More on progressive collapse at WTC.
This chap has done some research and found a few cases of progressive collapse in steel-frame high-rise buildings. http://911myths.com/html/progressive_collapse.html While none of these perfectly replicate the conditions at the WTC, they do show that once the load exceeds the structural integrity, progressive collapse is initiated. So we've established that the fire was hot enough to initiate the phase change in the steel (any heat over 600C), we've established that there have been other cases of progressive collapse. As for the Thermite: thermite is aluminium and iron oxide. If any of the beams were exposed, which they would have been after a plane flew through the central core, there may well have been rust about. We know there was aluminium flowing through the buliding, as the planes were made of it. It's entirely plausible that thermite reactions occurred at places, and these may have caused additional weakening. However, I think we've established that the heating of the steel beams to over 600C was probably sufficient to initiate collapse. Have a wander round that 911myths site, it's not bad as he provides pretty substantial references. Charlie ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Introductions (Was:Re: SCOUTED: Bush is Not Incompetent)
Thanks to all those who have said Hi! I have been a lurker for awhile but have decided it is time to jump into the online world with both feet. Though time may restrict how often I post. I am 58 yrs old. I have 5 kids( two of my own, two of my wife's and an unofficial adopted daughter) between them we have 5 grandchildren. I am a West Point grad and a Pepperdine MBA living in Austin, TX. Well South Austin anyway, down here in Bubaland we wonder if the City Council really knows we are incorporated. We presently own a parent teacher store called Teachers' Alley. Just like you Rob the first science fiction book that I read was Tom Swift jr and the Flying Hydrocopter. It was given to me by the next door neighbor who was an Army helicopter pilot. I believe I was in 4th grade and a very poor reader at the time. After that book I was hooked on reading. I read all the Sci Fi books in the school library by the end of 5th grade. I believe that Asimov, Clarke and Heinlein in a very really way influenced my way of groking the world. In the 90's it was the three B's when I had time. Benford's Deep Time made a very lasting impression on me and I would never have read it if it had not been for his fiction books. I believe that many of our country's problems today stem from the lack of long term thinking. This brought me to the Long Now foundation and the podcasts of its seminars and David Brin's talk there. and that led me to his blog and this group. I look forward to our conversations. have a great day! Chris Frandsen On Jun 30, 2006, at 6:53 PM, Robert G. Seeberger wrote: On 6/30/2006 3:48:49 PM, Chris Frandsen ([EMAIL PROTECTED]) wrote: Howdy Chris! Don't feel like the Lone Texas RangerG Dan and I live in opposite ends of Houston and Julia is in Austin. There are several former Texas posters here and may still be a few current members still hanging around. I live in Lampsens former district that was swallowed by Delays district, so I'm with you on the redistricting. It has been a topic of conversation here in the past, so we are at least familiar with the subject. We have a couple of new people! So how about we regulars introduce ourselves? Hi, my name is Rob and I'm a recovering bonehead.G I work as an electrician with some oilfield industry quality control in my past. I build my own PCs because I like em better that way. I'm a 40 year + Sci-Fi reader, but I learned to read when I was 4. My first Sci-Fi book was either Tom Swift and his Jetmarine or the War Of The Worlds, I can never decide which was first. For many years I collected comics, tropical fish, rocks, and for a number of years grew a kidney stone that I passed just a couple of years ago. (I have it saved in a test tube and named it Jr) I'm opinionated and somewhat obstinate, but I think I respond well to a well thought out argument. I write poetry and lyrics when I'm in the mood, and have album (albums that no one ever heard of) credits for lyrics. ( http://www.amycd.com ) I'm becoming a big fan of Anime and am a devoted watcher of Adult Swim on Saturday nights. (well.OKToonami tooG) I'm the proud father of an 11 year old who is brilliant and everything I might have been and never was. When I grow up, I want to be one of the good guys. xponent Amalgamated Texas Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Introductions (Was:Re: SCOUTED: Bush is Not Incompetent)
