ISF Logo   IS Forum
Forum Index Register Members List Events 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.
Reply
Old 16th May 2016, 11:32 AM   #121
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
No thanks....

I have nothing to present except what I presented... Of course as the collapse proceeds the slabs break into chunks and those chunks get ground and break up into smaller chunks and so on. In the process lots of dust is released and the no stone aggregate concrete will become lots of sand...

The trusses were mangled and ripped apart. They did little damage but were very damaged by the process. Facade columns were not involved... they fell away.

Steel in the core came down largely in the core area.. some of survived the collapse and ended up on TOP of the pile when it came down... the core columns stood to about floor 50... so perhaps 40% if the columns were on top of the pile.

The mech stuff which was heavy and outside the core would likely be destructive to the slabs. And there were some rolled sections and including columns outside the core on the mech floors... they beat up the slabs as well.

A perfectly compacted building would be 35' tall... But it was much higher... and lots of materials (dust) was carried away in the air...

No formulas will prove anything about the collapse.
JSanderO 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 16th May 2016, 07:17 PM   #122
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
I'll take your last statement first:

Originally Posted by JSanderO View Post
No formulas will prove anything about the collapse.
I could not disagree more.

Real Engineering IS "formulae".

With this statement, you are, in essence, arguing for "no engineering" (with regard to analyzing the collapses).

I'll hold out for "good engineering". Applying the correct formula & having a solid feel for sources of error & magnitudes of error bands.

I'm doing a math model right now (the reason I don't have the time to devote to this, at the moment) of a completely different system. It is absolutely critical to obtain a solid feeling about the magnitudes of various effects. The only way that one can do this is by solving the pertinent equations.

In the case of the collapse of the towers, the equation for kinetic energy of the upper block vs. the energy absorption capacity of each floor tells us a huge amount about the collapse. It tells us whether the collapse will arrest or continue to the ground.

The equations for the moment strength of the columns & for the lateral moment produced by the rotation of the upper block proves that the upper block will fall straight down rather than topple to the side.

I think those equations are useful, too.

Although not about the collapse, the old pressure-impulse curves (formulae) did a really good job elucidating what to expect from the plane impacting the side of the building. This was confirmed by the FEA analysis (formulae O'Plenty!) done by NIST, Purdue, & others. That process was pretty chaotic, too, but that didn't stop the calculations from working.

All the above formulae told us crucial things about the collapse (or the jet impacts).

Originally Posted by JSanderO View Post
Of course as the collapse proceeds the slabs break into chunks and those chunks get ground and break up into smaller chunks and so on.
I strongly believe that the same mechanisms that reduce the amount of destruction proceeding into the upper block also protect the chunks of concrete near the top of the debris pile from undergoing significant amounts of "grinding into smaller chunks".

Math formulae are incredibly useful for shedding light on exactly this sort of question.

I'm really NOT trying to be simply contrarian here, but I strongly disagree with you on this.

Formulae are the heart & soul of engineering.

If you take away formulae, pretty much the entire NIST report stops being engineering & becomes merely "opinion".

Last edited by tfk; 16th May 2016 at 07:18 PM.
tfk 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 17th May 2016, 01:02 AM   #123
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by tfk View Post
I'll take your last statement first:



I could not disagree more.

Real Engineering IS "formulae".

With this statement, you are, in essence, arguing for "no engineering" (with regard to analyzing the collapses).

I'll hold out for "good engineering". Applying the correct formula & having a solid feel for sources of error & magnitudes of error bands.

I'm doing a math model right now (the reason I don't have the time to devote to this, at the moment) of a completely different system. It is absolutely critical to obtain a solid feeling about the magnitudes of various effects. The only way that one can do this is by solving the pertinent equations.

In the case of the collapse of the towers, the equation for kinetic energy of the upper block vs. the energy absorption capacity of each floor tells us a huge amount about the collapse. It tells us whether the collapse will arrest or continue to the ground.

The equations for the moment strength of the columns & for the lateral moment produced by the rotation of the upper block proves that the upper block will fall straight down rather than topple to the side.

I think those equations are useful, too.

Although not about the collapse, the old pressure-impulse curves (formulae) did a really good job elucidating what to expect from the plane impacting the side of the building. This was confirmed by the FEA analysis (formulae O'Plenty!) done by NIST, Purdue, & others. That process was pretty chaotic, too, but that didn't stop the calculations from working.

All the above formulae told us crucial things about the collapse (or the jet impacts).



I strongly believe that the same mechanisms that reduce the amount of destruction proceeding into the upper block also protect the chunks of concrete near the top of the debris pile from undergoing significant amounts of "grinding into smaller chunks".

Math formulae are incredibly useful for shedding light on exactly this sort of question.

I'm really NOT trying to be simply contrarian here, but I strongly disagree with you on this.

Formulae are the heart & soul of engineering.

If you take away formulae, pretty much the entire NIST report stops being engineering & becomes merely "opinion".
Tom,

Really the strength of materials is settled science. Once mass... loads which were organized into and directed to the axial structure... and then to bedrock/foundation broke free... these loads caused local failures in predictable ways.

We don't need more than some basic statics calculations to know what loads fail the slabs, the connections of the slabs to the columns... the beams and so forth.

As I have stated too many times... the thing(s) that are of interest are how the fires managed to to free the mass to begin the runaway unstoppable destruction. The structure had 90 identically structured tenant floors and 8 stronger mech floors at 4 elevations in the building.

OBSERVATIONS reveal what was happening in the collapse phase... after the tops began to move downward. Once that happened it was obvious that arrest was not happening. This is a trivial matter.. and probably why it is of little interest to engineers.

You can turn your "math" attention to how the fires caused the mass to be released from the axial load paths... and perhaps destroyed axial alignment permitting the top sections (columns and what was attached to them) to drop.

CU CD has no relevance to this "problem".
JSanderO 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 17th May 2016, 01:18 AM   #124
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
There are relevant information in the NIST report.

