Einsteen:
Thanks for re-doing those plots.
However, Sugano and Omika's papers offer counter examples to your video analysis and provide data showing significant slowing of the tail sections of high-speed aircraft hitting "rigid" targets.
Are you saying a peer reviewed paper in an ASCE journal is incorrect?
Perhaps this is possible............
But on the topic of the F-4 crash test carried out at Sandia Laboratories in 1988, the paper I quote has EIGHT authors and contains a remarkable amount of data.
If your video analysis is correct, Figure 14 in Sugano's paper is incorrect and eight authors published a pile of crap back in 1993!
One "quick bitmap dump" by Einsteen and 5-year's work by an international team of scientists at Sandia Labs is debunked!
QUOTE (NEU-FONZE+Oct 13 2007, 05:41 PM)
One "quick bitmap dump" by Einsteen ...
It seems a powerful technique.
Maybe after poster OneWhiteEye has at it?
It seems a powerful technique.
Maybe after poster OneWhiteEye has at it?
The behavior of the Boeing 767 aircraft, designated as United Airlines Flight 175, that struck the south face of WTC 2 on the morning of September 11th, 2001, has been the subject of much debate and on-going controversy. In March 2007, Morgan Reynolds issued a letter to the National Institute of Standards and Technology (NIST) that included a Request for Correction (RFC) to the sections of the NIST Report on the World Trade Center (WTC) Disaster that purport to analyze the aircraft impacts on WTC 1 & 2. In particular Reynolds questions the validity of NIST’s conclusion that a Boeing 767 could penetrate into WTC 2, with little or no deceleration of its motion, as described by NIST on page 234 of NCSTAR 1-2B and on page 86 of NCSTAR 1-5A.
In April 2007 Gregory Jenkins published a critique of Reynold’s RFC in the Letters section of the Journal of 9/11 Studies. In his letter, Jenkins argues that the tail end of an aircraft impacting a rigid structure is quite capable of showing essentially no loss of velocity until the front section of the aircraft’s fuselage is crushed, concertina-like, against the rigid structure. Jenkins bases his argument on a video analysis of the well-known test carried out by Sandia in 1988, involving the high-speed collision of a F-4 Phantom jet and a massive concrete block. Jenkins’ video analysis shows that the tail end of the F-4 maintained a constant velocity until just before its destruction and he argues that the Boeing aircraft that hit WTC 2 would have shown essentially the same behavior. From this analysis, Jenkins concludes that there is no scientific basis for Reynold’s RFC to NIST.
I would argue that Jenkins’ analysis of the motion of the F-4 Phantom is not correct because the tail section of the F-4 in the Sandia test actually does show significant deceleration. Similarly, Reynold’s argument that the Boeing 767 showed no deceleration after striking WTC 2 is invalid based on video evidence (presented below) that shows Flight 175's velocity was significantly reduced during the initial stages of the impact.
In the context of the present discussion we need to consider a number of physical quantities related to the Boeing 767 aircraft that struck WTC 2 on 9/11. The aircraft in question was actually a Boeing 767-200ER with a fuselage that was 48.5 meters long and 5.4 meters in diameter at its widest cross section. NIST estimates that the mass of the aircraft, including the fuel it was carrying at the time of impact, was ~ 124,000 kg. There is some uncertainty in the impact velocity of Flight 175, (See the Table on page 173 of NCSTAR 1-2B for representative data), but NIST’s value of 242 m/s falls close to the average of impact velocities estimated by FEMA, MIT, and Hart-Weidlinger.
The length and speed of the aircraft may be used to calculate the parameter, Te, that is key to the following discussion. Te is the time, (after first contact of the nose of the aircraft with the face of WTC 2), for the full length of the aircraft to enter the tower assuming no deceleration occurred. The calculation of Te is straightforward because, to a very good approximation, Flight 175 was moving on a trajectory that was perpendicular to the south face of WTC 2. Thus, using time = distance/velocity, where the distance of interest is the length of the aircraft, we have Te = 48.5 (meters)/ 242 (meters per second) or Te = 0.2004 seconds which we can safely round off to 0.2 seconds.
This calculated value for Te is consistent with NIST’s Table 7.1 on page 86 of NCSTAR 1-5A that lists the time for the aircraft to completely disappear inside WTC 2 as 0.20 seconds. However, the fact that the NIST Report appears to be saying that the aircraft that struck WTC 2 penetrated all the way into the structure with no apparent resistance is problematical. Indeed, it is the main reason for Reynold’s assertion that NIST “violates scientific principles” because, as Reynold’s claims in his RFC, “a jetliner must decelerate at impact due to the laws of conservation of momentum and conservation of energy.” Now it is precisely the assertion that an aircraft must decelerate on impact that is challenged by Jenkins in his letter to the Journal of 9/11 Studies. Jenkins bases his challenge of Reynold’s RFC on a video analysis of a F-4 Phantom jet impacting a massive concrete structure. Therefore, before commenting on Jenkins’ analysis, we need to first look at the Sandia F-4 impact test in some detail.
In 1988, Sandia National Laboratories in Albuquerque, New Mexico, carried out a full-scale test of a high-speed military aircraft impacting a reinforced concrete target. The test results have been reported by T. Sugano et al. in Nuclear Engineering and Design 140, 373, (1993). Important details of the test derived from Sugano’s paper are as follows:
· The aircraft was a modified F-4 Phantom, mounted on a carriage running on 600 meter-long rails, driven by a pusher sled powered by a combination of Zuni and Nike rockets.
· The aircraft was 17.7 meters long, weighed 19,000 kg, and carried no fuel but included 4,800 kg of water that was added to simulate the fuel mass distribution.
· The aircraft was fitted with ten accelerometers along the length of its fuselage, and a telemetry package that allowed deceleration data to be transmitted to a receiving station.
· The target was a block of reinforced concrete, 7 meters square and 3.7 meters thick, weighing 469 tonnes.
· The target was mounted on ten air bearings that allowed for about 0.5 meters of horizontal recoil motion.
The measured impact velocity of the F-4 was 215 m/s and the aircraft was totally crushed in less than 0.1 seconds. The reinforced concrete target experienced a slight rocking motion during impact but overall was accelerated to a relatively constant recoil velocity of 8 m/s within about 0.08 seconds.
The most interesting data recorded during the F-4 impact test were the decelerations of the aircraft. Representative measurements are plotted in Figure 14 of Sugano’s Nuclear Engineering and Design report. These data show, for example, that decelerations were detectable after the first 6 meters of the fuselage had been crushed. Focusing on the tail section of the F-4, we have the following velocity reductions reported by Sugano et al.:
Time After First Contact / Measured Velocity / Percent Velocity Reduction
Units: (Seconds) / (m/s) / (%)
0.03; 213; 1.0;
0.04; 205; 4.7;
0.05; 196; 8.8;
0.06; 192; 10.7;
0.07; 179; 16.7;
These data are NOT consistent with Jenkins’ video analysis of the F-4 impact as summarized in an Appendix to his letter to the Journal of 9/11 Studies. Thus Jenkins claims that NO reduction in the velocity of the tail section of the aircraft was measurable, (to within an error of 3 %), during the crushing of the front 14.2 meters of fuselage, or 80 % of the total length of the aircraft. By comparison, Sugano’s data show a 16.7 % velocity reduction after 0.07 seconds, which would be approximately equivalent to Jenkins’ 80 % crushing of the aircraft.
The reason for the discrepancy between Sugano’s data and Jenkins’ measurements is not immediately apparent. However, one point concerning the two sets of measurements is obviously key, namely that Sugano et al. used accelerometers to measure velocity changes along the length of the aircraft’s fuselage while Jenkins used displacements of the image of the aircraft relative to a fixed vertical overlay. Interestingly, Sugano et al. also mention the use of high-speed cameras to measure the velocity reduction of the aircraft and include a curve labeled “High-Seed Film” in Figure 14 of their report. Compared to the accelerometer data given above for the tail section of the aircraft, the “High-Speed Film” curve shows more velocity reduction in the time interval up to 0.03 seconds and less reduction in the interval 0.03 to 0.07 seconds. Nevertheless, the velocity reduction of the aircraft after 0.07 seconds derived from Sugano’s photographic measurements is about 12 %, not 0 % as claimed by Jenkins.
We now return to the question of the velocity reduction of the Boeing 767-200ER that struck WTC 2 on 9/11..... Reynolds’ and Jenkins agree that little to no reduction in the velocity of the aircraft was observed during the first 0.2 seconds of impact, the time required for an unimpeded aircraft to “disappear” into the tower. Reynold’s asserts that this is physically impossible while Jenkins argues it is “not unexpected”; a conclusion based on Jenkins' video analysis of a F-4 Phantom subject to hard impact. However, given that that Jenkins’ method of motion analysis is not supported by more precise measurements, it would be prudent to look more closely at Jenkins’ claim that there was no observable reduction in the velocity of the aircraft that struck WTC 2.
A cursory survey of available information on the impact of Flight 175 on WTC 2 shows at least two instances of measurable velocity reductions: one derived from the Evan Fairbanks video footage, and the other based on a video analysis reported by Y. Omika et al. in the January 2005 issue of the Journal of Structural Engineering. Thus the Evan Fairbanks video, when viewed as still frames ~ 0.03 seconds apart, shows a measurable velocity reduction of the tail end of the aircraft, (of about 5 m/s), when the nose of the 767 had penetrated about 16 meters into WTC 2. This increases to a velocity reduction of about 30 m/s, or 12 % of the initial impact velocity, approximately 0.15 seconds into the impact. By comparison, Omika et al. use the analysis of an unnamed video to estimate a 50 m/s velocity reduction of the aircraft after 0.15 seconds, increasing to a 100 m/s reduction after 0.2 seconds.
While it is clear that significant velocity reductions are discernable from careful measurements of appropriate videos showing the impact of Flight 175 on WTC 2, NIST remain strangely silent on this topic. However, as previously discussed, NIST certainly imply in NCSTAR 1-2B and NCSTAR 1-5A that Flight 175 entered WTC 2 with little or no deceleration of its motion. NIST do, in fact, present calculated momentum vs. time plots for the aircraft impact on WTC 2 on page 224 of NCSTAR 1-2, but fail to compare this theoretical result with observational data. This omission is regrettable because NIST show elsewhere that it’s not averse to analyzing videos to obtain aircraft velocity data. Thus on page 99 of NCSTAR 1-5A NIST presents an analysis of a video by Scott Myers showing Flight 175 approaching WTC 2. NIST’s analysis of this video has been quoted by some researchers as evidence for the proposal that the aircraft did not slow down on impact with WTC 2. However, this is not valid because the sequence of frames used by NIST in NCSTAR 1-5A covers a time interval just before the aircraft struck the tower.
In conclusion, and to summarize, the proposal that Flight 175 did not slow down on impact with WTC 2 is simply incorrect. I would support this conclusion with two sets of data showing velocity reductions by Flight 175 as it entered WTC 2. In addition, Gregory Jenkins’ video analysis of the impact of a F-4 Phantom jet on a massive concrete block is not consistent with published data from Sandia Laboratories. These data include accelerometer measurements which show significant slowing of the tail section of the F-4 jet during the first 100 msec of the impact.
In April 2007 Gregory Jenkins published a critique of Reynold’s RFC in the Letters section of the Journal of 9/11 Studies. In his letter, Jenkins argues that the tail end of an aircraft impacting a rigid structure is quite capable of showing essentially no loss of velocity until the front section of the aircraft’s fuselage is crushed, concertina-like, against the rigid structure. Jenkins bases his argument on a video analysis of the well-known test carried out by Sandia in 1988, involving the high-speed collision of a F-4 Phantom jet and a massive concrete block. Jenkins’ video analysis shows that the tail end of the F-4 maintained a constant velocity until just before its destruction and he argues that the Boeing aircraft that hit WTC 2 would have shown essentially the same behavior. From this analysis, Jenkins concludes that there is no scientific basis for Reynold’s RFC to NIST.
I would argue that Jenkins’ analysis of the motion of the F-4 Phantom is not correct because the tail section of the F-4 in the Sandia test actually does show significant deceleration. Similarly, Reynold’s argument that the Boeing 767 showed no deceleration after striking WTC 2 is invalid based on video evidence (presented below) that shows Flight 175's velocity was significantly reduced during the initial stages of the impact.
In the context of the present discussion we need to consider a number of physical quantities related to the Boeing 767 aircraft that struck WTC 2 on 9/11. The aircraft in question was actually a Boeing 767-200ER with a fuselage that was 48.5 meters long and 5.4 meters in diameter at its widest cross section. NIST estimates that the mass of the aircraft, including the fuel it was carrying at the time of impact, was ~ 124,000 kg. There is some uncertainty in the impact velocity of Flight 175, (See the Table on page 173 of NCSTAR 1-2B for representative data), but NIST’s value of 242 m/s falls close to the average of impact velocities estimated by FEMA, MIT, and Hart-Weidlinger.
The length and speed of the aircraft may be used to calculate the parameter, Te, that is key to the following discussion. Te is the time, (after first contact of the nose of the aircraft with the face of WTC 2), for the full length of the aircraft to enter the tower assuming no deceleration occurred. The calculation of Te is straightforward because, to a very good approximation, Flight 175 was moving on a trajectory that was perpendicular to the south face of WTC 2. Thus, using time = distance/velocity, where the distance of interest is the length of the aircraft, we have Te = 48.5 (meters)/ 242 (meters per second) or Te = 0.2004 seconds which we can safely round off to 0.2 seconds.
This calculated value for Te is consistent with NIST’s Table 7.1 on page 86 of NCSTAR 1-5A that lists the time for the aircraft to completely disappear inside WTC 2 as 0.20 seconds. However, the fact that the NIST Report appears to be saying that the aircraft that struck WTC 2 penetrated all the way into the structure with no apparent resistance is problematical. Indeed, it is the main reason for Reynold’s assertion that NIST “violates scientific principles” because, as Reynold’s claims in his RFC, “a jetliner must decelerate at impact due to the laws of conservation of momentum and conservation of energy.” Now it is precisely the assertion that an aircraft must decelerate on impact that is challenged by Jenkins in his letter to the Journal of 9/11 Studies. Jenkins bases his challenge of Reynold’s RFC on a video analysis of a F-4 Phantom jet impacting a massive concrete structure. Therefore, before commenting on Jenkins’ analysis, we need to first look at the Sandia F-4 impact test in some detail.
In 1988, Sandia National Laboratories in Albuquerque, New Mexico, carried out a full-scale test of a high-speed military aircraft impacting a reinforced concrete target. The test results have been reported by T. Sugano et al. in Nuclear Engineering and Design 140, 373, (1993). Important details of the test derived from Sugano’s paper are as follows:
· The aircraft was a modified F-4 Phantom, mounted on a carriage running on 600 meter-long rails, driven by a pusher sled powered by a combination of Zuni and Nike rockets.
· The aircraft was 17.7 meters long, weighed 19,000 kg, and carried no fuel but included 4,800 kg of water that was added to simulate the fuel mass distribution.
· The aircraft was fitted with ten accelerometers along the length of its fuselage, and a telemetry package that allowed deceleration data to be transmitted to a receiving station.
· The target was a block of reinforced concrete, 7 meters square and 3.7 meters thick, weighing 469 tonnes.
· The target was mounted on ten air bearings that allowed for about 0.5 meters of horizontal recoil motion.
The measured impact velocity of the F-4 was 215 m/s and the aircraft was totally crushed in less than 0.1 seconds. The reinforced concrete target experienced a slight rocking motion during impact but overall was accelerated to a relatively constant recoil velocity of 8 m/s within about 0.08 seconds.
The most interesting data recorded during the F-4 impact test were the decelerations of the aircraft. Representative measurements are plotted in Figure 14 of Sugano’s Nuclear Engineering and Design report. These data show, for example, that decelerations were detectable after the first 6 meters of the fuselage had been crushed. Focusing on the tail section of the F-4, we have the following velocity reductions reported by Sugano et al.:
Time After First Contact / Measured Velocity / Percent Velocity Reduction
Units: (Seconds) / (m/s) / (%)
0.03; 213; 1.0;
0.04; 205; 4.7;
0.05; 196; 8.8;
0.06; 192; 10.7;
0.07; 179; 16.7;
These data are NOT consistent with Jenkins’ video analysis of the F-4 impact as summarized in an Appendix to his letter to the Journal of 9/11 Studies. Thus Jenkins claims that NO reduction in the velocity of the tail section of the aircraft was measurable, (to within an error of 3 %), during the crushing of the front 14.2 meters of fuselage, or 80 % of the total length of the aircraft. By comparison, Sugano’s data show a 16.7 % velocity reduction after 0.07 seconds, which would be approximately equivalent to Jenkins’ 80 % crushing of the aircraft.
The reason for the discrepancy between Sugano’s data and Jenkins’ measurements is not immediately apparent. However, one point concerning the two sets of measurements is obviously key, namely that Sugano et al. used accelerometers to measure velocity changes along the length of the aircraft’s fuselage while Jenkins used displacements of the image of the aircraft relative to a fixed vertical overlay. Interestingly, Sugano et al. also mention the use of high-speed cameras to measure the velocity reduction of the aircraft and include a curve labeled “High-Seed Film” in Figure 14 of their report. Compared to the accelerometer data given above for the tail section of the aircraft, the “High-Speed Film” curve shows more velocity reduction in the time interval up to 0.03 seconds and less reduction in the interval 0.03 to 0.07 seconds. Nevertheless, the velocity reduction of the aircraft after 0.07 seconds derived from Sugano’s photographic measurements is about 12 %, not 0 % as claimed by Jenkins.
We now return to the question of the velocity reduction of the Boeing 767-200ER that struck WTC 2 on 9/11..... Reynolds’ and Jenkins agree that little to no reduction in the velocity of the aircraft was observed during the first 0.2 seconds of impact, the time required for an unimpeded aircraft to “disappear” into the tower. Reynold’s asserts that this is physically impossible while Jenkins argues it is “not unexpected”; a conclusion based on Jenkins' video analysis of a F-4 Phantom subject to hard impact. However, given that that Jenkins’ method of motion analysis is not supported by more precise measurements, it would be prudent to look more closely at Jenkins’ claim that there was no observable reduction in the velocity of the aircraft that struck WTC 2.
A cursory survey of available information on the impact of Flight 175 on WTC 2 shows at least two instances of measurable velocity reductions: one derived from the Evan Fairbanks video footage, and the other based on a video analysis reported by Y. Omika et al. in the January 2005 issue of the Journal of Structural Engineering. Thus the Evan Fairbanks video, when viewed as still frames ~ 0.03 seconds apart, shows a measurable velocity reduction of the tail end of the aircraft, (of about 5 m/s), when the nose of the 767 had penetrated about 16 meters into WTC 2. This increases to a velocity reduction of about 30 m/s, or 12 % of the initial impact velocity, approximately 0.15 seconds into the impact. By comparison, Omika et al. use the analysis of an unnamed video to estimate a 50 m/s velocity reduction of the aircraft after 0.15 seconds, increasing to a 100 m/s reduction after 0.2 seconds.
