAINST Controlled Demolition. I need to fully understand how 58 structural columns provided NO slowdown to the final perimeter collapse for those 2.25 seconds. I remain the Devil's Advocate because I need either a better answer than I have so far or an admission that I haven't found a 100% satisfactory answer. I'm Ok saying either in the debate epilogue.
Chris;
The problem you face is strategic. "They" have got you arguing on the ground which they have defined. "They" have managed to create this myth that there is something special about free fall and, to their believers, the belief that "free fall"=="demolition". Both those claims are nonsense. In addition they have managed to switch "burden of proof" to you.

In addition "they" have you trying to explain away iron microspheres (insert any material here). They do that to find things that you cannot answer and which you have no need to answer. The only technical reason for having interest in microspheres or any other material is if they are using it to support demolition. The burden of proof is on them to show a plausible demolition scenario using or resulting in microspheres. Your legitimate position is "there was no demolition therefore the microspheres are irrelevant".

Sadly with their dishonest debating techniques they will not play by rules. You, like many others, are being generous and fighting from their chosen ground. Often you can still win because their case is not simply weak it is non-existent.

However, on this one, I don't think there is a winner way forward because the only answer they will concede and even that will be unwilling, is in the form that you have already framed it.

If I was in the corner you are in I would probably go down fighting. Which means reframing several of the statements you have made in these recent posts. You are framing in negatives matters which could be stated positively. I doubt that it fits with the style of debate you prefer to use but try this example.

Your current version: "I am not too proud to say I don't have a fully satisfactory explanation if it comes to that."

My version "I am proud to point out that in a complex matter like these building collapses it is almost certain that there will be bits of the structure which for brief periods fall at free fall acceleration. There is no way to even identify most of these let alone explain every mechanism involved. You are the ones claiming that there is something significant in free fall. Since there was no demolition what other cause to you attribute the free fall to..." (With the language polished up naturally)

As I said it isn't your style. Recall the reason that Richard Dawkins et al refuse to debate creationists. There is no argument "creationism" v "evolution". The only reason the creationists want the debate is for the credibility confronting Dawkins gives them and the way they can misrepresent the certain outcome to their followers.

There is no case in the main technical issues of 9/11 and, no matter how forgiving or understanding we may be, Gage is not in it for honest debate.

Last edited by ozeco41; 30th March 2011 at 04:19 PM. Reason: Spelin erers
ozeco41 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 06:37 PM   #189
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by chrismohr View Post
Hi Christopher7 and all,

Richard Gage and I have agreed to do two five-minute video "Epilogues" each, one each for the Twin Towers and Building 7. This will not be inserted into the debate, but will be a chance for each of us to do post-debate commentary and catch up on what we missed first time around.

Christopher7, your posts have been helpful. I take my time looking at things before jumping into rebuttal mode. Here are some things I've found in the RJ Lee report regarding the iron microspheres:

"The conflagration activated processes that caused materials to form into spherical particles such as metals (e.g., Fe, Zn, Pb) and spherical or vesicular silicates or fly ash. The heat generated during the WTC Event caused some plastics to form residual vesicular carbonaceous particles, and paints to form residual spherical particles."

Sorry for the spacing problems in this cut and paste, but they never said that normal office fires could not have produced temperatures high enough to cause this.
No worries but I had to replace the quotes. [and include a little some more of them]

Quote:
Further down, we read that

"Particles of materials that had been modified by exposure to high
temperature, such as spherical particles of iron and silicates, are common
in WTC Dust because of the fire that accompanied the WTC Event, but are
not common in “normal” interior office dust."

Again, they quietly assume that normal office fire temperatures would have been able to produce these spheres. Next passage makes it explicit:

"Fires that were a part of the WTC Event produced combustion-modified products that traveled with other components of WTC Dust.Considering the high temperatures reached during the destruction of the WTC, the following three types of combustion products would be expected to be present in WTC Dust. These products are:

• Vesicular carbonaceous particles primarily from plastics
• Iron-rich spheres from iron-bearing building components or contents
• High temperature aluminosilicate from building materials

You may be right that iron microspheres couldn't have been created by steel-melting acetelyne torches in 1972 (though I still think that is a reasonable hypothesis, with or without the RJ Lee study).
I am a contractor and in is necessary to vacuum the floors after finishing drywall. Health and safety codes would require that the slabs be vacuumed to prevent acquired dust from becoming airborne. Don't forget that the RE Lee Group report said the spheres were created during the WTC event.