What they seem to not get into is what goes on in "global collapse". They seem to be attempting to find the straw that broke the camels back... and jump from there to global collapse. That is my conception of their reports. I personally find their "straws" not terribly credible...

For example.... with respect to 7wtc... the key aspects of the structure was not col 79 or what may or may not have happened on a single floor - floor 13... but the load transfers which were located on floors 5-7. The collapse of the tower and the way it moved is explained by the collapse/failure of THOSE transfers which were all inter-connected.

Of course NIST decided to claim (without much substantiation I believe) that that region was not the initiating location... the straw as not down there. They had no visuals of fires... largely because it was enclosed and there were few windows down there as well. AND the main source of combustible material would not be office contents... but diesel fuel. And it seems that they didn't want to go there for some reason.

I found it interesting that Irwin Cantor, the engineer who DESIGNED the structure... made a statement that diesel fires "destroyed" the trusses (don't have the statement handy). And that FEMA also produced a similar explanation. This was tossed out with a simple assertion/statement (unsubstantiated) that all the stored diesel fuel was recovered.

Then of course we were told that some overheated sagging trussed led to global failure of the twin towers. WOW just WOW... they caused the entire 30 or so floors in 2wtc to tilt almost 20°.

And how did those sagging trussed make the antenna which was supported by the core to drop first?

I think they left a lot of people scratching their heads. Remember those pancakes? Presumably this theory was the work of engineers too.

Show me the math! hahahaha

We know engineers use formula and load tables and so on to DESIGN structures.

This was a heat / fire matter. Explain that!
JSanderO 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 17th May 2016, 04:06 AM   #125
Seymour Butz
Muse
 
Join Date: Jun 2008
Posts: 869
Originally Posted by JSanderO View Post

For example.... with respect to 7wtc... the key aspects of the structure was not col 79 or what may or may not have happened on a single floor - floor 13... but the load transfers which were located on floors 5-7. The collapse of the tower and the way it moved is explained by the collapse/failure of THOSE transfers which were all inter-connected.

You seem quite certain of yourself for someone who obviously has never done any research on the subject.


Quote:
Of course NIST decided to claim (without much substantiation I believe) that that region was not the initiating location... the straw as not down there. They had no visuals of fires... largely because it was enclosed and there were few windows down there as well. AND the main source of combustible material would not be office contents... but diesel fuel. And it seems that they didn't want to go there for some reason.

I've told you the reason before.

There are no combustibles in the transfer truss area. They were segregated off from the fires in a service area.

You haven't made this particular claim for a while, but here it is again, rearing its ugly head.

Why are you being like a truther and returning to debunked claims?

Just move on already....

Quote:
I found it interesting that Irwin Cantor, the engineer who DESIGNED the structure... made a statement that diesel fires "destroyed" the trusses (don't have the statement handy). And that FEMA also produced a similar explanation. This was tossed out with a simple assertion/statement (unsubstantiated) that all the stored diesel fuel was recovered.

And now you're lying.

There was no diesel in the truss area.
Seymour Butz 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 17th May 2016, 05:42 AM   #126
Gamolon
Master Poster
 
Gamolon's Avatar
 
Join Date: Dec 2006
Posts: 2,083
Originally Posted by JSanderO View Post
I found it interesting that Irwin Cantor, the engineer who DESIGNED the structure... made a statement that diesel fires "destroyed" the trusses (don't have the statement handy).
I can't find an actual quote where he said this. I found an article from March 2nd, 2002 in which the following was said.

Quote:
But Irwin Cantor, one of the building's original structural engineers, who is now a consulting engineer and member of the City Planning Commission, said the diesel-related failure of transfer trusses was a reasonable explanation for the collapse.
http://www.wanttoknow.info/020302nytimes

This comment was made in response to the first paragraph of the same article.
Quote:
Massive structural beams that functioned as a sort of bridge to hold up the 47-story skyscraper known as 7 World Trade Center were compromised in a disastrous blaze fed by diesel fuel, leading to the building's collapse on Sept. 11, investigators have concluded in a preliminary report.
As far as I can see, he never said the trusses were destroyed by diesel fires. Unless you have another quote from somewhere stating otherwise.
Gamolon 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 17th May 2016, 05:42 AM   #127
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Seymour Butz View Post
You seem quite certain of yourself for someone who obviously has never done any research on the subject.

I've told you the reason before.

There are no combustibles in the transfer truss area. They were segregated off from the fires in a service area.

You haven't made this particular claim for a while, but here it is again, rearing its ugly head.

Why are you being like a truther and returning to debunked claims?

Just move on already....

And now you're lying.

There was no diesel in the truss area.
"Research"?.... I have done a fair amount of reading, adding conferences... corresponded with "researchers" and "experts". I do not consider myself a researcher. I am an architect who is interested in understanding the collapses.

The collapse of a building is written in its structure. To understand how and why a building collapses one of the MAIN bits of information is the structural scheme. For example there are many types of structures call bridges.... they are built differently and will fail differently.

I don't lie.... I, like everyone else makes mistakes.

There were back up generators on floors 5-7 which were diesel fired and there were day tanks there. There was diesel piping to supply other diesel fired generators higher up in the building.

There were vids / pics of thick black smoke existing from just above this region. Smoke rises so one could assume the fire was BELOW where the smoke is scene. But there were few windows and the north side had massive air intake grillage.

If column 79 had a girder framed into it at flr 13 slide off.... tell us Mr Butz how this progresses to a total collapse of the building. Why was the approximate FF decent of the facade 104' +/- or for 2.25 secs +/-??? Why not a longer or shorter period? What slowed it down?

How was the 30,000 gallons of fuel accounted for? Recovered?
Do you think the tanks were topped up or partially full prior to 9/11?
Would you expect the piping to survive intact if parts of wtc1 were falling on 7wtc? Why? Why not?