While it is clear that significant velocity reductions are discernable from careful measurements of appropriate videos showing the impact of Flight 175 on WTC 2, NIST remain strangely silent on this topic. However, as previously discussed, NIST certainly imply in NCSTAR 1-2B and NCSTAR 1-5A that Flight 175 entered WTC 2 with little or no deceleration of its motion. NIST do, in fact, present calculated momentum vs. time plots for the aircraft impact on WTC 2 on page 224 of NCSTAR 1-2, but fail to compare this theoretical result with observational data. This omission is regrettable because NIST show elsewhere that it’s not averse to analyzing videos to obtain aircraft velocity data. Thus on page 99 of NCSTAR 1-5A NIST presents an analysis of a video by Scott Myers showing Flight 175 approaching WTC 2. NIST’s analysis of this video has been quoted by some researchers as evidence for the proposal that the aircraft did not slow down on impact with WTC 2. However, this is not valid because the sequence of frames used by NIST in NCSTAR 1-5A covers a time interval just before the aircraft struck the tower.
In conclusion, and to summarize, the proposal that Flight 175 did not slow down on impact with WTC 2 is simply incorrect. I would support this conclusion with two sets of data showing velocity reductions by Flight 175 as it entered WTC 2. In addition, Gregory Jenkins’ video analysis of the impact of a F-4 Phantom jet on a massive concrete block is not consistent with published data from Sandia Laboratories. These data include accelerometer measurements which show significant slowing of the tail section of the F-4 jet during the first 100 msec of the impact.
QUOTE (NEU-FONZE+Oct 14 2007, 12:41 AM)
Are you saying a peer reviewed paper in an ASCE journal is incorrect?is debunked!
Certainly not.. I would be an arrogant piece of .... if I think I am right and the rest of the world is wrong, but I'm wondering what is wrong then with the extraction method ? I really didn't manually move >200 bitmaps in order to get a straight line and to me it looks linear. It would also be strange to say it is not linear because some authority says it is linear. Personally I have no access to papers and I assume the one you mean is not online, would like to know their method then...
But assume it is not linear and the ones crashing into the twin towers are, what is the conclusion then ?
It is again too late...internet has changed man's life, glad I have some days off
Certainly not.. I would be an arrogant piece of .... if I think I am right and the rest of the world is wrong, but I'm wondering what is wrong then with the extraction method ? I really didn't manually move >200 bitmaps in order to get a straight line and to me it looks linear. It would also be strange to say it is not linear because some authority says it is linear. Personally I have no access to papers and I assume the one you mean is not online, would like to know their method then...
But assume it is not linear and the ones crashing into the twin towers are, what is the conclusion then ?
It is again too late...internet has changed man's life, glad I have some days off
I'm having trouble getting too worked up over the issue, one way or the other.
The deceleration of the tail section would've been a matter of how much force was carried by the airframe from the impact zone (nose) to the tail, and a commercial jet isn't designed to be more rigid in that axis than is necessary. It was never designed as a "bunker-buster", it's just a tube full of people, the skin's there to keep the air in and the wind out of their hair.
The main component of deceleration would be at the point of contact, and only then up to the point where the impacted structure itself disintegrated. Once the nose hit the perimeter column and snapped it, the nose got decelerated significantly and the section of the perimeter column in its way got accelerated, but the tail wouldn't have seen much deceleration from that impact, as it wasn't the strength of the airframe that shattered the perimeter column but the momentum of the part of the nose that slammed into it.
This is the sort of physics that boxers understand better than physicists do. It's the difference between a punch that has your whole body behind it versus a slap.
Incidentally, an F-4 versus a commercial aircraft is an apples&oranges comparison. The F-4 was designed for supersonic travel and for carrying munitions. It was a very solid piece of machinery. Commercial jets are very flimsy in comparison, mostly air and styrofoam.
The deceleration of the tail section would've been a matter of how much force was carried by the airframe from the impact zone (nose) to the tail, and a commercial jet isn't designed to be more rigid in that axis than is necessary. It was never designed as a "bunker-buster", it's just a tube full of people, the skin's there to keep the air in and the wind out of their hair.
The main component of deceleration would be at the point of contact, and only then up to the point where the impacted structure itself disintegrated. Once the nose hit the perimeter column and snapped it, the nose got decelerated significantly and the section of the perimeter column in its way got accelerated, but the tail wouldn't have seen much deceleration from that impact, as it wasn't the strength of the airframe that shattered the perimeter column but the momentum of the part of the nose that slammed into it.
This is the sort of physics that boxers understand better than physicists do. It's the difference between a punch that has your whole body behind it versus a slap.
Incidentally, an F-4 versus a commercial aircraft is an apples&oranges comparison. The F-4 was designed for supersonic travel and for carrying munitions. It was a very solid piece of machinery. Commercial jets are very flimsy in comparison, mostly air and styrofoam.
QUOTE (wcelliott+Oct 13 2007, 06:36 PM)
I'm having trouble getting too worked up over the issue, one way or the other.
The F-4 was designed for supersonic travel and for carrying munitions.
Me too, except for the concern about the data extraction method.
Not to mention as high G turns as the pilot can stand.
The F-4 was designed for supersonic travel and for carrying munitions.
Me too, except for the concern about the data extraction method.
Not to mention as high G turns as the pilot can stand.
QUOTE
Not to mention as high G turns as the pilot can stand.
Indeed, I should've mentioned it.
The BV crush-down equation is better than the modified Beck crush-down equation in explaining the drop data by a measly 3.9 decibans. According to Sir Harold, that is barely worth mentioning.
Before getting too worked up about this, I'll have to be rerun using the more substantial new data sets. That will require a completely new program (although I can salvage some portions of the existing one). Patience.
Before getting too worked up about this, I'll have to be rerun using the more substantial new data sets. That will require a completely new program (although I can salvage some portions of the existing one). Patience.
QUOTE (einsteen+Oct 14 2007, 01:31 AM)
Certainly not.. I would be an arrogant piece of .... if I think I am right and the rest of the world is wrong, but I'm wondering what is wrong then with the extraction method ?
Feel a little like Danny Jowenko?
"Of course that's a CD, what do you take me for? But, no, of course it isn't. It's impossible, are you crazy?"
hahaaha, just giving you a little levity.
Fascinating stuff. I gather the controversy revolves around whether or not the tail section of a jet experiences any force at all while the front end is getting plowed like I will be doing later on tonight. Don't know anything about that, but it sure seems like it would.
There is nothing wrong with the extraction technique. At a glance, I see what einsteen has done and it is fine. I blew up the picture he posted, drew my own line, came to the same conclusion.
I'll run my own extractions when I can and see if I still come to the same conclusion but it's hard to imagine it turning out any differently. Have to run right now because I have a Halloween party to go to, and a reputation of scandalous behavior to uphold.
PS. Before I got to NEU-FONZE's post, words like accelerometer and high-speed camera were popping in to my head. Can't say I've been involved in a test like this before (jealous) but I've done things involving high speed cameras and instrumentation like accelerometers, strain gages, load cells, thermocouples, and all those gross engineering-thingy things.
They work pretty well, too. So I don't know what to say, except I'll take a real look when I get back and dry out awhile.
Feel a little like Danny Jowenko?
"Of course that's a CD, what do you take me for? But, no, of course it isn't. It's impossible, are you crazy?"
hahaaha, just giving you a little levity.
Fascinating stuff. I gather the controversy revolves around whether or not the tail section of a jet experiences any force at all while the front end is getting plowed like I will be doing later on tonight. Don't know anything about that, but it sure seems like it would.
There is nothing wrong with the extraction technique. At a glance, I see what einsteen has done and it is fine. I blew up the picture he posted, drew my own line, came to the same conclusion.
I'll run my own extractions when I can and see if I still come to the same conclusion but it's hard to imagine it turning out any differently. Have to run right now because I have a Halloween party to go to, and a reputation of scandalous behavior to uphold.
PS. Before I got to NEU-FONZE's post, words like accelerometer and high-speed camera were popping in to my head. Can't say I've been involved in a test like this before (jealous) but I've done things involving high speed cameras and instrumentation like accelerometers, strain gages, load cells, thermocouples, and all those gross engineering-thingy things.
They work pretty well, too. So I don't know what to say, except I'll take a real look when I get back and dry out awhile.
QUOTE
the controversy revolves around whether or not the tail section of a jet experiences any force at all while the front end is getting plowed
From what I can tell, it's more an issue of whether someone feels a few percent of deceleration is worth discussing when the velocity itself isn't known to higher accuracy than that.
The tail section would've slowed down, but not by much. Commercial aircraft fuselages aren't that strong, and the force needed to decelerate the tail section significantly would be much higher than a crushing aluminum tube could sustain.
Also, how much resistance would you expect severed-columns to offer? The aircraft made a cookie-cutter imprint of itself in the perimeter wall. Once the hole was made, the rest of the aircraft was simply passing through the hole.
The parts of the aircraft that made the cookie-cutter hole were slowed significantly, but they weren't strongly-coupled to the rest of the airframe.
Arthur:
Misrepresentation.
Misrepresentation.
ROTFLMAO
QUOTE
That's it????
You think you've put together a CONCLUSIVE LIST that proves demolition????
You think you've put together a CONCLUSIVE LIST that proves demolition????
Misrepresentation.
QUOTE (->
| QUOTE |
| That's it???? You think you've put together a CONCLUSIVE LIST that proves demolition???? |
Misrepresentation.
ROTFLMAO
Appeal to ridicule #1.
That's it???? Your entire post consisted of nothing more than ad hominem insults and another intentional misrepresentation.
Shame on you.
wcelliot:
I suggest you do further studying, yourself.
Look up two terms:
1) Clipping
2) Undersampling
In order to capture a waveform, you need to have sufficient dynamic range to capture the peak amplitude of the signal within the system's dynamic range. Failure results in the top of the signal getting "clipped". Explosions exceed the amplitude of any acoustic system capable of capturing quiet sounds, as they generate overpressures capable of ripping steel apart. That means that the peak of the signal is too big for your digitizer to capture, so it "max's out" at the MaxVal of your system.
In order to capture the "complex waveform" associated with a sound, you need to have a sufficient sampling rate to capture all the significant features of that waveform. Explosives detonate at very high speeds. A four-inch brick of C-4 detonates in 10 microseconds. A 40kHz audio sampling rate means that each sample represents 25 microseconds. That's just simple math. That means, at best, your digital recording of an explosion contains precisely **ONE** sample during which time the C-4 changes from solid to a ball of hot gas expanding in all directions. That "________|__________" waveform is accurate. It represents the silence preceeding the detonation, one sample representing the MaxVal (clipped) response of your recorder, and the dead silence following the passing of the shock wave past your microphone.
Incidentally, that function is well-known in Communications and Signal theory as a "unit impulse". Take the Fourier Transform of that unit impulse, and you get a flat response in the frequency-domain that's identical to white noise's spectrum.
You say it's physically-unrealizable, which is true, but so is white noise of infinite bandwidth. So all the "white noise" that you've ever encountered was bandwidth-limited white noise, and likewise, the unit impulse is the mathematical ideal that's approximated by a single non-zero sample in an otherwise zero-populated sound file. "0, 0, 0, 0, MaxVal, 0, 0, 0, 0" is the same as the closest you can get to
_______|_________. That's what you get when you record the detonation of a 4-inch brick of C-4, dead-silence, one MaxVal sample, dead silence.
Anything else, any "complex waveform", and that's just the artifacts of the environment, the echo of the "____|____" bouncing around off the walls, ceilings, etc., all superimposed. Change the environment, and you'll get a different waveform.
Incidentally, my undergrad was in EE - Signals and Systems emphasis, and my Masters was in Electrical and Computer Engineering - Signals and Sensors emphasis. I understand that you're very proud of your sound system, but when I was working on my Masters, I also designed an acoustic phased-array aperture, including designing a digital signal processor from discrete components. If you don't know what that is, just ask, I'll explain it to you.
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
As if that's not enough, all of the matter that the explosion front is plowing through has to have some effect on the shape of the waveform (not just it's intensity).
In fact, if it weren't for all the intervening and reflecting surfaces, the explosion would be completely featureless, acoustically. All of the "complex waveform" coming from an explosion is precisely and only that, the reflections off the environment of that initial 10microsecond pulse. That makes a recording from inside a structure 100% artifact, the sound of the initial detonation isn't present (due to undersampling and clipping) and the whole of the recording is just the reflections superimposed upon one another.
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
I agree with you on that . But it meant the fires were going to keep spreading until an enormous inferno , or it was going to collapse outside its footprint . Both options are disasters by its self. So when you are able to find a demolition team that wants to do the job because you also pay them very well than that's the smartest thing to do . A controlled collapse prevents other still in tact buildings from being destroyed, and makes the fire a lot easier to fight.
How far away were other in tact buildings from WTC 7, I wonder, about 50 meters ?
The towers' perimeter columns offered resistance only momentarily. As soon as the aircraft hit, the columns broke immediately, and offered no further resistance. The momentum of the aircraft parts caused the damage, but those parts weren't stongly-coupled to the airframe. They weren't *driven* through the columns by the structural rigidity of the airframe, so the force wasn't directed back into the airframe's structure (which would've slowed the airframe).
The aircraft wasn't built to be a "bunker-buster", so what forces there were at-impact simply broke the mounts to those parts with minimal transfer of those forces to the airframe, decoupling the parts that had smashed through the perimeter columns with their own momentum.
It's a mistake to think of the aircraft as having one velocity, and that measured (?) velocity of the aircraft's tail was some indicator of the velocity of the whole aircraft. You'd have to redefine what was meant by "average velocity", as the parts that actually did the damage to the perimeter columns decelerated significantly more than the airframe.
NIST: "We are Unable to Provide a Full Explanation of the Total Collapse"
On April 11th, 2007, family members Bill Doyle and Bob McIlvaine, scientists Steven Jones and Kevin Ryan, architect Richard Gage and the group Scholars for 9/11 Truth and Justice filed a petition with NIST demanding that it correct its erroneous methods and findings.
On September 27th, NIST finally replied.
While the reply is mainly bogus, and the filers of the petition intend to appeal the decision of NIST not to correct the many fatal errors in its reports, attorney James Gourley (who drafted the petition) has pointed out one interesting statement. Specifically, NIST says in its reply:
"We are unable to provide a full explanation of the total collapse".
...
georgewashington.blogspot.com/
Finaly officially admited. NIST "unable to provide a full explanation of the total collapse" unless it stops covering up the evidence that the Twin Towers and were brought down with explosives.
You realize that "0.2 seconds" isn't exactly the same thing as "0.200 seconds", right? It could as easily mean "0.249 seconds", or "0.151 seconds".
Most of the deceleration occurred *at* the perimeter wall, by the stuff that was colliding with it directly.
The force available to decelerate the plane was limited by how much force could be coupled to the airframe. That's probably not as much as you'd think. Most of the stuff impacting the WTC simply would've sheared from the airframe due to the impact.
Incidentally, the way to interpret that 0.2seconds for the plane to enter the tower and 0.2seconds for it to decelerate by 60% is to recognize that it did all its deceleration at the perimeter wall and inside the tower. The stuff outside didn't decelerate enough to measure, for the reasons cited.
QUOTE
(Oh, and Al, I particularly liked your including the Silverstein "Pull it" reference. although it typically is only employed by those with IQs significantly < normal, )
Appeal to ridicule #2.That's it???? Your entire post consisted of nothing more than ad hominem insults and another intentional misrepresentation.
Shame on you.
wcelliot:
QUOTE (->
| QUOTE |
| (Oh, and Al, I particularly liked your including the Silverstein "Pull it" reference. although it typically is only employed by those with IQs significantly < normal, ) |
Appeal to ridicule #2.
That's it???? Your entire post consisted of nothing more than ad hominem insults and another intentional misrepresentation.
Shame on you.
wcelliot: Did you know that that "_________|_________" waveform I suggested you synthesize and play on your expensive sound system also has the same spectrum as white noise?
It is not a waveform, it is an impossible quantum leap from rarifaction to compression and back to rarifaction in an instant.
I suggest you "bone up" on acoustics. Get yourself a copy of the Yamaha Sound Reinforcement Handbook.
repeat of some burning questions:
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
That's it???? Your entire post consisted of nothing more than ad hominem insults and another intentional misrepresentation.
Shame on you.
wcelliot: Did you know that that "_________|_________" waveform I suggested you synthesize and play on your expensive sound system also has the same spectrum as white noise?
It is not a waveform, it is an impossible quantum leap from rarifaction to compression and back to rarifaction in an instant.
I suggest you "bone up" on acoustics. Get yourself a copy of the Yamaha Sound Reinforcement Handbook.
repeat of some burning questions:
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
QUOTE (Al Khwarizmi - step-by-step+Oct 14 2007, 05:58 PM)
repeat of some burning questions:
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
There's no evidence of Thermate in thatimage.
Look closely at it.
Look closely at the mulitude of images showing thermate in use on the internet.
I'm sure you'll be able to see the difference.
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
There's no evidence of Thermate in thatimage.
Look closely at it.
Look closely at the mulitude of images showing thermate in use on the internet.
I'm sure you'll be able to see the difference.
QUOTE
wcelliot:
QUOTE
Did you know that that "_________|_________" waveform I suggested you synthesize and play on your expensive sound system also has the same spectrum as white noise?
It is not a waveform, it is an impossible quantum leap from rarifaction to compression and back to rarifaction in an instant.
QUOTE
Did you know that that "_________|_________" waveform I suggested you synthesize and play on your expensive sound system also has the same spectrum as white noise?
It is not a waveform, it is an impossible quantum leap from rarifaction to compression and back to rarifaction in an instant.
I suggest you do further studying, yourself.
Look up two terms:
1) Clipping
2) Undersampling
In order to capture a waveform, you need to have sufficient dynamic range to capture the peak amplitude of the signal within the system's dynamic range. Failure results in the top of the signal getting "clipped". Explosions exceed the amplitude of any acoustic system capable of capturing quiet sounds, as they generate overpressures capable of ripping steel apart. That means that the peak of the signal is too big for your digitizer to capture, so it "max's out" at the MaxVal of your system.
In order to capture the "complex waveform" associated with a sound, you need to have a sufficient sampling rate to capture all the significant features of that waveform. Explosives detonate at very high speeds. A four-inch brick of C-4 detonates in 10 microseconds. A 40kHz audio sampling rate means that each sample represents 25 microseconds. That's just simple math. That means, at best, your digital recording of an explosion contains precisely **ONE** sample during which time the C-4 changes from solid to a ball of hot gas expanding in all directions. That "________|__________" waveform is accurate. It represents the silence preceeding the detonation, one sample representing the MaxVal (clipped) response of your recorder, and the dead silence following the passing of the shock wave past your microphone.
Incidentally, that function is well-known in Communications and Signal theory as a "unit impulse". Take the Fourier Transform of that unit impulse, and you get a flat response in the frequency-domain that's identical to white noise's spectrum.