Quote:
But it sure looks to me like this study is awfully calm about the iron microspheres. The authors clearly expect iron microspheres to be a natural byproduct of this kind of office fire. Why is that? I would expect them to say, "Iron microspheres can only be created with 2800 degree temperatures, and the fires in the WTC buildings never got over 1800 degrees. WHAT THE HELL IS GOING ON HERE?" Or some scientific-sounding version of this.
That paragraph is somewhat misleading. Bottom line, they are aware that carbon based fires [wood and petroleum based plastics] burn at a maximum of about 1800F unless air is forced thru the fuel such as a bellows or a blast furnace.
"The maximum flame temperature increase for burning hydrocarbons (jet fuel) in air is, thus, about 1,000°C—hardly sufficient to melt steel at 1,500°C."
http://www.tms.org/pubs/journals/jom...agar-0112.html


Quote:
It's worth mentioning, too, that they identified all kinds of plastics, asbestos, other hazardous materials, iron microspheres etc, but they never suggested that they found any kinds of thermites, explosive residues, or anything that would offer solid support for a controlled demolition theory. Since they were especially sensitive about searching for environmentally hazardous materials, wouldn't one expect that they would have found such deadly things as thermates or nanothermitic dust, both of which would be extremely hazardous to breathe and therefore be of great interest to the authors of this study?
No, they were looking for hazardous materials. The nano-thermite chips were iron oxide, aluminum silicate and organic materials. There was no significant amount of the toxic components that they were looking for.

Thank you for your reply and I hope you find this information useful.

Chris
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 07:28 PM   #190
Senenmut
Graduate Poster
 
Senenmut's Avatar
 
Join Date: Nov 2008
Posts: 1,372
Originally Posted by chrismohr View Post
Outrageous or not, I'm new to JREF and somehow I ended up debating Richard Gage. I'll yank a good narrative out of someone yet. The part about focusing only on the 2.25 seconds (above) is a good start... as in, eight seconds from east penthouse collapse, then a couple seconds perimeter collapse slower than freefall, then freefall for 2.25 seconds which completely 100% overwhelms the 58 perimeter support columns because.... ??
here's a good one for ya. this will most likely help a building to acheive "freefall." who knows how much of this "vaporized" / "evaporated" steel was in the pile. Professor Astaneh - Asl saw this only 8 days after wtc 7 came down. 15.9mm of A36 steel gone in only 8 days!!!!

"One piece Dr. Astaneh-Asl saw was a charred horizontal I-beam from 7 World Trade Center, a 47-story skyscraper that collapsed from fire eight hours after the attacks. The beam, so named because its cross-section looks like a capital I, had clearly endured searing temperatures. Parts of the flat top of the I, once five-eighths of an inch thick, had vaporized.

Less clear was whether the beam had been charred after the collapse, as it lay in the pile of burning rubble, or whether it had been engulfed in the fire that led to the building's collapse, which would provide a more telling clue.

The answer lay in the beam's twisted shape. As weight pushed down, the center portion had buckled outward.

''This tells me it buckled while it was attached to the column,'' not as it fell, Dr. Astaneh-Asl said, adding, ''It had burned first, then buckled.''

http://query.nytimes.com/gst/fullpag...53C1A9679C8B63

did ya get that last part. an engineer that actually looked at some forensic evidence! it burned/vaporized (lost 15.9mm of a36 steel) then collapsed! it buckled while attached to the building, not as it lay in the pile!

and that was not the only piece of steel that caught peoples attention. Professor Barnett of WPI also stated:
"A combination of an uncontrolled fire and the structural damage might have been able to bring the building down, some engineers said. But that would not explain steel members in the debris pile that appear to have been partly evaporated in extraordinarily high temperatures, Dr. Barnett said.

notice he stated steel member's. plural. more than one! maybe you could email him and find out just how many. Professor Sisson has stated that he could get "little metal" to dissolve with his experiments with placing powders on steel. ive tried to find out how little that "little" exactly was but there was NO answer! maybe you could email him and find that out too?
http://query.nytimes.com/gst/fullpag...pagewanted=all
Senenmut is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 08:26 PM   #191
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by chrismohr View Post
The weakest moment in my March 6 Mohr/Gage debate was explaining the 2.25 seconds of free-fall collapse in Building 7.