Fuel, piping and generators were segregated? Where were the main below grade tanks? Where was the segregated area? Where were the day tanks on the upper floors? Where were the diesel risers? What was the mechanism for day tank replenishment?

++++

Do you think the column 79 "buckled"? Where did it buckle? It weighed about 920,000 lbs per 2 stories.

Your turn.
Attached Images
File Type: jpg col 79.jpg (50.5 KB, 11 views)
JSanderO 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 17th May 2016, 05:47 AM   #128
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Gamolon View Post
I can't find an actual quote where he said this. I found an article from March 2nd, 2002 in which the following was said.


http://www.wanttoknow.info/020302nytimes

This comment was made in response to the first paragraph of the same article.


As far as I can see, he never said the trusses were destroyed by diesel fires. Unless you have another quote from somewhere stating otherwise.
Mr Butz... do some research and talk to Irwin Cantor... He is on the NYC Panning Board.

He said according the article:

"Massive structural beams (meaning "transfers structures") that functioned as a sort of bridge to hold up the 47-story skyscraper known as 7 World Trade Center were compromised in a disastrous blaze fed by diesel fuel..."

Last edited by JSanderO; 17th May 2016 at 05:48 AM.
JSanderO 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 17th May 2016, 06:05 AM   #129
Gamolon
Master Poster
 
Gamolon's Avatar
 
Join Date: Dec 2006
Posts: 2,083
Originally Posted by JSanderO View Post
Mr Butz... do some research and talk to Irwin Cantor... He is on the NYC Panning Board.

He said according the article:

"Massive structural beams (meaning "transfers structures") that functioned as a sort of bridge to hold up the 47-story skyscraper known as 7 World Trade Center were compromised in a disastrous blaze fed by diesel fuel..."
First of all, I'm not Mr. Butz.

Second of all, Irwin Cantor was not "quoted" as saying the above. Those are the words of the authors, James Glantz and Eric Lipton, based on what "investigators" said in the preliminary report. Here is the actual quote and first paragraph of the article in question.
Quote:
Massive structural beams that functioned as a sort of bridge to hold up the 47-story skyscraper known as 7 World Trade Center were compromised in a disastrous blaze fed by diesel fuel, leading to the building's collapse on Sept. 11, investigators have concluded in a preliminary report.
See then end of the paragraph where it says "...investigators have concluded in a preliminary report"? It was the "investigators", whomever "they" were, that made that claim. How can you directly attribute that paragraph to Cantor?

Cantor, later in the same article, said that what the "investigators" stated in the preliminary report, was a reasonable explanation.

If you have another quote directly from Cantor, please provide it.

Last edited by Gamolon; 17th May 2016 at 06:07 AM.
Gamolon 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 17th May 2016, 06:19 AM   #130
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Gamolon View Post
First of all, I'm not Mr. Butz.

Second of all, Irwin Cantor was not "quoted" as saying the above. Those are the words of the authors, James Glantz and Eric Lipton, based on what "investigators" said in the preliminary report. Here is the actual quote and first paragraph of the article in question.


See then end of the paragraph where it says "...investigators have concluded in a preliminary report"? It was the "investigators", whomever "they" were, that made that claim. How can you directly attribute that paragraph to Cantor?

Cantor, later in the same article, said that what the "investigators" stated in the preliminary report, was a reasonable explanation.

If you have another quote directly from Cantor, please provide it.
This is splitting hairs. I don't speak for Cantor nor quote him. It reads like he was asked if the early "theory" of the transfers failing from diesel was reasonable. He seemed to agree. Who knows... there may be actual quotes because he was questioned.

Don't you think "investigators" would query the engineer who designed the building? That would make sense.... No? He would be the best "engineer" to know the structure and how it might have collapsed. Or maybe that would be Mr Butz or Tfk both engineers... or Cole or Tony.
JSanderO 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 17th May 2016, 07:09 AM   #131
Gamolon
Master Poster
 
Gamolon's Avatar
 
Join Date: Dec 2006
Posts: 2,083
Originally Posted by JSanderO View Post
This is splitting hairs. I don't speak for Cantor
Actually, you did...

Originally Posted by JSanderO View Post
I found it interesting that Irwin Cantor, the engineer who DESIGNED the structure... made a statement that diesel fires "destroyed" the trusses (don't have the statement handy).
He never "made that statement". Saying something within a PRELIMINARY report is reasonable is a far cry from directly and definitively stating that he believes that is the cause.

Originally Posted by JSanderO View Post
nor quote him.
Which is the problem.

Originally Posted by JSanderO View Post
It reads like he was asked if the early "theory" of the transfers failing from diesel was reasonable.
So you're telling me that you originally claiming Cantor stated that "diesel fires destroyed the trusses" compared to him stating that "a theory that diesel fires compromised the trusses as presented in a PRELIMINARY report is reasonable" is splitting hairs?! Saying a "THEORY in a PRELIMINARY report is REASONABLE" is NOT the same as directly saying "diesel fires destroyed the trusses".

Originally Posted by JSanderO View Post
He seemed to agree. Who knows... there may be actual quotes because he was questioned.
But you don't have those actual quotes and you are attributing a statement to him that you have not provided proof of.

Originally Posted by JSanderO View Post
Don't you think "investigators" would query the engineer who designed the building? That would make sense.... No? He would be the best "engineer" to know the structure and how it might have collapsed. Or maybe that would be Mr Butz or Tfk both engineers... or Cole or Tony.
What does it matter what you or I think? The bottom line is he never made that statement and until you or someone else finds a quote that says otherwise, you're wrong.

It's not splitting hairs when I do a Google search for "Irwin Cantor, diesel, fire" and the majority of the links I click are attributed to you in a variety of forums pushing the same information. People will use that supposed quote from Cantor to try and show NIST lied, are incompetent, and are part of the conspiracy. It may be one little thing, but when you add up all the misinformation, it becomes a big deal.

As it stands now, Cantor never said what you claimed.