You say it's physically-unrealizable, which is true, but so is white noise of infinite bandwidth. So all the "white noise" that you've ever encountered was bandwidth-limited white noise, and likewise, the unit impulse is the mathematical ideal that's approximated by a single non-zero sample in an otherwise zero-populated sound file. "0, 0, 0, 0, MaxVal, 0, 0, 0, 0" is the same as the closest you can get to
_______|_________. That's what you get when you record the detonation of a 4-inch brick of C-4, dead-silence, one MaxVal sample, dead silence.
Anything else, any "complex waveform", and that's just the artifacts of the environment, the echo of the "____|____" bouncing around off the walls, ceilings, etc., all superimposed. Change the environment, and you'll get a different waveform.
Incidentally, my undergrad was in EE - Signals and Systems emphasis, and my Masters was in Electrical and Computer Engineering - Signals and Sensors emphasis. I understand that you're very proud of your sound system, but when I was working on my Masters, I also designed an acoustic phased-array aperture, including designing a digital signal processor from discrete components. If you don't know what that is, just ask, I'll explain it to you.
Just for Al's benefit.
Further to what WCElliot is saying.
Here's some real wave form data from some real explosions:
Image 1 Image 2
Notice the N shape - the N shape occurs because with (most) explosions you have a sudden expansion, followed by a sudden rarefaction.
Pay real close attention, and then bare in mind that any situation which produces a sudden compression is going produce a wave form similar to this.
Or do you honestly believe that Sonic booms are called sonic booms because explsives are involved.
Further to what WCElliot is saying.
Here's some real wave form data from some real explosions:
Image 1 Image 2
Notice the N shape - the N shape occurs because with (most) explosions you have a sudden expansion, followed by a sudden rarefaction.
Pay real close attention, and then bare in mind that any situation which produces a sudden compression is going produce a wave form similar to this.
Or do you honestly believe that Sonic booms are called sonic booms because explsives are involved.
QUOTE (adoucette+Oct 10 2007, 01:43 PM)
But you believe that:
A) People who work for a demolition company would WILLINGLY go into a DAMAGED BURNING UNSTABLE Building, over and over again, carrying det cord and placing high explosives?????
B ) After doing what would be clearly a very HEROIC ACT for the City of NY by people from a PRIVATE COMPANY, they would then participate with the City, the NYPD, the BATF and the FDNY to COVER UP ALL EVIDENCE that they had acted heroicly?
C ) Keep the fact that the City/NYFD/FDNY had placed explosives and blown up WTC 7 hidden from both FEMA and NIST and allow them to spend MILLIONS of dollars trying to figure out how the WTC 7 tower collapsed
Arthur
A) in the first hours after the collapses of the towers there wasn't very much fire in WTC 7 ,certainly not in the basement or on the first few floors.
everything about 9/11 was revealed right away ? Lots of money was involved,who was going to pay the price for the destruction of WTC 7 ?
C) And investigation was going to be there anyway.
"lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it "
Looking at the damage it was very likely the building would fall like a tree or certainly not fall within its own footprint .
A) People who work for a demolition company would WILLINGLY go into a DAMAGED BURNING UNSTABLE Building, over and over again, carrying det cord and placing high explosives?????
B ) After doing what would be clearly a very HEROIC ACT for the City of NY by people from a PRIVATE COMPANY, they would then participate with the City, the NYPD, the BATF and the FDNY to COVER UP ALL EVIDENCE that they had acted heroicly?
C ) Keep the fact that the City/NYFD/FDNY had placed explosives and blown up WTC 7 hidden from both FEMA and NIST and allow them to spend MILLIONS of dollars trying to figure out how the WTC 7 tower collapsed
Arthur
A) in the first hours after the collapses of the towers there wasn't very much fire in WTC 7 ,certainly not in the basement or on the first few floors.
everything about 9/11 was revealed right away ? Lots of money was involved,who was going to pay the price for the destruction of WTC 7 ? C) And investigation was going to be there anyway.
"lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it "
Looking at the damage it was very likely the building would fall like a tree or certainly not fall within its own footprint .
QUOTE (Trippy+Oct 14 2007, 09:43 AM)
Just for Al's benefit.
Further to what WCElliot is saying.
Here's some real wave form data from some real explosions:
Image 1 Image 2
Notice the N shape - the N shape occurs because with (most) explosions you have a sudden expansion, followed by a sudden rarefaction.
Pay real close attention, and then bare in mind that any situation which produces a sudden compression is going produce a wave form similar to this.
Or do you honestly believe that Sonic booms are called sonic booms because explsives are involved.
Can you show us waveforms corresponding to explosions emanating from within an enclosed area? And furthermore, explosions which pulverize wallboard, concrete, etc., as they expand from within their enclosed space?
If you take a 5 lb. bag of sugar and smack it with a baseball bat, I don't think it'll make a very loud noise, compared to hitting, say, a 5 pound piece of plastic that stays intact. This isn't quite a fair comparison, because the act of pulverizing a solid will have a noise associated with it, itself.
However, that noise need not be all that noisy. If you smack a 5 pound sheet of glass, I'm sure you'll hear a loud noise. However, when I recently saw a demolition guy break up a long piece of concrete by dropping it from 10 - 15 feet, it made a relatively quiet "thud".
A shock front which is simultaneously pulverizing and accelerating enclosing walls and floors, as well as office contents, must do work in doing so, and thus lose energy. While that is not sufficient to prevent a very noticeable cracking sound in the case of HE CD, I consider it somewhat disingenuous to assume that WTC CD's must be done in exactly the same manner. Indeed, it stands to reason that a CD, undertaken as a psyop (which I assume most CTs believe was the case on 911), should not be too obvious.
As if that's not enough, all of the matter that the explosion front is plowing through has to have some effect on the shape of the waveform (not just it's intensity).
I have posted a reference, recently, which contained a graph of a thermobaric pressure versus time, together with that of a high explosive. The thermobaric's initial compressive phase is about half the maximum pressure of that of the HE, and twice the duration.
The thermobaric Hellfire's payload, that Rumsfeld told us could take out a floor of a building, and leave the building standing, weighs all of 27.5 lbs. I would guess that a recording of it being tested exists somewhere. Where that "somewhere" is, is unknown to me. This class of weapons is highly classified.
Further to what WCElliot is saying.
Here's some real wave form data from some real explosions:
Image 1 Image 2
Notice the N shape - the N shape occurs because with (most) explosions you have a sudden expansion, followed by a sudden rarefaction.
Pay real close attention, and then bare in mind that any situation which produces a sudden compression is going produce a wave form similar to this.
Or do you honestly believe that Sonic booms are called sonic booms because explsives are involved.
Can you show us waveforms corresponding to explosions emanating from within an enclosed area? And furthermore, explosions which pulverize wallboard, concrete, etc., as they expand from within their enclosed space?
If you take a 5 lb. bag of sugar and smack it with a baseball bat, I don't think it'll make a very loud noise, compared to hitting, say, a 5 pound piece of plastic that stays intact. This isn't quite a fair comparison, because the act of pulverizing a solid will have a noise associated with it, itself.
However, that noise need not be all that noisy. If you smack a 5 pound sheet of glass, I'm sure you'll hear a loud noise. However, when I recently saw a demolition guy break up a long piece of concrete by dropping it from 10 - 15 feet, it made a relatively quiet "thud".
A shock front which is simultaneously pulverizing and accelerating enclosing walls and floors, as well as office contents, must do work in doing so, and thus lose energy. While that is not sufficient to prevent a very noticeable cracking sound in the case of HE CD, I consider it somewhat disingenuous to assume that WTC CD's must be done in exactly the same manner. Indeed, it stands to reason that a CD, undertaken as a psyop (which I assume most CTs believe was the case on 911), should not be too obvious.
As if that's not enough, all of the matter that the explosion front is plowing through has to have some effect on the shape of the waveform (not just it's intensity).
I have posted a reference, recently, which contained a graph of a thermobaric pressure versus time, together with that of a high explosive. The thermobaric's initial compressive phase is about half the maximum pressure of that of the HE, and twice the duration.
The thermobaric Hellfire's payload, that Rumsfeld told us could take out a floor of a building, and leave the building standing, weighs all of 27.5 lbs. I would guess that a recording of it being tested exists somewhere. Where that "somewhere" is, is unknown to me. This class of weapons is highly classified.
QUOTE (Al Khwarizmi - step-by-step+Oct 14 2007, 12:58 AM)
That's it???? Your entire post consisted of nothing more than ad hominem insults and another intentional misrepresentation.
That's all you deserve.
PULL IT.
Go on Al, pull the other one.
Arthur
That's all you deserve.
PULL IT.
Go on Al, pull the other one.
Arthur
QUOTE
"lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it "
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
QUOTE (->
| QUOTE |
| "lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it " |
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
As if that's not enough, all of the matter that the explosion front is plowing through has to have some effect on the shape of the waveform (not just it's intensity).
In fact, if it weren't for all the intervening and reflecting surfaces, the explosion would be completely featureless, acoustically. All of the "complex waveform" coming from an explosion is precisely and only that, the reflections off the environment of that initial 10microsecond pulse. That makes a recording from inside a structure 100% artifact, the sound of the initial detonation isn't present (due to undersampling and clipping) and the whole of the recording is just the reflections superimposed upon one another.
QUOTE (metamars+Oct 14 2007, 08:12 AM)
Can you show us waveforms corresponding to explosions emanating from within an enclosed area?
Why aren't some of the Troofers taking some of the blood money they are making from the sale of Books, DVDs and T-Shirts and PAY for a Forensic Audio study?
Arthur
Why aren't some of the Troofers taking some of the blood money they are making from the sale of Books, DVDs and T-Shirts and PAY for a Forensic Audio study?
Arthur
QUOTE (wcelliott+Oct 14 2007, 03:54 PM)
Or, "Hey, you've already lost so many firefighters in my buildings today, who's going to notice a few more? "
The decision not to fight the fire in WTC7 was clearly made on the basis that they'd lost too many firefighters that day and the owners didn't want to risk any more NYFD lives just to attempt to save WTC7. It was obvious from the tone of the man's voice that he felt bad about what'd happened, and didn't want anybody else to die.
I agree with you on that . But it meant the fires were going to keep spreading until an enormous inferno , or it was going to collapse outside its footprint . Both options are disasters by its self. So when you are able to find a demolition team that wants to do the job because you also pay them very well than that's the smartest thing to do . A controlled collapse prevents other still in tact buildings from being destroyed, and makes the fire a lot easier to fight.
How far away were other in tact buildings from WTC 7, I wonder, about 50 meters ?
QUOTE (atmosphere+Oct 14 2007, 06:29 AM)
A) in the first hours after the collapses of the towers there wasn't very much fire in WTC 7 ,certainly not in the basement or on the first few floors.
everything about 9/11 was revealed right away ? Lots of money was involved,who was going to pay the price for the destruction of WTC 7 ?
C) And investigation was going to be there anyway.
"lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it "
Looking at the damage it was very likely the building would fall like a tree or certainly not fall within its own footprint .
Your ANSWERS didn't actually address any of the questions.
Why would people who work for a demolition company WILLINGLY go into a DAMAGED BURNING UNSTABLE Building, over and over again, carrying det cord and placing high explosives?????
Why, after doing what would be clearly a very HEROIC ACT for the City of NY by people from a PRIVATE COMPANY, they would then participate with the City, the NYPD, the BATF and the FDNY to COVER UP ALL EVIDENCE that they had acted heroicly?
The NIST has been trying for YEARS to figure out how/why WTC collapsed, given that the City/NYFD/FDNY KNEW they had placed explosives and blown up WTC 7 why would this be hidden from both FEMA and NIST and allow them to WASTE MILLIONS of dollars?
Sorry, your hypothesis has more holes than a round of Swiss Cheese.
Arthur
everything about 9/11 was revealed right away ? Lots of money was involved,who was going to pay the price for the destruction of WTC 7 ? C) And investigation was going to be there anyway.
"lets just wait for an uncontrolled demolition because we are sure the building is going to collapse in a way that no other buildings Will come down with it "
Looking at the damage it was very likely the building would fall like a tree or certainly not fall within its own footprint .
Your ANSWERS didn't actually address any of the questions.
Why would people who work for a demolition company WILLINGLY go into a DAMAGED BURNING UNSTABLE Building, over and over again, carrying det cord and placing high explosives?????
Why, after doing what would be clearly a very HEROIC ACT for the City of NY by people from a PRIVATE COMPANY, they would then participate with the City, the NYPD, the BATF and the FDNY to COVER UP ALL EVIDENCE that they had acted heroicly?
The NIST has been trying for YEARS to figure out how/why WTC collapsed, given that the City/NYFD/FDNY KNEW they had placed explosives and blown up WTC 7 why would this be hidden from both FEMA and NIST and allow them to WASTE MILLIONS of dollars?
Sorry, your hypothesis has more holes than a round of Swiss Cheese.
Arthur
QUOTE (atmosphere+Oct 14 2007, 10:05 AM)
How far away were other in tact buildings from WTC 7, I wonder, about 50 meters ?
Depends upon what you mean by intact, but the Verizon building was just across a relatively narrow street. Maybe 15 meters.
And the firefighters had no idea about exactly how WTC 7 was going to fall.
Also, the decision to not try to fight the fires was made solely by the NYFD officers. No matter how that quote is misinterpreted, Silverstein was merely on the receiving end of further bad news.
Depends upon what you mean by intact, but the Verizon building was just across a relatively narrow street. Maybe 15 meters.
And the firefighters had no idea about exactly how WTC 7 was going to fall.
Also, the decision to not try to fight the fires was made solely by the NYFD officers. No matter how that quote is misinterpreted, Silverstein was merely on the receiving end of further bad news.
QUOTE (adoucette+Oct 14 2007, 10:50 AM)
Sorry, your hypothesis has more holes than a round of Swiss Cheese.
Spongiform.
Spongiform.
Einsteen:
Please don't misunderstand my comments on your video analysis method! I have always thought it was a great idea and I was, I believe, one of the first to compliment you on it. All I am saying is that there is a serious discrepancy between your analysis of the F-4 impact and the results reported by Sugano in his 1993 paper in Nuclear Engineering and Design. Since Sugano's data were obtained from accelerometers on the aircraft AND high-speed photography, I am inclined to accept the 1993 paper and wonder what's the problem with your technique.
One point I would ask you to clarify: does your technique show a velocity reduction for any of the available videos of Flight 175 as it enters WTC 2?
Please don't misunderstand my comments on your video analysis method! I have always thought it was a great idea and I was, I believe, one of the first to compliment you on it. All I am saying is that there is a serious discrepancy between your analysis of the F-4 impact and the results reported by Sugano in his 1993 paper in Nuclear Engineering and Design. Since Sugano's data were obtained from accelerometers on the aircraft AND high-speed photography, I am inclined to accept the 1993 paper and wonder what's the problem with your technique.
One point I would ask you to clarify: does your technique show a velocity reduction for any of the available videos of Flight 175 as it enters WTC 2?
QUOTE (NEU-FONZE+Oct 14 2007, 02:20 PM)
Einsteen:
Please don't misunderstand my comments on your video analysis method! I have always thought it was a great idea and I was, I believe, one of the first to compliment you on it. All I am saying is that there is a serious discrepancy between your analysis of the F-4 impact and the results reported by Sugano in his 1993 paper in Nuclear Engineering and Design. Since Sugano's data were obtained from accelerometers on the aircraft AND high-speed photography, I am inclined to accept the 1993 paper and wonder what's the problem with your technique.
One point I would ask you to clarify: does your technique show a velocity reduction for any of the available videos of Flight 175 as it enters WTC 2?
I think a more careful analysis of Einsteen's picture will show the MINOR amount of deceleration that occurred.
Take a more careful look.
It helps to save it and blow it up, then note that it is NOT truely linear.
http://i23.tinypic.com/2937sk6.png
Of course one would expect that thes amount of deceleration would be greater than in the WTC crashes, where the plane does NOT run into an inpenetrable object.
Arthur
Please don't misunderstand my comments on your video analysis method! I have always thought it was a great idea and I was, I believe, one of the first to compliment you on it. All I am saying is that there is a serious discrepancy between your analysis of the F-4 impact and the results reported by Sugano in his 1993 paper in Nuclear Engineering and Design. Since Sugano's data were obtained from accelerometers on the aircraft AND high-speed photography, I am inclined to accept the 1993 paper and wonder what's the problem with your technique.
One point I would ask you to clarify: does your technique show a velocity reduction for any of the available videos of Flight 175 as it enters WTC 2?
I think a more careful analysis of Einsteen's picture will show the MINOR amount of deceleration that occurred.
Take a more careful look.
It helps to save it and blow it up, then note that it is NOT truely linear.
http://i23.tinypic.com/2937sk6.png
Of course one would expect that thes amount of deceleration would be greater than in the WTC crashes, where the plane does NOT run into an inpenetrable object.
Arthur
I did a rough calculation for a case of a 50 m/s reduction in velocity at the 0.2 second mark and assumed a constant deceleration over that time interval. That gives a deceleration of 250 m/s2. The time needed for the tail to reach the wall of WTC2 after nose impact is about 0.226 s with the deceleration compared with about 0.2 s with no deceleration of the tail.
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
For fast moving objects and ordinary video cameras, one would almost have to start looking at how the image is skewed from left to right as the horizontal video lines are being scanned. There would be a skewing of the image as the plane was moving left to right and the lines were being scanned from top to bottom. That would give some information that is on a time scale which is shorter than the vertical scan rate.
QUOTE (shagster+Oct 14 2007, 03:59 PM)
I did a rough calculation for a case of a 50 m/s reduction in velocity at the 0.2 second mark and assumed a constant deceleration over that time interval. That gives a deceleration of 250 m/s2. The time needed for the tail to reach the wall of WTC2 after nose impact is about 0.226 s with the deceleration compared with about 0.2 s with no deceleration of the tail.
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
Its a moot point.
We have no photo's taken at 90 degrees to the tower so we don't know PRECISELY how long it took for the plane to fully enter the building.
Nor do we know PRECISELY what the speed of the initial impact was.
Nor do we know PRECISELY what the Approach angles were.
Nor do we know PRECISELY where on a floor the plane it (between floors or more in line with a floor)
All are needed for that level of precision.
What NIST did was estimate the amount of energy transferred over time, which is all in NIST 1-2b, including how they came to ALL of their many estimations.
Arthur
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
Its a moot point.
We have no photo's taken at 90 degrees to the tower so we don't know PRECISELY how long it took for the plane to fully enter the building.
Nor do we know PRECISELY what the speed of the initial impact was.
Nor do we know PRECISELY what the Approach angles were.
Nor do we know PRECISELY where on a floor the plane it (between floors or more in line with a floor)
All are needed for that level of precision.
What NIST did was estimate the amount of energy transferred over time, which is all in NIST 1-2b, including how they came to ALL of their many estimations.