A collapse, yes, absolutely. Totally free fall for 8 or 9 stories with strong steel supports right in the perimeter walls? I'm searching for a short, simple narrative that can really nail this.

The Chris Mohr 911 Prize will be awarded for the best explanation. I'll even mail you a $9.11 money order for your pains if you want. And I have to be 100% convinced myself. You have to account for the 58 perimeter support columns, especially on the north face where fire damage had not completely wiped out that side of the building. I am not too proud to say I don't have a fully satisfactory explanation if it comes to that.
It may not be the answer you wanted but the best explanation is "All 58 exterior columns were removed simultaneously on 7 or 8 floors by some combination of incendiaries and/or explosives". You can donate the $9.11 to the "Remember Building 7" campaign. http://rememberbuilding7.org/

It wasn't just the north face that fell at free fall acceleration.
NCSTAR 1A pg 55 [pdf pg 97]
The entire building above the buckled-column region then moved downward in a single unit, as observed, completing the global collapse sequence.

At a Tech briefing on 8-26-08, lead investigator for NIST, Shyam Sunder, stated:
"a free fall time would be an object that has no structural components below it . . . there was structural resistance that was provided in this particular case. And you had a sequence of structural failures that had to take place. Everything was not instantaneous."

In other words, the NIST progressive collapse hypothesis does not include a period of free fall acceleration because there is always structural resistance.

WTC 7 had moment frames. In layman's terms - A steel belt around the exterior walls every other floor. This held the exterior frame together as it buckled. Note that the NIST computer simulation confirms what Shyam Sunder said "there was structural resistance that was provided in this particular case". The exterior columns are buckling in an irregular manner, providing resistance. The fourth screen capture is about 1 second into the free fall acceleration portion of the collapse. The simulation does not match the actual collapse.




Last edited by Christopher7; 30th March 2011 at 08:46 PM.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 09:04 PM   #192
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
Of course ozeco41 is right. One can no more assume controlled demolition based on free fall than one can assume fairies brought it down, or death rays from outer space, or mininukes. I know well where the burden of proof lies and will reclaim that in due time in my debate Epilogue, but first I will see if I can answer Richard's challenge on his own terms. I have some ideas, and more good ideas may come from this thread. Sorry Chris, I'm saving the $9.11 prize for someone who can 100% convince me.

However, Chris has one point. I too saw the video of what Chris is referring to above when he wrote: At a Tech briefing on 8-26-08, lead investigator for NIST, Shyam Sunder, stated:
"a free fall time would be an object that has no structural components below it . . . there was structural resistance that was provided in this particular case. And you had a sequence of structural failures that had to take place. Everything was not instantaneous."

This was at the "Public Comment" meeting re the draft report on Building 7. You can see it on the new David Chandler 911 Truth video. Now, NIST has not been strong on explaining the actual collapse of the Twin Towers or Building 7. They focused on how the collapse started, so Sunder's remark can be taken as off-hand. Still, as long as I'm playing devil's advocate, the final 2008 NIST Report on Building 7 ignores Sunder's statement, and NIST never answered my questions about this. They always say once the collapse started, gravity took care of the rest and we don't need to study that.

They're right from a scientific point of view, but it does make my debate a bit harder! And Oystein, thanks for your ideas; I cut and pasted them for possible use.
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 09:47 PM   #193
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by chrismohr View Post
Of course ozeco41 is right. One can no more assume controlled demolition based on free fall than one can assume fairies brought it down, or death rays from outer space, or mininukes.
When you have eliminated the impossible, whatever remains, however improbable, must be the truth. -- Sir Arthur Conan Doyle


Quote:
I know well where the burden of proof lies and will reclaim that in due time in my debate Epilogue, but first I will see if I can answer Richard's challenge on his own terms. I have some ideas, and more good ideas may come from this thread. Sorry Chris, I'm saving the $9.11 prize for someone who can 100% convince me.
Darn!

Quote:
However, Chris has one point. I too saw the video of what Chris is referring to above when he wrote: At a Tech briefing on 8-26-08, lead investigator for NIST, Shyam Sunder, stated:
"a free fall time would be an object that has no structural components below it . . . there was structural resistance that was provided in this particular case. And you had a sequence of structural failures that had to take place. Everything was not instantaneous."

