QUOTE (Hambone+Sep 5 2007, 01:42 PM)
Didn't you just put out a paper with Bazant and Greening giving the end of crush-down at around 12.7 seconds?
Yes. The authors are Bazant/Le/Greening/Benson.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
Yes. The authors are Bazant/Le/Greening/Benson.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
The video and audio on the Fox 5 and Mark Heath tapes give some clues about the collapse durations. There's also ABC video from the ground level from the east side of WTC2 that shows the collapse front near the mechanical levels 75/76 and 41/42. That video along with the Fox 5 video yields a few data points of the front position vs. time for WTC2 well after the first 4 seconds of collapse. Ground level video close to the footprint has the advantage of being inside the dust shroud and being able to see the collapse front longer compared with an elevated view.
Another useful audio tape is that of the Naudet brothers when they were in WTC1 when WTC2 was collapsing. The length of the rumble on their tape seems to agree with that of the Fox 5 audio.
It's probably easier to use the audio/video data than to try to interpret the seismic data. I'm not an expert on seismic data interpretation.
Another useful audio tape is that of the Naudet brothers when they were in WTC1 when WTC2 was collapsing. The length of the rumble on their tape seems to agree with that of the Fox 5 audio.
It's probably easier to use the audio/video data than to try to interpret the seismic data. I'm not an expert on seismic data interpretation.
QUOTE (einsteen+Sep 5 2007, 03:59 PM)
From video observation I would say that wtc2 took at least 15 seconds (the bulk of the collapsing mass) but I will later try to figure it out precisely. If the collapse takes more than the theoretical maximum then the model should also be wrong.
You might want to try to analyze the audio from the Fox 5 and Naudet brothers tape. I'd have to look back at my notes but I remember the rumble being about 14 to 15 seconds for WTC2. That seems to agree reasonably with the collapse front being near the top of WTC3 near the 12 second mark as seen in the Fox 5 video. The front would have required another couple seconds to reach the ground.
The rumble on the audio on the Fox 5 video seems to end with a thud. I interpret that as the front hitting the ground, although it could be something else. After the thud there isn't any more rumble but there is some shimmering noise that sounds like many small pieces of glass or concrete raining down. There are similar sounds for WTC1 on the Heath tape. The rumble ends and then there is the sounds of what seems to be small pieces raining down. I think someone else listened to the audio on the Heath tape and the total length of the rumble was close to 18 seconds. I'd have to go back and listen to it again. I thought it was a few seconds more than WTC2, around 18 seconds. One of the 911 sites, I think 911Research, shows the frames every second or so for the WTC1 collapse all the way up to 18 seconds.
You might want to try to analyze the audio from the Fox 5 and Naudet brothers tape. I'd have to look back at my notes but I remember the rumble being about 14 to 15 seconds for WTC2. That seems to agree reasonably with the collapse front being near the top of WTC3 near the 12 second mark as seen in the Fox 5 video. The front would have required another couple seconds to reach the ground.
The rumble on the audio on the Fox 5 video seems to end with a thud. I interpret that as the front hitting the ground, although it could be something else. After the thud there isn't any more rumble but there is some shimmering noise that sounds like many small pieces of glass or concrete raining down. There are similar sounds for WTC1 on the Heath tape. The rumble ends and then there is the sounds of what seems to be small pieces raining down. I think someone else listened to the audio on the Heath tape and the total length of the rumble was close to 18 seconds. I'd have to go back and listen to it again. I thought it was a few seconds more than WTC2, around 18 seconds. One of the 911 sites, I think 911Research, shows the frames every second or so for the WTC1 collapse all the way up to 18 seconds.
Imight be able to help with the seismogram - I've studied Geology (I was originally going to do a double major) and might be able to provide some insight is someone can provide me with a high enough quality digital copy of it.
QUOTE (shagster+Sep 6 2007, 05:00 AM)
You might want to try to analyze the audio from the Fox 5 and Naudet brothers tape. ...etc.
Yesterday I looked at a few wtc2 videos, but I was really too optimistic, visually that is near impossible.. The audio could indeed be useful, I have to say that a lot of the videos I downloaded have (over)dubbed audio, one needs original material of course.
btw as far as I understand the NIST only estimated the time when the first chunks reached the ground, Probably that has also to do with the chaos of the situation.
Yesterday I looked at a few wtc2 videos, but I was really too optimistic, visually that is near impossible.. The audio could indeed be useful, I have to say that a lot of the videos I downloaded have (over)dubbed audio, one needs original material of course.
btw as far as I understand the NIST only estimated the time when the first chunks reached the ground, Probably that has also to do with the chaos of the situation.
I think the Pallisades(sp?) seismograph has the best record, but I'm not sure where to start looking for resources like that in the US.
QUOTE (David B. Benson+Sep 5 2007, 09:30 PM)
Yes. The authors are Bazant/Le/Greening/Benson.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
I can't remember any explicit values from that paper.
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
I can't remember any explicit values from that paper.
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
QUOTE (einsteen+Sep 6 2007, 07:06 AM)
I can't remember any explicit values from that paper.
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
My intepretation of the videos at onset has most of the top block being destroyed in the first few seconds. Does anyone else see this?
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
My intepretation of the videos at onset has most of the top block being destroyed in the first few seconds. Does anyone else see this?
I'm no professional video interpreter but I would say that the monstersize chunks ejected in the beginning is most of the mass of the top block. Didn't the seismic data also say this ? If it is only a few panels and perimeter columns then it would not lead to a peak in seismic data. If you assume a pancake model and only 20 % of the total mass ejected and further only energy transfer storywise then the big peaks should be when the collapsing mass hits the ground. I'm also no expert in that data but if you look at this for example (wtc1)
http://i4.tinypic.com/63jp7w7.jpg
then I'm wondering what all those things mean, how does it look normally ? There will be a background noise but I would say that there is something ongoing that takes 40 seconds.
http://i4.tinypic.com/63jp7w7.jpg
then I'm wondering what all those things mean, how does it look normally ? There will be a background noise but I would say that there is something ongoing that takes 40 seconds.
QUOTE (einsteen+Sep 6 2007, 09:40 PM)
I'm no professional video interpreter but I would say that the monstersize chunks ejected in the beginning is most of the mass of the top block. Didn't the seismic data also say this ? If it is only a few panels and perimeter columns then it would not lead to a peak in seismic data. If you assume a pancake model and only 20 % of the total mass ejected and further only energy transfer storywise then the big peaks should be when the collapsing mass hits the ground. I'm also no expert in that data but if you look at this for example (wtc1)
http://i4.tinypic.com/63jp7w7.jpg
then I'm wondering what all those things mean, how does it look normally ? There will be a background noise but I would say that there is something ongoing that takes 40 seconds.
Not neccessarily actually, remember that it rings like a bell.
Being struck once causes it to oscilate several times.
Actually, it occurs to me that although the Palisades record is (alegedly) the highest quality and the most complete, I'll need to see more then one.
http://i4.tinypic.com/63jp7w7.jpg
then I'm wondering what all those things mean, how does it look normally ? There will be a background noise but I would say that there is something ongoing that takes 40 seconds.
Not neccessarily actually, remember that it rings like a bell.
Being struck once causes it to oscilate several times.
Actually, it occurs to me that although the Palisades record is (alegedly) the highest quality and the most complete, I'll need to see more then one.
Found what I was looking for.
QUOTE (David B. Benson+Sep 5 2007, 09:30 PM)
Yes. The authors are Bazant/Le/Greening/Benson.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
The bang could be the "spire" falling.
For WTC 1 crush-down ends at about 13 seconds and from the audio of the Dr. Marc Heath video, shagster hears a loud bang at 18 seconds, preceded by rumbling sounds. I interpret the bang as a sizable portion of the west wall falling into West Street, preceded by crush-up noises. So, from this, crush-up required a surprisingly long 5 seconds or so...
The bang could be the "spire" falling.
WTC1 debris hitting WTC7.
Grumpy
What an amazing picture isn't it Grumpy. Don't let your kids play with matchsticks, you see what it can do.
Your pathetic attempt to be funny is out of line.
People are DYING in that picture.
Arthur
People are DYING in that picture.
Arthur
QUOTE (Hambone+Sep 6 2007, 12:03 PM)
The bang could be the "spire" falling.
The amplitude of the bang will indicate the energy imparted by the object to the air, it is unlikely to be the spire it is more likely too be the impact of the intact head truss with the ground though the core beams still attached to it.
The amplitude of the bang will indicate the energy imparted by the object to the air, it is unlikely to be the spire it is more likely too be the impact of the intact head truss with the ground though the core beams still attached to it.
QUOTE
Not necessarily actually, remember that it rings like a bell.
Being struck once causes it to oscillate several times.
Being struck once causes it to oscillate several times.
A key point to remember here is that it isn't just the WTC Towers that would be oscillating, but all the skyscrapers in the area. The other buildings' resonances would have to be taken into consideration when analyzing that data.
QUOTE (Chainsaw,+Sep 6 2007, 02:25 PM)
The amplitude of the bang will indicate the energy imparted by the object to the air, it is unlikely to be the spire it is more likely too be the impact of the intact head truss with the ground though the core beams still attached to it.
Did the hat truss land on the ground?
Did the hat truss land on the ground?
QUOTE (wcelliott+Sep 6 2007, 02:45 PM)
A key point to remember here is that it isn't just the WTC Towers that would be oscillating, but all the skyscrapers in the area. The other buildings' resonances would have to be taken into consideration when analyzing that data.
I have wondered quite often how the impact energy (i.e. building mass hitting bedrock) translates into seismic energy. Anyone have any sources on this?
Arthur, indeed sometimes one should take a step back from the formula's and realize what a drama occured there. We are talking about compressed stories like they are pieces of cookies, but indeed my joke was infantile, apologies.
Hambone:
Don't forget the aircraft impacts on each tower gave measurable seismic signals, but very little debris actually hit the ground from these events.
Don't forget the aircraft impacts on each tower gave measurable seismic signals, but very little debris actually hit the ground from these events.
QUOTE
the aircraft impacts on each tower gave measurable seismic signals
This would be the key, IMO, to analyzing the seismic signals.
It's common practice to characterize the resonances of a system by subjecting the system to an impulse and noting the response. This is similar to striking a bell and noting what frequencies are in the response and how long it takes them to extinguish.
In the WTC complex, each tower was struck by an aircraft, and this would suffice as a good "impulse". The seismic response to each impulse would help determine the resonances of the complex of buildings in the immediate area.
One complicating factor, though, is that the towers themselves contribute significantly to the resonances of the complex, and when they fell, that changed the system's resonances.
Still, one could theoretically determine the seismic resonances of the system by characterizing each tower's contribution and factoring that out, as appropriate, based on which tower was falling and whether the other was still standing at the time the seismic data was collected. Both towers were standing (albeit damaged) when the planes struck, so when the first tower fell, the one remaining tower would've contributed its resonances to the system. When the second tower fell, you'd have to remove both towers' contributions from the overall system's resonance characteristics, such that only the resonance of the remaining buildings in the system (immediate surroundings) would be present.
This assumes that there would be no significant resonant characteristics of either collapsed tower, which seems a reasonable first-approximation.
It should be noted, however, that each collapsing tower would've contributed resonances during the collapse due to the resonances of the remaining structure as a function of time. Each floor's failure would be expected to have a rich acoustic signature associated with the failure of each truss and each bracket. As I've noted before, when a structural member fails under load, it goes "BANG!". There'd be a lot of those in each collapse, all superimposed on each other, all resonating with the remaining/intact/lower structures. Not an easy thing to model or analyze, but after the collapse, the remaining buildings would resonate in a manner that could be more-easily analyzed.
QUOTE (Hambone+Sep 6 2007, 02:49 PM)
I have wondered quite often how the impact energy (i.e. building mass hitting bedrock) translates into seismic energy. Anyone have any sources on this?
Check out the 1993 bombing it did not register on seismographs, it was a hydrogen accelerated air blast though concrete basically.
The planes direct contact with the steel alto ugh less energetic than the 1993 bombing did show up on seismographs, any direct impact with the structural steel set in bed rock would most likely have some noticeable seismological effect.