Arthur
QUOTE (David B. Benson+Oct 14 2007, 05:50 PM)
Depends upon what you mean by intact, but the Verizon building was just across a relatively narrow street. Maybe 15 meters.
And the firefighters had no idea about exactly how WTC 7 was going to fall.
Also, the decision to not try to fight the fires was made solely by the NYFD officers. No matter how that quote is misinterpreted, Silverstein was merely on the receiving end of further bad news.
I completely agree. Silverstein did not decide anything, he just received a call on what already happened .
Makes sense to me that the ones in charge (NYFD officers) decided withdraw their men from the building . Something just went terribly wrong in de towers ,lots of fireman were still inside and lost their lives . For an officer it must be the worst nightmare to send your men in and never see them back again . But in case the towers never collapsed and no firemen were killed, would they have entered WTC 7 ? It could be that the chance of a collapse wasn't that big at all ,especially in the first hours after the collapses of the twin towers. Firefighters mus thave felt like every building could collapse any time.
What would have happened if the building didn't collapse ? this was a very realistic scenario . It was on fire ,so what happens when you stop fighting the fires in a building like that with the sprinkler systems broken?
I have been discussing this on a dutch board and decided to try and find some Americans opinions on this subject ,because you must have a better understanding about everything involved . On the board over here nobody ever talks about the fire men's position ,and emotions that day. Now that is different on this board ( I'm glad ). I will not get into politics by the way .
And the firefighters had no idea about exactly how WTC 7 was going to fall.
Also, the decision to not try to fight the fires was made solely by the NYFD officers. No matter how that quote is misinterpreted, Silverstein was merely on the receiving end of further bad news.
I completely agree. Silverstein did not decide anything, he just received a call on what already happened .
Makes sense to me that the ones in charge (NYFD officers) decided withdraw their men from the building . Something just went terribly wrong in de towers ,lots of fireman were still inside and lost their lives . For an officer it must be the worst nightmare to send your men in and never see them back again . But in case the towers never collapsed and no firemen were killed, would they have entered WTC 7 ? It could be that the chance of a collapse wasn't that big at all ,especially in the first hours after the collapses of the twin towers. Firefighters mus thave felt like every building could collapse any time.
What would have happened if the building didn't collapse ? this was a very realistic scenario . It was on fire ,so what happens when you stop fighting the fires in a building like that with the sprinkler systems broken?
I have been discussing this on a dutch board and decided to try and find some Americans opinions on this subject ,because you must have a better understanding about everything involved . On the board over here nobody ever talks about the fire men's position ,and emotions that day. Now that is different on this board ( I'm glad ). I will not get into politics by the way .
atmosphere --- If WTC 1 had not collapsed the way it did, the old WTC 7 would still be standing. It was the impact damage from exterior wall panels (or larger sections) from WTC 1 which damaged the structure and presumably started the fire.
When WTC 1 collapsed it broke the water mains, so the firemen had no water pressure with which to attempt to fight the fire. The situation was hopeless.
What comes as a surprise to me, at least, is that the building stood as long as it did. Typical insulation ratings were 2 to 3 hours.
When WTC 1 collapsed it broke the water mains, so the firemen had no water pressure with which to attempt to fight the fire. The situation was hopeless.
What comes as a surprise to me, at least, is that the building stood as long as it did. Typical insulation ratings were 2 to 3 hours.
Arthur:
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
QUOTE (David B. Benson+Oct 15 2007, 09:26 AM)
atmosphere --- If WTC 1 had not collapsed the way it did, the old WTC 7 would still be standing. It was the impact damage from exterior wall panels (or larger sections) from WTC 1 which damaged the structure and presumably started the fire.
When WTC 1 collapsed it broke the water mains, so the firemen had no water pressure with which to attempt to fight the fire. The situation was hopeless.
What comes as a surprise to me, at least, is that the building stood as long as it did. Typical insulation ratings were 2 to 3 hours.
There's actually video footage of some rather large pieces of the building hitting WTC7.
When WTC 1 collapsed it broke the water mains, so the firemen had no water pressure with which to attempt to fight the fire. The situation was hopeless.
What comes as a surprise to me, at least, is that the building stood as long as it did. Typical insulation ratings were 2 to 3 hours.
There's actually video footage of some rather large pieces of the building hitting WTC7.
QUOTE (Trippy+Oct 14 2007, 03:11 PM)
There's actually video footage of some rather large pieces of the building hitting WTC7.
All I have seen is the great picture, taken from an airplane high overhead, posted earlier by poster Grumpy.
Was this a clip from a video?
All I have seen is the great picture, taken from an airplane high overhead, posted earlier by poster Grumpy.
Was this a clip from a video?
QUOTE (NEU-FONZE+Oct 15 2007, 10:05 AM)
Arthur:
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
Easily.
The fuselage has some give along it's length, it can crush.
Add to the fact that the aircraft is (essentially) being forcebly 'veered' on either side of the floor that it impacted with (it's obvious from the photos that the floor structure sustained at least some crushing damage).
In essence, the rare of the fuselage can be considered decoupled from the front of the fuselage. The front of the fuselage, in fact, everything in the direction of travel from the point where the fuselage is being crushed has deccelerated, or is in the process of the decceleration, where as everything in the opposite direction is still travelling at much the same speed in much the same direction - especially if the energy released by the crushing and splitting of the fuselage is significantly less then the kinetic energy available to the aircraft.
In essence, if you measure the velocity of the tail of the aircraft, you'll find that it's travelling at a higher velocity then the center of gravity of the plane as a whole (the motion of which is influenced by the loss of inertia to the building, and the disruption/dispersion of the fuselage).
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
Easily.
The fuselage has some give along it's length, it can crush.
Add to the fact that the aircraft is (essentially) being forcebly 'veered' on either side of the floor that it impacted with (it's obvious from the photos that the floor structure sustained at least some crushing damage).
In essence, the rare of the fuselage can be considered decoupled from the front of the fuselage. The front of the fuselage, in fact, everything in the direction of travel from the point where the fuselage is being crushed has deccelerated, or is in the process of the decceleration, where as everything in the opposite direction is still travelling at much the same speed in much the same direction - especially if the energy released by the crushing and splitting of the fuselage is significantly less then the kinetic energy available to the aircraft.
In essence, if you measure the velocity of the tail of the aircraft, you'll find that it's travelling at a higher velocity then the center of gravity of the plane as a whole (the motion of which is influenced by the loss of inertia to the building, and the disruption/dispersion of the fuselage).
QUOTE (David B. Benson+Oct 15 2007, 11:16 AM)
All I have seen is the great picture, taken from an airplane high overhead, posted earlier by poster Grumpy.
Was this a clip from a video?
POssibly, I'm not sure (might have to repost the image).
There's no detail, it's just that in the process of collapse, you can see a piece of debri with a larger significant entrained dust cloud sail in a lovely arc towards wtc 7.
I think, ironically enough it might even be one of the images that people point at while jumping up and down exclaiming "See, it was controlled demolition".
Was this a clip from a video?
POssibly, I'm not sure (might have to repost the image).
There's no detail, it's just that in the process of collapse, you can see a piece of debri with a larger significant entrained dust cloud sail in a lovely arc towards wtc 7.
I think, ironically enough it might even be one of the images that people point at while jumping up and down exclaiming "See, it was controlled demolition".
QUOTE (Trippy+Oct 14 2007, 03:25 PM)
There's no detail, it's just that in the process of collapse, you can see a piece of debri[sic] with a larger significant entrained dust cloud sail in a lovely arc towards wtc 7.
I think, ironically enough it might even be one of the images that people point at while jumping up and down exclaiming "See, it was controlled demolition".
Ah yes. From the east. I've seen a clip from that one. I wasn't completely convinced that exterior wall section hit WTC 7 until Grumpy posted the aerial shot. In that picture you can see that it did overlap the top of WTC 7.
Yes, I fear so. One of the aspects of the collapses which is not yet well-explained is the lateral movement of large exterior wall sections.
I think, ironically enough it might even be one of the images that people point at while jumping up and down exclaiming "See, it was controlled demolition".
Ah yes. From the east. I've seen a clip from that one. I wasn't completely convinced that exterior wall section hit WTC 7 until Grumpy posted the aerial shot. In that picture you can see that it did overlap the top of WTC 7.
Yes, I fear so. One of the aspects of the collapses which is not yet well-explained is the lateral movement of large exterior wall sections.
QUOTE (David B. Benson+Oct 15 2007, 11:35 AM)
Ah yes. From the east. I've seen a clip from that one. I wasn't completely convinced that exterior wall section hit WTC 7 until Grumpy posted the aerial shot. In that picture you can see that it did overlap the top of WTC 7.
Yes, I fear so. One of the aspects of the collapses which is not yet well-explained is the lateral movement of large exterior wall sections.
Last time I checked, the exterior colums didn't fall any further horizontally then the tower was tall, and most of them fell less than that - didn't they?
Yes, I fear so. One of the aspects of the collapses which is not yet well-explained is the lateral movement of large exterior wall sections.
Last time I checked, the exterior colums didn't fall any further horizontally then the tower was tall, and most of them fell less than that - didn't they?
QUOTE (Trippy+Oct 14 2007, 03:41 PM)
Last time I checked, the exterior colums[sic] didn't fall any further horizontally then the tower was tall, and most of them fell less than that - didn't they?
The furthest seem to be those going all the way across the plaza to impact the WTC buildings there (I don't recall the building numbers). And I don't recall how far that was.
I believe you are correct in your estimate. Still, that means those outliers (at least) received quite a significant lateral impulse, yet to be fully explained...
The furthest seem to be those going all the way across the plaza to impact the WTC buildings there (I don't recall the building numbers). And I don't recall how far that was.
I believe you are correct in your estimate. Still, that means those outliers (at least) received quite a significant lateral impulse, yet to be fully explained...
N-F,
I once took two independent videos and they look also linear to me.
But accelerometers ? Are those built in the tail section, like FDRs ?
We have to remember that a building contains a lot of open sections and the sections that are not open will scatter some material away. My idea is that if it is even in the F4 test hard to see that there is deceleration (extracted bitmaps of a slowed down movie) then for flight 175 certainly not with those few frames. And the F4 jet collided on a 100% impenetrable wall, the wtc had open sections.
Further there are some other options.
1) there is a deceleration, but the force is not large because it needs to be provided by the weak damaged fuselage, it is too small to notice
2) the plane explodes and/or the combination of a kind of fast fracture effect, in other words when it hits the wall/building (like a glass that breaks) it completely consisting of small parts that each have their momentum, but no (or minimal) interactions between.
I guess the normal calculation of the phantom jet would be the same as a kind of crush-up equation but then with no gravity.
I once took two independent videos and they look also linear to me.
But accelerometers ? Are those built in the tail section, like FDRs ?
We have to remember that a building contains a lot of open sections and the sections that are not open will scatter some material away. My idea is that if it is even in the F4 test hard to see that there is deceleration (extracted bitmaps of a slowed down movie) then for flight 175 certainly not with those few frames. And the F4 jet collided on a 100% impenetrable wall, the wtc had open sections.
Further there are some other options.
1) there is a deceleration, but the force is not large because it needs to be provided by the weak damaged fuselage, it is too small to notice
2) the plane explodes and/or the combination of a kind of fast fracture effect, in other words when it hits the wall/building (like a glass that breaks) it completely consisting of small parts that each have their momentum, but no (or minimal) interactions between.
I guess the normal calculation of the phantom jet would be the same as a kind of crush-up equation but then with no gravity.
Hey DBB, I have an idea on the horizontal velocities, I have a coupel of ideas on how horizontal impulses might be expected to be applied to the exterior sections, I even have some ideas on where to go with the maths. I'll work out some of the details on paper (or try to) and post more when I have more (and more time).
I hope it helps in some way.
Meanwhile, is there anybody who's doing the video analysis that might be able to provide an estimate as to which floor(s) the object in question originated from?
I hope it helps in some way.
Meanwhile, is there anybody who's doing the video analysis that might be able to provide an estimate as to which floor(s) the object in question originated from?
QUOTE (Trippy+Oct 14 2007, 04:01 PM)
I hope it helps in some way.
Meanwhile, is there anybody who's doing the video analysis that might be able to provide an estimate as to which floor(s) the object in question originated from?
I do as well.
You mean the big one that hit WTC 7?
Meanwhile, is there anybody who's doing the video analysis that might be able to provide an estimate as to which floor(s) the object in question originated from?
I do as well.
You mean the big one that hit WTC 7?
QUOTE (David B. Benson+Oct 15 2007, 12:09 PM)
I do as well.
You mean the big one that hit WTC 7?
That would be correct, yes - an object falling from the 80th floor would require a significantly smaller lateral impulse to impact on WTC 7 then an object falling from the 70th floor.
You mean the big one that hit WTC 7?
That would be correct, yes - an object falling from the 80th floor would require a significantly smaller lateral impulse to impact on WTC 7 then an object falling from the 70th floor.
QUOTE (Trippy+Oct 14 2007, 04:18 PM)
That would be correct, yes - an object falling from the 80th floor would require a significantly smaller lateral impulse to impact on WTC 7 then an object falling from the 70th floor.
I'll estimate that that particular exterior wall section was 6 or 9 stories tall (maybe even 12), with the upper end terminating at floor 98, max. However, if the lateral force is applied by the pressure of the crushing front, then it might have occurred further down.
One way to estimate is by noting the shape of the parabola it formed. These are about the same curvature as the diagrams for crush-down in B&V, for example. So the trajectory is, crudely put, more vertical than horizontal once the exterior wall section left the dust clouds behind.
I'll estimate that that particular exterior wall section was 6 or 9 stories tall (maybe even 12), with the upper end terminating at floor 98, max. However, if the lateral force is applied by the pressure of the crushing front, then it might have occurred further down.
One way to estimate is by noting the shape of the parabola it formed. These are about the same curvature as the diagrams for crush-down in B&V, for example. So the trajectory is, crudely put, more vertical than horizontal once the exterior wall section left the dust clouds behind.
QUOTE (shagster+Oct 14 2007, 07:59 PM)
I did a rough calculation for a case of a 50 m/s reduction in velocity at the 0.2 second mark and assumed a constant deceleration over that time interval. That gives a deceleration of 250 m/s2. The time needed for the tail to reach the wall of WTC2 after nose impact is about 0.226 s with the deceleration compared with about 0.2 s with no deceleration of the tail.
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
Your calculations are good but what you've demonstrated is that, if this were a full speed video, the total duration of capture (portion including crush) would be 0.2sec*(25fps)=5frames.
I have only now downloaded and dumped the frames from the WMV file that eintsteen linked and haven't looked at them, but from the picture einsteen posted of the extraction, I would assume this is a copy of high speed film to video rather than a video at the scene. einsteen surely extracted from more than 5 frames to make those bitmaps.
We have to derive the time scale from measurements taken from the video, absent this information provided by documentation. Then a scale factor can be added to your calculations.
...Just had a quick look and I see the video is a composite of many clips. Some have alignment marks for high speed film and indeed plenty of clips are dumps of HS film to video. I'm not sure what's going on here since there seems to be more than one test recorded....
Must spend more time before commenting with any certainty.
The time difference is 0.226 - 0.2 = 0.026 s. One frame of video in NTSC spans about 1/30th of second or 0.0333 s. The difference in the time at which the tail arrived at the wall with and without deceleration is less than one frame of video in this example. One field spans 1/60th of a second or 0.0167 s, which is already close to 0.026 s.
High speed cameras or accelerometers are preferred.
Others here should go through the calculations and see what they get.
Your calculations are good but what you've demonstrated is that, if this were a full speed video, the total duration of capture (portion including crush) would be 0.2sec*(25fps)=5frames.
I have only now downloaded and dumped the frames from the WMV file that eintsteen linked and haven't looked at them, but from the picture einsteen posted of the extraction, I would assume this is a copy of high speed film to video rather than a video at the scene. einsteen surely extracted from more than 5 frames to make those bitmaps.
We have to derive the time scale from measurements taken from the video, absent this information provided by documentation. Then a scale factor can be added to your calculations.
...Just had a quick look and I see the video is a composite of many clips. Some have alignment marks for high speed film and indeed plenty of clips are dumps of HS film to video. I'm not sure what's going on here since there seems to be more than one test recorded....
Must spend more time before commenting with any certainty.
Trippy:
So I suppose there was no longitudinal wave traveling at 5100 m/s down the aircraft. The tail was decoupled.... right...... of course........
All you are saying is that it was a "soft" impact, which is the F-4 case...
But Flight 175 colliding with WTC 2 wasn't a purely "soft" impact (where the target is essentially undamaged and the projectile is crushed); it was a combination of a "hard and soft" impact; that is an impact where both the target and the projectile are crushed.
So I suppose there was no longitudinal wave traveling at 5100 m/s down the aircraft. The tail was decoupled.... right...... of course........
All you are saying is that it was a "soft" impact, which is the F-4 case...
But Flight 175 colliding with WTC 2 wasn't a purely "soft" impact (where the target is essentially undamaged and the projectile is crushed); it was a combination of a "hard and soft" impact; that is an impact where both the target and the projectile are crushed.
The dump of WMV to frames was 26 minutes in (93% thru), 1.4 Gigs of bitmaps, when I noticed that I'd inadvertently resampled the time frame to 15fps, a leftover setting. That would screw the results.
QUOTE (OneWhiteEye+Oct 15 2007, 12:25 AM)
Your calculations are good but what you've demonstrated is that, if this were a full speed video, the total duration of capture (portion including crush) would be 0.2sec*(25fps)=5frames.
I was referring to the the aircraft impact of WTC2 in that post. I don't know of any high speed videos of that impact.
I was referring to the the aircraft impact of WTC2 in that post. I don't know of any high speed videos of that impact.
Oh, my apologies, I thought you were explaining why the extraction might not be applicable.
Edit: Guess I should have noted the reference to WTC in your post! I didn't say my drying out period was over!
Edit: Guess I should have noted the reference to WTC in your post! I didn't say my drying out period was over!
QUOTE (NEU-FONZE+Oct 15 2007, 01:38 PM)
Trippy:
So I suppose there was no longitudinal wave traveling at 5100 m/s down the aircraft. The tail was decoupled.... right...... of course........
All you are saying is that it was a "soft" impact, which is the F-4 case...
But Flight 175 colliding with WTC 2 wasn't a purely "soft" impact (where the target is essentially undamaged and the projectile is crushed); it was a combination of a "hard and soft" impact; that is an impact where both the target and the projectile are crushed.
they look like some kind of words, but I can't make any sense of them.
I'm sorry if you interpreted what I said that way, but I thought it was clear that that wasn't what I meant when I elaborated further by saying that "The center of mass of the plane and the tail of the plane weren't neccessarily deccelerating at the same rate".
Edit:
Upon review I realized that I said the velocities were different, which implies the accelerations of the cente rof mass and tail were different. Point being that they should only be the same (under these conditions) if the plane is behaving as a rigid body, which it clearly wasn't.