This was at the "Public Comment" meeting re the draft report on Building 7. You can see it on the new David Chandler 911 Truth video. Now, NIST has not been strong on explaining the actual collapse of the Twin Towers or Building 7.
Now there's an understatement.

Quote:
They focused on how the collapse started, so Sunder's remark can be taken as off-hand.
Off hand or not, it is a statement of fact. Free fall acceleration means falling thru air - no resistance, and their model always provides resistance.

Quote:
Still, as long as I'm playing devil's advocate, the final 2008 NIST Report on Building 7 ignores Sunder's statement, and NIST never answered my questions about this.
They have no answer because it is incompatible with their "progressive collapse".


Quote:
They always say once the collapse started, gravity took care of the rest and we don't need to study that. They're right from a scientific point of view, but it does make my debate a bit harder!
They are sidestepping/ignoring the impossibility of free fall acceleration in their "progressive collapse"


ETA: Look again at the screen captures and Figure 12-63. Do you see the frame buckling during the time when WTC 7 was in free fall?

Last edited by Christopher7; 30th March 2011 at 09:50 PM.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 09:49 PM   #194
ergo
Illuminator
 
ergo's Avatar
 
Join Date: Aug 2010
Posts: 4,339
Originally Posted by chrismohr View Post
Of course ozeco41 is right. One can no more assume controlled demolition based on free fall than one can assume fairies brought it down, or death rays from outer space, or mininukes. I know well where the burden of proof lies and will reclaim that in due time in my debate Epilogue, but first I will see if I can answer Richard's challenge on his own terms. I have some ideas, and more good ideas may come from this thread. Sorry Chris, I'm saving the $9.11 prize for someone who can 100% convince me.
Actually ozeco, like NIST, simply makes the claim without ever explaining it, and tries to throw the conundrum onto truthers.

Originally Posted by ozeco41 View Post
My version ... "Since there was no demolition..."
(Yeah, that'll win you converts. )

As Chris Mohr points out, the question is being posed to you guys. You have to explain how that resistance across and through a steel-framed building was removed. How was resistance removed globally to allow the building to descend through itself--not through air; through itself--in the time that it did?

Merely saying that something that is highly unusual--unprecedented, in fact--outside of CD is actually "nothing unusual" without bothering to explain why isn't an argument. It's an unfounded assertion. You dismiss the idea of controlled demolition, but then insist that truthers come up with an alternative answer for you. You come up with it. NIST doesn't answer it. What's your answer? Where do you think the building fell?
__________________
“Much of the 9/11 story has not been told to the public" - Steven Badger, attorney for insurance litigators affected by the WTC disaster.
ergo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 10:17 PM   #195
chrismohr
Master Poster
 
chrismohr's Avatar
 
Join Date: Mar 2011
Posts: 2,080
Hi Ergo,

You wrote, "As Chris Mohr points out, the question is being posed to you guys. You have to explain how that resistance across and through a steel-framed building was removed. How was resistance removed globally to allow the building to descend through itself--not through air; through itself--in the time that it did?"

Actually, I'm posing these questions as a Devil's Advocate (and having fun doing it). No one is obligated to answer, obviously, nor do I believe the reverse scientific method that says "Some nonscientist guy in Denver can't explain free fall collapse, therefore it must be controlled demolition." I'm only trying to draw out a convincing argument that rings true for me, if I can get it. I'm a patient guy. As Carl Sagan said, extraordinary claims require extraordinary proof, which I have not found in the Controlled Demolition camp. I laid out 103 reasons in my recent debate why CD makes no sense. If you assert the extraordinary claim of CD, you must prove my objections wrong. More than that, you must provide an airtight theory. I don't have to explain every anomaly, but I'm having fun trying!
chrismohr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 10:31 PM   #196
R.Mackey
Philosopher
 
Join Date: Apr 2006
Posts: 7,854
Originally Posted by chrismohr View Post
The weakest moment in my March 6 Mohr/Gage debate was explaining the 2.25 seconds of free-fall collapse in Building 7. It may have been a curtain-fall collapse of the outside perimeter, but those are most common in masonry walls. Since there were 58 steel perimeter columns offering structural support to the outside of Building 7, it doesn't seem logical to assert that the interior collapsed and therefore the perimeter walls had no support.