The reason for that is that the steel structure was such a good transmission device for the energy into the ground, you should literally be able to see the buildings core coming apart in the data.
Check out the 1993 bombing it did not register on seismographs, it was a hydrogen accelerated air blast though concrete basically.
The planes direct contact with the steel alto ugh less energetic than the 1993 bombing did show up on seismographs, any direct impact with the structural steel set in bed rock would most likely have some noticeable seismological effect.
The reason for that is that the steel structure was such a good transmission device for the energy into the ground, you should literally be able to see the buildings core coming apart in the data.
QUOTE (einsteen+Sep 6 2007, 12:06 AM)
I can't remember any explicit values from that paper.
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
The calculation was that crush-down ended at 12.7 seconds and is indeed in the paper.
Yes, I am reasonably sure about the 5 seconds, being unable to otherwise explain the rumbling sounds on the audio. Read the Bazant/Verdure paper regarding how crush-up becomes slower and slower towards the end. It is certainly possible or I wouldn't hold to this conclusion.
I have yet to read or see any evidence that suggests that the top block of WTC 1 did not survive largely intact throughout the entire crush-down. In particular, the ejecta you see is surely the top portions of the lower block's exterior wall panel sections.
Are you sure about those 5 seconds, I think if that is true it is really strange, then the model should really be revised. A crush-up of 5 seconds for wtc1 requires that the 53 meter high block caves in with about 11 m/s (while it hits the ground with about 50 m/s) That is impossible. And furthermore not much of the original top block will be left at the end of the collapse, most of it is ejected outwards from the very first beginning.
The calculation was that crush-down ended at 12.7 seconds and is indeed in the paper.
Yes, I am reasonably sure about the 5 seconds, being unable to otherwise explain the rumbling sounds on the audio. Read the Bazant/Verdure paper regarding how crush-up becomes slower and slower towards the end. It is certainly possible or I wouldn't hold to this conclusion.
I have yet to read or see any evidence that suggests that the top block of WTC 1 did not survive largely intact throughout the entire crush-down. In particular, the ejecta you see is surely the top portions of the lower block's exterior wall panel sections.
QUOTE (Hambone+Sep 6 2007, 01:41 AM)
My intepretation[sic] of the videos at onset has most of the top block being destroyed in the first few seconds. Does anyone else see this?
This is in complete disagreement with the Bazant & Verdure paper.
Indeed, after about 1.6 seconds there is about 2 meters of crushed materials protecting the top block of WTC 1. See my previous post.
This is in complete disagreement with the Bazant & Verdure paper.
Indeed, after about 1.6 seconds there is about 2 meters of crushed materials protecting the top block of WTC 1. See my previous post.
QUOTE (Hambone+Sep 6 2007, 05:03 AM)
The bang could be the "spire" falling.
According to NIST, the spire fell down about 19--23 seconds after collapse initiation, or so I recall being informed here. Haven't found it in the NCSTAR1 volumes myself. However, the spire fell apart and so the various portions would each make a separate noise, not just a single bang.
What is clear from the pictorial evidence is that a large portion of the west wall of WTC 1 fell over by being pushed by the crushed materials, hinged at about floor 9. I estimate that this tall section required about 5 seconds to fall to the ground. Thus the interpretation of the bang at 18 seconds.
According to NIST, the spire fell down about 19--23 seconds after collapse initiation, or so I recall being informed here. Haven't found it in the NCSTAR1 volumes myself. However, the spire fell apart and so the various portions would each make a separate noise, not just a single bang.
What is clear from the pictorial evidence is that a large portion of the west wall of WTC 1 fell over by being pushed by the crushed materials, hinged at about floor 9. I estimate that this tall section required about 5 seconds to fall to the ground. Thus the interpretation of the bang at 18 seconds.
So, here's what I've noticed looking at the seismic records.
First off, I'll state that I've actually managed to pull the archive of the original record for 9/11 from the Lamont-Doherty Co-operative Seismographic Network, rather then having to deal with the dozens of interpreted results that may or may not have information missing.
So, looking at the Palisades record (with access to others) some things become apparent.
I've linked one of the annotated/prefiltered results, but it's the same data that I'm looking at, as you can see, yes, the aircraft impacts both register, but the first impact registers a lot more clearly then the second impact.
Looking at the records between 0959 and 1000 (Don't forget travel times) a couple of interesting features stand out.
There is (as expected) at least two phases of collapse.
There's a small signal generated at 09:59:09
There's not a lot of energy in this signal, but it preceeds what appears to be the beginning of the collapse by approximately 4.5 seconds. The signal is weak, and it's amplitude is baarely above the background noise, so it could be nothing, but it's spectrum seems to be similar to that generated by the collapse of the tower.
The 4.5 seconds between the two signals appears to be consistent with the background noise.
For the CDers in the thread, the delay is too long for explosives, and the signature is wrong for explosives.
There's an event at approx 09:59:25 which at this point I am provisionaly interpreting as the onset of the S waves at the Palisades station which appears to last until approx 09:59:55 which appears to be the main phase of the collapse.
There is an event between approx 09:59:18 and approx 09:59:21.6 that is similar to the one generated at 09:59:09 but the amplitude increases slowly, before escalating into what I am, at this point interpreting as the onset of the P-waves associated with the main phase of the collapse.
I'm not sure (at this point) how to translate these times into event times in NYC, because that requires knowing the average velocity of the P-waves through the ground between NYC and the Palisades station - something which I have been (thus far) unable to determine.
Edit: There is also evidence in osme of the traces I've come across that indicates secondary collapse events, which are probably best interpreted at this point as things such as the collapse of air pockets.
First off, I'll state that I've actually managed to pull the archive of the original record for 9/11 from the Lamont-Doherty Co-operative Seismographic Network, rather then having to deal with the dozens of interpreted results that may or may not have information missing.
So, looking at the Palisades record (with access to others) some things become apparent.
I've linked one of the annotated/prefiltered results, but it's the same data that I'm looking at, as you can see, yes, the aircraft impacts both register, but the first impact registers a lot more clearly then the second impact.
Looking at the records between 0959 and 1000 (Don't forget travel times) a couple of interesting features stand out.
There is (as expected) at least two phases of collapse.
There's a small signal generated at 09:59:09
There's not a lot of energy in this signal, but it preceeds what appears to be the beginning of the collapse by approximately 4.5 seconds. The signal is weak, and it's amplitude is baarely above the background noise, so it could be nothing, but it's spectrum seems to be similar to that generated by the collapse of the tower.
The 4.5 seconds between the two signals appears to be consistent with the background noise.
For the CDers in the thread, the delay is too long for explosives, and the signature is wrong for explosives.
There's an event at approx 09:59:25 which at this point I am provisionaly interpreting as the onset of the S waves at the Palisades station which appears to last until approx 09:59:55 which appears to be the main phase of the collapse.
There is an event between approx 09:59:18 and approx 09:59:21.6 that is similar to the one generated at 09:59:09 but the amplitude increases slowly, before escalating into what I am, at this point interpreting as the onset of the P-waves associated with the main phase of the collapse.
I'm not sure (at this point) how to translate these times into event times in NYC, because that requires knowing the average velocity of the P-waves through the ground between NYC and the Palisades station - something which I have been (thus far) unable to determine.
Edit: There is also evidence in osme of the traces I've come across that indicates secondary collapse events, which are probably best interpreted at this point as things such as the collapse of air pockets.
QUOTE (Trippy+Sep 7 2007, 07:32 AM)
There is an event between approx 09:59:18 and approx 09:59:21.6 that is similar to the one generated at 09:59:09 but the amplitude increases slowly, before escalating into what I am, at this point interpreting as the onset of the P-waves associated with the main phase of the collapse.
Actually. After examining some new evidence, I wish to change this interpretation, the event I'm refering to here is in fact (I believe) the onset of the P-waves, with the event at 09:59:21.6 representing the onset of the S-waves.
Actually. After examining some new evidence, I wish to change this interpretation, the event I'm refering to here is in fact (I believe) the onset of the P-waves, with the event at 09:59:21.6 representing the onset of the S-waves.
QUOTE (Trippy+Sep 6 2007, 12:38 PM)
Actually. After examining some new evidence, I wish to change this interpretation, the event I'm refering[sic] to here is in fact (I believe) the onset of the P-waves, with the event at 09:59:21.6 representing the onset of the S-waves.
On the first of this three part thread (so far), there was a link to a report by a seismologist (I recall from AZ) who specialized in the seismograph traces from explosions. He stated that the aircraft seismograph traces were due to Love waves and the collapse traces to Raleigh waves.
This, of course, after a initial P wave. It is certainly not clear to me that any S wave would be generated by these surficial events, but then it has been many years since I studied a bit of geology.
But I do recall, after some review in the last couple of years, that P waves are the fastest, following by S waves, and then eventually the surface waves come chugging along...
On the first of this three part thread (so far), there was a link to a report by a seismologist (I recall from AZ) who specialized in the seismograph traces from explosions. He stated that the aircraft seismograph traces were due to Love waves and the collapse traces to Raleigh waves.
This, of course, after a initial P wave. It is certainly not clear to me that any S wave would be generated by these surficial events, but then it has been many years since I studied a bit of geology.
But I do recall, after some review in the last couple of years, that P waves are the fastest, following by S waves, and then eventually the surface waves come chugging along...
QUOTE
It was anticipated that the actual compounds and materials present in the plume would be similar to those found in building fires or implosion of collapsed buildings. The primary differences would be the simultaneous occurrence of each type of event, the intense fire (> 1,000°C), the extremely large mass of material (> 10 times symbol 106 tons) reduced to dust and smoke, and the previously unseen degree of pulverization of the building materials.
the quote is from this report
David, I have the calculation of Greening's old paper in my mind, in that case it was simply height/average_speed and the reason was of course that the E1s of the top block are equal to the others. I have to say that I don't get those 5 seconds, maybe I have to read the new paper carefully, but the top block's kinetic energy from wtc1 starts with roughly 2.4GJ and at the bottom it is a factor
(52/8.5)^2 higher, i.e. about 90GJ, what does the block are about those 0.5GJ per story, even if you count it up it is a couple of orders lower. My conclusion is that the discrete model doesn't explain it.
(52/8.5)^2 higher, i.e. about 90GJ, what does the block are about those 0.5GJ per story, even if you count it up it is a couple of orders lower. My conclusion is that the discrete model doesn't explain it.
QUOTE (David B. Benson+Sep 7 2007, 07:47 AM)
On the first of this three part thread (so far), there was a link to a report by a seismologist (I recall from AZ) who specialized in the seismograph traces from explosions. He stated that the aircraft seismograph traces were due to Love waves and the collapse traces to Raleigh waves.
This, of course, after a initial P wave. It is certainly not clear to me that any S wave would be generated by these surficial events, but then it has been many years since I studied a bit of geology.
But I do recall, after some review in the last couple of years, that P waves are the fastest, following by S waves, and then eventually the surface waves come chugging along...
Note, that I did say they were barely discernable from the background noise (the P-waves that is).
This, of course, after a initial P wave. It is certainly not clear to me that any S wave would be generated by these surficial events, but then it has been many years since I studied a bit of geology.
But I do recall, after some review in the last couple of years, that P waves are the fastest, following by S waves, and then eventually the surface waves come chugging along...
Note, that I did say they were barely discernable from the background noise (the P-waves that is).
Strange question - what could be causing the appearance of a beat frequency in the data (or at least something resembling one)?
QUOTE (einsteen+Sep 6 2007, 12:52 PM)
My conclusion is that the discrete model doesn't explain it.
Greening simply assumed that crush-up happened with no resistance at all. Bezant & Verdure treat the case that the top block (portions) offer resistance during crush-up. This has the (to me, unexpected) effect of slowing the collapse during crush-up, and quite significantly so.
Greening simply assumed that crush-up happened with no resistance at all. Bezant & Verdure treat the case that the top block (portions) offer resistance during crush-up. This has the (to me, unexpected) effect of slowing the collapse during crush-up, and quite significantly so.