So I suppose there was no longitudinal wave traveling at 5100 m/s down the aircraft. The tail was decoupled.... right...... of course........
All you are saying is that it was a "soft" impact, which is the F-4 case...
But Flight 175 colliding with WTC 2 wasn't a purely "soft" impact (where the target is essentially undamaged and the projectile is crushed); it was a combination of a "hard and soft" impact; that is an impact where both the target and the projectile are crushed.
they look like some kind of words, but I can't make any sense of them.
I'm sorry if you interpreted what I said that way, but I thought it was clear that that wasn't what I meant when I elaborated further by saying that "The center of mass of the plane and the tail of the plane weren't neccessarily deccelerating at the same rate".
Edit:
Upon review I realized that I said the velocities were different, which implies the accelerations of the cente rof mass and tail were different. Point being that they should only be the same (under these conditions) if the plane is behaving as a rigid body, which it clearly wasn't.
[removed: no sci-tech]
QUOTE (Trippy+Oct 15 2007, 11:21 AM)
...(it's obvious from the photos that the floor structure sustained at least some crushing damage)...
... (the motion of which is influenced by the loss of inertia to the building, and the disruption/dispersion of the fuselage)...
And once again, you're taking what I actually said out of context, and distorting it, although I will admit that perhaps I should have said "Fuselage and floor" rather then "fuselage".
... (the motion of which is influenced by the loss of inertia to the building, and the disruption/dispersion of the fuselage)...
And once again, you're taking what I actually said out of context, and distorting it, although I will admit that perhaps I should have said "Fuselage and floor" rather then "fuselage".
QUOTE (Al Khwarizmi - step-by-step+Oct 13 2007, 03:51 PM)
Arthur:
===============
"your view that the (explosion) NOISES recorded that day HAD to have come from explosives"
===============
I wish you luck in finding my claim to that effect when you quote me.
"Noise" in acoustic parlance, btw, refers to the simutaneous production of all frequencies in the audible spectrum at the same time. It is analogous to that mess of all visible freqencies we call "white."
wcelliot:
============
OK, take an acoustic guitar, remove all but one string. With that one string taut, cut it with a wire cutter.
BANG!
=============
My steel-string acoustic doesn't produce a sound resembling an explosion on those rare ocassions when a string snaps -- nor does "bang" adequately describe the sound produced when intentionally cutting any string, regardless of how many remain. Not surprisingly, "SNAP!" is a very appropriate description.
I would be astonished if my guitar ever produced a noise similar to a shaped-charge explosive under any circumstances.
Oh - and it is best to replace guitar strings one at a time.
"I heard they had a space program when they sing you can't hear there's no air sometimes I think I kinda like that and other times I think I'm already there."
-- They Might Be Giants.
Did you know that you can't hear an explosion without an atmosphere in which to propogate a cascade of particle collisions?
Did you know that you have thrice argued that an explosion produces a physically impossible sound envelope with attack, sustain and release occuring at the same instant -- a zero duration waveform?
What is the rate of attack in this graph of a classic waveform?
What will this wave sound like when played once at maximum amplitude on an average modern HiFi system?
What will this wave sound like when repeated 100 times per second (100Hz) for several seconds?
That was the dumbest thing I have ever read on hear, comparing the sound wave distortion created by a guitar string snapping to the sound of steel beams being breaking.
Why don't you try that experiment on high test 3/4 cable, which will definitely make a sound, sonic disruption breaking the sound barrier as loud or Louder than many high explosives a very loud Boom sonic boom to be exact.
Or better yet attach a six foot sidewinder bush hog behind a 60 HP tractor and rev the tractor up to 2400 RPM, then drive over the largest rock you can find when the blade breaks on the rock, you will hear a sonic disruption similar to the sound of the world trade center collapses.
When steel snaps faster than the speed of sound it makes a sonic boom!
Sonic Booms and Explosives can not be distinguished by the human ear so some one reporting sounds of explosions is meaningless because the source is UN definable.
===============
"your view that the (explosion) NOISES recorded that day HAD to have come from explosives"
===============
I wish you luck in finding my claim to that effect when you quote me.
"Noise" in acoustic parlance, btw, refers to the simutaneous production of all frequencies in the audible spectrum at the same time. It is analogous to that mess of all visible freqencies we call "white."
wcelliot:
============
OK, take an acoustic guitar, remove all but one string. With that one string taut, cut it with a wire cutter.
BANG!
=============
My steel-string acoustic doesn't produce a sound resembling an explosion on those rare ocassions when a string snaps -- nor does "bang" adequately describe the sound produced when intentionally cutting any string, regardless of how many remain. Not surprisingly, "SNAP!" is a very appropriate description.
I would be astonished if my guitar ever produced a noise similar to a shaped-charge explosive under any circumstances.
Oh - and it is best to replace guitar strings one at a time.
"I heard they had a space program when they sing you can't hear there's no air sometimes I think I kinda like that and other times I think I'm already there."
-- They Might Be Giants.
Did you know that you can't hear an explosion without an atmosphere in which to propogate a cascade of particle collisions?
Did you know that you have thrice argued that an explosion produces a physically impossible sound envelope with attack, sustain and release occuring at the same instant -- a zero duration waveform?
What is the rate of attack in this graph of a classic waveform?
What will this wave sound like when played once at maximum amplitude on an average modern HiFi system?
What will this wave sound like when repeated 100 times per second (100Hz) for several seconds?
That was the dumbest thing I have ever read on hear, comparing the sound wave distortion created by a guitar string snapping to the sound of steel beams being breaking. Why don't you try that experiment on high test 3/4 cable, which will definitely make a sound, sonic disruption breaking the sound barrier as loud or Louder than many high explosives a very loud Boom sonic boom to be exact.
Or better yet attach a six foot sidewinder bush hog behind a 60 HP tractor and rev the tractor up to 2400 RPM, then drive over the largest rock you can find when the blade breaks on the rock, you will hear a sonic disruption similar to the sound of the world trade center collapses.
When steel snaps faster than the speed of sound it makes a sonic boom!
Sonic Booms and Explosives can not be distinguished by the human ear so some one reporting sounds of explosions is meaningless because the source is UN definable.
QUOTE
But Flight 175 colliding with WTC 2 wasn't a purely "soft" impact (where the target is essentially undamaged and the projectile is crushed); it was a combination of a "hard and soft" impact; that is an impact where both the target and the projectile are crushed.
The towers' perimeter columns offered resistance only momentarily. As soon as the aircraft hit, the columns broke immediately, and offered no further resistance. The momentum of the aircraft parts caused the damage, but those parts weren't stongly-coupled to the airframe. They weren't *driven* through the columns by the structural rigidity of the airframe, so the force wasn't directed back into the airframe's structure (which would've slowed the airframe).
The aircraft wasn't built to be a "bunker-buster", so what forces there were at-impact simply broke the mounts to those parts with minimal transfer of those forces to the airframe, decoupling the parts that had smashed through the perimeter columns with their own momentum.
It's a mistake to think of the aircraft as having one velocity, and that measured (?) velocity of the aircraft's tail was some indicator of the velocity of the whole aircraft. You'd have to redefine what was meant by "average velocity", as the parts that actually did the damage to the perimeter columns decelerated significantly more than the airframe.
.
Hi everyone!
As you will have guessed, adoucette, Grumpy, NF, Skippy et al, I had a relapse in my optic erve allergic inflamation problem.
All my own silly fault, really; because when a few months ago my doctor said I could get back to 'normal' screenwork etc, I 'blithely interpreted that as a 'green light' to go on a practically 24/7 catch-up reading spree of all the relevant Physorg posts I had missed from my initial 6-month absence due to the nerve inflammatory problem...with the inevitable/predictable result! Ouch.
Anyway, I am back and am allowed to use my eyes for reading/writing and graphic work ONLY ONE HOUR per day. Serves me right for being so cavalier about my recovery last time, hehehe. So I will only post some sporadic inputs here and in selected other forum topics until I get the REAL go-ahead for normal eye use from my doctors...who SWEAR that they will wash their hands of me if I do such a silly thing again!
So, I've spent almost an hour catching up HERE, and will make my fist brief contribution in connection with the 'steel temperatures' possible in localised/crucial areas of 'core' and 'perimeter' and certain areas of 'floor-truss' and 'connection/damper' structures.
As you all may recall, some time back I pointed out and emphasised the 'reverberative furnace'-like behaviour of the floor spaces and conctrete membranes between the VAST ACREAGE of floor areas over many levels in WTC1/2. I especially empasised that fires in succeeding higher floor-levels were being essentially fire-stack-draft fed with PRE-SUPERHEATED air, steam, CO2 and CO etc from fires below (going up broken shafts and cracks/disconnection and existing spacer-gap dicontinuities of all kinds (in that 'sieve' of a building especially after the plane impacts etc broke window-glass, shafts etc).
This preheating and reverberative aspect is crucial to understanding what went on in certain areas throught the buildings in the hour after the initial widespread fires lit/accelerated by the plane impact/fuel.
Also important is the debris mounds created when the planes 'bulldozed' and 'PILED UP' plastics, woods, metals paper, and the dousing with plane kero fuel of such LARGE mounds of preshredded (mostly organic) combustible materials.
Here is why.
In ancient IRON AGE times, they used a two-stage burner system was used to smelt iron ORE (and scrap from broken weapons, utensils and previous smelts).
They made use of a FIRST fire-point BURNER just outside the actual 'clay furnace' hollow mound, which burned wood (and probably low-quality charcoal from less successful charcoal production 'runs' in nearby woods) to create a supply of PREHEATED air and CO/CO2 etc.
This was fed via a clay-brick duct into the SECOND BURNER in the furnace proper; which contained the higher quality charcoal mixed roughly with ore/scrap-iron).
NOTE: NATURAL (unassisted by bellows or any other mechanically-forced draft system) drove the superheated air, CO etc into and up through the smelting mixture...the arrangement of the 'level' between the fire points produced a strong enough draft to move the superheated PREBURNER gases into the smelting chamber proper....naturally inducted through a HYPERCAUST DUCT which ALSO BECAME SUPERHEATED after a time in the process....thus delivering superhot gases to the high-grade charcoal which ITSELF then reacted with the already superhot gases from the hypercaust inputs to the oxidation/reduction reactipon 'PILE' contained within the reverberative furnace structure walls.
The relevance to 9/11 WTC processes?
The Steel in certain spots therein may have been heated by similar NATURAL drafted, preheating/hypercaust/reverberative furnace-like arrangement as provided by the piles of debris 'charcoaled' by the initial heat/fire of jet fuel and other loosely scattered material (both in the piles and nearby).
These initial fires would have been FUEL-RICH due to vast quantities of jet fuel kerosene and qucikly-consumed office material 'fuels'. PERFECT for 'charcoaling' the LARGER piles of office/plane debris forced into/against the core and some perimeter wall structures.
So what do we 'get'?
We get INITIAL firepoint preheated air being DUCTED into SECONDARY fire-points consisting of a mixture of 'high value' partially/wholly 'charcoaled' (pyrolised) plastics, wood, paper, cloth/textile (and even carbon black 'soot') from pyrolised kerosene jet fuel).
Can you imagine what even naturally-drafted superhot-gas-fed combustion of those vast piles of partially 'charcoaled' piles of debris would do to the LOCALISED TEMPS in CRITICAL INTERCONNECTED PARTS of the core/and walls...especially since they were ALREADY damaged and under starin from weight-redistribution and impact deformation of critical GEOMETRIES/INTERCONNECTIONS?
And lesat anyone doubt what natural drafting can do even in 'small' height-differential fire-path cases, one need only recall the evidence of the firemen fighting an earlier office fire in one WTC tower (back in the 80's, I think. He said that the flames issuing from the cable risers etc were like BLOWTORCHES').
And then too there is the fact that 'charcoal' fires burn with almost no 'flame' (or in the 'dirty' WTC case, less flame than would be evident from a 'normal' unpyrolised fuel pile).
Which means that THOSE most critical fires causing the most critical heat damage/compromising to the steel components would be hard to see to the full extent....so one can imagine a 'tip of the iceberg' situation existing between the flames that WERE observed during a BRIGHT SUNLIT MORNING, and what REVERBERATIVE-SMELTER-LIKE FURNACE processes were ACTUALLY going on UNSEEN (not only due to INTRINSIC flame-gases 'transparency', but also due to all that infra-red absorbing clouds of SOOT and concrete/drywall etc particulate matter).
Conclusion?
Any such vast piles of preshredded and partially pyrolised fuel materials being naturally fed by PRE-super-HEATED air from initial fires which heated the 'reverberative' insulating floor-concrete etc would AT LEAST CERTAINLY and disastrously SOFTEN iron/steel....at least at certain locations having the necessary parts/conditions as in the ancient iron smelters.
Sorry guys, that's all for now. I can just hear my doctors' threatening words ringing in my ears-----not only that they will refuse see me in future, but also that if I DON'T do as I am told, my next inflammatory attack could be the last straw for my eyesight....and THEN how would I discuss such fascinating things with my friends at PhysorgForums!
Cheers all! I'll see ya'll around the forums when next I can focus and read my computer screen without risking THIS round of recovery, hehehe.
RC.
PS: SKIPPY: Sorry I haven't been around to continue our 'Contextual Mathematics' discussion, mate! I will probably do that the next time I can see the screen without wincing too much from the eye-ache it brings on. Cheers! RC.
..
Hi everyone!
As you will have guessed, adoucette, Grumpy, NF, Skippy et al, I had a relapse in my optic erve allergic inflamation problem.
All my own silly fault, really; because when a few months ago my doctor said I could get back to 'normal' screenwork etc, I 'blithely interpreted that as a 'green light' to go on a practically 24/7 catch-up reading spree of all the relevant Physorg posts I had missed from my initial 6-month absence due to the nerve inflammatory problem...with the inevitable/predictable result! Ouch.
Anyway, I am back and am allowed to use my eyes for reading/writing and graphic work ONLY ONE HOUR per day. Serves me right for being so cavalier about my recovery last time, hehehe. So I will only post some sporadic inputs here and in selected other forum topics until I get the REAL go-ahead for normal eye use from my doctors...who SWEAR that they will wash their hands of me if I do such a silly thing again!
So, I've spent almost an hour catching up HERE, and will make my fist brief contribution in connection with the 'steel temperatures' possible in localised/crucial areas of 'core' and 'perimeter' and certain areas of 'floor-truss' and 'connection/damper' structures.
As you all may recall, some time back I pointed out and emphasised the 'reverberative furnace'-like behaviour of the floor spaces and conctrete membranes between the VAST ACREAGE of floor areas over many levels in WTC1/2. I especially empasised that fires in succeeding higher floor-levels were being essentially fire-stack-draft fed with PRE-SUPERHEATED air, steam, CO2 and CO etc from fires below (going up broken shafts and cracks/disconnection and existing spacer-gap dicontinuities of all kinds (in that 'sieve' of a building especially after the plane impacts etc broke window-glass, shafts etc).
This preheating and reverberative aspect is crucial to understanding what went on in certain areas throught the buildings in the hour after the initial widespread fires lit/accelerated by the plane impact/fuel.
Also important is the debris mounds created when the planes 'bulldozed' and 'PILED UP' plastics, woods, metals paper, and the dousing with plane kero fuel of such LARGE mounds of preshredded (mostly organic) combustible materials.
Here is why.
In ancient IRON AGE times, they used a two-stage burner system was used to smelt iron ORE (and scrap from broken weapons, utensils and previous smelts).
They made use of a FIRST fire-point BURNER just outside the actual 'clay furnace' hollow mound, which burned wood (and probably low-quality charcoal from less successful charcoal production 'runs' in nearby woods) to create a supply of PREHEATED air and CO/CO2 etc.
This was fed via a clay-brick duct into the SECOND BURNER in the furnace proper; which contained the higher quality charcoal mixed roughly with ore/scrap-iron).
NOTE: NATURAL (unassisted by bellows or any other mechanically-forced draft system) drove the superheated air, CO etc into and up through the smelting mixture...the arrangement of the 'level' between the fire points produced a strong enough draft to move the superheated PREBURNER gases into the smelting chamber proper....naturally inducted through a HYPERCAUST DUCT which ALSO BECAME SUPERHEATED after a time in the process....thus delivering superhot gases to the high-grade charcoal which ITSELF then reacted with the already superhot gases from the hypercaust inputs to the oxidation/reduction reactipon 'PILE' contained within the reverberative furnace structure walls.
The relevance to 9/11 WTC processes?
The Steel in certain spots therein may have been heated by similar NATURAL drafted, preheating/hypercaust/reverberative furnace-like arrangement as provided by the piles of debris 'charcoaled' by the initial heat/fire of jet fuel and other loosely scattered material (both in the piles and nearby).
These initial fires would have been FUEL-RICH due to vast quantities of jet fuel kerosene and qucikly-consumed office material 'fuels'. PERFECT for 'charcoaling' the LARGER piles of office/plane debris forced into/against the core and some perimeter wall structures.
So what do we 'get'?
We get INITIAL firepoint preheated air being DUCTED into SECONDARY fire-points consisting of a mixture of 'high value' partially/wholly 'charcoaled' (pyrolised) plastics, wood, paper, cloth/textile (and even carbon black 'soot') from pyrolised kerosene jet fuel).
Can you imagine what even naturally-drafted superhot-gas-fed combustion of those vast piles of partially 'charcoaled' piles of debris would do to the LOCALISED TEMPS in CRITICAL INTERCONNECTED PARTS of the core/and walls...especially since they were ALREADY damaged and under starin from weight-redistribution and impact deformation of critical GEOMETRIES/INTERCONNECTIONS?
And lesat anyone doubt what natural drafting can do even in 'small' height-differential fire-path cases, one need only recall the evidence of the firemen fighting an earlier office fire in one WTC tower (back in the 80's, I think. He said that the flames issuing from the cable risers etc were like BLOWTORCHES').
And then too there is the fact that 'charcoal' fires burn with almost no 'flame' (or in the 'dirty' WTC case, less flame than would be evident from a 'normal' unpyrolised fuel pile).
Which means that THOSE most critical fires causing the most critical heat damage/compromising to the steel components would be hard to see to the full extent....so one can imagine a 'tip of the iceberg' situation existing between the flames that WERE observed during a BRIGHT SUNLIT MORNING, and what REVERBERATIVE-SMELTER-LIKE FURNACE processes were ACTUALLY going on UNSEEN (not only due to INTRINSIC flame-gases 'transparency', but also due to all that infra-red absorbing clouds of SOOT and concrete/drywall etc particulate matter).
Conclusion?
Any such vast piles of preshredded and partially pyrolised fuel materials being naturally fed by PRE-super-HEATED air from initial fires which heated the 'reverberative' insulating floor-concrete etc would AT LEAST CERTAINLY and disastrously SOFTEN iron/steel....at least at certain locations having the necessary parts/conditions as in the ancient iron smelters.