Last edited by Gamolon; 17th May 2016 at 07:21 AM.
Gamolon 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 17th May 2016, 08:46 AM   #132
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Gamolon View Post
Actually, you did...



He never "made that statement". Saying something within a PRELIMINARY report is reasonable is a far cry from directly and definitively stating that he believes that is the cause.


Which is the problem.


So you're telling me that you originally claiming Cantor stated that "diesel fires destroyed the trusses" compared to him stating that "a theory that diesel fires compromised the trusses as presented in a PRELIMINARY report is reasonable" is splitting hairs?! Saying a "THEORY in a PRELIMINARY report is REASONABLE" is NOT the same as directly saying "diesel fires destroyed the trusses".


But you don't have those actual quotes and you are attributing a statement to him that you have not provided proof of.


What does it matter what you or I think? The bottom line is he never made that statement and until you or someone else finds a quote that says otherwise, you're wrong.

It's not splitting hairs when I do a Google search for "Irwin Cantor, diesel, fire" and the majority of the links I click are attributed to you in a variety of forums pushing the same information. People will use that supposed quote from Cantor to try and show NIST lied, are incompetent, and are part of the conspiracy. It may be one little thing, but when you add up all the misinformation, it becomes a big deal.

As it stands now, Cantor never said what you claimed.
You don't know that he never made a statement... You found no evidence in your google searches or whatever.

I am not going to speak for someone else... and claim to know what they said or didn't say.

I do know that the first explanations which surfaced about 7wtc's collapse were related to its transfers and diesel. I suspect that no one knew much about the building... that it was erected to span over a huge power station and had transfers and 30,000 gal of diesel fuel. In fact, I didn't pay much attention to the building and NIST took something like 7 or 8 years to release their report. That seems an awfully long time.

Of course you don't answer my questions...

Why was the collapse at about FF for 104 ft or 2.25 seconds?

Maybe you are not an engineer or a physicist....
JSanderO 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 17th May 2016, 08:56 AM   #133
Crazy Chainsaw
Illuminator
 
Crazy Chainsaw's Avatar
 
Join Date: Aug 2006
Posts: 4,737
Originally Posted by JSanderO View Post
You don't know that he never made a statement... You found no evidence in your google searches or whatever.

I am not going to speak for someone else... and claim to know what they said or didn't say.

I do know that the first explanations which surfaced about 7wtc's collapse were related to its transfers and diesel. I suspect that no one knew much about the building... that it was erected to span over a huge power station and had transfers and 30,000 gal of diesel fuel. In fact, I didn't pay much attention to the building and NIST took something like 7 or 8 years to release their report. That seems an awfully long time.

Of course you don't answer my questions...

Why was the collapse at about FF for 104 ft or 2.25 seconds?

Maybe you are not an engineer or a physicist....
The Collapse of seven was at free fall because the steel frame toppled over, and that kicked out the lower Facade, causing the top to move inward do to it's own inertia.

Last edited by Crazy Chainsaw; 17th May 2016 at 09:08 AM.
Crazy Chainsaw 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 17th May 2016, 09:08 AM   #134
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Crazy Chainsaw View Post
The Collapse of seven was at free fall because the steel frame toppled over, and that kicked out the lower Facade, causing the top to move inward do to it's on inertia.
Could you elaborate on this... what steel frame toppled over? What made it topple? What is the lower facade? Where does it end and where does the upper facade start?
JSanderO 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 17th May 2016, 09:30 AM   #135
Newtons Bit
Penultimate Amazing
 
Newtons Bit's Avatar
 
Join Date: Apr 2007
Posts: 10,016
Originally Posted by JSanderO View Post
"Research"?.... I have done a fair amount of reading, adding conferences... corresponded with "researchers" and "experts". I do not consider myself a researcher. I am an architect who is interested in understanding the collapses.

The collapse of a building is written in its structure. To understand how and why a building collapses one of the MAIN bits of information is the structural scheme. For example there are many types of structures call bridges.... they are built differently and will fail differently.

I don't lie.... I, like everyone else makes mistakes.

There were back up generators on floors 5-7 which were diesel fired and there were day tanks there. There was diesel piping to supply other diesel fired generators higher up in the building.

There were vids / pics of thick black smoke existing from just above this region. Smoke rises so one could assume the fire was BELOW where the smoke is scene. But there were few windows and the north side had massive air intake grillage.

If column 79 had a girder framed into it at flr 13 slide off.... tell us Mr Butz how this progresses to a total collapse of the building. Why was the approximate FF decent of the facade 104' +/- or for 2.25 secs +/-??? Why not a longer or shorter period? What slowed it down?

How was the 30,000 gallons of fuel accounted for? Recovered?
Do you think the tanks were topped up or partially full prior to 9/11?
Would you expect the piping to survive intact if parts of wtc1 were falling on 7wtc? Why? Why not?

Fuel, piping and generators were segregated? Where were the main below grade tanks? Where was the segregated area? Where were the day tanks on the upper floors? Where were the diesel risers? What was the mechanism for day tank replenishment?

++++

Do you think the column 79 "buckled"? Where did it buckle? It weighed about 920,000 lbs per 2 stories.

Your turn.
You still can't correctly calculate a radius of gyration.
__________________
"Structural Engineering is the art of molding materials we do not wholly understand into shapes we cannot precisely analyze so as to understand forces we cannot really assess in such a way that the community at large has no reason to suspect the extent of our own ignorance." James E Amrhein
Newtons Bit 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 17th May 2016, 09:39 AM   #136
Crazy Chainsaw
Illuminator
 
Crazy Chainsaw's Avatar
 
Join Date: Aug 2006
Posts: 4,737
Originally Posted by JSanderO View Post
Could you elaborate on this... what steel frame toppled over? What made it topple? What is the lower facade? Where does it end and where does the upper facade start?
The interior steel frame toppled over towards the damaged side when the welds on the cantilevered section failed there is even a video where you can see the building is hulled out, as the progressive collapse nears it's end the Columns thrust back, into the lower facade and cause the now hollow outer shell to be pushed off it's foundations slightly the top tilts inward and the Facade collapses.
9/11: WTC 7 east penthouse collapse (partial vide…: http://youtu.be/OUkvnfV606w

Watch it closely the windows show movement though them then the bottom moves toward the Camera and the top falls.