QUOTE (Trippy+Sep 6 2007, 01:25 PM)
Strange question - what could be causing the appearance of a beat frequency in the data (or at least something resembling one)?
Bedrock is elastic, although somewhat an-isotropically so. So the solutions to the wave equation will produce oscillations at a characteristic frequency which depends somewhat on the rock type and more so on the form of wave propagation. I interpret the seismograph traces for the collapse events as largely driven by the impact of the crushed mass on the concrete in the lowest sub-basement. Thereafter, while there is some additional energy supplied by crush-up, mostly what is seen in the traces is simply the bedrock oscillations, which eventually die away.
Somewhat similar traces occur when explosions are set off underground, or even on the surface. The main difference is a distinct and large initial P wave...
Bedrock is elastic, although somewhat an-isotropically so. So the solutions to the wave equation will produce oscillations at a characteristic frequency which depends somewhat on the rock type and more so on the form of wave propagation. I interpret the seismograph traces for the collapse events as largely driven by the impact of the crushed mass on the concrete in the lowest sub-basement. Thereafter, while there is some additional energy supplied by crush-up, mostly what is seen in the traces is simply the bedrock oscillations, which eventually die away.
Somewhat similar traces occur when explosions are set off underground, or even on the surface. The main difference is a distinct and large initial P wave...
QUOTE (David B. Benson+Sep 7 2007, 08:48 AM)
Bedrock is elastic, although somewhat an-isotropically so. So the solutions to the wave equation will produce oscillations at a characteristic frequency which depends somewhat on the rock type and more so on the form of wave propagation. I interpret the seismograph traces for the collapse events as largely driven by the impact of the crushed mass on the concrete in the lowest sub-basement. Thereafter, while there is some additional energy supplied by crush-up, mostly what is seen in the traces is simply the bedrock oscillations, which eventually die away.
Somewhat similar traces occur when explosions are set off underground, or even on the surface. The main difference is a distinct and large initial P wave...
I agree with you, for the most part.
What you're saying about the elasticity of the bedrock is absolutely right, and you would expect to observe some native oscilations.
If you look at the E-W velocity data in the Palisades record, apply the Butwerworth filter, use a low pass of 0.6 Hz, and a high pass of 5 Hz, and look carefully there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse.
The other thing that has caught my eye is that there appears to be a beat frequency present in the data on the order of 0.05 Hz, that may or may not be interfering with another oscilation/beat frequency somewhere around 0.017 Hz. This oscilation/effect is present up to 6 minutes before the collapse trace, and may be present for longer then that.
Somewhat similar traces occur when explosions are set off underground, or even on the surface. The main difference is a distinct and large initial P wave...
I agree with you, for the most part.
What you're saying about the elasticity of the bedrock is absolutely right, and you would expect to observe some native oscilations.
If you look at the E-W velocity data in the Palisades record, apply the Butwerworth filter, use a low pass of 0.6 Hz, and a high pass of 5 Hz, and look carefully there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse.
The other thing that has caught my eye is that there appears to be a beat frequency present in the data on the order of 0.05 Hz, that may or may not be interfering with another oscilation/beat frequency somewhere around 0.017 Hz. This oscilation/effect is present up to 6 minutes before the collapse trace, and may be present for longer then that.
QUOTE (Trippy+Sep 6 2007, 09:08 PM)
I agree with you, for the most part.
What you're saying about the elasticity of the bedrock is absolutely right, and you would expect to observe some native oscilations.
If you look at the E-W velocity data in the Palisades record, apply the Butwerworth filter, use a low pass of 0.6 Hz, and a high pass of 5 Hz, and look carefully there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse.
The other thing that has caught my eye is that there appears to be a beat frequency present in the data on the order of 0.05 Hz, that may or may not be interfering with another oscilation/beat frequency somewhere around 0.017 Hz. This oscilation/effect is present up to 6 minutes before the collapse trace, and may be present for longer then that.
Time it with the collapse and you will find that the beat frequency is consistent with Both the towers bolted and welded joints failing in a regular manor during the collapse. After all the beat does speed up as collapse progresses, and the towers went boom boom boom. I noticed it months ago, as I said you can see the collapse in the data, I am curious about certain aspects of the collapsing air pockets though that is why I did my resent experiments.
PS. I have helped work on seismic studies in the Easton oil fields of Hancock Co. KY. They have been running seismic studies around here since before I was born looking for trapped gas and oil.
What you're saying about the elasticity of the bedrock is absolutely right, and you would expect to observe some native oscilations.
If you look at the E-W velocity data in the Palisades record, apply the Butwerworth filter, use a low pass of 0.6 Hz, and a high pass of 5 Hz, and look carefully there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse.
The other thing that has caught my eye is that there appears to be a beat frequency present in the data on the order of 0.05 Hz, that may or may not be interfering with another oscilation/beat frequency somewhere around 0.017 Hz. This oscilation/effect is present up to 6 minutes before the collapse trace, and may be present for longer then that.
Time it with the collapse and you will find that the beat frequency is consistent with Both the towers bolted and welded joints failing in a regular manor during the collapse. After all the beat does speed up as collapse progresses, and the towers went boom boom boom. I noticed it months ago, as I said you can see the collapse in the data, I am curious about certain aspects of the collapsing air pockets though that is why I did my resent experiments.
PS. I have helped work on seismic studies in the Easton oil fields of Hancock Co. KY. They have been running seismic studies around here since before I was born looking for trapped gas and oil.
QUOTE (Trippy+Sep 6 2007, 02:08 PM)
If you look at the E-W velocity data in the Palisades record, apply the Butwerworth[sic] filter, use a low pass of 0.6 Hz, and a high pass of 5 Hz, and look carefully there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse.
Did you mean low pass of 0.06 Hz?
And this approximately 0.1 Hz frequency occurs during both collapses?
The other stuff, that you say appears to be present, is, I presume, quite low amplitude and might just be due to trucks stopping and restarting at traffic lights, or...
Did you mean low pass of 0.06 Hz?
And this approximately 0.1 Hz frequency occurs during both collapses?
The other stuff, that you say appears to be present, is, I presume, quite low amplitude and might just be due to trucks stopping and restarting at traffic lights, or...
QUOTE (Trippy+Sep 6 2007, 08:25 PM)
Strange question - what could be causing the appearance of a beat frequency in the data (or at least something resembling one)?
timed explosions.
timed explosions.
QUOTE (newton+Sep 6 2007, 02:36 PM)
timed explosions.
One each 10 seconds?
One each 10 seconds?
QUOTE (David B. Benson+Sep 7 2007, 09:23 AM)
Did you mean low pass of 0.06 Hz?
And this approximately 0.1 Hz frequency occurs during both collapses?
The other stuff, that you say appears to be present, is, I presume, quite low amplitude and might just be due to trucks stopping and restarting at traffic lights, or...
No, I meant 0.6 Hz - remember it's a beat frequency I'm talking about, I'm looking at change in the pattern of amplitude which is sinusoidal (or approximately sinusoidal).
As for it being background noise, yeah, I had wondered about that (hence raising teh questions here).
It could be traffic near where the siesmograph is located.
At the local university they have a seismograph in the Geology department.
That seismograph registers approx 90 sec to 2 minutes of activity, nothing, then approx 4-6 minutes later another 90 sec - 2 minutes of activity, followed by 50 minutes of inactivity.
It registers this every day, Monday - Friday, between the hours of 8am and 6pm.
QUOTE
there is what appears to be a beat frequency somewhere on the order of 0.1 Hz during the trace created by the collapse
I would expect this to be more likely a resonance of the other buildings in the area.
I seem to recall someone posting the resonant frequency of the WTC towers, it was, IIRC, on this order.
When the WTC towers fell, they shook all the buildings in the neighborhood. They'd oscillate at about this frequency.
Another thought, how many mechanical floors were there, and what was the timing (delta-t) between their failures?
QUOTE (carterelliott+Sep 7 2007, 09:57 AM)
I would expect this to be more likely a resonance of the other buildings in the area.
I seem to recall someone posting the resonant frequency of the WTC towers, it was, IIRC, on this order.
When the WTC towers fell, they shook all the buildings in the neighborhood. They'd oscillate at about this frequency.
Another thought, how many mechanical floors were there, and what was the timing (delta-t) between their failures?
I was just about to suggest something along thos elines actually.
One possible source for the 0.05 Hz Oscillation could be if the WTC were oscilating at slightly different frequencies, which would make sense because (as far as I've been able to tell) they had slightly different masses due to the communications antenna, and the construction of the roof to accomodate the communications antenna.
As far as the bedrock is concerned, WTC 1, and WTC 2 would effectively represent a tuning fork with a small weight on one arm.
Additional overtones/interference could be due to either differeing vibrational modes in the towers, or vibrational modes being excited in WTC 3-7, which could explain the 0.017 Hz Beat Frequency.
The towers' fundamental period was about 12 seconds. So when WTC 2 collapsed this mode would receive some energy in WTC 1, as well as the higher frequencies.
If I recall correctly, the vibration modes are well explained in NCSTAR1-2A.
If I recall correctly, the vibration modes are well explained in NCSTAR1-2A.
Something occured to me (in the shower, I seem to do some of my best thinking in the shower).
COnsider the earlier analogy, and model WTC 1 & WTC 2 as a Tuning fork with a weight on one arm.
Now consider what happens if we're able to make the other branch (the one without the weight) progressively shorter. The frequencies of it's oscilations changes, I imagine some of the energy would be transfered to the remaining arm, but more importantly, you now open the path for constrcutive/destructive interference of the oscillation modes, leading to the creation of beat frequencies.
This could be helpful in establishing timing as far as collapse goes.
A beer coaster calculation gives me a figure of 2.829 *10^18 Joules for the energy released by the first collapse. I'm not sure how this stacks up against other estimates, but, it it results in being less, then this can easily be explained as being the portion of energy transfered to the bedrock.
I'm not sure how precise this figure is though, I'll have another look when I have more time.
COnsider the earlier analogy, and model WTC 1 & WTC 2 as a Tuning fork with a weight on one arm.
Now consider what happens if we're able to make the other branch (the one without the weight) progressively shorter. The frequencies of it's oscilations changes, I imagine some of the energy would be transfered to the remaining arm, but more importantly, you now open the path for constrcutive/destructive interference of the oscillation modes, leading to the creation of beat frequencies.
This could be helpful in establishing timing as far as collapse goes.
A beer coaster calculation gives me a figure of 2.829 *10^18 Joules for the energy released by the first collapse. I'm not sure how this stacks up against other estimates, but, it it results in being less, then this can easily be explained as being the portion of energy transfered to the bedrock.
I'm not sure how precise this figure is though, I'll have another look when I have more time.
QUOTE (David B. Benson+Sep 7 2007, 10:46 AM)
The towers' fundamental period was about 12 seconds. So when WTC 2 collapsed this mode would receive some energy in WTC 1, as well as the higher frequencies.
If I recall correctly, the vibration modes are well explained in NCSTAR1-2A.
Approximately the same scale as the beat frequency I was looking at.
If I recall correctly, the vibration modes are well explained in NCSTAR1-2A.
Approximately the same scale as the beat frequency I was looking at.
And for the CT'ers in the thread.
So much for WTC7 falloing into it's on footprint
So much for WTC7 falloing into it's on footprint
QUOTE (David B. Benson+Sep 6 2007, 08:37 PM)
Greening simply assumed that crush-up happened with no resistance at all. Bezant & Verdure treat the case that the top block (portions) offer resistance during crush-up. This has the (to me, unexpected) effect of slowing the collapse during crush-up, and quite significantly so.
Ok then the discrete model should also give that. I assume it is a matter of setting up the recursive relations (in the same way as crush-down). The slow down will be significant in the last few floors because the collapsing mass decreases and the significance of E1 plays a major role. But I think the model is still a little bit strange because when the top block hits the ground it is nothing more than a classical implosion but a superior one, because that 52 m/s speed is a big present. I would say that the whole structure breaks simultaneously at the impact and not storywise. And I still think that a normal implosion also is not something that happens storywise. The proof is of course that an implosion is a near g fall.