Hi Julia: thanks for the welcome. but you folks north of the river are in a foreign land aren't you. I know when I was growing up in Northern Virginia I thought that it took a passport to go to Maryland. something like that for Pflugerville for us Bubaland folk. I sympathize with you on SH130. We need the road but not as a toll road. I participated in Envision Austin's growth planning exercises two years ago and most of the groups wanted growth to move to the East to protect water shed etc. But tolling the road will slow that down, I think. Chris On Jul 1, 2006, at 11:05 AM, Julia Thompson wrote: Robert G. Seeberger wrote: On 6/30/2006 3:48:49 PM, Chris Frandsen ([EMAIL PROTECTED]) wrote: Howdy Chris! Don't feel like the Lone Texas RangerG Dan and I live in opposite ends of Houston and Julia is in Austin. There are several former Texas posters here and may still be a few current members still hanging around. Shouldn't have hit send so soon. :) I'm not IN Austin, I'm NEAR Austin. If anyone in Austin asks, and I tell them what city it is whose ETJ I live in and get a blank look, I just say Northeast of Pflugerville which is about right for where my house is, anyway. I'm EAST of the SH 130 currently under construction (and whose construction is making it take longer to GET anywhere but up to town, and we don't go up to town except to go to the school and get pizza, there's an awesome pizza place on US 79 on that little stretch where it's concurrent with FM 1660), but once the highway network is in place, all it's going to take to get anywhere is toll money and the ability to do it using MoPac instead of I-35 (but you don't want to take I-35 anyway, right?). Blathering. Right. I'll shut up for a few more minutes Julia ___ http://www.mccmedia.com/mailman/listinfo/brin-l ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Introductions (Was:Re: SCOUTED: Bush is Not Incompetent)
D. C. Frandsen Jr wrote: Thanks to all those who have said Hi! I have been a lurker for awhile but have decided it is time to jump into the online world with both feet. Though time may restrict how often I post. I am 58 yrs old. I have 5 kids( two of my own, two of my wife's and an unofficial adopted daughter) between them we have 5 grandchildren. I am a West Point grad and a Pepperdine MBA living in Austin, TX. Well South Austin anyway, down here in Bubaland we wonder if the City Council really knows we are incorporated. We presently own a parent teacher store called Teachers' Alley. Just looked it up on Yahoo, and yikes! that's a bit of a haul from me -- but if someone's asking after a teaching supply store and they're in that part of town, I will definitely tell them to check it out. (I have twins and belong to Austin Mothers of Multiples, and that's the sort of thing that comes up now and again.) Bubbaland sounds nice some days. :) Just like you Rob the first science fiction book that I read was Tom Swift jr and the Flying Hydrocopter. It was given to me by the next door neighbor who was an Army helicopter pilot. I believe I was in 4th grade and a very poor reader at the time. After that book I was hooked on reading. I read all the Sci Fi books in the school library by the end of 5th grade. I believe that Asimov, Clarke and Heinlein in a very really way influenced my way of groking the world. In the 90's it was the three B's when I had time. The first SF I can remember was Asimov's _The Best New Thing_ which we checked out of the library repeatedly. My father figured out the best way to hook me in my pre-teen years was stuff like Andre Norton and Anne McCaffrey (the first book with a cover price over $2.50 that I bought with my own money was _Crystal Singer_), and then encouraged me to read the harder stuff. :) I like space opera a lot, if it's well done, and harder SF. Not much patience with fantasy anymore, although I've had some *good* stuff recommended in the last few years, so I'm at least willing to try it. Benford's Deep Time made a very lasting impression on me and I would never have read it if it had not been for his fiction books. I believe that many of our country's problems today stem from the lack of long term thinking. This brought me to the Long Now foundation and the podcasts of its seminars and David Brin's talk there. and that led me to his blog and this group. I look forward to our conversations. have a great day! Chris Frandsen It's nice having you here! Julia ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Introductions (Was:Re: SCOUTED: Bush is Not Incompetent)
D. C. Frandsen Jr wrote: Hi Julia: thanks for the welcome. but you folks north of the river are in a foreign land aren't you. I know when I was growing up in Northern Virginia I thought that it took a passport to go to Maryland. something like that for Pflugerville for us Bubaland folk. I sympathize with you on SH130. We need the road but not as a toll road. I participated in Envision Austin's growth planning exercises two years ago and most of the groups wanted growth to move to the East to protect water shed etc. But tolling the road will slow that down, I think. Chris Having the road as a toll road won't do as much good in the next 10 years as they'd like it to, that's for sure, but if it saves me half an hour, I'll pay the darn toll. :) (It's likely to save me a good deal once I can use SH 45 -- can't go east or west worth a darn around here; the only good east-west road I can name in the whole area is Ben White. And that's a bit of a haul for me to take advantage of. :) I know all sorts of tricks involving Howard Lane now, which is the next exit north of Parmer, that SH 45 will render moot.) Julia ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
Ahoy all, I trust we are enjoying our long weekend.