Last edited by Crazy Chainsaw; 17th May 2016 at 09:48 AM.
Crazy Chainsaw 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 17th May 2016, 09:52 AM   #137
Newtons Bit
Penultimate Amazing
 
Newtons Bit's Avatar
 
Join Date: Apr 2007
Posts: 10,016
Originally Posted by JSanderO View Post
Do you think the column 79 "buckled"? Where did it buckle? It weighed about 920,000 lbs per 2 stories.
730lb/ft column + 354lb/ft plates = 1083lb/ft.

Am I supposed to believe that each story is 424ft, JSanderO? 920,000lbs... yea...
__________________
"Structural Engineering is the art of molding materials we do not wholly understand into shapes we cannot precisely analyze so as to understand forces we cannot really assess in such a way that the community at large has no reason to suspect the extent of our own ignorance." James E Amrhein
Newtons Bit 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 17th May 2016, 09:58 AM   #138
Crazy Chainsaw
Illuminator
 
Crazy Chainsaw's Avatar
 
Join Date: Aug 2006
Posts: 4,737
Originally Posted by Newtons Bit View Post
730lb/ft column + 354lb/ft plates = 1083lb/ft.

Am I supposed to believe that each story is 424ft, JSanderO? 920,000lbs... yea...
I got a little over 50,000 LBS, for the intire Column and it looks like the side plates were welded, on, Construction of the column would determine factors of sheer failure.
Crazy Chainsaw 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 17th May 2016, 10:32 AM   #139
Gamolon
Master Poster
 
Gamolon's Avatar
 
Join Date: Dec 2006
Posts: 2,083
Originally Posted by JSanderO View Post
I am not going to speak for someone else... and claim to know what they said or didn't say.


Yet you did just that in your claim above didn't you?
Gamolon 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 17th May 2016, 12:10 PM   #140
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Newtons Bit View Post
730lb/ft column + 354lb/ft plates = 1083lb/ft.

Am I supposed to believe that each story is 424ft, JSanderO? 920,000lbs... yea...
OOOPS... had a senior moment

The cross sectional area of the column and the plate = 1.85 SF

steel weights 490# (not 940)

column was 29 ft tall

29'x(1.49'+.36') x 490# = 26,302#

Sorry... my bad... YIKES!

Last edited by JSanderO; 17th May 2016 at 12:29 PM.
JSanderO 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 17th May 2016, 12:11 PM   #141
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by Gamolon View Post


Yet you did just that in your claim above didn't you?
Stop it.... I simply reported what I read 6 years ago and don't keep a file of articles and quotes. Claim?
JSanderO 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 17th May 2016, 12:50 PM   #142
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Originally Posted by JSanderO View Post
Tom,
Sander,

Or, I should probably say,
J,

Originally Posted by JSanderO View Post
Really the strength of materials is settled science.
Look at the title of this thread.
“Strength of material” is a tiny, tiny, tiny component of that topic.

I tried to lay out - in the OP…!!, the FIRST post in this thread - what I believe to be the key considerations of … the topic of this thread.

Thus far, you’ve posted many replies in this thread, and despite REPEATED REQUESTS from me, you’ve not said one word about the thesis that I outlined in the OP.

Originally Posted by JSanderO View Post
Once mass... loads which were organized into and directed to the axial structure... and then to bedrock/foundation broke free... these loads caused local failures in predictable ways.
The loads that the masses exerted on the structure, right down to bedrock, are given by “formulae” (aka, “calculation”). They are relevant only in the sense that they can tell what load any particular component was capable of supporting (once one includes the factor of safety). But, “load” is only one of two key components in determining whether the part will survive. The other one, the more important one, is toughness.

Once the “mass broke free, the loads that they impressed on the structure down to bedrock” … went to zero.

The load (& energy that the structure needed to absorb in order to bring the collapse to a halt) arose when that falling piece crashed into the next piece below.

And THAT load & energy can NOT be calculated by just considering static conditions.

You’ve got to do some calculations (aka, “use formulae”) in order to figure that out.

Excuse me to hell & back. I said that ALL WRONG.

I should have written: “You’ve got to do some COMPETENT calculations (aka, “use the correct formulae, in a correct manner”) in order to figure that out."

Originally Posted by JSanderO View Post
We don't need more than some basic statics calculations to know what loads fail the slabs, the connections of the slabs to the columns... the beams and so forth.
Things do not fail by loads alone.

You can use “loads & toughness”, or the equivalent “pressure & impulse” calculations. (After all, it is a “collision”.)

And in order to figure out the energy or the impulse or the new, aberrant disposition of both, you have to do some calculations (aka, “use correct formulae, correctly”).

Originally Posted by JSanderO View Post
As I have stated too many times... the thing(s) that are of interest are how the fires managed to to free the mass to begin the runaway unstoppable destruction. The structure had 90 identically structured tenant floors and 8 stronger mech floors at 4 elevations in the building.
You really, really, really need to distinguish between “the things that are of interest” and “the things that are of interest to you”.

There are lots & lots & lots of things that are of no interest to you (or to me) that are of great interest to others.

The topic of this thread is “of some interest” to me.

If it is not of interest to you, I suggest you stop posting in this thread.

But to come here & attempt to ordain that “crush down, crush up” is not one of the “things of interest” - in a thread entitled "Another Crush Down / Crush Up Thread" - is pretty … oh, I don’t know … bizarre, don't you think.?