Ok then the discrete model should also give that. I assume it is a matter of setting up the recursive relations (in the same way as crush-down). The slow down will be significant in the last few floors because the collapsing mass decreases and the significance of E1 plays a major role. But I think the model is still a little bit strange because when the top block hits the ground it is nothing more than a classical implosion but a superior one, because that 52 m/s speed is a big present. I would say that the whole structure breaks simultaneously at the impact and not storywise. And I still think that a normal implosion also is not something that happens storywise. The proof is of course that an implosion is a near g fall.
QUOTE
This has the (to me, unexpected) effect of slowing the collapse during crush-up, and quite significantly so.
It isn't obvious, but it does make sense. If there was no resistance at all to the upper block's descent, then it'd be weightless, falling at 1g. It would still have the structure relatively intact, though, so there would be an intact structure sustaining zero stress. The stress it sustains would be proportional to the deceleration of the block times its weight (2/3rds g would be 2/3rds the normal load at one g.) It's being supported by the other 1/3rd g times its mass via abnormal but distributed means, collisions with rubble below.
This would be like a stunt man falling into a pile of packing peanuts which slow his fall, supplying only 1/3rd his weight. When he runs out of packing peanuts is when he gets hurt, but not before.
QUOTE (einsteen+Sep 7 2007, 07:46 AM)
Ok then the discrete model should also give that. I assume it is a matter of setting up the recursive relations (in the same way as crush-down). The slow down will be significant in the last few floors because the collapsing mass decreases and the significance of E1 plays a major role. But I think the model is still a little bit strange because when the top block hits the ground it is nothing more than a classical implosion but a superior one, because that 52 m/s speed is a big present. I would say that the whole structure breaks simultaneously at the impact and not storywise. And I still think that a normal implosion also is not something that happens storywise. The proof is of course that an implosion is a near g fall.
I see serious implosion by a continuous brake up of floors. _____________________
~~ The events of floor and beam failure could cause________________________
~~~the inward fall pattern. Looking at some of _______________________
~~~~~the images I noticed upward particle _______________________
~X~~X~~X clouds in a rising pattern.______________________
~~XXX~~~~Pressure builds up______________________
~X~X~X~X~X~as the im-___________________
------------------XXXXXXX____________
___________plosion builds from ________
________being feed from more and__________
____more concentrated materials funneling.____________
__A chain reaction of floor failures would create________________
a path where material fell at a compounded rate caused________________
by gravitational pulling through a centerline being guided by___________________
the delay of brake down of the outer walls or (funnel). The pressure_____________
could escape through exploding windows. Then after this implosion has___________
created such pressures, an explosion would occur of epic proportions.It would______
-----------be the perfect storm of deception for our reasoning.--------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I see serious implosion by a continuous brake up of floors. _____________________
~~ The events of floor and beam failure could cause________________________
~~~the inward fall pattern. Looking at some of _______________________
~~~~~the images I noticed upward particle _______________________
~X~~X~~X clouds in a rising pattern.______________________
~~XXX~~~~Pressure builds up______________________
~X~X~X~X~X~as the im-___________________
------------------XXXXXXX____________
___________plosion builds from ________
________being feed from more and__________
____more concentrated materials funneling.____________
__A chain reaction of floor failures would create________________
a path where material fell at a compounded rate caused________________
by gravitational pulling through a centerline being guided by___________________
the delay of brake down of the outer walls or (funnel). The pressure_____________
could escape through exploding windows. Then after this implosion has___________
created such pressures, an explosion would occur of epic proportions.It would______
-----------be the perfect storm of deception for our reasoning.--------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
QUOTE (rethinker+Sep 7 2007, 05:27 AM)
Looking at some of _______________________
~~~~~the images I noticed upward particle _______________________
~X~~X~~X clouds in a rising pattern.______________________
This is an illusion that you get by looking at Photographs.
The debris cloud does not rise, the tower simply falls faster.
You can see this in the videos.
Arthur
~~~~~the images I noticed upward particle _______________________
~X~~X~~X clouds in a rising pattern.______________________
This is an illusion that you get by looking at Photographs.
The debris cloud does not rise, the tower simply falls faster.
You can see this in the videos.
Arthur
The data on the tower vibration modes is in NCSTAR1-2, page 28 (142 ordinal). The frequencies of the first three vibration modes are
0.088, 0.094, 0.202 (all Hz)
as the averages of several measurements on WTC1. These are for N-S, E-W and torsion, respectfully.
The next three, but only by calculation, have frequencies of 0.227, 0.250, 0.455 Hz, from the previous page.
0.088, 0.094, 0.202 (all Hz)
as the averages of several measurements on WTC1. These are for N-S, E-W and torsion, respectfully.
The next three, but only by calculation, have frequencies of 0.227, 0.250, 0.455 Hz, from the previous page.
The fireman describe this:
http://www.youtube.com/watch?v=y2A8VMg_B64
Then we hear this:
http://video.google.com/videoplay?docid=-5860825099435530591
I have always been haunted by the series of explosions heard at the beginning of this collapse video. In my minds eye, I can see the demolition charges going off in a regular, non accelerated fashion, witnessed in so many official controlled demolitions. You hear them in the first few seconds because the background roar is just beginning. The fixed frequency of the explosions bears no relation to the accelerating collapse front. If the series were indeed, the initial sounds of floors impacting, as the OFT's claim, then you would not hear such a distinct even spacing, for several seconds after the initiation.
Once the upper section was in motion, the suspended floors would represent insignificant deceleration platforms, and therefore those regular explosive sounds could not be from the effects of concussion. Lets not forget how tilted the upper section of the south tower was. The base was not parallel to the floor plane and therefore the initial contact would have been more incidental because the interface was skewed and oblique. This does not produced the slamming effect required to generate those explosive sounds. You can't have it both ways. If the floors gave way, then there would be no substantial mechanism in effect to produce such substantial and distinct sounds. Gravity would not allow such linear emanations. The bam----bam----bam----bam goes on too long and is too periodic. If it were the consequence of the collapse front, it should have been closer to bam----bam--bam-bam. The sounds of the explosions are eventually attenuated relative to the growing roar. At the point where you can no longer percieve them, the mind extrapolates their disappearance as the result of impending acceleration into the pace of the front. IMO, they retain their regular emanations, down the lower section, even as sound is subsumed by the rapidly accelerating roar of the wave front.
IMHO, the recorded sounds, early, on this video, are clearly suspicious. If indeed they are determined to be periodic, as they appear to be, than it's a smoking gun suggesting an assisted collapse.
Watch it again and listen!
http://www.youtube.com/watch?v=y2A8VMg_B64
Then we hear this:
http://video.google.com/videoplay?docid=-5860825099435530591
I have always been haunted by the series of explosions heard at the beginning of this collapse video. In my minds eye, I can see the demolition charges going off in a regular, non accelerated fashion, witnessed in so many official controlled demolitions. You hear them in the first few seconds because the background roar is just beginning. The fixed frequency of the explosions bears no relation to the accelerating collapse front. If the series were indeed, the initial sounds of floors impacting, as the OFT's claim, then you would not hear such a distinct even spacing, for several seconds after the initiation.
Once the upper section was in motion, the suspended floors would represent insignificant deceleration platforms, and therefore those regular explosive sounds could not be from the effects of concussion. Lets not forget how tilted the upper section of the south tower was. The base was not parallel to the floor plane and therefore the initial contact would have been more incidental because the interface was skewed and oblique. This does not produced the slamming effect required to generate those explosive sounds. You can't have it both ways. If the floors gave way, then there would be no substantial mechanism in effect to produce such substantial and distinct sounds. Gravity would not allow such linear emanations. The bam----bam----bam----bam goes on too long and is too periodic. If it were the consequence of the collapse front, it should have been closer to bam----bam--bam-bam. The sounds of the explosions are eventually attenuated relative to the growing roar. At the point where you can no longer percieve them, the mind extrapolates their disappearance as the result of impending acceleration into the pace of the front. IMO, they retain their regular emanations, down the lower section, even as sound is subsumed by the rapidly accelerating roar of the wave front.
IMHO, the recorded sounds, early, on this video, are clearly suspicious. If indeed they are determined to be periodic, as they appear to be, than it's a smoking gun suggesting an assisted collapse.
Watch it again and listen!
[no sci-tech]
So, according to Bin Laden it goes against the holy laws of the Koran to burn living beings. I wonder why he hasn't condemned the 19 young men who used fire as their weapon and burned so many helpless people the majority of whom were mostly innocent (of the crimes he describes).
What did they accomplish? Did they kill one major player? Why didn't they attack Halliburton, Carlisle, Boeing, Northropp-Grumman, Martin-Marietta, GE, Rockwell, Unocal, General Dynamics, etc.
Do terrorists understand the psychology of our psychopathic leaders? Do they understand the psychological manipulation of the general public by the media steered entirely by financial interests? Do they understand their own need to be important and powerful? Do they understand that they are manipulated by others with an agenda?
It is easy to kill and create fear and disorder. Much easier than creating order and a fair world society--much easier than to peacefully convince wrong-doers of the errors of their ways.
The laws of the Koran are not the word of god any more than my writing here. There are many useful lessons in all the worlds holy books but do not be fooled. They are the words of man. There is no god.
What did they accomplish? Did they kill one major player? Why didn't they attack Halliburton, Carlisle, Boeing, Northropp-Grumman, Martin-Marietta, GE, Rockwell, Unocal, General Dynamics, etc.
Do terrorists understand the psychology of our psychopathic leaders? Do they understand the psychological manipulation of the general public by the media steered entirely by financial interests? Do they understand their own need to be important and powerful? Do they understand that they are manipulated by others with an agenda?
It is easy to kill and create fear and disorder. Much easier than creating order and a fair world society--much easier than to peacefully convince wrong-doers of the errors of their ways.
The laws of the Koran are not the word of god any more than my writing here. There are many useful lessons in all the worlds holy books but do not be fooled. They are the words of man. There is no god.
QUOTE
Once the upper section was in motion, the suspended floors would represent insignificant deceleration platforms, and therefore those regular explosive sounds could not be from the effects of concussion. Lets not forget how tilted the upper section of the south tower was. The base was not parallel to the floor plane and therefore the initial contact would have been more incidental because the interface was skewed and oblique. This does not produced the slamming effect required to generate those explosive sounds.
The sounds *weren't* from the impact of floor-on-floor, as you assert, but the sounds of the floors detaching from their supports, and the sudden-unloading of the structure resulted in it's own sudden lurching skyward.
The steel in the towers was compressed by the burden, and when that burden was removed, the steel shot straight up, about a foot. The recoil is what caused the "BANG!", the energy of the compressed structure being released suddenly being transferred to a lot of diaphragms that moved a lot of air.
What you *don't* see at either WTC collapse is any evidence of any explosion. The difference between the "BANG!" of a steel structure failing and the "BANG!" of an explosion is that the explosives create a supersonic shock-wave that's clearly visible by any video camera from any angle, as it propagates radially in all directions in a spherical wavefront. Videotapes of real explosions always have this, but you never see it in movie explosions, because they never use real explosives in the movies (none capable of severing steel, at least). This shock-wave is essential for any high explosive to be used for cutting steel, because without the sudden release of energy (i.e., if you used a low-explosive like gunpowder, like in the movies) the shock wave propagates slower than the speed of sound in steel, and the force just gets distributed via the whole length of the steel structure instead of being concentrated where the steel is supposed to be cut.
The visible signature of a high explosive looks like the shimmering above a hot highway, except that it's a spherical shell expanding about the speed of sound. Since all shots of the WTC collapses are long-range footage (by definition, the collapse started 1000 feet up in the air), the shock wave from an explosion would be visible within the FOV of the camera at that range long enough to see it. None are visible. No explosives were used.
Another point that gets overlooked is that explosives have a distinctive smell, and that smell is known to anyone who's ever been in the military. That's a sizable fraction of the general population of NYC. Nobody smelled explosives.