I've just done some quick updating the conversation these last few days
and have some additional thoughts.
On Jun 30, 2006, at 8:01 PM, Julia Thompson wrote:
[EMAIL PROTECTED] wrote:
The History Channel occasionally runs its 9/11 special. IIRC their
conclusion was that the heat caused the structural beams to sag,
pulling away from the anchors and thus causing the floors to pancake
on top of each other. At a sufficient weight the lower floors were no
longer able to support the weight...
Is that the one where they have some footage with the architect?
Julia
Why the Towers Fell aired on PBS, proposing the FEMA theory {via the
American Society of Civil Engineers - ASCE} about the floor trusses
growing hot and the sagging to the breaking point. That show ends on
the sorrowful figure of a junior architect {name escapes me} and leaves
the audience wondering if he designed poorly and bearing great remorse.
It also incorrectly fingers him as the keystone designer, but in
reality he was an underling for senior partner John Kittling who did
the actual designs, had the experience, and states that this building
was over-built. I've also noticed a number of diagrams from news
stories at the time which vastly under represent the strength of the
exterior column walls. This building was designed to withstand
hurricanes as well as plane impacts and as Kittling still says, it
should no have failed as it did.
This documentary rang true enough the first time I saw this, but when
it came around again I started doubting. The NIST {National Institute
for Standards and Technology} report abandons this theory and in fact
states these trusses would have been drawn to the core structure and
and this caused the break - kinda-sorta opposite theories, but the
story has lodged in the public's mind - I dare say as it was intended
to.
How the debris we see falling {I would point out it's much more akin to
exploding outward and then down} exterior to the building can match an
interior descent flies in the face of logic. I simply cannot accept
that the core structure, a thick _lattice_ of crossing steel, would
offer the same resistance as the air outside slowing the debris.
Recap, to believe this theory one has to accept that the interior steel
structure has to completely and utterly fail up and down the entire
length and I just don't see how a shock-wave from one collapsing floor
can do this: the building has give and sway precisely to bend to
hurricane winds, earthquakes, let alone the 100+ MPH winds skyscrapers
routinely handles during their lifetime.To believe this you need to
accept a brittleness to these structures that defies their original
program.
Collapsing steel buildings tip in one direction - the area of failure -
with the remaining building falling {damn near} intact on top of the
failed section... examples include earthquakes {Iran}, terrorists
{Russia - bombs placed in parking area collapsed apartment building}
poor construction {Turkey} all demonstrate this. For structures that
do start falling down initially they invariably begin tipping one
direction once the floors below bunch up - inevitably collecting in one
area over another because nature does not operate symmetrically on a
failing structure - unless coerced. I had already considered the
collapses mentioned in previous posts, but put them aside because they
always seem to occur during construction - obviously as this is the
most dangerous and fragile period of a building's life when it's
integrity has not been finalized and loads are shifting dramatically.
The only way symmetry in a collapse occurs is when its made to collapse
- when thought and energy has gone into weakening critical points.
It's why crews that perform such demolition are considered elite
specialists.
I am not convinced the discussion of heat-softened steel justifies
extrapolating complete failure. I can find no study in their report
about the wicking nature of steel and how this offsets a {potential}
high-temp fire in one locale _not_ being distributed away. Rio de
Janeiro had a steel skyscraper burn for 24+ hours over multiple floors
yet it had no such catastrophic collapse, was reconditioned and in use
today {with upgraded fire suppression}. Those fires on the South Tower
had burned less than an hour, were in fact almost out {watch the smoke
volume decrease dramatically by end of sequence} and firemen had
reached the scene said they could handle it - yet that building falls
first.