Sorry guys, that's all for now. I can just hear my doctors' threatening words ringing in my ears-----not only that they will refuse see me in future, but also that if I DON'T do as I am told, my next inflammatory attack could be the last straw for my eyesight....and THEN how would I discuss such fascinating things with my friends at PhysorgForums!
Cheers all! I'll see ya'll around the forums when next I can focus and read my computer screen without risking THIS round of recovery, hehehe.
RC.
PS: SKIPPY: Sorry I haven't been around to continue our 'Contextual Mathematics' discussion, mate! I will probably do that the next time I can see the screen without wincing too much from the eye-ache it brings on. Cheers! RC.
..
.
My bad, Trippy!
That postscript to 'SKIPPY' in my above post was meant for you, of course.
I couldn't see all that well by the time I finished that post! Ouch.
My bad, Trippy!
That postscript to 'SKIPPY' in my above post was meant for you, of course.
I couldn't see all that well by the time I finished that post! Ouch.
QUOTE (RealityCheck+Oct 15 2007, 05:10 AM)
.
Hi everyone!
As you will have guessed, adoucette, Grumpy, NF, Skippy et al, I had a relapse in my optic erve allergic inflamation problem.
All my own silly fault, really; because when a few months ago my doctor said I could get back to 'normal' screenwork etc, I 'blithely interpreted that as a 'green light' to go on a practically 24/7 catch-up reading spree of all the relevant Physorg posts I had missed from my initial 6-month absence due to the nerve inflammatory problem...with the inevitable/predictable result! Ouch.
Anyway, I am back and am allowed to use my eyes for reading/writing and graphic work ONLY ONE HOUR per day. Serves me right for being so cavalier about my recovery last time, hehehe. So I will only post some sporadic inputs here and in selected other forum topics until I get the REAL go-ahead for normal eye use from my doctors...who SWEAR that they will wash their hands of me if I do such a silly thing again!
Hi everyone!
As you will have guessed, adoucette, Grumpy, NF, Skippy et al, I had a relapse in my optic erve allergic inflamation problem.
All my own silly fault, really; because when a few months ago my doctor said I could get back to 'normal' screenwork etc, I 'blithely interpreted that as a 'green light' to go on a practically 24/7 catch-up reading spree of all the relevant Physorg posts I had missed from my initial 6-month absence due to the nerve inflammatory problem...with the inevitable/predictable result! Ouch.
Anyway, I am back and am allowed to use my eyes for reading/writing and graphic work ONLY ONE HOUR per day. Serves me right for being so cavalier about my recovery last time, hehehe. So I will only post some sporadic inputs here and in selected other forum topics until I get the REAL go-ahead for normal eye use from my doctors...who SWEAR that they will wash their hands of me if I do such a silly thing again!
Glad to see you posting again. Have you looked into a text to speech program? Maybe some of the other posters have some experience with the various text to speech software and could recommend something.
QUOTE
Conclusion?
Any such vast piles of preshredded and partially pyrolised fuel materials being naturally fed by PRE-super-HEATED air from initial fires which heated the 'reverberative' insulating floor-concrete etc would AT LEAST CERTAINLY and disastrously SOFTEN iron/steel....at least at certain locations having the necessary parts/conditions as in the ancient iron smelters.
I think that your WTC furnace scenario makes some sense, I've considered that possibility myself.Any such vast piles of preshredded and partially pyrolised fuel materials being naturally fed by PRE-super-HEATED air from initial fires which heated the 'reverberative' insulating floor-concrete etc would AT LEAST CERTAINLY and disastrously SOFTEN iron/steel....at least at certain locations having the necessary parts/conditions as in the ancient iron smelters.
QUOTE (RealityCheck+Oct 15 2007, 05:10 AM)
I had a relapse in my optic erve allergic inflamation problem.
Disregulation of the "master energy" hormone leptin is associated with all manner of inflammatory conditions, via interaction with other hormones that promote inflammation. See the book "mastering leptin" by Richards and Richards. Also, I think you need the right mix of omega fatty acids in the diet to avoid inflammation, and quercitin will help keep allergies in check. See udoerasmus.com for more info on oils.
While not relevant to your condition, I have it on good authority that carnosine will actually help reverse capillary stiffness due to diabetes (from, I think, glucose/protein cross linking). This could save the eye sight of some diabetics.
That this information is not widely known is a crime.
BTW, I was on the way home from Gary Null's health food store in Manhattan, reading another book on leptin by Richards. I was reading the section wherein he describes how leptin disregulation in a pregnant woman (with a female) will adversely affect her grandchildren, as her foetus is being formed with all the eggs she will ever have. I was lamenting the fact that parents don't know the simple rules of eating to avoid leptin disregulation.
Who comes onto the subway I was on but Anderson Cooper. I told him that I'd be happy to give him my book if he'd take a look at it. He was quite friendly, and graciously said okay.
No idea if he subsequently covered it on his show.
Disregulation of the "master energy" hormone leptin is associated with all manner of inflammatory conditions, via interaction with other hormones that promote inflammation. See the book "mastering leptin" by Richards and Richards. Also, I think you need the right mix of omega fatty acids in the diet to avoid inflammation, and quercitin will help keep allergies in check. See udoerasmus.com for more info on oils.
While not relevant to your condition, I have it on good authority that carnosine will actually help reverse capillary stiffness due to diabetes (from, I think, glucose/protein cross linking). This could save the eye sight of some diabetics.
That this information is not widely known is a crime.
BTW, I was on the way home from Gary Null's health food store in Manhattan, reading another book on leptin by Richards. I was reading the section wherein he describes how leptin disregulation in a pregnant woman (with a female) will adversely affect her grandchildren, as her foetus is being formed with all the eggs she will ever have. I was lamenting the fact that parents don't know the simple rules of eating to avoid leptin disregulation.
Who comes onto the subway I was on but Anderson Cooper. I told him that I'd be happy to give him my book if he'd take a look at it. He was quite friendly, and graciously said okay.
No idea if he subsequently covered it on his show.
QUOTE (RealityCheck+Oct 14 2007, 11:21 PM)
I couldn't see all that well by the time I finished that post! Ouch.
Glad you are back.
Take it easy now...
Glad you are back.
Take it easy now...
Follow-up Comments to Flight 175 Impact Article (Based on Initial Feedback)
1. It appears that many of the videos showing Flight 175 entering WTC 2 were taken with cameras operating at 30 frames per second. It follows that these videos provide a series of still frames separated by 33.3 milliseconds. Given that Flight 175 was traveling at about 250 m/s, the aircraft moved about 8 meters between frames or 1/6th of the length of the fuselage. This also means that each video record of the impact, from the moment the aircraft made contact with WTC 2, to the moment the aircraft disappeared into the building, actually consists of only six images of the aircraft. Thus only six velocities, and, if the aircraft was being slowed, only six velocity decrements may be extracted from any particular video of the impact of Flight 175 on WTC 2. Nevertheless, the precision and accuracy of these velocity measurements is not limited by the paucity of video frames but by the photographic resolution of each frame.
2. An inspection of selected frames from some of the better quality videos of the impact of Flight 175 indicates a photographic resolution of about 0.5 meters. It appears that the effective shutter speed of the cameras that were used to record the videos must have been at least 1/500th of a second since very little motion blur is apparent in the still frames. Based on these estimates I would argue that a velocity decrement of about 10 m/s, (as opposed to the 5 m/s mentioned in my article), would be detectable in the best available videos. Omika’s data show a velocity decrement of almost 100 m/s about 0.2 seconds after first contact of Flight 175 with the south face of WTC 2. This means the tail of the aircraft was about 6 meters short of the position it would have reached if the building had offered no resistance to the impact.
3. Morgan Reynolds, in a written response to my article, suggests that I should “admit my contention that Newton’s Laws of mechanics are defunct … (because) … the aluminum plane cuts right through steel and disappears inside the Tower. This is impossible. Structural steel is far stronger than aluminum… and would suffer only light damage compared to complete and utter destruction/rejection of an aluminum airplane, with most of its debris scattered outside the building, especially wings, tail section and a majority of the shattered fuselage.” All I can say to this is that a number of specialists in the field of engineering mechanics, such as T. Wierzbicki, H. Astaneh and M. Karim have published independent analyses of the aircraft impacts on the Twin Towers and concluded that the facile and complete penetration of the perimeter walls of WTC 1 & 2 was to be expected for a Boeing 767 aircraft traveling at over 200 m/s. Wierzbicki’s calculations also show that only 3 % of the initial kinetic energy of Flight 175 was expended by the aircraft cutting through the perimeter wall of WTC 2.
4. High-speed impacts of aircraft flying into buildings may be classified as “hard” or “soft”. In a hard impact some portion of the stationary target is crushed by the moving projectile, which itself remains undamaged. In a “soft” impact the projectile is crushed while the target remains largely undamaged. The Sandia test of the impact of a F-4 jet into a concrete wall approximate a “soft” impact because the aircraft was totally pulverized and the concrete was relatively undamaged. Only in a purely “soft” impact would the motion of the tail of the aircraft be totally decoupled from the motion of the nose of the aircraft. In the impact of Flight 175 on WTC 2, the aircraft had sufficient kinetic energy to penetrate the open, cage-like, structure of the building. This gave the Flight 175 impact some “hard” characteristics so that the entire aircraft should be slowed to some degree as it penetrated the building.
5. Let’s estimate the deceleration of an aircraft striking a massive structure. We will follow the methodology of J. Riera as published in Nuclear Engineering and Design 8, 415, (1968). In this classic paper on aircraft impact Riera showed that the deceleration of a large commercial aircraft striking a building is governed by the aircraft’s mass distribution. In the case of a Boeing 767 weighing 124,000 kg, the average mass per unit length is 2557 kg/m. However, because the massive engines, fuel tanks and undercarriage assemblies are located near the center of the aircraft, about 75 % of the aircraft’s mass is confined to a relatively short section starting approximately 16 meters from the nose of the aircraft. Because of this mass distribution, the reaction load and deceleration of a fuselage section at the rear of the aircraft will be very small during the initial stages of an impact. Following Riera’s approach, I would estimate that the peak reaction load on Flight 175 was about 250 MN at about 0.1 seconds into the impact, (dropping to zero at 0.2 seconds). Very roughly this means there was an average reaction force of 125 MN acting on Flight 175 for 0.1 seconds. Using Newton’s 2nd Law, (Yes Morgan, I haven’t abandoned it!), this implies a deceleration of about 100 g’s! From these numbers we may calculate the velocity of Flight 175 when it was 0.2 seconds into its impact with WTC 2 to be about 150 m/s in good agreement with Omika’s result.
1. It appears that many of the videos showing Flight 175 entering WTC 2 were taken with cameras operating at 30 frames per second. It follows that these videos provide a series of still frames separated by 33.3 milliseconds. Given that Flight 175 was traveling at about 250 m/s, the aircraft moved about 8 meters between frames or 1/6th of the length of the fuselage. This also means that each video record of the impact, from the moment the aircraft made contact with WTC 2, to the moment the aircraft disappeared into the building, actually consists of only six images of the aircraft. Thus only six velocities, and, if the aircraft was being slowed, only six velocity decrements may be extracted from any particular video of the impact of Flight 175 on WTC 2. Nevertheless, the precision and accuracy of these velocity measurements is not limited by the paucity of video frames but by the photographic resolution of each frame.
2. An inspection of selected frames from some of the better quality videos of the impact of Flight 175 indicates a photographic resolution of about 0.5 meters. It appears that the effective shutter speed of the cameras that were used to record the videos must have been at least 1/500th of a second since very little motion blur is apparent in the still frames. Based on these estimates I would argue that a velocity decrement of about 10 m/s, (as opposed to the 5 m/s mentioned in my article), would be detectable in the best available videos. Omika’s data show a velocity decrement of almost 100 m/s about 0.2 seconds after first contact of Flight 175 with the south face of WTC 2. This means the tail of the aircraft was about 6 meters short of the position it would have reached if the building had offered no resistance to the impact.
3. Morgan Reynolds, in a written response to my article, suggests that I should “admit my contention that Newton’s Laws of mechanics are defunct … (because) … the aluminum plane cuts right through steel and disappears inside the Tower. This is impossible. Structural steel is far stronger than aluminum… and would suffer only light damage compared to complete and utter destruction/rejection of an aluminum airplane, with most of its debris scattered outside the building, especially wings, tail section and a majority of the shattered fuselage.” All I can say to this is that a number of specialists in the field of engineering mechanics, such as T. Wierzbicki, H. Astaneh and M. Karim have published independent analyses of the aircraft impacts on the Twin Towers and concluded that the facile and complete penetration of the perimeter walls of WTC 1 & 2 was to be expected for a Boeing 767 aircraft traveling at over 200 m/s. Wierzbicki’s calculations also show that only 3 % of the initial kinetic energy of Flight 175 was expended by the aircraft cutting through the perimeter wall of WTC 2.
4. High-speed impacts of aircraft flying into buildings may be classified as “hard” or “soft”. In a hard impact some portion of the stationary target is crushed by the moving projectile, which itself remains undamaged. In a “soft” impact the projectile is crushed while the target remains largely undamaged. The Sandia test of the impact of a F-4 jet into a concrete wall approximate a “soft” impact because the aircraft was totally pulverized and the concrete was relatively undamaged. Only in a purely “soft” impact would the motion of the tail of the aircraft be totally decoupled from the motion of the nose of the aircraft. In the impact of Flight 175 on WTC 2, the aircraft had sufficient kinetic energy to penetrate the open, cage-like, structure of the building. This gave the Flight 175 impact some “hard” characteristics so that the entire aircraft should be slowed to some degree as it penetrated the building.
5. Let’s estimate the deceleration of an aircraft striking a massive structure. We will follow the methodology of J. Riera as published in Nuclear Engineering and Design 8, 415, (1968). In this classic paper on aircraft impact Riera showed that the deceleration of a large commercial aircraft striking a building is governed by the aircraft’s mass distribution. In the case of a Boeing 767 weighing 124,000 kg, the average mass per unit length is 2557 kg/m. However, because the massive engines, fuel tanks and undercarriage assemblies are located near the center of the aircraft, about 75 % of the aircraft’s mass is confined to a relatively short section starting approximately 16 meters from the nose of the aircraft. Because of this mass distribution, the reaction load and deceleration of a fuselage section at the rear of the aircraft will be very small during the initial stages of an impact. Following Riera’s approach, I would estimate that the peak reaction load on Flight 175 was about 250 MN at about 0.1 seconds into the impact, (dropping to zero at 0.2 seconds). Very roughly this means there was an average reaction force of 125 MN acting on Flight 175 for 0.1 seconds. Using Newton’s 2nd Law, (Yes Morgan, I haven’t abandoned it!), this implies a deceleration of about 100 g’s! From these numbers we may calculate the velocity of Flight 175 when it was 0.2 seconds into its impact with WTC 2 to be about 150 m/s in good agreement with Omika’s result.
QUOTE (NEU-FONZE+Oct 16 2007, 08:00 AM)
1. It appears that many of the videos showing Flight 175 entering WTC 2 were taken with cameras operating at 30 frames per second. It follows that these videos provide a series of still frames separated by 33.3 milliseconds. Given that Flight 175 was traveling at about 250 m/s, the aircraft moved about 8 meters between frames or 1/6th of the length of the fuselage. This also means that each video record of the impact, from the moment the aircraft made contact with WTC
I disagree with aspects of this statement (for what it's worth) because it should be possible to interpolate data between the frames based on the profile of the motion bluring.
If it is possible to characterize the transperancy of the tail section against the background, then the rate of change of that transperancy should provide information about the decceleration.
Take, as an example a 1/220 sec exposure (something you might use for an ISO 100 film on a bright day). In that 1/220 sec exposure, flight 175 would have moved approx 1.14m, which would blur the back end of the tail. If the plane is travelling at a constant velocity, and if we can characterize the transperancy (I can't think of any better word for it) of the motion blur, then what we should find is a linear relationship between the distance from the leading edge of the tail, and the transperancy ranging from 100% at (say for example) x+1.15m to 0% at x m, where x is simply the width of the tail section being analyzed.
It follows then that if we observe a curve in this data, the shape of this curve will give us direct information about the acceleration experienced by the tail section of the plane.
I disagree with aspects of this statement (for what it's worth) because it should be possible to interpolate data between the frames based on the profile of the motion bluring.
If it is possible to characterize the transperancy of the tail section against the background, then the rate of change of that transperancy should provide information about the decceleration.
Take, as an example a 1/220 sec exposure (something you might use for an ISO 100 film on a bright day). In that 1/220 sec exposure, flight 175 would have moved approx 1.14m, which would blur the back end of the tail. If the plane is travelling at a constant velocity, and if we can characterize the transperancy (I can't think of any better word for it) of the motion blur, then what we should find is a linear relationship between the distance from the leading edge of the tail, and the transperancy ranging from 100% at (say for example) x+1.15m to 0% at x m, where x is simply the width of the tail section being analyzed.
It follows then that if we observe a curve in this data, the shape of this curve will give us direct information about the acceleration experienced by the tail section of the plane.
QUOTE (Trippy+Oct 15 2007, 07:49 PM)
If it is possible to characterize the transperancy of the tail section against the background, then the rate of change of that transperancy should provide information about the decceleration.
Perhaps. This is similar to what shagster said earlier. Practically speaking, it could be a real PITA, but maybe not.
NEU_FONZE goes on to say that there is very little motion blur and that the limiting factor would seem to be spatial resolution. NEU-FONZE, could you post a couple of those select frames here?
Perhaps. This is similar to what shagster said earlier. Practically speaking, it could be a real PITA, but maybe not.
NEU_FONZE goes on to say that there is very little motion blur and that the limiting factor would seem to be spatial resolution. NEU-FONZE, could you post a couple of those select frames here?
OneWhiteEye --- Please give me additional information regarding your count of
18 stories = 258.67 +/- 1 pixels at the wall.
Does this include the upper mechanical floors (count 2), floor 110 (count 1) and then the inward sloping roof up to the flat roof of the PH (count 1)?
Thanks.
18 stories = 258.67 +/- 1 pixels at the wall.
Does this include the upper mechanical floors (count 2), floor 110 (count 1) and then the inward sloping roof up to the flat roof of the PH (count 1)?
Thanks.
QUOTE (David B. Benson+Oct 15 2007, 09:42 PM)
OneWhiteEye --- Please give me additional information regarding your count of
18 stories = 258.67 +/- 1 pixels at the wall.
Does this include the upper mechanical floors (count 2), floor 110 (count 1) and then the inward sloping roof up to the flat roof of the PH (count 1)?
Thanks.
No, it only included floors that appeared uniform in extent. Floor 104/105 is the top floor in that measurement, best as I can tell from looking at some NIST diagrams, but I can't really tell.
The top of the measurement (the green line) is shown here, see what you think:
http://i24.tinypic.com/28u31gp.jpg
18 stories = 258.67 +/- 1 pixels at the wall.
Does this include the upper mechanical floors (count 2), floor 110 (count 1) and then the inward sloping roof up to the flat roof of the PH (count 1)?
Thanks.