A "BANG!" doesn't imply an explosion, as a "BANG!" is just a lot of air moving one direction suddenly. Kick a metal garbage can, it'll sound like a bomb went off. The WTC towers were built with lots of large flat surfaces and lots of steel under a lot of stress. Every time something breaks, the energy in the steel gets released, and is coupled directly to a big diaphragm that moves, mostly, in one direction. The acoustic energy is going to be a large fraction of the energy in the beam, which is the load imposed on it by the design times the displacement due to compression or stretching of the beam itself. It doesn't take much energy in absolute terms to make a deafening noise. "Boom-boxes" run on C-cell batteries for hours. Compare the energy in a C-cell to the energy in a truss carrying 100tons, and you'll understand where those "BANG!"s came from.
As for the political rhetoric, something everyone seems to overlook is that a President is responsible for the foreseeable consequences of his deliberate *inactions* as well as his actions. If he does nothing and something catastrophic results from his inaction, he'll get the blame for doing nothing. (Remember, Clinton got blamed for *not* killing bin Laden when he had the chance.)
Ordinary civilians assume that so long as they do nothing, there's no way they can get in trouble, so whenever they're in doubt as to what the right thing to do is, they sit on their hands and do nothing. Presidents can't afford that luxury, and sometimes have to act with incomplete/inaccurate information, because doing nothing could be worse than doing the wrong thing. If Bush had done nothing post-9/11, how many more terrorists would've crawled out of the woodwork, figuring Bush is too weak to retaliate in any meaningful way? How many countries with ambitions on expanding their borders would've seen Bush's inaction as a green light for them to attack their neighbors and grab as much land as they could, believing that if Bush wouldn't respond to 9/11, he'd certainly not respond to some third-world country expanding its borders in some distant land?
Real-world problems seldom have perfect solutions, and sometimes you just have to choose the lesser of two evils whether you like it or not.
Bin Laden is the one who plotted the 9/11 attacks and carried them out, not Bush. Those who accuse Bush of 9/11 have no evidence whatsoever to back it up, just the physics that they don't understand because they couldn't be bothered to take any of the hard courses in high school. Just be glad that the US government considers citizens to be innocent until proven guilty, even though some people assume the government to be guilty until proven innocent.
QUOTE
Bin Laden is the one who plotted the 9/11 attacks and carried them out, not Bush. Those who accuse Bush of 9/11 have no evidence whatsoever to back it up, just the physics that they don't understand because they couldn't be bothered to take any of the hard courses in high school. Just be glad that the US government considers citizens to be innocent until proven guilty, even though some people assume the government to be guilty until proven innocent.
As has been mentioned before, the burden on proof is on the person making the claim , which in this case is you.
"Glad that the US government considers citizens to be innocent until proven guilty?"
Maybe you should spend some time reading the patriot act.
"Just six weeks after the September 11 attacks, a panicked Congress passed the “USA PATRIOT Act,” an overnight revision of the nation's surveillance laws that vastly expanded the government's authority to spy on its own citizens and reduced checks and balances on those powers, such as judicial oversight. The government never demonstrated that restraints on surveillance had contributed to the attack, and indeed much of the new legislation had nothing to do with fighting terrorism. Rather, the bill represented a successful use of the terrorist attacks by the FBI to roll back unwanted checks on its power. . . . Under these changes and other authorities asserted by the Bush Administration, U.S. intelligence agents could conduct a secret search of an American citizen's home, use evidence found there to declare him an “enemy combatant,” and imprison him without trial. The courts would have no chance to review these decisions -- indeed, they might never even find out about them."
--Jay Stanley and Barry Steinhardt, "Bigger Monster, Weaker Chains:
The Growth of an American Surveillance SocietyState,"
ACLU Technology and Liberty Program, 1/15/03
Get with the program Frater, even OBL admits the towers (and Pentagon) were taken down by the 19 men.
Arthur
Arthur
[removed, no sci-tech]
QUOTE (adoucette+Sep 3 2007, 02:11 AM)
This BS about a pyroclastic flow has been discussed previously on this thread and clearly shown to be false.
There were THOUSANDS of people engulfed by both clouds.
There were NO EXAMPLES of PEOPLE burned to death by said pyroclastic cloud.
There were PLENTY of flamable materials in the debris cloud which did not ignite.
The Debris cloud was only a SMALL portion of the building.
The Debris cloud was NOT hot.
The Debris cloud was mainly GYPSUM dust.
If you PERSIST in spreading these lies then you CLEARLY are NOT a Critical Thinker.
Arthur
Strange that bone fragments and bone dust were found on the Deutsch Bank Building roof.
The question remains: "How could a normal collapse cause a bone dust cloud whose remains of more than 700 human bone fragments were found on the roof of the former Deutsch Bank building on Liberty St. in 2006?"
"Many" of the bone fragments "are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office."
Pyroclastic dust flows they were not, however it appears a substantial number of victims were vaporized.
By the way, "flammable" is spelled with two "'m's"
There were THOUSANDS of people engulfed by both clouds.
There were NO EXAMPLES of PEOPLE burned to death by said pyroclastic cloud.
There were PLENTY of flamable materials in the debris cloud which did not ignite.
The Debris cloud was only a SMALL portion of the building.
The Debris cloud was NOT hot.
The Debris cloud was mainly GYPSUM dust.
If you PERSIST in spreading these lies then you CLEARLY are NOT a Critical Thinker.
Arthur
Strange that bone fragments and bone dust were found on the Deutsch Bank Building roof.
The question remains: "How could a normal collapse cause a bone dust cloud whose remains of more than 700 human bone fragments were found on the roof of the former Deutsch Bank building on Liberty St. in 2006?"
"Many" of the bone fragments "are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office."
Pyroclastic dust flows they were not, however it appears a substantial number of victims were vaporized.
By the way, "flammable" is spelled with two "'m's"
QUOTE
Strange that bone fragments and bone dust were found on the Deutsch Bank Building roof.
Not at all. There were plenty of people on those floors that got hit by the planes. The same fire that weakened the steel, burned the occupants of those floors.
When the building(s) collapsed, there was 22 tons of air in each floor that had to get out of the way. That air went out, and had very little time to do so, creating gale-force winds as it escaped. It blew the lighter pieces of debris significant distances, as anyone with an understanding of high school physics should understand. The heaviest objects had the highest ballistic coefficient, so they got accelerated the least by the gale-force winds escaping the towers. Going slow, they didn't get too far. The lightest particles had the lowest ballistic coefficients, so they quickly achieved the same speed as the air accelerating them, but they didn't go much farther than the airstream carrying them for the same reason. The particles that went the farthest would be the ones that could be picked up by the gale-force winds and accelerated to high speeds, but have a ballistic coefficient high enough for them to keep going once out of the immediate blast of air. These would be roughly bullet-sized pieces of bone. Like that found on the roof of the Deutsch Bank Building.
QUOTE (beijingyank+Sep 8 2007, 05:51 PM)
Strange that bone fragments and bone dust were found on the Deutsch Bank Building roof.
The question remains: "How could a normal collapse cause a bone dust cloud whose remains of more than 700 human bone fragments were found on the roof of the former Deutsch Bank building on Liberty St. in 2006?"
"Many" of the bone fragments "are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office."
Pyroclastic dust flows they were not, however it appears a substantial number of victims were vaporized.
By the way, "flammable" is spelled with two "'m's"
By compressing air human bodies and steel dust with concrete, carbon, water, and aluminum, It is what I would expect to happen in the collapse after my last round of experiments human bodies are a source of oxidation in highly compressed air.
The calciums in the bones would not react however they would be pulverized in the collapse.
compression of the air would cause it to release heat to what ever was inside it, and its environment.
Falling debris in the elevator shafts at free fall, in the core act like injectors injecting burning debris ahead of the collapse front. Then when the burning debris is collapsed it creates areas of higher than normal temperatures that cause other reactions.
The collapse of the towers is an excellent environment for chemical reactions, and also HCl can form hydrochloric acid that can dissolve flesh as can sulfates and sulfides. Hydrochloric acid was used in cleaning corpses for Skeletal displays.
I am sure if you did some research instead of reading conspiracy websites you would find the answers the choice is of course yours!
The question remains: "How could a normal collapse cause a bone dust cloud whose remains of more than 700 human bone fragments were found on the roof of the former Deutsch Bank building on Liberty St. in 2006?"
"Many" of the bone fragments "are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office."
Pyroclastic dust flows they were not, however it appears a substantial number of victims were vaporized.
By the way, "flammable" is spelled with two "'m's"
By compressing air human bodies and steel dust with concrete, carbon, water, and aluminum, It is what I would expect to happen in the collapse after my last round of experiments human bodies are a source of oxidation in highly compressed air.
The calciums in the bones would not react however they would be pulverized in the collapse.
compression of the air would cause it to release heat to what ever was inside it, and its environment.
Falling debris in the elevator shafts at free fall, in the core act like injectors injecting burning debris ahead of the collapse front. Then when the burning debris is collapsed it creates areas of higher than normal temperatures that cause other reactions.
The collapse of the towers is an excellent environment for chemical reactions, and also HCl can form hydrochloric acid that can dissolve flesh as can sulfates and sulfides. Hydrochloric acid was used in cleaning corpses for Skeletal displays.
I am sure if you did some research instead of reading conspiracy websites you would find the answers the choice is of course yours!
QUOTE (Chainsaw,+Sep 8 2007, 12:00 PM)
... the choice is of course yours!
What a pair of total bonehead.
You know what occurs to me as I sit here reading their posts?
In all of the pre-amble about pre-planted explosives, blah-blah-blah, they over look one crucial thing.
There exists (at least 1) 911 call, placed from inside the towers. I'm not 100% certain where it is in relation to the impact sights, but the call ends with the sound of the tower collapsing, and you can NOT hear any explosives.
You know what occurs to me as I sit here reading their posts?
In all of the pre-amble about pre-planted explosives, blah-blah-blah, they over look one crucial thing.
There exists (at least 1) 911 call, placed from inside the towers. I'm not 100% certain where it is in relation to the impact sights, but the call ends with the sound of the tower collapsing, and you can NOT hear any explosives.
I am no chemist and I can't manage to locate the answer to:
Burning carbon in air releases how much energy per unit of carbon?
Burning carbon in air releases how much energy per unit of carbon?
1 Kilo Carbon = 33 MJ
Arthur
Arthur
[removed, no science]
QUOTE (Trippy+Sep 8 2007, 09:04 PM)
What a pair of total bonehead.
You know what occurs to me as I sit here reading their posts?
In all of the pre-amble about pre-planted explosives, blah-blah-blah, they over look one crucial thing.
There exists (at least 1) 911 call, placed from inside the towers. I'm not 100% certain where it is in relation to the impact sights, but the call ends with the sound of the tower collapsing, and you can NOT hear any explosives.
The 911 call you refer to was placed very high up in the tower.
The tower was hermetically sealed to prevent the spread of fire, so it was very unlikely sound of the explosions taking place in the basement or below the strike site would reach the top of the tower where the caller was.
Explosions were taking place.
You know what occurs to me as I sit here reading their posts?
In all of the pre-amble about pre-planted explosives, blah-blah-blah, they over look one crucial thing.
There exists (at least 1) 911 call, placed from inside the towers. I'm not 100% certain where it is in relation to the impact sights, but the call ends with the sound of the tower collapsing, and you can NOT hear any explosives.
The 911 call you refer to was placed very high up in the tower.
The tower was hermetically sealed to prevent the spread of fire, so it was very unlikely sound of the explosions taking place in the basement or below the strike site would reach the top of the tower where the caller was.
Explosions were taking place.
Master wcelliott, again we meet. I recall our last encounter very well; not for the quality of rhetoric, but the quantity of consequence. Let's see, all my posts were deleted, all my forum fouls hitherto acquired, and last but hardly least; the "Off Topic" sub-forum was changed in mid stream and re-designated "Other Sci-Tech Topics" (only!). It would not surprise me, if it was you who brought down the wrath of the moderators. I have since seen plenty of politically slanted posts left undeleted; their authors not flagged. I suppose that's one way to prevail when circular logic doesn't.
Censorship of the PhysOrgForum has indeed, come full circle. I have to be cautious when expressing peaceful dissent in public and now I have to walk on egg shells here. I do hear some crunching beneath my feet; perhaps my eventual suspension might be sooner than later. It is interesting how you post your political bias with no fear of repudiation.