Originally Posted by JSanderO View Post
OBSERVATIONS reveal what was happening in the collapse phase... after the tops began to move downward. Once that happened it was obvious that arrest was not happening. This is a trivial matter.. and probably why it is of little interest to engineers.
No, as a matter of fact, observation reveals NOTHING about the topic of this thread.
Because, just as soon as the building began to collapse, the collapse front, and the subject of this thread (“CD/CU”) disappeared into a cloud of obscuring debris.

If that collapse front had been visible, this entire conversation would have been settled in the late afternoon of Sept. 11, 2001.

Originally Posted by JSanderO View Post
You can turn your "math" attention to how the fires caused the mass to be released from the axial load paths... and perhaps destroyed axial alignment permitting the top sections (columns and what was attached to them) to drop.
No, J.

YOU can turn YOUR math attention to those topics … in a thread that YOU start pertaining to those topics.

OK?

Fortunately, you don’t have to turn your math attention to those topics. A dozen PhD engineers, whose specific expertise is in precisely that field, have already done the homework for you.

But, perhaps being the intellectual renegade you pride yourself, you’ll want to check their math with some of your own.

Originally Posted by JSanderO View Post
CU CD has no relevance to this "problem".
And, any “problem to which CD CU has no relevance”, has no relevance in a thread entitled “Another Crush Down / Crush Up Thread”.

Ironic, no??

WHAT THE HELL is it, with you & Oz, trying to dictate the “approved topics” that other people are allowed to discuss???

It's childishly simple: If you do not wish to discuss this topic ... just leave.
If you want to talk about your topic ... start a thread on it.

For a couple of allegedly "independent guys", you sure do spend a fair amount of effort trying to manage the discussions of other people.

More irony.

Last edited by tfk; 17th May 2016 at 12:58 PM.
tfk 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 17th May 2016, 02:10 PM   #143
JSanderO
Master Poster
 
JSanderO's Avatar
 
Join Date: Mar 2013
Location: nyc
Posts: 2,683
Originally Posted by tfk View Post
Sander,

Or, I should probably say,
J,



Look at the title of this thread.
“Strength of material” is a tiny, tiny, tiny component of that topic.

I tried to lay out - in the OP…!!, the FIRST post in this thread - what I believe to be the key considerations of … the topic of this thread.

Thus far, you’ve posted many replies in this thread, and despite REPEATED REQUESTS from me, you’ve not said one word about the thesis that I outlined in the OP.



The loads that the masses exerted on the structure, right down to bedrock, are given by “formulae” (aka, “calculation”). They are relevant only in the sense that they can tell what load any particular component was capable of supporting (once one includes the factor of safety). But, “load” is only one of two key components in determining whether the part will survive. The other one, the more important one, is toughness.

Once the “mass broke free, the loads that they impressed on the structure down to bedrock” … went to zero.

The load (& energy that the structure needed to absorb in order to bring the collapse to a halt) arose when that falling piece crashed into the next piece below.

And THAT load & energy can NOT be calculated by just considering static conditions.

You’ve got to do some calculations (aka, “use formulae”) in order to figure that out.

Excuse me to hell & back. I said that ALL WRONG.

I should have written: “You’ve got to do some COMPETENT calculations (aka, “use the correct formulae, in a correct manner”) in order to figure that out."



Things do not fail by loads alone.

You can use “loads & toughness”, or the equivalent “pressure & impulse” calculations. (After all, it is a “collision”.)

And in order to figure out the energy or the impulse or the new, aberrant disposition of both, you have to do some calculations (aka, “use correct formulae, correctly”).



You really, really, really need to distinguish between “the things that are of interest” and “the things that are of interest to you”.

There are lots & lots & lots of things that are of no interest to you (or to me) that are of great interest to others.

The topic of this thread is “of some interest” to me.

If it is not of interest to you, I suggest you stop posting in this thread.

But to come here & attempt to ordain that “crush down, crush up” is not one of the “things of interest” - in a thread entitled "Another Crush Down / Crush Up Thread" - is pretty … oh, I don’t know … bizarre, don't you think.?



No, as a matter of fact, observation reveals NOTHING about the topic of this thread.
Because, just as soon as the building began to collapse, the collapse front, and the subject of this thread (“CD/CU”) disappeared into a cloud of obscuring debris.

If that collapse front had been visible, this entire conversation would have been settled in the late afternoon of Sept. 11, 2001.



No, J.

YOU can turn YOUR math attention to those topics … in a thread that YOU start pertaining to those topics.

OK?

Fortunately, you don’t have to turn your math attention to those topics. A dozen PhD engineers, whose specific expertise is in precisely that field, have already done the homework for you.

But, perhaps being the intellectual renegade you pride yourself, you’ll want to check their math with some of your own.



And, any “problem to which CD CU has no relevance”, has no relevance in a thread entitled “Another Crush Down / Crush Up Thread”.

Ironic, no??

WHAT THE HELL is it, with you & Oz, trying to dictate the “approved topics” that other people are allowed to discuss???

It's childishly simple: If you do not wish to discuss this topic ... just leave.
If you want to talk about your topic ... start a thread on it.

For a couple of allegedly "independent guys", you sure do spend a fair amount of effort trying to manage the discussions of other people.

More irony.
I have nothing to contribute to this thread. Sorry for the derails.
JSanderO 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 17th May 2016, 02:44 PM   #144
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Originally Posted by JSanderO View Post
I have nothing to contribute to this thread. Sorry for the derails.
No prob.

Sorry to let my inner "Nurse Ratched" off the leash...
tfk 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 19th May 2016, 04:38 AM   #145
pgimeno
Illuminator
 
pgimeno's Avatar
 
Join Date: Feb 2009
Location: Spain
Posts: 3,258
Originally Posted by tfk View Post
First, it is nearly impossible to get any substance, be it liquid or solid, to change its actual volume. Virtually all solids & liquids are “incompressible”. Virtually all substances will expand laterally (the amount it expands is called Poisson’s Ratio, and is ≈ 0.3 for most substances) while you compress it vertically. It’s total volume does NOT change.