No, it only included floors that appeared uniform in extent. Floor 104/105 is the top floor in that measurement, best as I can tell from looking at some NIST diagrams, but I can't really tell.
The top of the measurement (the green line) is shown here, see what you think:
http://i24.tinypic.com/28u31gp.jpg
QUOTE (OneWhiteEye+Oct 15 2007, 03:00 PM)
Floor 104/105 is the top floor in that measurement, best as I can tell from looking at some NIST diagrams, but I can't really tell.
Floor 105 is the uppermost of floors 79 through 105 that were all 12 feet high. Is that what you mean?
As usual, I am unable to make out anything (other than the green line).
Floor 105 is the uppermost of floors 79 through 105 that were all 12 feet high. Is that what you mean?As usual, I am unable to make out anything (other than the green line).
Trippy and OneWhiteEYE:
I think I see what Trippy is suggesting and I guess it WOULD be a way to get velocity change data.
Sorry, I am not good a keeping track of all the video clips out there. However, I would suggest you look at Figure 7-12 on page 98 of NIST NCSTAR 1-5A for some good examples of the type of images I am referring to. These images show very little motion blur.
I think I see what Trippy is suggesting and I guess it WOULD be a way to get velocity change data.
Sorry, I am not good a keeping track of all the video clips out there. However, I would suggest you look at Figure 7-12 on page 98 of NIST NCSTAR 1-5A for some good examples of the type of images I am referring to. These images show very little motion blur.
Yes, all floors (ETA: of the measurement) are the same height in the image. I can't easily tell if it's floor 104 or 105 without resizing and overlaying the reference diagram and waiting til dark. Edge enhancement, contrast and brightness adjustments all tend to obliterate the detail of the fine floor lines.
QUOTE (NEU-FONZE+Oct 15 2007, 10:40 PM)
Trippy and OneWhiteEYE:
I think I see what Trippy is suggesting and I guess it WOULD be a way to get velocity change data.
Sorry, I am not good a keeping track of all the video clips out there. However, I would suggest you look at Figure 7-12 on page 98 of NIST NCSTAR 1-5A for some good examples of the type of images I am referring to. These images show very little motion blur.
Thanks, I'll look that up.
By the way, I haven't forgotten about the question of the F4 data vs. extraction, etc. It's just a pretty long process with 12,535 frames (2.88 GB) of source video. There are 17 segments and I'm still finding the split points and segregating them into their own directories.
One thing that I see as a possibility for a wildcard in this is the 2nd rocket motor might actually be producing some thrust at the time of nose contact. It's at the tail end of the burn right around that time; I think maybe they should have added a few meters to the track or a few kg more water because they really cut it close. Just a possibility, wouldn't put any stock in it until examined thoroughly.
Likely there would be a load cell on the frame mounting the motor to the sled so residual thrust could be measured, though I'm not sure that helps when the F4 is breaking up.
I think I see what Trippy is suggesting and I guess it WOULD be a way to get velocity change data.
Sorry, I am not good a keeping track of all the video clips out there. However, I would suggest you look at Figure 7-12 on page 98 of NIST NCSTAR 1-5A for some good examples of the type of images I am referring to. These images show very little motion blur.
Thanks, I'll look that up.
By the way, I haven't forgotten about the question of the F4 data vs. extraction, etc. It's just a pretty long process with 12,535 frames (2.88 GB) of source video. There are 17 segments and I'm still finding the split points and segregating them into their own directories.
One thing that I see as a possibility for a wildcard in this is the 2nd rocket motor might actually be producing some thrust at the time of nose contact. It's at the tail end of the burn right around that time; I think maybe they should have added a few meters to the track or a few kg more water because they really cut it close. Just a possibility, wouldn't put any stock in it until examined thoroughly.
Likely there would be a load cell on the frame mounting the motor to the sled so residual thrust could be measured, though I'm not sure that helps when the F4 is breaking up.
Neu-Fonze,
I went through my archive and found another video (25 fps with a steady camera)
The nice thing of this image is that you also see a part of the plane going through the building, within the building it really decelerates!
http://i23.tinypic.com/2jxio.png
And for those who missed it (I posted them at LC weeks ago and recently at JREF) here the other two in a single image
http://i16.tinypic.com/4y9cdqb.jpg
I don't think there is much more, the same with original resolution would be nice.
I went through my archive and found another video (25 fps with a steady camera)
The nice thing of this image is that you also see a part of the plane going through the building, within the building it really decelerates!
http://i23.tinypic.com/2jxio.png
And for those who missed it (I posted them at LC weeks ago and recently at JREF) here the other two in a single image
http://i16.tinypic.com/4y9cdqb.jpg
I don't think there is much more, the same with original resolution would be nice.
QUOTE (OneWhiteEye+Oct 15 2007, 03:40 PM)
... I can't easily tell if it's floor 104 or 105 ...
Thank you. Whether it was 104 or 105 at the top does not matter.
I have what matters: all 18 stories were 12 feet high.
Thank you. Whether it was 104 or 105 at the top does not matter.
I have what matters: all 18 stories were 12 feet high.
QUOTE (David B. Benson+Oct 10 2007, 09:43 PM)
(1) Does floor 110, just above the uppermost pair of mechanical floors, have windows?
I don't see windows on 110 in the photos and diagrams in the NIST reports.
The highest story with windows was 107 and those windows were taller than the windows on the average office stories.
I don't see windows on 110 in the photos and diagrams in the NIST reports.
The highest story with windows was 107 and those windows were taller than the windows on the average office stories.
QUOTE (NEU-FONZE+Oct 15 2007, 10:40 PM)
...I would suggest you look at Figure 7-12 on page 98 of NIST NCSTAR 1-5A for some good examples of the type of images I am referring to.
I've downloaded the video from which those are taken. Not first generation, maybe, but very interesting all the same. It can be viewed on Scott Myers' website (if you can view MOV files):
Scott Myers Video
The movement of the moire pattern on the side of the building after the strike is incredible.
I've downloaded the video from which those are taken. Not first generation, maybe, but very interesting all the same. It can be viewed on Scott Myers' website (if you can view MOV files):
Scott Myers Video
The movement of the moire pattern on the side of the building after the strike is incredible.
QUOTE (NEU-FONZE+Oct 14 2007, 05:05 PM)
Arthur:
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
Neu, please note that when you quote from DIFFERENT NIST chapters you are CHANGING methodologies.
NIST 1-5 for instance deals with the VIDEO Analysis.
That .20 deals with what they measured via the VIDEOs.
NIST 1-2 deals with the MODELED results.
The Modeled efforts pick a SPECIFIC SPEED AND SPECIFIC ANGLES AND a SPECIFIC IMPACT point and try to get as close to the visual evidence as MODELING ALLOWS.
Why do you insist on comparing APPLES to ORANGES and asking why they aren't the same?
Arthur
NIST's Table 7-1 of NCSTAR 1-5A quotes timings down to 1/100th of a second and specifies that Flight 175 entered WTC 2 in 0.20 seconds. This implies that the tail of the aircraft was not decelerated by more than a few m/s.
However, Fig 9-28 of NCSTAR 1-2B shows that the aircraft had lost 60 % of its momentum 0.2 seconds into the impact.
NIST also states in NCSTAR 1-2B that Flight 175 penetrated the 81st floor slab that "sliced the fuselage in half."
How is all this possible?
Neu, please note that when you quote from DIFFERENT NIST chapters you are CHANGING methodologies.
NIST 1-5 for instance deals with the VIDEO Analysis.
That .20 deals with what they measured via the VIDEOs.
NIST 1-2 deals with the MODELED results.
The Modeled efforts pick a SPECIFIC SPEED AND SPECIFIC ANGLES AND a SPECIFIC IMPACT point and try to get as close to the visual evidence as MODELING ALLOWS.
Why do you insist on comparing APPLES to ORANGES and asking why they aren't the same?
Arthur
OneWhiteEye:
Thanks for the link but I am unable to view it right now with my 9 year old computer.
Anyway, I think you are correct about the issue of exactly when the engines shut off, (or were disconnected from the fuselage), is important for the F-4 AND the Flight 175 crashes. The engines were providing a driving force that was being countered by air resistance and the resistance of the concrete block/building. To analyze the crash properly you need to know precisely when the rockets/engines were no longer acting on the aircraft's fuselage.
Einsteen:
I think you are showing the same engine disconnection effect in your latest "smear-o-gram". (I dont know what else to call it!)
Nice work!!!!!
By the way, I am sure you have been asked this before but, is there a way to put some time and displacement units on the axes of these plots?
Thanks for the link but I am unable to view it right now with my 9 year old computer.
Anyway, I think you are correct about the issue of exactly when the engines shut off, (or were disconnected from the fuselage), is important for the F-4 AND the Flight 175 crashes. The engines were providing a driving force that was being countered by air resistance and the resistance of the concrete block/building. To analyze the crash properly you need to know precisely when the rockets/engines were no longer acting on the aircraft's fuselage.
Einsteen:
I think you are showing the same engine disconnection effect in your latest "smear-o-gram". (I dont know what else to call it!)
Nice work!!!!!
By the way, I am sure you have been asked this before but, is there a way to put some time and displacement units on the axes of these plots?
Arthur:
A time is a time is a time.... NIST state that Flight 175 "disappeared completely" inside WTC 2 in 0.2 seconds.
NIST's "best estimate" of the speed of Flight 175 was 542 mph = 242 m/s.
The time for an aircraft 48.5 meters long to "disappear completely" inside WTC 2 is 48.5/242 = 0.2004 seconds.
But this means that Flight 175 DID NOT SLOW DOWN WHEN IT ENTERED WTC 2.
Which is incorrect!
Are the apples and oranges that I should not be comparing simply different CONSULTANT's REPORTS that were not cross-checked by the NIST editors?
A time is a time is a time.... NIST state that Flight 175 "disappeared completely" inside WTC 2 in 0.2 seconds.
NIST's "best estimate" of the speed of Flight 175 was 542 mph = 242 m/s.
The time for an aircraft 48.5 meters long to "disappear completely" inside WTC 2 is 48.5/242 = 0.2004 seconds.
But this means that Flight 175 DID NOT SLOW DOWN WHEN IT ENTERED WTC 2.
Which is incorrect!
Are the apples and oranges that I should not be comparing simply different CONSULTANT's REPORTS that were not cross-checked by the NIST editors?
QUOTE (NEU-FONZE+Oct 16 2007, 12:29 AM)
Thanks for the link but I am unable to view it right now with my 9 year old computer.
That's the downside of an old machine. The upside is less malware intrusion. If mine still ran I'd be using it.
Give me a few to post a GIF; you've got to see this moire.
That's the downside of an old machine. The upside is less malware intrusion. If mine still ran I'd be using it.
Give me a few to post a GIF; you've got to see this moire.
QUOTE (shagster+Oct 16 2007, 12:33 AM)
http://www.youtube.com/watch?v=IWhJsY4cf_A
Yes, that's it, at a different res than on the Myer page. Let me get that as well. Moire not so obvious on this one.
Edit: actually it's the same resolution and frame rate, just didn't look that way on YouTube.
Yes, that's it, at a different res than on the Myer page. Let me get that as well. Moire not so obvious on this one.
Edit: actually it's the same resolution and frame rate, just didn't look that way on YouTube.
QUOTE (NEU-FONZE+Oct 15 2007, 08:39 PM)
Arthur:
A time is a time is a time.... NIST state that Flight 175 "disappeared completely" inside WTC 2 in 0.2 seconds.
NIST's "best estimate" of the speed of Flight 175 was 542 mph = 242 m/s.
The time for an aircraft 48.5 meters long to "disappear completely" inside WTC 2 is 48.5/242 = 0.2004 seconds.
But this means that Flight 175 DID NOT SLOW DOWN WHEN IT ENTERED WTC 2.
Which is incorrect!
Are the apples and oranges that I should not be comparing simply different CONSULTANT's REPORTS that were not cross-checked by the NIST editors?
No, and read SLOWLY Neu.
ONE IS A VISUAL ANALYSIS based on the VIDEOS.
Do you DISAGREE with the timings derived from the VISUAL ANALYSIS?
Why do you insist on using 542 MPH when the airspeed derived from the video evidence is 542 MPH +/- 24 MPH?
Do you disagree with the figure E-36 in 1-2B where this VIDEO derived reference point is only shown for REFERENCE?
What, pray tell, is YOUR POINT, Neu?
Arthur
A time is a time is a time.... NIST state that Flight 175 "disappeared completely" inside WTC 2 in 0.2 seconds.
NIST's "best estimate" of the speed of Flight 175 was 542 mph = 242 m/s.
The time for an aircraft 48.5 meters long to "disappear completely" inside WTC 2 is 48.5/242 = 0.2004 seconds.
But this means that Flight 175 DID NOT SLOW DOWN WHEN IT ENTERED WTC 2.
Which is incorrect!
Are the apples and oranges that I should not be comparing simply different CONSULTANT's REPORTS that were not cross-checked by the NIST editors?
No, and read SLOWLY Neu.
ONE IS A VISUAL ANALYSIS based on the VIDEOS.
Do you DISAGREE with the timings derived from the VISUAL ANALYSIS?
Why do you insist on using 542 MPH when the airspeed derived from the video evidence is 542 MPH +/- 24 MPH?
Do you disagree with the figure E-36 in 1-2B where this VIDEO derived reference point is only shown for REFERENCE?
What, pray tell, is YOUR POINT, Neu?
Arthur
QUOTE
NIST: "We are Unable to Provide a Full Explanation of the Total Collapse"
On April 11th, 2007, family members Bill Doyle and Bob McIlvaine, scientists Steven Jones and Kevin Ryan, architect Richard Gage and the group Scholars for 9/11 Truth and Justice filed a petition with NIST demanding that it correct its erroneous methods and findings.
On September 27th, NIST finally replied.
While the reply is mainly bogus, and the filers of the petition intend to appeal the decision of NIST not to correct the many fatal errors in its reports, attorney James Gourley (who drafted the petition) has pointed out one interesting statement. Specifically, NIST says in its reply:
"We are unable to provide a full explanation of the total collapse".
...
georgewashington.blogspot.com/
Finaly officially admited. NIST "unable to provide a full explanation of the total collapse" unless it stops covering up the evidence that the Twin Towers and were brought down with explosives.
Nothing new.
NIST never claimed to provide any more than an explanation for what caused the towers to START to collapse.
BUT
Other scientists (Bazant et al) have shown that from that point on, collapse is inevitable.
What this is
http://www.911proof.com/NIST.pdf
is a bitch slap to Jones, Ryan and Gage
Arthur
NIST never claimed to provide any more than an explanation for what caused the towers to START to collapse.
BUT
Other scientists (Bazant et al) have shown that from that point on, collapse is inevitable.
What this is
http://www.911proof.com/NIST.pdf
is a bitch slap to Jones, Ryan and Gage
Arthur
A cropped clip from the Myers video in GIF form. I opted not to embed it because of inconvenience to anyone on dialup trying to load this page. Should run OK on old computers.
http://i20.tinypic.com/2mwxyfk.gif
http://i20.tinypic.com/2mwxyfk.gif
QUOTE
NIST state that Flight 175 "disappeared completely" inside WTC 2 in 0.2 seconds.
You realize that "0.2 seconds" isn't exactly the same thing as "0.200 seconds", right? It could as easily mean "0.249 seconds", or "0.151 seconds".
Most of the deceleration occurred *at* the perimeter wall, by the stuff that was colliding with it directly.
The force available to decelerate the plane was limited by how much force could be coupled to the airframe. That's probably not as much as you'd think. Most of the stuff impacting the WTC simply would've sheared from the airframe due to the impact.
Incidentally, the way to interpret that 0.2seconds for the plane to enter the tower and 0.2seconds for it to decelerate by 60% is to recognize that it did all its deceleration at the perimeter wall and inside the tower. The stuff outside didn't decelerate enough to measure, for the reasons cited.
Pay attention to the content of the questions, Trippy:
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
you replied: There's no evidence of Thermate in thatimage.
But I didn't ask "Where is the evidence of thermite in this image of a metal fire?" ---- did I???
Perhaps you can't answer the questions because "your ignorance is showing."
That being the case, simply ignore the questions, or reply "I don't know the answers."
Simple, huh?
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
wcelliot:
The capacity of a microphone diaphram to respond to the pattern of compression and rarefaction produced in the wake of an explosion does not exceed its capacity or induce clipping when placed at a reasonable distance from the event, wc.
Already you must know this to be the case.
Amplitude follows an inverse square law, and distance from explosion thus must effect the amplitude of sound recorded.
You are still showing your ignorance and arrogance in persisting to define the sound produced in the wake of an explosion in terms of the duration of chemical chain reaction that occurs upon ignition.
This is extremely misleading and dishonest, technically impossible and FALSE.
wcelliot:
The capacity of a microphone diaphram to respond to the pattern of compression and rarefaction produced in the wake of an explosion does not exceed its capacity or induce clipping when placed at a reasonable distance from the event, wc.
Already you must know this to be the case.
Amplitude follows an inverse square law, and distance from explosion thus must effect the amplitude of sound recorded.
You are still showing your ignorance and arrogance in persisting to define the sound produced in the wake of an explosion in terms of the duration of chemical chain reaction that occurs upon ignition.
This is extremely misleading and dishonest, technically impossible and FALSE.
wcelliot: I also designed an acoustic phased-array aperture,
Did you really? - I'll try to remember that next time I have an ultrasound!!!
Can you please, once again, provide a link to
(1) any sound produced by a"catastrophic brittle failure,"
and to
(2) those collapse "pops" you spent so much time trying to explain.
Funny, you've made two errors in one statement.
The acoustic array I designed and built worked in the audio range.
And, the energy of the explosive detonation is in the ultrasonic regime. It starts, goes off, and finishes in less time than your digital recording system allocates to ONE SAMPLE. That's how high explosives work, they release their energy in a very short period of time.
For a 40kHz sampling system, one sample represents 25microseconds of sound. That's one number that's assigned to the amplitude of the signal during that 25microsecond interval.
A four-inch brick of C-4 goes from solid to gas in 10 microseconds. Whatever it was going to do, is already done by the 11th microsecond. It is, at that point, an expanding shock wave. If you want to see what complexities that waveform has, you'd need to sample at a rate that allows you to see the complexities, say, 1MHz. If you had a recording system that sampled a million times per second, and a microphone that didn't saturate with pressures in the thousands of pounds-per-square-inch, then you could gather as many as 10 datapoints describing the intrinsic sound of an explosion.
Go ahead and provide me a link to a recording of an explosion that was made with a 1MHz sampling rate.
Anything short of that is a sound file that has ONE SAMPLE taken during the explosion, and the rest is recording the various echoes of that explosion bouncing off the environment that the explosion took place in.
Maybe explosives *do* have a characteristic waveform. But you won't see it with a system that samples at 40kHz.
"NIST never claimed to provide any more than an explanation for what caused the towers to START to collapse."