The censorship started with the conditional termination of the Utopian singularity known as the BP thread, and completes with the closure of the last bastion of unclassified thought, that remote enclave, formerly known as "off topic". Like the predominance of "dark matter" in the universe: the who, what, where, when, how and why of 9/11 research dwarfs the observable "sci-tech" matter. The universe doesn't make any sense without it, so to, the quest to understand what happened 6 years ago, almost to the day, will be left unaccounted and lingering in the shadows. There is no longer a sanctioned place to discuss the dark matter in the 9/11 universe. Few here will shed tears over this.
Since being on this forum, I have lost what little belief I had in the unbiased application of the scientific method. Scientists, like most of us, engage in symbiosis with their hosts; in their case, government and corporate institutions. All are replete with bias, especially amongst the lock step, rabid alliances found in the current corporatocracy. Under the obligation to maintain position and patronage, the objectivity inherent in pure science, can and does yield to subjectivity. Why else would there be a tolerance amongst science departments to consider teaching creationism along side evolution. The fundamentalist faction influencing this regime, believes the world is 6000 years old. The geologists, working for the oil oligarchs, understand that 10's of millions of years of accumulated bio-mass are required to produce all of the oil used and yet to be used on this planet.
Only a fatally disturbed entity would destroy something in order to prevent it's destruction. Protecting Americans from a loosely defined "others who hate our freedoms" apparently will require the destruction of the sole document that guaranties those freedoms in the first place. You would think that the real reason they hate us might be because we're an oil thirsty, blood letting empire, building the largest embassies and military bases ever in history, throughout the middle east. The US and Britain have been meddling in the affairs of the middle east for most of the 20th century, and exponentially so after WW2. That couldn't be the real reason they're so upset, could it? It wouldn't bother you if the Chinese, (who, by the way, hold our collective mortgage), started building military installations in your county, would it? Don't fret, there is one freedom that will remain intact; the freedom to mass consume approved media, Monsanto frankenfood, and cheap Chinese goods.
Ironically, the people who care the most about the integrity of this constitutional democracy are repudiated. Consumme enough NeoCon Koolaide, and love and hate will equate. Steady-state war will be excepted as peace, and don't forget to put the cart before the horse when discussing issues with deep historical implications that you know nothing about. God bless the U$A.
Now on to your assertions:(if this post is still here)
"The sounds *weren't* from the impact of floor-on-floor, as you assert,..."
I"m asserting, that based on the prolonged regularity of the series of (explosive) sounds heard on the video, it would suggest: (1) mechanisms not subject to the non-linear effects of gravity, and (2) by logical extension, a reason to consider
the presence of controlled demolition explosives wired in series-parallel. Each level was parallel wired and blown simultaneously. A linear distribution device triggered successive levels ahead of the front. Nowhere in your reply do you address the core of my argument: the sustained, periodic nature of the sounds (explosions). Gravity is not linear.
"The steel in the towers was compressed by the burden, and when that burden was removed, the steel shot straight up, about a foot."
I've never this variant of the collapse mechanism, but then again it's hard to keep up. When does the "burden" ever stand down? Isn't gravity a sort of a 24 /7 kinda' thing? I don't follow, besides you're implying that all the floors joints, at each level, snapped at the same moment. The interface of the impact zone was not parallel because of the list. Therefore the floor snap across the levels just below the impact zone would be progressive, not instantaneous. This would spread the audio amplitude out over time, reducing the crisp transients heard on the video into more of a blurred drone. I'm sorry I don't buy your explanation.
"What you *don't* see at either TC collapse is any evidence of any explosion."
Shape charges transmit a highly focused force inward against the designated component of infrastructure. An even distribution of non excessive charges around the level would cancel out the external manifestation of the demolition force.
"...explosives have a distinctive smell..."
Indeed, but when you consider the micron pulverization of every utilitarian substance known to man, suspended in the air, burning and chocking the lungs of anyone foolish or desperate enough to breath with out a mask, I seriously doubt the smell of explosives could have been pervasive.
"Every time something breaks, the energy in the steel gets released, and is coupled directly to a big diaphragm that moves, mostly, in one direction."
The floors where encased in light weight cement; that would dampen sound energy. The outer perimeter was essentially an open structural grid network. What diaphragm? What coupling? The towers were as non-acoustically resonant as a structure could be. The internal sheathing of drywall is an extremely poor transmitter of sound energy.
Censorship of the PhysOrgForum has indeed, come full circle. I have to be cautious when expressing peaceful dissent in public and now I have to walk on egg shells here. I do hear some crunching beneath my feet; perhaps my eventual suspension might be sooner than later. It is interesting how you post your political bias with no fear of repudiation.
The censorship started with the conditional termination of the Utopian singularity known as the BP thread, and completes with the closure of the last bastion of unclassified thought, that remote enclave, formerly known as "off topic". Like the predominance of "dark matter" in the universe: the who, what, where, when, how and why of 9/11 research dwarfs the observable "sci-tech" matter. The universe doesn't make any sense without it, so to, the quest to understand what happened 6 years ago, almost to the day, will be left unaccounted and lingering in the shadows. There is no longer a sanctioned place to discuss the dark matter in the 9/11 universe. Few here will shed tears over this.
Since being on this forum, I have lost what little belief I had in the unbiased application of the scientific method. Scientists, like most of us, engage in symbiosis with their hosts; in their case, government and corporate institutions. All are replete with bias, especially amongst the lock step, rabid alliances found in the current corporatocracy. Under the obligation to maintain position and patronage, the objectivity inherent in pure science, can and does yield to subjectivity. Why else would there be a tolerance amongst science departments to consider teaching creationism along side evolution. The fundamentalist faction influencing this regime, believes the world is 6000 years old. The geologists, working for the oil oligarchs, understand that 10's of millions of years of accumulated bio-mass are required to produce all of the oil used and yet to be used on this planet.
Only a fatally disturbed entity would destroy something in order to prevent it's destruction. Protecting Americans from a loosely defined "others who hate our freedoms" apparently will require the destruction of the sole document that guaranties those freedoms in the first place. You would think that the real reason they hate us might be because we're an oil thirsty, blood letting empire, building the largest embassies and military bases ever in history, throughout the middle east. The US and Britain have been meddling in the affairs of the middle east for most of the 20th century, and exponentially so after WW2. That couldn't be the real reason they're so upset, could it? It wouldn't bother you if the Chinese, (who, by the way, hold our collective mortgage), started building military installations in your county, would it? Don't fret, there is one freedom that will remain intact; the freedom to mass consume approved media, Monsanto frankenfood, and cheap Chinese goods.
Ironically, the people who care the most about the integrity of this constitutional democracy are repudiated. Consumme enough NeoCon Koolaide, and love and hate will equate. Steady-state war will be excepted as peace, and don't forget to put the cart before the horse when discussing issues with deep historical implications that you know nothing about. God bless the U$A.
Now on to your assertions:(if this post is still here)
"The sounds *weren't* from the impact of floor-on-floor, as you assert,..."
I"m asserting, that based on the prolonged regularity of the series of (explosive) sounds heard on the video, it would suggest: (1) mechanisms not subject to the non-linear effects of gravity, and (2) by logical extension, a reason to consider
the presence of controlled demolition explosives wired in series-parallel. Each level was parallel wired and blown simultaneously. A linear distribution device triggered successive levels ahead of the front. Nowhere in your reply do you address the core of my argument: the sustained, periodic nature of the sounds (explosions). Gravity is not linear.
"The steel in the towers was compressed by the burden, and when that burden was removed, the steel shot straight up, about a foot."
I've never this variant of the collapse mechanism, but then again it's hard to keep up. When does the "burden" ever stand down? Isn't gravity a sort of a 24 /7 kinda' thing? I don't follow, besides you're implying that all the floors joints, at each level, snapped at the same moment. The interface of the impact zone was not parallel because of the list. Therefore the floor snap across the levels just below the impact zone would be progressive, not instantaneous. This would spread the audio amplitude out over time, reducing the crisp transients heard on the video into more of a blurred drone. I'm sorry I don't buy your explanation.
"What you *don't* see at either TC collapse is any evidence of any explosion."
Shape charges transmit a highly focused force inward against the designated component of infrastructure. An even distribution of non excessive charges around the level would cancel out the external manifestation of the demolition force.
"...explosives have a distinctive smell..."
Indeed, but when you consider the micron pulverization of every utilitarian substance known to man, suspended in the air, burning and chocking the lungs of anyone foolish or desperate enough to breath with out a mask, I seriously doubt the smell of explosives could have been pervasive.
"Every time something breaks, the energy in the steel gets released, and is coupled directly to a big diaphragm that moves, mostly, in one direction."
The floors where encased in light weight cement; that would dampen sound energy. The outer perimeter was essentially an open structural grid network. What diaphragm? What coupling? The towers were as non-acoustically resonant as a structure could be. The internal sheathing of drywall is an extremely poor transmitter of sound energy.
QUOTE
blah, blah, blah...
When does the "burden" ever stand down? Isn't gravity a sort of a 24 /7 kinda' thing? I don't follow, besides you're implying that all the floors joints, at each level, snapped at the same moment.
When does the "burden" ever stand down? Isn't gravity a sort of a 24 /7 kinda' thing? I don't follow, besides you're implying that all the floors joints, at each level, snapped at the same moment.
If something's falling, it isn't being supported. When the upper blocks started falling, they weren't being supported by the structural columns below, so those columns would've been unburdened, and would've shot skyward about a foot.
As for the simultaneity of the each floor's collapse, the floors were approaching the point where their structures couldn't hold them up, with the steel being weakened and the brackets failing one by one, once the last bracket broke that provided the last 0.0001% margin, the remaining brackets would've snapped in rapid succession, too rapid to be identified individually by their sounds.
Actually, that raises an interesting point. Your central thesis is that the BANGs heard represented explosives simultaneously-detonated floor-by-floor. How far apart, physically, do you think they were planted? Sound travels at 1100 feet per second, give or take, and true detonations are virtually instantaneous from an acoustic POV. I'm wondering how widely-dispersed explosives end up sounding like one BANG per floor instead of "POP-POP-POP...".
Gravity isn't linear, but it can drive systems in a linear manner. Grandfather clocks are linear systems driven by gravity, their "ticks" are evenly spaced in time. To explain the timing of the BANGs, you have to understand how the floors collapsed. You haven't figured that out, yet, nor have you attempted to, as evidenced by your nonsensical assertion of explosives in the basement when the towers clearly fell from the points of impact. All you've done is wallow in radical rhetoric so that you can pose as an avant garde elitist thinker. So much easier than putting in the real study necessary to understand how things really work. You have to understand how things work before you can understand how things fail. How they work is the easier part, they teach that in school. How they fail is the harder part, and that's where the benefit of experience really comes into play. Any fresh-out-of-school engineer can design something that could work, it takes an experienced engineer to know how something will fail (and prevent it).
I'd be interested in seeing just how regularly-timed those "explosives" actually were. With even the cheapest-available components, those "explosives" would've been timed to millisecond accuracy, if triggered in the "series-parallel" approach you've described. Cite some numbers, do the hard work, and then let's discuss this apparent "smoking-gun" evidence of a massive conspiracy. (I think that if you actually look at the real numbers, you'll find that the BANGS aren't linear as you say, but do, in fact, accelerate, which is consistent with the known pancake-collapse model.)
QUOTE (wcelliott+Sep 9 2007, 08:27 PM)
I'd be interested in seeing just how regularly-timed those "explosives" actually were. With even the cheapest-available components, those "explosives" would've been timed to millisecond accuracy, if triggered in the "series-parallel" approach you've described. Cite some numbers, do the hard work, and then let's discuss this apparent "smoking-gun" evidence of a massive conspiracy. (I think that if you actually look at the real numbers, you'll find that the BANGS aren't linear as you say, but do, in fact, accelerate, which is consistent with the known pancake-collapse model.)
I agree.
In all honesty, I here I think maybe 3 or 4 distinct popping sounds.