A collapse, yes, absolutely. Totally free fall for 8 or 9 stories with strong steel supports right in the perimeter walls? I'm searching for a short, simple narrative that can really nail this. NIST does not think it's important, they just studied the probable collapse sequence up to its start and then they say gravity took care of the actual collapse from there. The best help I've gotten so far has been from Ryan Mackey, who mentioned that one interior support column eight stories in length remained attached and helped actually drag the perimeter wall down during that 2.25 seconds.
Hi Chris,

I think I gave you some kind of explanation in e-mail, but I can try again.

This is a hard thing to explain, however, simply because it seems pretty obvious from where I'm standing. It's fake controversy -- the argument makes no scientific sense. But to explain it properly one has to get into the mind and understand the thinking of the opposition.

I can't do this. The "free-fall" argument makes no sense. But even without any scientific training, there is also the word of firefighters to consider, notably Chief Nigro. They saw clearly, with their own eyes, how the structure's integrity deteriorated as it burned, enough so that they got well away from it, fearing a collapse, hours before it actually fell. Not even the craziest Truther has suggested there were bombs detonated during this time period. But this is tantamount to accepting that fire can cause structural degradation and, yes, collapse of a steel-framed skyscraper. In essense, they aren't denying the fact of collapse, they're merely denying the style of collapse.

Simply put, if a regular collapse wouldn't behave like this, and the mystery saboteurs needed to put a huge excess of silent, priceless nanotech explosives to cause this effect, why did they do it? It's nonsense.

So with that in mind, let me try the second-best approach, namely by walking through a series of thought experiments, each in increasing complexity until we approach the problem.

Here's the first thought experiment. Suppose we have a slender column supporting a significant weight. If you want to play along at home, say we've got a cardboard packing tube, and we've stacked a number of phone books carefully on top of it. As we approach its failure point, we start adding weight very slowly, until it collapses.

How will it collapse? It will probably not just topple over, and it certainly will not topple over if we have the base of it fixed to the floor. Why would it? Toppling requires the tube to remain straight. The only way it topples is if a tiny bit at the bottom bends first, and the rest remains intact. Why would it fail there first, when the stress is basically the same over the whole tube?

What happens instead is the tube will buckle. It will bend in the middle, the phone books will start to fall virtually straight down, and we wind up with a bent tube and pile of books on the floor. This is classic column buckling in action.

Now, suppose we measure the vertical progression of this collapse, using a high-speed camera and a ruler, Mythbusters style. The collapse will have three distinct phases. First, there will be a barely perceptible shortening of the structure as the column bows, then begins to kink -- the phone books will only drop a matter of millimeters during this stage, since the bowing and kinking don't change the effective height of the column very much. This stage will take a little time, maybe a second or two. During this time the tube is absorbing energy, undergoing plastic strain at the kink, until it yields.

After this, there is the second stage, where the column is kinked. At this point it provides almost no strength whatsoever. Think about it -- once bent, can you straighten up that tube and put weight on it again? Nope. After buckling, its strength is gone forever. So, the books fall. The tube does not absorb energy during this stage, or at least not enough to notice, because it's already buckled. It has reached its yield point and can't even support itself any longer. Try it: After buckling, it won't even stand up on its own. The upper part just flops around. Thus, strength has gone to zero, so the books fall at "free-fall speed" (really at ~ 1 g of acceleration).

Then the books hit the ground, and stop. Once they encounter something that does have strength -- the floor, in this case -- they no longer fall at 1 g. That's the third stage.

These three stages are exactly what we see in the WTC 7 perimeter collapse. Deceitfully, the Truthers only consider the second stage.

---

Now on to the second thought experiment. "That's just one column," you're thinking, "and we added weight until it collapsed. WTC 7 didn't add weight." That's correct. What really matters, though, is not the amount of weight, but rather the demand to capacity ratio, or the relationship between weight and the carrying ability of the structure. To gradually build up to collapse, we can either add weight like we did the first time, or we can reduce the strength of our column. Once the buckling point is reached, it behaves the same regardless of how we got there.

For our second thought experiment, instead of just a simple column we're going to set up some buttresses. Beside our cardboard tube I'm going to build three very strong stacks of bricks, all round the cardboard tube at the same distance, spaced just far enough that I can wedge a paper cup between the bricks and the tube. I'll put three cups total, all halfway up the tube. Then I'll start stacking phone books on the tube just like before.