[...]

"Incompressible" includes things that we generally think of as “compressible”, such as rubber, elastomers & foams.
Rubbers & elastomers aren’t really compressible, they are “easily deformable”.

A round slug of rubber or elastomer may have a very soft durometer (be very compressible) while unconstrained. But if you constrain them laterally (place a slug of rubber in a close fitting, strong metal tube), suddenly it isn’t compressible at all. In order for it to compress vertically, it MUST expand laterally.

Foams are a very high percent entrapped (closed cell foams), or non-entrapped (open cell foams) air. The solid component of the foams form long, thin easily deformable walls. But again, once the foam is compressed down, such that all the air is removed & it is compressing “thin wall on thin wall”, it becomes nearly incompressible, too.

In order to compress something’s volume, you’ve got to overcome intermolecular repulsion forces. these are orders of magnitude stronger than the shear forces that are responsible for “deformation”.
Shocking, due to everyday experience, but logical when you think about it. That was very instructive, thank you. I've separated this paragraph for further comment:


Originally Posted by tfk View Post
Water, for example, is almost completely incompressible. This is exactly why pressurized containers of water are harmless (i.e., not “bombs”), whereas compressed containers of gas ARE bombs. The energy stored in the contents is a product of the pressure x the compression. Even at very, very high pressures, the compression of water is approximately zero, so the amount of energy stored in the water is approximately zero. If the wall of the container ruptures, nothing happens. No energy is released.
I've researched this a bit more. Wikipedia lists the compressibility of water as something around 5.1×10-10 Pa-1 near 0°C. At the bottom of the Mariana trench, which is at the very respectable pressure of ~1.1×108 Pa (about 1000 times normal atmospheric pressure), that quantity becomes non-negligible, resulting in an increased water density, due to compression alone, of ~5%. That is, there's about 5% more water in the same volume. Pretty curious. I also found an experiment of water being compressed to 70,000 times atmospheric pressure, causing it to be at more than 100°C... yet turning it into ice. But I digress.


Originally Posted by tfk View Post
There was certainly nowhere near the pressure required to produce volumetric compression any of the towers debris. Including desks, fragile ceramic & porcelain fixtures, pipes, tubes or (sadly) humans.
Now that I have a better understanding of these things, I understand and agree (perhaps with the nitpick of needing the adjective "detectable" or "significant" or the like).

This whole part of your comment to JSanderO is somewhat related to our discussion of deceleration-or-not due to momentum transfer in the floor collapses. A topic that I'm still interested in.

I'm still curious about having some numbers to explain whether there's any likeliness of having the collisions not decelerate the falling mass (or that's what I interpreted that you were offering). I remember one of your objections was that the assemblies are not nearly as resistant as the bulk materials, which I understand. I wondered if the kind of numbers that you offered were related to that, or your focus was elsewhere. Either way, I wanted you to know that I haven't lost interest, but I understand it's just very tangentially on topic, if at all.
__________________
Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.
pgimeno 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 22nd May 2016, 12:34 AM   #146
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Just a quick elaboration on "dimensionality of a model".

I was trying to think of a good example to demonstrate the concept.
This one jumped off of the pages of US Sport's pages, over the last 2 years: “DeflateGate”.

Suppose that one wanted to create a model of the pressure inside of footballs.

The STATIC Case

The defining equation for the STATIC state is the old: PV = nRT

The first thing that most people need to realize is that “pressure is NOT a measure of the amount of air in a football”.

In this case, "n" represents the amount of air inside a football, and since R is a constant, then

n ∝ PV/T
“∝” means “is proportional to”.

If one assumes that no air is put in or let out of the football, and one assumes that the volume doesn't change, then in the steady state, one can use a 1 dimensional model.

P2 / P1 = (T1 / T2)

The absolute pressure ratio depends on ONLY one parameter: the absolute temperature ratio.

__

The Dynamic Case:

But, in the real case, there are two more factors that are required to produce an accurate model: water absorption and time.

It turns out that the volume, thermal mass & thermal conductivity of the football all increase when the ball absorbs moisture.

And since the footballs were brought from the cold outdoors to the warm indoors in order to be measured, the temperature of the air inside was changing with time.

When all is said & done, the pressure inside the football requires the following factors:

P = f{initial pressure, initial temperature, field temperature, half-time temperature, volume, thermal mass of the football, thermal conductivity, warming time}.

This is a 6 dimensional model. Pressure (the dependent variable) depends on {initial pressure, temperatures, volume, thermal mass, thermal conductivity & time}

Note that the water absorption plays a defining role in three of these factors: the changed volume, thermal mass & thermal conductivity of the footballs.

If each of these equations can be determined experimentally, then we can reduce the dimensionality to just 4 variables:

Pressure depends on {initial pressure, temperatures, water absorption & warming time}.
__

The point here is that simply going from the static case to the dynamic case changes the required dimensionality of the model.

There are lots of considerations like this when constructing models of systems.
tfk 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 11th February 2017, 01:38 PM   #147
Fonebone
persona non grata
 
Fonebone's Avatar
 
Join Date: Nov 2009
Posts: 479
Originally Posted by Crazy Chainsaw View Post
However the Collisions are not plastic in nature, rapid formation of fulcrums from compression forces induce rapid sheer, pressure is exerted by collisions on the side of the columns by the falling mass. Collisions in the retained mass induce fractures in the columns themselves as collisions occurs not only between the building and the falling mass but also by column and floor segments within the mass.

The Columns do not have to impact end to end for crush down crush up, the mass and movements and forces will occur with column misalignments as well as long as the two masses interact, destruction of any structure will be governed by collisions of mass with mass. So it is not as simple as ROOSD, or Crush Down, Crush Up, there is also side crush and peal because energy is never solely Vector.