They do seem (to me at least) to be slightly closer together as time progresses, then they almost seem to be overtaken by a background noise that sounds like a rapid succession of collisions, kind of like dragging a comb over a ruler - only something on the order of several collisions per second.
I agree.
In all honesty, I here I think maybe 3 or 4 distinct popping sounds.
They do seem (to me at least) to be slightly closer together as time progresses, then they almost seem to be overtaken by a background noise that sounds like a rapid succession of collisions, kind of like dragging a comb over a ruler - only something on the order of several collisions per second.
[removed, no sci-tech]
QUOTE (zoktoberfest+Sep 9 2007, 03:16 AM)
Since being on this forum, I have lost what little belief I had in the unbiased application of the scientific method.
WHY?????
You have OBVIOUSLY never paid any attention to it.
You post a LONG diatribe about the WTC collapse that YOU CLAIM supports your assertion based on WHAT?
That it didn't SOUND RIGHT?
Then you go off onto WILDLY SPECULATIVE assertions about series-parallel wiring to shaped charges.
All without a SHRED of evidence to support it at all.
All while CONVENIENTLY IGNORING all of the finding of the multi-year multi-million dollar SCIENTIFIC study that explains how the cumulative effects of the impact and fire caused the slow bowing in of one of the walls leading to collapse.
WCElliot is correct, you're just a poser.
And not a very good one at that.
Arthur
WHY?????
You have OBVIOUSLY never paid any attention to it.
You post a LONG diatribe about the WTC collapse that YOU CLAIM supports your assertion based on WHAT?
That it didn't SOUND RIGHT?
Then you go off onto WILDLY SPECULATIVE assertions about series-parallel wiring to shaped charges.
All without a SHRED of evidence to support it at all.
All while CONVENIENTLY IGNORING all of the finding of the multi-year multi-million dollar SCIENTIFIC study that explains how the cumulative effects of the impact and fire caused the slow bowing in of one of the walls leading to collapse.
WCElliot is correct, you're just a poser.
And not a very good one at that.
Arthur
QUOTE (adoucette+Sep 9 2007, 01:49 PM)
All while CONVENIENTLY IGNORING all of the finding of the multi-year multi-million dollar SCIENTIFIC study that explains how the cumulative effects of the impact and fire caused the slow bowing in of one of the walls leading to collapse.
Arthur
Arthur,
Get out while you still can.
The "multi-million dollar SCIENTIFIC study" you talk about will never stand up to the course of time. It will do as well at the "multi-million dollar" Warren Commission study.
Save yourself Arthur. Your handlers could give a rat's arse about you because as far as they are concerned you are a M 0 R 0 N.
Arthur
Arthur,
Get out while you still can.
The "multi-million dollar SCIENTIFIC study" you talk about will never stand up to the course of time. It will do as well at the "multi-million dollar" Warren Commission study.
Save yourself Arthur. Your handlers could give a rat's arse about you because as far as they are concerned you are a M 0 R 0 N.
QUOTE
Save yourself Arthur.
Hey, BeijingYank, here's another forum thread I think you'll be interested in:
http://community.discovery.com/eve/forums/.../2491939909/p/2
It's about how the moon landings were all faked.
Jump in, you'll feel right at home.
QUOTE (beijingyank+Sep 9 2007, 10:40 AM)
Arthur,
Get out while you still can.
The "multi-million dollar SCIENTIFIC study" you talk about will never stand up to the course of time. It will do as well at the "multi-million dollar" Warren Commission study.
Save yourself Arthur. Your handlers could give a rat's arse about you because as far as they are concerned you are a M 0 R 0 N.
That's why its a waste of time to argue with conspiracy nuts.
They think lack of proof IS proof.
Sorry BY, but you don't have a CLUE.
Tell us again about how
Get out while you still can.
The "multi-million dollar SCIENTIFIC study" you talk about will never stand up to the course of time. It will do as well at the "multi-million dollar" Warren Commission study.
Save yourself Arthur. Your handlers could give a rat's arse about you because as far as they are concerned you are a M 0 R 0 N.
That's why its a waste of time to argue with conspiracy nuts.
They think lack of proof IS proof.
Sorry BY, but you don't have a CLUE.
Tell us again about how
QUOTE (beijingwanker+)
The tower was hermetically sealed
ROTFLMAO
Arthur
ROTFLMAO
Arthur
QUOTE (adoucette+Sep 8 2007, 05:28 PM)
1 Kilo Carbon = 33 MJ
Arthur
Thank you!
Arthur
Thank you!
QUOTE (adoucette+Sep 9 2007, 04:56 PM)
That's why its a waste of time to argue with conspiracy nuts.
They think lack of proof IS proof.
Sorry BY, but you don't have a CLUE.
Tell us again about how
They think lack of proof IS proof.
Sorry BY, but you don't have a CLUE.
Tell us again about how
QUOTE (beijingwanker+)
The tower was hermetically sealed
ROTFLMAO
Arthur
Joel S. Hirschhorn, PhD
Sept. 5, 2007 – In an online editorial yesterday, Joel S. Hirschhorn, PhD, former Senior Staff Member of the Congressional Office of Technology Assessment (OTA), called for a new investigation of 9/11. “First, let the technical truth emerge. Then, if necessary, cope with the inevitable political, conspiracy and other questions. But let us not allow a possible painful truth block the primary task of determining once and for all what caused the collapse of the WTC towers and building no. 7.”
Dr. Hirschhorn is a nationally recognized engineer who has testified before Congress more than 50 times on technology, science, and environmental issues. In addition to his work for the OTA, Dr. Hirschhorn also served as Director of Environment, Energy and Natural Resources for the National Governors Association.
Dr. Hirschhorn admitted to his own personal “growing skepticism about the official WTC story”. He wrote “analyses by many experts reveal the collapse of the three WTC buildings was not caused by the two airplanes exploding into the twin towers.” He noted “the general view is that the buildings were brought down by
controlled demolition.”
Dr. Hirschhorn endorsed the efforts of a new group, Architects and Engineers for 9/11 Truth, to launch a new, honest and comprehensive investigation that considers all the evidence and which examines the possibility of controlled demolition.
Dr. Hirschhorn issued a challenge to supporters of the official account of 9/11, “If those that believe the official 9/11 story - especially elected officials - trust their views, then let them support a serious effort to test the validity of the controlled demolition hypothesis. If they fear and reject doing so, then let us see that as suspicious and unacceptable.”
He concluded, “Horrific possible answers can cause us to shun a question. But clearing our minds of the fear of painful truths is essential to clearing our nation of destructive lies. Otherwise, we stay stuck in a delusional democracy."
The full text of Dr. Hirschhorn’s statement can be found at http://blogcritics.org
Prior to his 13 years of service at the Congressional Office of Technology Assessment, Dr. Hirschhorn was Professor of Metallurgical Engineering at the University of Wisconsin, Madison from 1965 - 1978. He has a Bachelors and Masters degree in Metallurgical Engineering and a PhD in Materials Engineering. He has been a consultant to industrial and chemical companies, DOE laboratories, state governments, and public interest organizations. He currently is a Member of the Board of Directors of the National Foundation for Environmental Education and a Member of the Board of Directors of Sustainability Now! He is the author of more than 150 papers, articles, guest editorials, and book chapters on environmental science and technology.
Dr. Hirschhorn is one of 200 engineers and architects who have publicly criticized the official account of 9/11. Statements and short bios of many of the others can be found at PatriotsQuestion911.com .
Take action -- http://www.usalone.net/cgi-bin/oen.cgi?qnum=2599Contact Your Representativeclick here to contact your local newspaper or congress people:
Initiate New, Thorough Investigation into 9/11
Alan Miller is author of the website http://www.PatriotsQuestion911.com
You do realize that one ton is 2000 pounds, not 1000 pounds, and a metric ton is 1000kg, right?
You do realize that one ton is 2000 pounds, not 1000 pounds, and a metric ton is 1000kg, right?
If you read the article, I'm sure you will see that I am very clear on what US(short) tons and metric tonnes are. The in-service weight was much less than the oft quoted 500,000 tons.
David B. Benson and all
This topic may help us to find a way to not let such loss be possible in the future.
May we also remember all the families who are today (9/11/07) still in pain.
...And may the organizers of 9-11 pay for the consequences of their actions..
That's what our troops are doing in Afghanistan.
That's what our troops are doing in Afghanistan.
Punishing the organizers of 9-11?
ROTFLMAO
Arthur
Joel S. Hirschhorn, PhD
Sept. 5, 2007 – In an online editorial yesterday, Joel S. Hirschhorn, PhD, former Senior Staff Member of the Congressional Office of Technology Assessment (OTA), called for a new investigation of 9/11. “First, let the technical truth emerge. Then, if necessary, cope with the inevitable political, conspiracy and other questions. But let us not allow a possible painful truth block the primary task of determining once and for all what caused the collapse of the WTC towers and building no. 7.”
Dr. Hirschhorn is a nationally recognized engineer who has testified before Congress more than 50 times on technology, science, and environmental issues. In addition to his work for the OTA, Dr. Hirschhorn also served as Director of Environment, Energy and Natural Resources for the National Governors Association.
Dr. Hirschhorn admitted to his own personal “growing skepticism about the official WTC story”. He wrote “analyses by many experts reveal the collapse of the three WTC buildings was not caused by the two airplanes exploding into the twin towers.” He noted “the general view is that the buildings were brought down by
controlled demolition.”
Dr. Hirschhorn endorsed the efforts of a new group, Architects and Engineers for 9/11 Truth, to launch a new, honest and comprehensive investigation that considers all the evidence and which examines the possibility of controlled demolition.
Dr. Hirschhorn issued a challenge to supporters of the official account of 9/11, “If those that believe the official 9/11 story - especially elected officials - trust their views, then let them support a serious effort to test the validity of the controlled demolition hypothesis. If they fear and reject doing so, then let us see that as suspicious and unacceptable.”
He concluded, “Horrific possible answers can cause us to shun a question. But clearing our minds of the fear of painful truths is essential to clearing our nation of destructive lies. Otherwise, we stay stuck in a delusional democracy."
The full text of Dr. Hirschhorn’s statement can be found at http://blogcritics.org
Prior to his 13 years of service at the Congressional Office of Technology Assessment, Dr. Hirschhorn was Professor of Metallurgical Engineering at the University of Wisconsin, Madison from 1965 - 1978. He has a Bachelors and Masters degree in Metallurgical Engineering and a PhD in Materials Engineering. He has been a consultant to industrial and chemical companies, DOE laboratories, state governments, and public interest organizations. He currently is a Member of the Board of Directors of the National Foundation for Environmental Education and a Member of the Board of Directors of Sustainability Now! He is the author of more than 150 papers, articles, guest editorials, and book chapters on environmental science and technology.
Dr. Hirschhorn is one of 200 engineers and architects who have publicly criticized the official account of 9/11. Statements and short bios of many of the others can be found at PatriotsQuestion911.com .
Take action -- http://www.usalone.net/cgi-bin/oen.cgi?qnum=2599Contact Your Representativeclick here to contact your local newspaper or congress people:
Initiate New, Thorough Investigation into 9/11
Alan Miller is author of the website http://www.PatriotsQuestion911.com
QUOTE (beijingyank+Sep 9 2007, 02:29 PM)
Joel S. Hirschhorn, PhD
is sadly misinformed.
Invite him, and indeed, the 200 others, to ask questions here...
is sadly misinformed.
Invite him, and indeed, the 200 others, to ask questions here...
QUOTE (David B. Benson+Sep 9 2007, 09:50 PM)
is sadly misinformed.
Invite him, and indeed, the 200 others, to ask questions here...
I agree invite him here, I have personally emailed him, I would like to see him here expressing his views.
Invite him, and indeed, the 200 others, to ask questions here...
I agree invite him here, I have personally emailed him, I would like to see him here expressing his views.
QUOTE (Chainsaw,+Sep 9 2007, 04:46 PM)
... I have personally emailed him ...
Aha! Then you could invite him as well...
Aha! Then you could invite him as well...
QUOTE (David B. Benson+Sep 9 2007, 09:50 PM)
is sadly misinformed.