When I do this, I find that now the tube can handle a whole lot more weight than it could before. Why? Well, remember, our tube bent in the middle. I've got these buttresses in place now that keep the tube from bending in the middle. If I want the tube to buckle now, it needs to form a more complicated shape, like an "S" instead of just a "C" shape. That more complicated shape takes more energy. As a result, the buttressed tube is stronger. In structural engineering, we talk about the "effective length" of a column -- a slender column with good bracing is just as strong as a shorter column of the same diameter.

Instead of overloading this column, let's give it the same weight it took to collapse our unbraced column. The tube will handle this weight and stay standing. Or, at least it will until something happens to the paper cups. Say I knock them out, or set them on fire...

As soon as the cups are gone or fail, the tube will fail, and we get a collapse. This collapse behaves exactly the same as the one in our first thought experiment.

---

On to the third trial. What if there's more than one column?

Well, let's set it up. The perimeter of WTC 7 is more like a mesh than a bunch of totally disassociated columns, so the load is shared between them. Let's set up a row of cardboard tubes and put a solid load on top of them -- say, a stack of wooden planks. We'll put in buttresses just like before, one on each side of the columns in the middle, and on three sides of the columns at the ends.

Finally, we put buttresses between adjacent tubes. Even though they're all the same strength, the tubes actually do support each other by keeping each other straight and true.

Now we start knocking out the cups, one by one. We'll leave the ones between tubes in place, just hit the ones on the outside. What happens?

Wherever cups are knocked out, the tubes will start to buckle. When this happens, it means the load is transferred to other tubes -- the buckled one will shorten a tiny bit, but that's all. If you aren't measuring carefully, you can miss it.

When we knock out enough cups so that the total strength of the tubes isn't enough, then we can't redistribute the load any more. At that point all of the tubes will buckle, and we'll precipitate a total collapse. It will look quite a lot like the previous experiments -- brief period of buckling, followed by free-fall of our load, followed by the load hitting the ground.

In the actual structure, the load redistribution takes place at the speed of sound in steel, or several thousand meters per second. This is so fast that it may as well be instantaneous, compared to collapses that last a few seconds.

One thing, though, in our little experiment it is possible to get a little bit of tilting, and this may cause our stack of boards to actually fall off, leaving some columns looking much more kinked than others. In the actual WTC 7, however, this can't happen. The load there is not an ideal load concentrated on the top and just balanced there. The actual load is the weight of the columns themselves, which are, again, more of a mesh. It's got nowhere to go, except down.

---

The last thought experiment is to note that columns can also buckle at different locations than the middle, if there's something that causes them to be weaker there. For instance, we could cut part of our tube a quarter of the way up. It'll buckle there first instead of at the middle, even though it'll still carry almost as much load as the intact tube before that happens.

Another way is to actually push on the tube. This is the opposite of our buttresses. In structural engineering this is called an "eccentric load," i.e. a load that isn't axial, or all vertical and centered over the column's base. You could have a string tugging on the tube, for instance, and if you did, you'd notice it took significantly less weight for the tube to collapse. The reasoning by now should be simple -- the side load causes the tube to bend, because it's already bent it has less "springiness" to resist buckling, and it absorbs less energy when it buckles.

---

Now let's relate it all to WTC 7. We have visual and simulation evidence that demonstrates the core was basically collapsed before the perimeter begins to move. We are then left with the perimeter alone, which is a network of columns all tied together, and made of steel.

The core collapse is like our buttresses failing. When we have solid columns supporting each other, with the floor beams, at every story, the columns have a short effective length and are quite strong. But when the core is gone, they're no longer supported. Their effective length goes up by ten, twenty, maybe even thirty times! After this happens, their strength is vastly reduced -- reduced so far, in fact, that they now don't even have enough strength to hold themselves up.

The core collapse also introduces eccentric loads. The collapsing material has to go somewhere. It's a big pile in the interior, but it won't make a neat pile. Instead, it flows, and it pushes the perimeter columns outward. This further weakens the perimeter columns, and it makes them more likely to buckle low in the structure, where the eccentric load is.

Additionally, there is one corner of the WTC 7 lower floors that is expected to survive, attached to the perimeter, while the rest falls away. This is because that one corner experiences less fire and is predicted to have more intact connections to the perimeter. Guess what this means? That's right, even more eccentric load.