It's up to the government to explain this event and they have offered a
very faulty proposition obscured with copious preliminary detail around
the plane crash, engines, fire, wing members, down to the damn
turban-fans ... with but a few pages explaining events AFTER the
building BEGINS to collapse. The narrative doesn't even match the
illustrations. The only
Re: Physics Prof Finds Thermate in WTC Physical Samples
On 03/07/2006, at 8:06 PM, Gibson Jonathan wrote:
How the debris we see falling {I would point out it's much more
akin to exploding outward and then down} exterior to the building
can match an interior descent flies in the face of logic. I simply
cannot accept that the core structure, a thick _lattice_ of
crossing steel, would offer the same resistance as the air outside
slowing the debris.
It doesn't. The building collapsed very rapidly, but not as fast as
most of the debris.
Rio de Janeiro had a steel skyscraper burn for 24+ hours over
multiple floors yet it had no such catastrophic collapse, was
reconditioned and in use today {with upgraded fire suppression}.
Had it had a plane full of kerosene fly into it?
One final and glaring omission from the official NIST report is
rarely commented on: once the collapse takes place they virtually
ignore the entire structural analysis of the pancake theory and how
the various materials acted {or didn't}... as thought the report
ends once collapse is initiated.
Because progressive collapses are well-documented.
Charlie
___
http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
Why would we assume the building MUST collapse in one direction (the point of failure)? This assumes the failure was in the essential superstructure that brought it down; on an externally supported building (IIRC much of the structural strength came from the external walls, rather than the internal structure, which I believe was innovative at the time). However, the Pancake theory does not support an external failure to satisfy it's conclusions; instead the falling mass of debris compromised internal support mechanisms. Indeed, if a falling mass of debris impacts previously uncompromised floors, the support structure may very well draw the walls *in*. Therefore, the strength of the external walls may very well served to channel the debris internally. I think the idea of jets is inconsistent with the idea of thermite cutting steel; It might be with *explosives,* but thermite burns extremely vigorously, not explodes... Damon. Damon Agretto [EMAIL PROTECTED] Qui desiderat pacem, praeparet bellum. http://www.geocities.com/garrand.geo/index.html Now Building: Alan's Panzer IIC -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.1.394 / Virus Database: 268.9.5/376 - Release Date: 6/26/2006 ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: Physics Prof Finds Thermate in WTC Physical Samples
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Gibson Jonathan
Sent: Monday, July 03, 2006 12:07 PM
To: Killer Bs Discussion
Subject: Re: Physics Prof Finds Thermate in WTC Physical Samples
How the debris we see falling {I would point out it's much more akin to
exploding outward and then down} exterior to the building can match an
interior descent flies in the face of logic. I simply cannot accept
that the core structure, a thick _lattice_ of crossing steel, would
offer the same resistance as the air outside slowing the debris.
That's not quite what happened. While conspiracy sites argue that the
building fell at the rate one would expect from free fall, other sites, and
my own analysis indicated that it took 2 seconds longer than what one would
expect from free fall.
As Charlie has pointed out, some debris did fall just a bit faster than the
building, which makes sense. Small debris, due to the square-cubed law, met
relatively high air resistance, which resulted in a lower terminal velocity,
so there is a point where the smaller loose debris did fall slower than the
lowest structure. To intuit this, think low long a dust cloud can remain in
the air, or think of why raindrops don't hurt when they fall on you.
Recap, to believe this theory one has to accept that the interior steel
structure has to completely and utterly fail up and down the entire
length and I just don't see how a shock-wave from one collapsing floor
can do this:
That's not really accurate. To believe this theory one needs to accept that
the physics of rigid objects can be counterintuitive at times. I'm not sure
why this would be hard to accept. I gave one model of this, which didn't
get much response, but I'll try another. I'm going to construct a toy model
(a very simplified steel girder building) and show how the physics works
with this building. The actual building is more complicated, of course, but
that's what the engineering architecture finite element analysis programs
(I believe those are the kinda programs that are used) are for.
Anyways, my building is build of these items:
Rigid Steel Beams,
||
| OO |
||
Bolts
_
|_|
Rigid steel floors
_/ /_
/ /
/ /
/ /
/ /
/__/
/___/
The beams are bolted together at the corners, and the floors are put on top
of the horizontal beams. Only the bolts have any give to them, and that
give is rather small.