Invite him, and indeed, the 200 others, to ask questions here...
Misinformed?...and WTC1 weighed 576,000 tons...and the top section remained intact until crush-down was complete. What was that saying about glass houses?
Invite him, and indeed, the 200 others, to ask questions here...
Misinformed?...and WTC1 weighed 576,000 tons...and the top section remained intact until crush-down was complete. What was that saying about glass houses?
QUOTE (Hambone+Sep 9 2007, 05:00 PM)
...and WTC1 weighed 576,000 tons...
and the top section remained intact until crush-down was complete.
Surely that weight is far too high. Poster shagster puts it at about 300,000 tonnes. What is your estimate?
For WTC 1, largely so, it appears. Not completely so, since the temporary spire poked though it. However, the timing determined by audio analysis is consistent with this, since there has to be something to crush-up. See the recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website.
and the top section remained intact until crush-down was complete.
Surely that weight is far too high. Poster shagster puts it at about 300,000 tonnes. What is your estimate?
For WTC 1, largely so, it appears. Not completely so, since the temporary spire poked though it. However, the timing determined by audio analysis is consistent with this, since there has to be something to crush-up. See the recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website.
What was the height of the first tower to collapse? (in meters).
Isn't it more important (in a uniform model) to use the ratio ? for example roughly
E1/M_tower=1.5 J/kg
E1/M_tower=1.5 J/kg
QUOTE (David B. Benson+Sep 10 2007, 12:12 AM)
Surely that weight is far too high. Poster shagster puts it at about 300,000 tonnes. What is your estimate?
For WTC 1, largely so, it appears. Not completely so, since the temporary spire poked though it. However, the timing determined by audio analysis is consistent with this, since there has to be something to crush-up. See the recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website.
576,000 (522,000 tonnes) tons is the weight used in the "recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website", although not explicity stated.
My detailed analysis (proof reading version) is available at:
http://www.cool-places.0catch.com/docs/MassAndPeWtc1.pdf
Please take a look at it. There are few people with your detailed knowledge of the NIST reports which makes your comments very valuable.
I get 288,100 metric tonnes. I have taken floor types and the hat truss into account in accord with your previous comments. In the discussion, the result is compared to Shagster's numbers from the SAP model as well as other buildings and the amount of debris. The BLGB mass is calculated in the Introduction.
For WTC 1, largely so, it appears. Not completely so, since the temporary spire poked though it. However, the timing determined by audio analysis is consistent with this, since there has to be something to crush-up. See the recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website.
576,000 (522,000 tonnes) tons is the weight used in the "recent Bazant/Le/Greening/Benson preprint, available on Professor Bazant's website", although not explicity stated.
My detailed analysis (proof reading version) is available at:
http://www.cool-places.0catch.com/docs/MassAndPeWtc1.pdf
Please take a look at it. There are few people with your detailed knowledge of the NIST reports which makes your comments very valuable.
I get 288,100 metric tonnes. I have taken floor types and the hat truss into account in accord with your previous comments. In the discussion, the result is compared to Shagster's numbers from the SAP model as well as other buildings and the amount of debris. The BLGB mass is calculated in the Introduction.
QUOTE
576,000 (522,000 tonnes) tons is the weight used
...
I get 288,100 metric tonnes.
...
I get 288,100 metric tonnes.
You do realize that one ton is 2000 pounds, not 1000 pounds, and a metric ton is 1000kg, right?
QUOTE (wcelliott+Sep 10 2007, 03:07 PM)
You do realize that one ton is 2000 pounds, not 1000 pounds, and a metric ton is 1000kg, right?
If you read the article, I'm sure you will see that I am very clear on what US(short) tons and metric tonnes are. The in-service weight was much less than the oft quoted 500,000 tons.
It just seemed an odd coincidence, since 2 x 288 = 576.
QUOTE (Hambone+Sep 10 2007, 07:31 AM)
http://www.cool-places.0catch.com/docs/MassAndPeWtc1.pdf
Your paper is quite good. Some suggestions.
I am fairly sure that normal weight concrete was used in all core areas, with a fixed thickness, except possibly on the mechanical floors. It may make little difference, but the normal weight concrete was most likely 4.5" thick, due to the traffic live loads.
15 psf for floor loadings is quite minimal. (2.3.6.1)
2.3.7.1 seems, in part, to repeat what was said before. I suggest reorganizing so it is not necessary to repeat. (Also 2.3.7.2 and 2.37.3)
From floor 1 down, the extra steel was there as protection against earthquakes, although little was understood that long ago about how to design to withstand these shocks.
LLA and LLW are to different ways of estimating the in-service live loads. It is a mistake to add them. LLW appears to be the original design estimates, while LLA uses the later ASCE7-02 standard. See NCSTAR1-2A, page 72 (106 ordinal). Using the latter as more realistic, you and shagster agree quite well. I'm impressed.
Poster einsteen makes the important point that only the mass specific energy matters during crush-down. So knowing the actual mass at each elevation then enables one to determine the energy consumed at that level, due to crushing the materials. This is separate from the energy for comminution and pushing the air out of the way.
(I didn't understand your calculation of the BLGB preprint mass, but I'll have to get back to it later...)
Your paper is quite good. Some suggestions.
I am fairly sure that normal weight concrete was used in all core areas, with a fixed thickness, except possibly on the mechanical floors. It may make little difference, but the normal weight concrete was most likely 4.5" thick, due to the traffic live loads.
15 psf for floor loadings is quite minimal. (2.3.6.1)
2.3.7.1 seems, in part, to repeat what was said before. I suggest reorganizing so it is not necessary to repeat. (Also 2.3.7.2 and 2.37.3)
From floor 1 down, the extra steel was there as protection against earthquakes, although little was understood that long ago about how to design to withstand these shocks.
LLA and LLW are to different ways of estimating the in-service live loads. It is a mistake to add them. LLW appears to be the original design estimates, while LLA uses the later ASCE7-02 standard. See NCSTAR1-2A, page 72 (106 ordinal). Using the latter as more realistic, you and shagster agree quite well. I'm impressed.
Poster einsteen makes the important point that only the mass specific energy matters during crush-down. So knowing the actual mass at each elevation then enables one to determine the energy consumed at that level, due to crushing the materials. This is separate from the energy for comminution and pushing the air out of the way.
(I didn't understand your calculation of the BLGB preprint mass, but I'll have to get back to it later...)
QUOTE (Hambone+Sep 10 2007, 07:31 AM)
http://www.cool-places.0catch.com/docs/MassAndPeWtc1.pdf
See NCSTAR1-1 for discussions of building modifications which increased the weight. The only ones I know about were in WTC 2, but there might have been some in WTC 1 as well.
Your report will be better if you compare your masses to the loadings described in NCSTAR1-6 and NCSTAR1-6D for floors 105 and 93--98 (Table 9-7, NCSTAR1-6D, p. 176 (240 ordinal)).
You could even use the floor 105 (for adjustment) and the floors 78--83 data for WTC 2 in the following table.
See NCSTAR1-1 for discussions of building modifications which increased the weight. The only ones I know about were in WTC 2, but there might have been some in WTC 1 as well.
Your report will be better if you compare your masses to the loadings described in NCSTAR1-6 and NCSTAR1-6D for floors 105 and 93--98 (Table 9-7, NCSTAR1-6D, p. 176 (240 ordinal)).
You could even use the floor 105 (for adjustment) and the floors 78--83 data for WTC 2 in the following table.
QUOTE (Trippy+Sep 9 2007, 06:07 PM)
What was the height of the first tower to collapse? (in meters).
Greening gives the height (above ground level) of WTC 2 as 415 meters.
Why do you ask?
Greening gives the height (above ground level) of WTC 2 as 415 meters.
Why do you ask?
It is interesting to consider each WTC tower as a cantilever beam set in the ground. The fundamental frequency, omega, depends on the length, mass and flexural rigidity of the tower. In theory this presents a way to determine the mass of a tower...... in theory!
It turns out that there is very little published data on actual measurements of the drifts and accelerations of the upper sections of the WTC towers, even though good data of this type exist for the Empire State Building.
NIST do a nice job of extracting some vibrational data from the Moire patterns seen on a number of videos of the aircraft impacts on WTC 2. NIST use very low values for the mass of the tower in their analysis of the data.
I would say, using what other data are available, that the flexural rigidity of a tower, (EI), looks to be ~ 10^14 N.m^2.
It is very interesting that the aircraft impacts excited mainly the first AND SECOND MODES of vibration of the towers. I would expect this for an aircraft strike 3/4 of the way up the tower since this is also near the location of the maximum amplitude of the 2nd mode of vibration of the towers.
I wonder if this impact location was deliberately chosen by Osama for this reason...
P.S. The role of the viscoelastic dampers in all this remains very mysterious!
It turns out that there is very little published data on actual measurements of the drifts and accelerations of the upper sections of the WTC towers, even though good data of this type exist for the Empire State Building.
NIST do a nice job of extracting some vibrational data from the Moire patterns seen on a number of videos of the aircraft impacts on WTC 2. NIST use very low values for the mass of the tower in their analysis of the data.
I would say, using what other data are available, that the flexural rigidity of a tower, (EI), looks to be ~ 10^14 N.m^2.
It is very interesting that the aircraft impacts excited mainly the first AND SECOND MODES of vibration of the towers. I would expect this for an aircraft strike 3/4 of the way up the tower since this is also near the location of the maximum amplitude of the 2nd mode of vibration of the towers.
I wonder if this impact location was deliberately chosen by Osama for this reason...
P.S. The role of the viscoelastic dampers in all this remains very mysterious!
QUOTE (NEU-FONZE+Sep 10 2007, 05:03 PM)
NIST use very low values for the mass of the tower in their analysis of the data.
P.S. The role of the viscoelastic dampers in all this remains very mysterious!
Could you tell us the mass used?
Not at all, assuming these are designed as linear systems (dashpots). Then the vibrational modes of the towers would be essentially independent of the damping. All the dampers would do is cause the vibrations to damp down sooner than without them.
P.S. The role of the viscoelastic dampers in all this remains very mysterious!
Could you tell us the mass used?
Not at all, assuming these are designed as linear systems (dashpots). Then the vibrational modes of the towers would be essentially independent of the damping. All the dampers would do is cause the vibrations to damp down sooner than without them.
DBB/Hambone:
NIST NCSTAR 1-5D, page 43, gives 1.67 x 10^6 kg per floor = 183,700,000 kg for each tower.
And also see a value of 370 x 10^6 kg reported in a paper in J. Struct Eng.,
published in Jan 2005 by Y. Omika et al.
NIST NCSTAR 1-5D, page 43, gives 1.67 x 10^6 kg per floor = 183,700,000 kg for each tower.
And also see a value of 370 x 10^6 kg reported in a paper in J. Struct Eng.,
published in Jan 2005 by Y. Omika et al.
According to NIST NCSTAR 1-5A, the aircraft impact kinetic energy delivered to WTC 2 that was actually converted into energy of consolidated motion of the towers, (mostly as the first and second modes of vibration), accounts for only about 1 % of the impact KE of the aircraft. However, this result is NOT consistent with the velocities and accelerations of WTC 2 calculated in NIST NCSTAR 1-5D.
David B. Benson and all
This topic may help us to find a way to not let such loss be possible in the future.
May we also remember all the families who are today (9/11/07) still in pain.
QUOTE (rethinker+Sep 11 2007, 04:15 AM)
David B. Benson and all
This topic may help us to find a way to not let such loss be possible in the future.
May we also remember all the families who are today (9/11/07) still in pain.
...And may the organizers of 9-11 pay for the consequences of their actions..
This topic may help us to find a way to not let such loss be possible in the future.
May we also remember all the families who are today (9/11/07) still in pain.
...And may the organizers of 9-11 pay for the consequences of their actions..
QUOTE
...And may the organizers of 9-11 pay for the consequences of their actions..
That's what our troops are doing in Afghanistan.
QUOTE (wcelliott+Sep 11 2007, 08:12 AM)
That's what our troops are doing in Afghanistan.
Punishing the organizers of 9-11?
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