I know this most likely disagrees with My Friends Frank, and DBB. And with Oz, who I deeply respect but experiments real experiments have shown me that the columns received impacts from the sides significantly strong enough to shatter welds, on Columns.
shatter welds

What is the definition of the term "shatter welds "?
__________________
Truth, like the sun, allows itself to be obscured;
but, like the sun, only for a time __Bovee

Truth once elicited never dies -Bancroft

twoofers versus twidiots , twaitors , twusters and boil-thuckers
Fonebone 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 11th February 2017, 02:07 PM   #148
DGM
Skeptic not Atheist
 
DGM's Avatar
 
Join Date: May 2007
Location: West of Northshore MA
Posts: 24,307
Originally Posted by Fonebone View Post
shatter welds

What is the definition of the term "shatter welds "?
I'm assuming a force strong enough to break the weld.
__________________
"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 online now   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 11th February 2017, 02:55 PM   #149
rwguinn
Penultimate Amazing
 
rwguinn's Avatar
 
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 10,852
Originally Posted by DGM View Post
I'm assuming a force strong enough to break the weld.
I would have to ask, but if that's all I had the assumption would be brittle shear or tensile failure.
__________________
"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
"
I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275
rwguinn 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 11th February 2017, 05:55 PM   #150
Crazy Chainsaw
Illuminator
 
Crazy Chainsaw's Avatar
 
Join Date: Aug 2006
Posts: 4,737
Originally Posted by rwguinn View Post
I would have to ask, but if that's all I had the assumption would be brittle shear or tensile failure.
Exactly, with evidence of sheer lag failure.

Sheer lag is when something breaks without induced ductile sheer.

Ductile sheer requires time the steel crystals simply change as the forces is applied, if the force is applied faster than the crystals can reorganize the crystals fracture.

Different metals experience different forms is sheer, a brittle failures, welds are particularly venerable.
Crazy Chainsaw 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 11th February 2017, 09:26 PM   #151
beachnut
Penultimate Amazing
 
beachnut's Avatar
 
Join Date: Oct 2006
Location: Dog House
Posts: 24,801
Originally Posted by Fonebone View Post
shatter welds

What is the definition of the term "shatter welds "?
Quote:
There was no evidence to indicate that the joining method, weld materials, or welding procedures were inadequate. Fractures of the columns in areas away from a welded joint were the result of stretching and thinning. Perimeter columns hit by the plane tended to fracture along heat-affected zones adjacent to welds = NIST
oops, shattered welds

Quote:
The floor truss and the perimeter panel floor truss connectors typically failed at welds and bolts.
Did you read NIST, or skip directly to the Inside Job, ignoring all evidence, and all research, the rational kind.

Lost in fantasy world of CD and an insane claim of an inside job, 9/11 truth.
__________________
"Common sense is the collection of prejudices acquired by age eighteen" - Albert Einstein
"... education as the means of developing our greatest abilities" - JFK
https://folding.stanford.edu/ fold with your computer - join team 13232
beachnut 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 12th February 2017, 12:06 PM   #152
fuelair
Cythraul Enfys
 
fuelair's Avatar
 
Join Date: May 2006
Posts: 55,394
Originally Posted by pgimeno View Post
As a proponent of the necessary deceleration during descent, I think I need to make a clarification.

My proposed scenario where deceleration is necessary is the collapse of the floors that occurred ahead of the huge dust cloud. In other words, it applies to the part of the collapse causing the ejections seen on the wall here:

http://femr2.ucoz.com/_ph/6/2/139901890.gif

I'll try to be very precise with what I'm asserting:

Let's call v1 the vertical speed of the falling piece of rigid material that first touches a floor assembly, right at the instant before it touches it. By "rigid material" I mean the steel from the columns, girders, beams, trusses and floor pans and the concrete of the floors.

Let's call v2 the vertical speed of the floor assembly's centre of mass once it is detached and falls with the rest of the debris.

Assuming that the collision between the piece and the floor assembly is overwhelmingly of a plastic nature, I assert that v2 < v1. In other words, the collision will result in a loss of vertical speed, a.k.a. deceleration.



I would refine this as follows:

If the apparent weight of a descending object exceeds m·g at any instant, then it necessarily experiments net deceleration at that instant.

And for the apparent weight to not exceed m·g during a collision, the cushioning effect must be big, so the materials must be reeeeeeally soft and easy to compress.

Steel and concrete aren't, therefore v2 < v1.

Do you agree?
May I safely assume you meant experiences rather than the altered by me above? If not, could you explain the meaning of experiments in the sentence?
__________________
There is no problem so great that it cannot be fixed by small explosives carefully placed.

Wash this space!

We fight for the Lady Babylon!!!
fuelair 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 12th February 2017, 12:43 PM   #153
pgimeno
Illuminator
 
pgimeno's Avatar
 
Join Date: Feb 2009
Location: Spain
Posts: 3,258
Originally Posted by fuelair View Post
May I safely assume you meant experiences rather than the altered by me above? If not, could you explain the meaning of experiments in the sentence?
Yes, sorry. I was confused by a false friend. http://www.wordreference.com/es/tran...ord=experience (sixth entry).
__________________
Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.
pgimeno 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 12th February 2017, 01:05 PM   #154
fuelair
Cythraul Enfys
 
fuelair's Avatar
 
Join Date: May 2006
Posts: 55,394
Originally Posted by pgimeno View Post
Yes, sorry. I was confused by a false friend. http://www.wordreference.com/es/tran...ord=experience (sixth entry).
Ahh - figuring that did not make sense (defining experiment (Spanish) as experience (English translation). I clicked on the word itself in the sixth entry - all that it took me to were uses of it for experiment, none for experience. Possibly the site itself messed up - since it contradicted itself by omission.
__________________
There is no problem so great that it cannot be fixed by small explosives carefully placed.

Wash this space!

We fight for the Lady Babylon!!!
fuelair 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

Bookmarks

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 02:25 PM.
Powered by vBulletin. Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
© 2014, TribeTech AB. All Rights Reserved.
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.