What keeps the building from collapsing? It's the bolts. Now, in reality,
there is more than 1 bolt per corner, and the corners are often welded
together. But, the basic physics of the question is not affected by the
difference.
The building is held up by the sheer strength of the bolt. Lets assume that
the building about the floor we are considering has a mass of 10,000 metric
tons. That means there is a force of about 2.5*10^7 Newtons on each of the
bolts (10,000 metric tons is 10^7 kg, acceleration due to gravity is 9.8
m/s^2, 4 bolts).
Let's have the bolts rated to 2.5*10^8 Newtons. That means that the
shearing force applied to the bolts needs to be 2.5*10^8 Newtons before the
bolts break.
So, let's have the floor immediately above the floor we are considering
collapse. Let's also assume that the distance between floors is 4 meters.
The top of the building, with a mass of 10,000 metric tons free falls those
4 meters.
It takes about 0.9 sec to free fall those 4 meters. The velocity after the
fall is about 9 m/sec. So, we have a rigid object falling at 9 m/sec
hitting another rigid object. The give, we are assuming, is in the bolts.
The critical question is how far will the bolts bend before breaking? The
reason for this is that, for the floor we are considering to hold the
falling mass, it must decelerate it to a stop before the mass falls enough
to bend the bolts beyond the breaking point.
Steel, as others observe, doesn't bend much over short intervals. Let's
assume a stress strain relationship for our toy model where 2.5*10^8 Newtons
of force strains the bolts 5 cm. Any greater force, even 1 more Newton,
breaks the bolts.
Given this, the falling floors are decelerated by the floor we are
considering until the deceleration of the mass is at 9 g's (we have to
consider the constant gravity force of 1 g). At this point, the bolts
break. Now, if we assume a linear stress-strain relationship (simplifies
the problem, but isn't essential), we can see the change in velocity of the
falling mass due to
Roots of human family tree are shallow
delurking http://news.yahoo.com/s/ap/20060701/ap_on_sc/brotherhood_of_man Whoever it was probably lived a few thousand years ago, somewhere in East Asia — Taiwan, Malaysia and Siberia all are likely locations. He — or she — did nothing more remarkable than be born, live, have children and die. Yet this was the ancestor of every person now living on Earth — the last person in history whose family tree branches out to touch all 6.5 billion people on the planet today. That means everybody on Earth descends from somebody who was around as recently as the reign of Tutankhamen, maybe even during the Golden Age of ancient Greece. There's even a chance that our last shared ancestor lived at the time of Christ. It's a mathematical certainty that that person existed, said Steve Olson, whose 2002 book Mapping Human History traces the history of the species since its origins in Africa more than 100,000 years ago. [...] greetings my global relatives, Ticia ',:) -- [EMAIL PROTECTED] lurk ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Crack found in foam on shuttle fuel tank
Crack found in foam on shuttle fuel tank By MIKE SCHNEIDER, Associated Press Writer 2 hours, 7 minutes ago CAPE CANAVERAL, Fla. - http://search.news.yahoo.com/search/news/?p=NASANASA managers weren't ruling out a Fourth of July launch for space shuttle Discovery on Monday, even after inspectors found a 5-inch-long crack in the foam insulation on its external fuel tank. Full article at: http://news.yahoo.com/s/ap/20060703/ap_on_he_me/space_shuttle;_ylt=ArZteL39QoMWGllEYAgx8LNxieAA;_ylu=X3oDMTA3MzV0MTdmBHNlYwM3NTM- -- Ronn! :) ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Scientists say dodos killed by natural disaster
It's not our fault . . . Scientists say dodos killed by natural disaster By Tim Cocks Mon Jul 3, 10:47 AM ET PORT LOUIS (Reuters) - Scientists who unearthed a mass dodo grave in Mauritius say they have found evidence showing the birds were killed by a natural disaster long before humans arrived on the Indian Ocean island. Full article at: http://news.yahoo.com/s/nm/20060703/sc_nm/mauritius_dodos_dc;_ylt=AtOU.k5Ts05m9mcLpCkJjQ5xieAA;_ylu=X3oDMTA4NmhocGZ1BHNlYwMxNzAw ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Roots of human family tree are shallow