This last factor explains why the buckle happened how it did. Because the supports are gone and yield strength has dropped below its self-weight, some buckling is inevitable. Because the perimeter columns are tied together, rapid load redistribution bewteen them is expected, so when it buckles it'll buckle pretty much all together, and the last few remaining columns will be pulled down by their buckled neighbors. But it could happen over the entire height, or it could happen over a few floors.

The individual columns in WTC 7 are not tubes, and they have many imperfections that each could start the buckle. The columns are built up from many individual pieces of steel, and welded together. Any one of these welds is a weak point. So we could see a fracture of three welds, say, for an initial buckle of two pieces of steel. Or we could see more.

What we actually see is an eight-story buckle, and this is due to the eccentric loading in the corner. That chunk of remaining floors attached to the perimeter after the core fails literally pulls in eight stories of column.

But not at once. Look at NIST's displacement curve. In the first few seconds, the perimeter only moves slightly. This is the eccentric load pulling inward, shortening the wall slightly, while the wall resists bending but slowly deforms. And then it buckles.

After it buckles, of course we see some "free fall." There is no strength whatsoever at that point. The very last supports between the top of the perimeter wall and the ground are gone.

After eight stories, the upper part of the columns basically hit the rubble pile, and then they slow down. The collapse continues, of course, but now it's a confusion of rubble piling on rubble, and already-buckled columns breaking and tumbling further. There is resistance because upper and ground are touching, but it's not a stable load path -- it's a big pile of junk.

---

And that, frankly, is all there is to it. If you build another structure like WTC 7 and fail its core first, you'll see much the same behavior at the perimeter. "Explosives" is a fairy tale.

Last edited by R.Mackey; 30th March 2011 at 10:34 PM.
R.Mackey is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 11:18 PM   #197
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
If you can't convince them with facts . . . . . . baffle them with a 2,247 word Babylon Soliloquy.

To make a long story short:

This is not rocket surgery.


Ryan,

Do you understand that free fall acceleration only occurs when there is NO resistance?

Can you see that in the NIST computer simulation screen captures and Figure 12-63 that the exterior frame is providing resistance as Shyam Sunder said?

Last edited by Christopher7; 30th March 2011 at 11:22 PM.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 30th March 2011, 11:51 PM   #198
Christopher7
Philosopher
 
Christopher7's Avatar
 
Join Date: Aug 2006
Posts: 6,538
Originally Posted by chrismohr View Post
. . . . . nor do I believe the reverse scientific method that says "Some nonscientist guy in Denver can't explain free fall collapse, therefore it must be controlled demolition."
That is what is known as a strawman. No one is making that claim.

The point I am making is: The PhD's at NIST can't explain the free fall acceleration.

Free fall acceleration means No resistance. The NIST model always provides resistance.

The NIST simulation does not match the actual collapse.
Christopher7 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 31st March 2011, 03:42 AM   #199
Disbelief
Illuminator
 
Disbelief's Avatar
 
Join Date: Mar 2007
Posts: 3,306
Originally Posted by Christopher7 View Post
Do you understand that free fall acceleration only occurs when there is NO resistance?
Ever find a CD that exhibited freefall acceleration? You have been asked many times to support freefall as an indicator of CD, but you have failed like all other truthers to prove this.
__________________
Zensmack (LastChild, Laughing Assassin, RazetheFlag, Wastrel, TruthbyDecree) - Working his way up the sock puppet chain, trying to overtake P'Doh. Or, are they the same?

Quote me where I said conspiracists use evidence. - mchapman
Disbelief is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 31st March 2011, 05:30 AM   #200
Carlos
Critical Thinker
 
Carlos's Avatar
 
Join Date: Aug 2009
Posts: 285
Originally Posted by Christopher7 View Post
Free fall acceleration means No resistance. The NIST model always provides resistance.

Strictly speaking, no resistance is only possible in vacuum. In these circumstances, a controlled demolished building did not collapse at free fall acceleration.

Maybe you mean "negligible resistance". In this case multiple structural failures at one or more floors can do this.
__________________
In most cases debating with a 9/11 truther is rather like trying to play chess with a pigeon; it knocks the pieces over, craps on the board, and flies back to its flock to claim victory.

The customer with the knife is always right - Quohog, the bartender
Carlos is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Conspiracies and Conspiracy Theories » 9/11 Conspiracy Theories

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 02:45 AM.
Powered by vBulletin. Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.