From: Ticia [EMAIL PROTECTED] delurking http://news.yahoo.com/s/ap/20060701/ap_on_sc/brotherhood_of_man Whoever it was probably lived a few thousand years ago, somewhere in East Asia Taiwan, Malaysia and Siberia all are likely locations. He or she did nothing more remarkable than be born, live, have children and die. Yet this was the ancestor of every person now living on Earth the last person in history whose family tree branches out to touch all 6.5 billion people on the planet today. That means everybody on Earth descends from somebody who was around as recently as the reign of Tutankhamen, maybe even during the Golden Age of ancient Greece. There's even a chance that our last shared ancestor lived at the time of Christ. It's a mathematical certainty that that person existed, said Steve Olson, whose 2002 book Mapping Human History traces the history of the species since its origins in Africa more than 100,000 years ago. [...] Didn't native americans cross the land bridge circa 14,000 years ago, and remained relatively unconnected to other human populations until circa 1492? There are other similarly isolated populations I could point out. I'm not buying it. There was no common ancestor as of 2000 ya or even 3000 ya. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Roots of human family tree are shallow
On 04/07/2006, at 12:56 AM, The Fool wrote: Didn't native americans cross the land bridge circa 14,000 years ago, and remained relatively unconnected to other human populations until circa 1492? Apart from Vikings in Newfoundland and Greenland in the 8th/9th century... Charlie ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Roots of human family tree are shallow
Apart from Vikings in Newfoundland and Greenland in the 8th/9th century... There was a scholarly discussion about this on one of my history groups just last week. One of the conclusions they came to is that there is no strong evidence to suggest either interbreeding with the Inuit or not. So I think this is very much a perhaps...but.. Damon. Damon Agretto [EMAIL PROTECTED] Qui desiderat pacem, praeparet bellum. http://www.geocities.com/garrand.geo/index.html Now Building: Alan's Panzer IIC -- Internal Virus Database is out-of-date. Checked by AVG Anti-Virus. Version: 7.1.394 / Virus Database: 268.9.5/376 - Release Date: 6/26/2006 ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Roots of human family tree are shallow
In a message dated 7/3/2006 3:51:45 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes: It's a mathematical certainty that that person existed, said Steve Olson, whose 2002 book Mapping Human History traces the history of the species since its origins in Africa more than 100,000 years ago. [...] It is also true that the person changes from time to time as lines drop out. The last common ancestor may move forward or back in time ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
- Original Message -
From: Dan Minette [EMAIL PROTECTED]
To: 'Killer Bs Discussion' brin-l@mccmedia.com
Sent: Monday, July 03, 2006 2:35 PM
Subject: RE: Physics Prof Finds Thermate in WTC Physical Samples
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On
Behalf Of Gibson Jonathan
Sent: Monday, July 03, 2006 12:07 PM
To: Killer Bs Discussion
Subject: Re: Physics Prof Finds Thermate in WTC Physical Samples
How the debris we see falling {I would point out it's much more
akin to
exploding outward and then down} exterior to the building can match
an
interior descent flies in the face of logic. I simply cannot
accept
that the core structure, a thick _lattice_ of crossing steel, would
offer the same resistance as the air outside slowing the debris.
That's not quite what happened.
[Snip-a-doodle]
Doing a bit of searching I have found a few failure modes noted by
NIST that have not been discussed here.
http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf
One glaring example that we missed was bolt hole tearing. This is
where force causes the bolt hole to deform til it slips around the
supporting bolt. I would suspect that this takes a bit more time than
bolt shearing, but I also feel it doesn't change the math enough to
matter.
As for the bolts themselves, they turn out to have been stronger than
original building specs called for, but again this makes small
difference.
It turns out that there were a very significant amount of welded joins
that failed in the collapse. If you know much about welding then you
are aware that the weld itself is much stronger than the base metal in
the heat affected zone and it turns out that many of the welds that
failed were torn in exactly that way.
The base metal that gets heated by the welding rod becomes weakened by
the heat. In many manufacturing processes the part being welded is
then heat treated to give the heat affected zone properties similar to
the base metal. this of course is not practical on a construction
site. So you end up with 2 qualities of welding in a building, the
high quality welding where heat treating was performed in a factory
( as a part of the normal manufacturing process for say I-beams) and
welding that was performed on site as apart of the construction
process.
Another concept we have not discussed is load re-distribution. When
some of the supports were knocked out by the impact of the planes, the
load of the buildings mass was supported by the remaining structural
members. NIST claims that evidence is seen that heat and load
re-distribution caused not just buckling (as expected) but also
necking. Necking is the thinning of a member under stress exceeding
its yield strength. When impact caused the load to re-distribute, heat
weakened structural members til some buckled and others necked and
eventually you had a structural failure. WTC was a fairly lightweight
structure for its size but the buildings were still very massive.
The more one looks at the failure modes of the WTC collapse, the more
complex it gets.
xponent
Standards Maru
rob
___
http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
To veer slightly pedantic, ISTR I-beams are actually extruded... Damon. Damon Agretto [EMAIL PROTECTED] Qui desiderat pacem, praeparet bellum. http://www.geocities.com/garrand.geo/index.html Now Building: Alan's Panzer IIC -- Internal Virus Database is out-of-date. Checked by AVG Anti-Virus. Version: 7.1.394 / Virus Database: 268.9.5/376 - Release Date: 6/26/2006 ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
On 7/3/2006 7:39:30 PM, Damon Agretto ([EMAIL PROTECTED]) wrote: To veer slightly pedantic, ISTR I-beams are actually extruded... Sure, but the trusses on the ends are welded on. Basically, the architect orders beams to a specification and the manufacturer custom makes them. Any parts beyond the basic I (read that as a Roman I/numeral-one) are welded on and heat treated for strength. xponent Works Around This Stuff Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
- Original Message - From: Dan Minette [EMAIL PROTECTED] To: 'Killer Bs Discussion' brin-l@mccmedia.com Sent: Monday, July 03, 2006 2:35 PM Subject: RE: Physics Prof Finds Thermate in WTC Physical Samples So, I think we've gotten to the point where, in order to still say I cannot accept the conventional explanation, then you will have to reject my basic physics argument. I'd be very interested to see what flaws you might see in this argument. OKG, I'll bite on this one.G The WTC towers were designed to withstand an impact by a 707 fully loaded with 23,000 gallons of fuel, yet the planes that actually hit them had less than half that amount (10,000 gallons) on board and much of that was expelled in the fireball associated with the impact. xponent Monkey Wrench WielderG Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: Physics Prof Finds Thermate in WTC Physical Samples
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Seeberger Sent: Monday, July 03, 2006 8:10 PM To: Killer Bs Discussion Subject: Re: Physics Prof Finds Thermate in WTC Physical Samples - Original Message - From: Dan Minette [EMAIL PROTECTED] To: 'Killer Bs Discussion' brin-l@mccmedia.com Sent: Monday, July 03, 2006 2:35 PM Subject: RE: Physics Prof Finds Thermate in WTC Physical Samples So, I think we've gotten to the point where, in order to still say I cannot accept the conventional explanation, then you will have to reject my basic physics argument. I'd be very interested to see what flaws you might see in this argument. OKG, I'll bite on this one.G The WTC towers were designed to withstand an impact by a 707 fully loaded with 23,000 gallons of fuel, yet the planes that actually hit them had less than half that amount (10,000 gallons) on board and much of that was expelled in the fireball associated with the impact. There is a very simple answer for this, as I guess you know. When designing a fail-safe system, one works through scenariosbut there can be scenarios that one has not thought of. The building did withstand the impact of the plane, itself. But, it did not survive everything that came with the impact. Would you like to see exactly what analysis was done concerning a 707 impact? I've got a beer that says that the airplane impact analysis before the collapse was rather limited compared to the after-the-fact analysis. Anyways, I actually curious to see how it was impossible for the collapse to be as fast as it was. Dan M. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
On Jul 3, 2006, at 5:16 PM, Robert Seeberger wrote: One glaring example that we missed was bolt hole tearing. This is where force causes the bolt hole to deform til it slips around the supporting bolt. It's also astonishingly painful. -- Warren Ockrassa, Publisher/Editor, nightwares Books http://books.nightwares.com/ Current work in progress The Seven-Year Mirror http://books.nightwares.com/ockrassa/Flat_Out.pdf http://books.nightwares.com/ockrassa/Storms_on_a_Flat_Placid_Sea.pdf ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
On 7/3/2006 10:11:19 PM, Warren Ockrassa ([EMAIL PROTECTED]) wrote: On Jul 3, 2006, at 5:16 PM, Robert Seeberger wrote: One glaring example that we missed was bolt hole tearing. This is where force causes the bolt hole to deform til it slips around the supporting bolt. It's also astonishingly painful. Yeah, it's pretty low on my list of things to do before I die. G Which brings me to the surgery I had several years ago. xponent I'm Sitting On It Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
- Original Message - From: Dan Minette [EMAIL PROTECTED] To: 'Killer Bs Discussion' brin-l@mccmedia.com Sent: Monday, July 03, 2006 8:47 PM Subject: RE: Physics Prof Finds Thermate in WTC Physical Samples -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Seeberger Sent: Monday, July 03, 2006 8:10 PM To: Killer Bs Discussion Subject: Re: Physics Prof Finds Thermate in WTC Physical Samples - Original Message - From: Dan Minette [EMAIL PROTECTED] To: 'Killer Bs Discussion' brin-l@mccmedia.com Sent: Monday, July 03, 2006 2:35 PM Subject: RE: Physics Prof Finds Thermate in WTC Physical Samples So, I think we've gotten to the point where, in order to still say I cannot accept the conventional explanation, then you will have to reject my basic physics argument. I'd be very interested to see what flaws you might see in this argument. OKG, I'll bite on this one.G The WTC towers were designed to withstand an impact by a 707 fully loaded with 23,000 gallons of fuel, yet the planes that actually hit them had less than half that amount (10,000 gallons) on board and much of that was expelled in the fireball associated with the impact. There is a very simple answer for this, as I guess you know. When designing a fail-safe system, one works through scenariosbut there can be scenarios that one has not thought of. The building did withstand the impact of the plane, itself. But, it did not survive everything that came with the impact. Would you like to see exactly what analysis was done concerning a 707 impact? Of course! TIA! I've got a beer that says that the airplane impact analysis before the collapse was rather limited compared to the after-the-fact analysis. I would expect it to be so in light of the actuality of later events. (More below) Anyways, I actually curious to see how it was impossible for the collapse to be as fast as it was. Beforehand I would expect it to be described as improbable. Just for the sake of curveballs, I'll posit that if some Cassandra had appeared on the list with a detailed description of what was to come at the WTC all hands onboard would give a cornucopia of reasons why it could never happen. I know it is an unfalsifiable proposition but I think such a consideration is a very good (and humbling) reason to go gently with believers. By the same token it is good reason for believers to practice patience with Skeptics. I strongly suspect that those who count themselves among the believers were more traumatized by the events of 911 than most of us. I know that plays into my feelings of suspicion with regard to the building collapse. (As I often try to make clear, I suspect as opposed to believe) The natural desire to blame and revenge a great wrong is frustrated, so the mind turns over events and finding seeming discrepancies, points a finger in seemingly likely directions. In moments of introspection I see something like this operative in my inner self, and I suspect that I am not alone in this mild form of PTSD. xponent Inner Universe Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Physics Prof Finds Thermate in WTC Physical Samples
On 04/07/2006, at 4:10 AM, Robert Seeberger wrote: The WTC towers were designed to withstand an impact by a 707 fully loaded with 23,000 gallons of fuel, yet the planes that actually hit them had less than half that amount (10,000 gallons) on board and much of that was expelled in the fireball associated with the impact. They did withstand the *impact*. In that sense, the design worked. But it seems clear that a combination of many factors, including where on the towers the plane struck (and so how much mass was above the damaged floors), fire (kerosene, office furniture, aluminium from the plane) weakened already damaged beams and trusses whose insulation had also been damaged in the impact, lead to the initiation of progressive collapse. The other mystery is that the South Tower went down first. It was struck far lower, and so had far more mass above the damaged portion. I'm finding this whole thread really weird because I'm usually the skeptic of official reportage, but in this case, I just don't see anything beyond some bad maths and some wishful thinking by haters of the neocons (and I normally count myself among those). Did the Bush Administration use 9/11 to further an agenda in the Middle East after it happened? Undoubtedly, and Blair did the same. Did it bring down the towers and fake portions of the attacks, or even directly instigate the attacks to those ends? Not a chance. Charlie ___ http://www.mccmedia.com/mailman/listinfo/brin-l