Nor do they explain how the entire upper section is able to fall into and displace through the lower section's core, as if nothing was there. The orderly descent of the antenna suggests the upper section's core is not undergoing any concussive deceleration, as it enters the lower section. Either the lower core just dropped away (???), or it somehow splayed apart (?). In light of the lateral force theories being accepted as sufficient to obliterate the core network, shouldn't Newton's Third Law be invoked here? Why would the massive core structure yield so quickly and completely to these forces. In either case the peripheral columns should have reacted, instead, the lower cage remained intact, even as the upper cage was being shoe-horned into it, (for the duration of the gif)
The following simulations remind us of the towers structural redundancy, and how it should have done a better job resisting collapse, especially in the N tower.
http://www.youtube.com/watch?v=qJ11i6fi7KQ...related&search=
http://www.youtube.com/watch?v=ExmSMU9ls-w
Note: I do not support the final conclusion speculated in this video.
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
you replied: There's no evidence of Thermate in thatimage.
But I didn't ask "Where is the evidence of thermite in this image of a metal fire?" ---- did I???
Perhaps you can't answer the questions because "your ignorance is showing."
That being the case, simply ignore the questions, or reply "I don't know the answers."
Simple, huh?
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
wcelliot:
QUOTE
. Failure results in the top of the signal getting "clipped". Explosions exceed the amplitude of any acoustic system capable of capturing quiet sounds, as they generate overpressures capable of ripping steel apart.
The capacity of a microphone diaphram to respond to the pattern of compression and rarefaction produced in the wake of an explosion does not exceed its capacity or induce clipping when placed at a reasonable distance from the event, wc.
Already you must know this to be the case.
Amplitude follows an inverse square law, and distance from explosion thus must effect the amplitude of sound recorded.
You are still showing your ignorance and arrogance in persisting to define the sound produced in the wake of an explosion in terms of the duration of chemical chain reaction that occurs upon ignition.
This is extremely misleading and dishonest, technically impossible and FALSE.
wcelliot:
QUOTE (->
| QUOTE |
| . Failure results in the top of the signal getting "clipped". Explosions exceed the amplitude of any acoustic system capable of capturing quiet sounds, as they generate overpressures capable of ripping steel apart. |
The capacity of a microphone diaphram to respond to the pattern of compression and rarefaction produced in the wake of an explosion does not exceed its capacity or induce clipping when placed at a reasonable distance from the event, wc.
Already you must know this to be the case.
Amplitude follows an inverse square law, and distance from explosion thus must effect the amplitude of sound recorded.
You are still showing your ignorance and arrogance in persisting to define the sound produced in the wake of an explosion in terms of the duration of chemical chain reaction that occurs upon ignition.
This is extremely misleading and dishonest, technically impossible and FALSE.
wcelliot: I also designed an acoustic phased-array aperture,
Did you really? - I'll try to remember that next time I have an ultrasound!!!
Can you please, once again, provide a link to
(1) any sound produced by a"catastrophic brittle failure,"
and to
(2) those collapse "pops" you spent so much time trying to explain.
QUOTE
Did you really? - I'll try to remember that next time I have an ultrasound!!!
Funny, you've made two errors in one statement.
The acoustic array I designed and built worked in the audio range.
And, the energy of the explosive detonation is in the ultrasonic regime. It starts, goes off, and finishes in less time than your digital recording system allocates to ONE SAMPLE. That's how high explosives work, they release their energy in a very short period of time.
For a 40kHz sampling system, one sample represents 25microseconds of sound. That's one number that's assigned to the amplitude of the signal during that 25microsecond interval.
A four-inch brick of C-4 goes from solid to gas in 10 microseconds. Whatever it was going to do, is already done by the 11th microsecond. It is, at that point, an expanding shock wave. If you want to see what complexities that waveform has, you'd need to sample at a rate that allows you to see the complexities, say, 1MHz. If you had a recording system that sampled a million times per second, and a microphone that didn't saturate with pressures in the thousands of pounds-per-square-inch, then you could gather as many as 10 datapoints describing the intrinsic sound of an explosion.
Go ahead and provide me a link to a recording of an explosion that was made with a 1MHz sampling rate.
Anything short of that is a sound file that has ONE SAMPLE taken during the explosion, and the rest is recording the various echoes of that explosion bouncing off the environment that the explosion took place in.
Maybe explosives *do* have a characteristic waveform. But you won't see it with a system that samples at 40kHz.
QUOTE (Al Khwarizmi - step-by-step+Oct 16 2007, 07:26 PM)
Pay attention to the content of the questions, Trippy:
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
I'm sorry. Did you miss the part where I didn't answer them.
The fact that I didn't answer them implies one of two things:
1) you didn't make it clear they were addressed to me.
2) I was ignoring them (as per the recommendations in your post).
1) I've already addressed this, but apparently you weren't paying attention. Eutectic mixtures of Iron and Iron sulfide have a significantly lower melting point then simple Iron (or steel) alone. Essentially it acts as an accelerant.
2) Energetically, AFAIK, the ONLY requirement is that the sulfur is molten, which requires a temperature of 115.21°C (239.38 °F) (well within the temperatures the fires are estimated to have burned at)
3/4) The melting point for Iron Sulfide is 1194 °C. The melting point of Steel is approx 1500°C. The melting point of eutectic mixtures is lower then either of the pure constituents (so the melting point of a eutectic mixture of Iron and Iron sulfide is below 1194 °C. The Euectic point of a binary Fe-S system is 988°C, this is the lowest temperature at which it can exist as a liquid, this occurs at 31.4% sulfur by weight.
Now, there's oxygen in the mix as well, this has a small effect.
A binary FeO-FeS mixture has a eutectic point of 940 °C.
Another important point to bare in mind is that Iron is actually miscible in liquid Sulfur - in other words, Iron will dissolve in liquid Sulfur.
What does all this mean?
If we have an Iron beam sitting around with Sulfur on it, when the sulfur (and obviously the beam) heat up to 115°C the Sulfur begins to melt, at this point the Iron begins to disolve in the sulfur, and also to react with the sulfur to form iron sulfide.
The iron sulfide exists on the surface of the iron.
As the iron continues to heat up, at any temperature above 940°C in the areas where the iron, iron sulfide, and Iron oxide are in conact with each other/mixed, however you want to describe it, localized mixing has the potential to occur (or recur). Of course, the thing about localized mixing occuring is that it will spread and consume more of the beam.
I don't know how much of this Al is going to debate, but ceartainly I hope this helps some of the other posters on this thread.
Oh, and for the record? If you weren't trying to imply that Thermate was involved with the metal fires then I suggest you be a little more careful about what images you post in conjunction with which statements - I'm farely certain I'm not the only person perusing this thread that thought that was what you were trying to insinuate.
===================================================
1) What is the function of the sulphur in thermate?
2) At what temperature will iron and sulphur combine to form iron-sulphide?
3) At what temperature will sulphur dissolve in a low-carbon steel? (say, 0.2%)
4) At what temperature will iron-sulphide dissolve in the same steel?
====================================================
I'm sorry. Did you miss the part where I didn't answer them.
The fact that I didn't answer them implies one of two things:
1) you didn't make it clear they were addressed to me.
2) I was ignoring them (as per the recommendations in your post).
1) I've already addressed this, but apparently you weren't paying attention. Eutectic mixtures of Iron and Iron sulfide have a significantly lower melting point then simple Iron (or steel) alone. Essentially it acts as an accelerant.
2) Energetically, AFAIK, the ONLY requirement is that the sulfur is molten, which requires a temperature of 115.21°C (239.38 °F) (well within the temperatures the fires are estimated to have burned at)
3/4) The melting point for Iron Sulfide is 1194 °C. The melting point of Steel is approx 1500°C. The melting point of eutectic mixtures is lower then either of the pure constituents (so the melting point of a eutectic mixture of Iron and Iron sulfide is below 1194 °C. The Euectic point of a binary Fe-S system is 988°C, this is the lowest temperature at which it can exist as a liquid, this occurs at 31.4% sulfur by weight.
Now, there's oxygen in the mix as well, this has a small effect.
A binary FeO-FeS mixture has a eutectic point of 940 °C.
Another important point to bare in mind is that Iron is actually miscible in liquid Sulfur - in other words, Iron will dissolve in liquid Sulfur.
What does all this mean?
If we have an Iron beam sitting around with Sulfur on it, when the sulfur (and obviously the beam) heat up to 115°C the Sulfur begins to melt, at this point the Iron begins to disolve in the sulfur, and also to react with the sulfur to form iron sulfide.
The iron sulfide exists on the surface of the iron.
As the iron continues to heat up, at any temperature above 940°C in the areas where the iron, iron sulfide, and Iron oxide are in conact with each other/mixed, however you want to describe it, localized mixing has the potential to occur (or recur). Of course, the thing about localized mixing occuring is that it will spread and consume more of the beam.
I don't know how much of this Al is going to debate, but ceartainly I hope this helps some of the other posters on this thread.
Oh, and for the record? If you weren't trying to imply that Thermate was involved with the metal fires then I suggest you be a little more careful about what images you post in conjunction with which statements - I'm farely certain I'm not the only person perusing this thread that thought that was what you were trying to insinuate.
"NIST never claimed to provide any more than an explanation for what caused the towers to START to collapse."
Nor do they explain how the entire upper section is able to fall into and displace through the lower section's core, as if nothing was there. The orderly descent of the antenna suggests the upper section's core is not undergoing any concussive deceleration, as it enters the lower section. Either the lower core just dropped away (???), or it somehow splayed apart (?). In light of the lateral force theories being accepted as sufficient to obliterate the core network, shouldn't Newton's Third Law be invoked here? Why would the massive core structure yield so quickly and completely to these forces. In either case the peripheral columns should have reacted, instead, the lower cage remained intact, even as the upper cage was being shoe-horned into it, (for the duration of the gif)
The following simulations remind us of the towers structural redundancy, and how it should have done a better job resisting collapse, especially in the N tower.
http://www.youtube.com/watch?v=qJ11i6fi7KQ...related&search=
http://www.youtube.com/watch?v=ExmSMU9ls-w
Note: I do not support the final conclusion speculated in this video.
Neu-Fonze,
The width of the wtc (64 m if I remember) and the 25 frames per second should give all info. But I assume you have no graphical tools, I will do it later, first some hobbying in da house.
The width of the wtc (64 m if I remember) and the 25 frames per second should give all info. But I assume you have no graphical tools, I will do it later, first some hobbying in da house.
Image for the collapse of WTC1 that I created using Einsteen's approach. This image was made by cropping the video down to the location of the antenna tower. I used the full resolution video from the DVD 'The First 24 Hours'.
http://i134.photobucket.com/albums/q91/sha...c1col1bsmc1.jpg
http://i134.photobucket.com/albums/q91/sha...c1col1bsmc1.jpg
Image of the aircraft striking WTC2. This video was poor quality. The cropping slice in this case is horizontal, as opposed to vertical in the case of the image for the WTC1 collapse.
http://i134.photobucket.com/albums/q91/sha...ing/wtc2st2.jpg
http://i134.photobucket.com/albums/q91/sha...ing/wtc2st2.jpg
QUOTE (zoktoberfest+Oct 16 2007, 06:08 AM)
Nor do they explain how the entire upper section is able to fall into and displace through the lower section's core, as if nothing was there. The orderly descent of the antenna suggests the upper section's core is not undergoing any concussive deceleration, as it enters the lower section.
No, it simply points out that the antenna is connected to the hat truss.
And NO, it doesn't fall "as if nothing was there"
That's just your silly bs.
What that Gif shows CLEARLY is that, as NIST points out, the collapse begins at the fire/impact floors and as the photographic evidence clearly shows, this was preceeded by a slow pull in on one side of the tower.
Things which NIST explains in great detail and which don't lend themselves to an initiating event based on explosives or thermate.
Arthur
No, it simply points out that the antenna is connected to the hat truss.
And NO, it doesn't fall "as if nothing was there"
That's just your silly bs.
What that Gif shows CLEARLY is that, as NIST points out, the collapse begins at the fire/impact floors and as the photographic evidence clearly shows, this was preceeded by a slow pull in on one side of the tower.
Things which NIST explains in great detail and which don't lend themselves to an initiating event based on explosives or thermate.
Arthur
Arthur/Wcelliott:
In Table 7.1 of NCSTAR 1-5A, NIST gives the entry time of Flight 175 into WTC 2 as 0.20 seconds. The rest of this table includes other timeline numbers like 0.56, 0.86, 1.02 seconds.... So NIST is obviously claiming a timing precision of 0.01 seconds. (This shoots down wcelliott's last post on this topic.)
Now it is painfully obvious that neither of you two gentlemen have taken the trouble to read Omika's paper in the ASCE Journal of Structural Engineering Volume 131 page 6, (2005). Until you do, you are really not in a position to comment on the fact that the tail of Flight 175 measurably slowed OUTSIDE THE BUILDING. And if you did read Omika's paper you wouldn't be making handwaving, unsubstantiated statements like: "The stuff outside didn't decelerate enough to measure."
So, Arthur, I am sorry you are not getting my point, but the question of the slowing of Flight 175 is very important because it allows a velocity reduction curve to be constructed based on OBSERVATIONS, not on some computer generated "global impact analysis." Omika, being a good scientist, carries out computer simulations of the impacts AND compares the result with observations in his Figure 15.
So, ignore Omika's paper all you want, but I would say that, unlike NIST, Omika did a proper SCIENTIFIC analysis of the Structural Response of the Twin Towers to aircraft impacts, simply because he compared theory with observation!
NIST SHOULD HAVE DONE THIS TYPE OF COMPARISON TOO, because it provides a means to verify computer generated models using REAL WORLD DATA.
In Table 7.1 of NCSTAR 1-5A, NIST gives the entry time of Flight 175 into WTC 2 as 0.20 seconds. The rest of this table includes other timeline numbers like 0.56, 0.86, 1.02 seconds.... So NIST is obviously claiming a timing precision of 0.01 seconds. (This shoots down wcelliott's last post on this topic.)
Now it is painfully obvious that neither of you two gentlemen have taken the trouble to read Omika's paper in the ASCE Journal of Structural Engineering Volume 131 page 6, (2005). Until you do, you are really not in a position to comment on the fact that the tail of Flight 175 measurably slowed OUTSIDE THE BUILDING. And if you did read Omika's paper you wouldn't be making handwaving, unsubstantiated statements like: "The stuff outside didn't decelerate enough to measure."
So, Arthur, I am sorry you are not getting my point, but the question of the slowing of Flight 175 is very important because it allows a velocity reduction curve to be constructed based on OBSERVATIONS, not on some computer generated "global impact analysis." Omika, being a good scientist, carries out computer simulations of the impacts AND compares the result with observations in his Figure 15.
So, ignore Omika's paper all you want, but I would say that, unlike NIST, Omika did a proper SCIENTIFIC analysis of the Structural Response of the Twin Towers to aircraft impacts, simply because he compared theory with observation!
NIST SHOULD HAVE DONE THIS TYPE OF COMPARISON TOO, because it provides a means to verify computer generated models using REAL WORLD DATA.
Sorry Neu, resolving a NIT like this is not worth $30 to me.
But, again, you MISS the point.
The .20 seconds came from the VISUAL ANALYSIS.
And NO, I don't agree with you that NIST was claiming a 1/100th of a second accuracy in these readings. Read the chapter and they clearly explain the limitations of their techniques, but in putting together a TIME LINE it would be VERY CONFUSING to state each time as a RANGE when CLEARLY some events took place AFTER others.
NIST doesn't make ANY claim about the deceleration of the plane as it entered the building.
Nor does NIST claim to be able to resolve the impact speed closer than +/- 24 MPH.
NOTE: Your use of the median speed and the .20 seconds and claiming that this means NIST is claiming the plane didn't decelerate verges on being DISHONEST. I know you are trying to discredit NIST, but Frank the ONLY thing you are hurting is your own reputation.
Unlike the visual analysis, the Global Analysis however had to work with SPECIFIC SPEEDs.
It relied on the VISUAL ANALYSIS to priovide that SPEED RANGE to work with and then ran three different models and chose the one that BEST modeled the VISUAL results.
Since NIST did NOT produce a VISUALIZATION of the modeled impact there is NO MODELED results to compare to the .20 seconds from the VISUAL analysis.
Finally, I am not at all surprised that a talented scientist focusing on a part of the WTC impact/fire/collapse can not improve on the results that NIST found, SEVERAL YEARS after NIST had provided their results.
Arthur
But, again, you MISS the point.
The .20 seconds came from the VISUAL ANALYSIS.
And NO, I don't agree with you that NIST was claiming a 1/100th of a second accuracy in these readings. Read the chapter and they clearly explain the limitations of their techniques, but in putting together a TIME LINE it would be VERY CONFUSING to state each time as a RANGE when CLEARLY some events took place AFTER others.
NIST doesn't make ANY claim about the deceleration of the plane as it entered the building.
Nor does NIST claim to be able to resolve the impact speed closer than +/- 24 MPH.
NOTE: Your use of the median speed and the .20 seconds and claiming that this means NIST is claiming the plane didn't decelerate verges on being DISHONEST. I know you are trying to discredit NIST, but Frank the ONLY thing you are hurting is your own reputation.
Unlike the visual analysis, the Global Analysis however had to work with SPECIFIC SPEEDs.
It relied on the VISUAL ANALYSIS to priovide that SPEED RANGE to work with and then ran three different models and chose the one that BEST modeled the VISUAL results.
Since NIST did NOT produce a VISUALIZATION of the modeled impact there is NO MODELED results to compare to the .20 seconds from the VISUAL analysis.
Finally, I am not at all surprised that a talented scientist focusing on a part of the WTC impact/fire/collapse can not improve on the results that NIST found, SEVERAL YEARS after NIST had provided their results.
Arthur
The Scott Myers video would pose a challenge to getting velocity reduction because of the limited number of frames and the fact that the plane is chopped off on the left side as it enters the frame. So far I've only found pairs of measurements of the same trailing surfaces possible - need at least three.
On the subject of the F4 video:
F4CrashTest.wmv, 320x240, 29.97fps, 12,535 frames. Consists of 17 segments taken by different cameras at different angles. Most are digitizations of high speed film, so the frame rate of the source video can't be used directly to determine time in seconds but strobes are visible in many of the clips for synchronization. The F4 and block both have targets to help obtain position data from images.
There's a lot of jitter in these clips. Whatever the transfer process from film to video, it's probably responsible for the movement.
Turns out to be a nice test of one of the methods I've been using on the tower video. I've examined the target on the block wall in Sequence 6 from the time the tail is fully in frame until smoke and debris contamination would render the technique invalid, frames 6730-6880. A plot of x position (increasing values are to the right in frame) by frame number:
http://i21.tinypic.com/ac7axj.png
The nose makes contact around frame 6775. Isn't that obvious?
Here's a view of how the target looks in the video:
On the subject of the F4 video:
F4CrashTest.wmv, 320x240, 29.97fps, 12,535 frames. Consists of 17 segments taken by different cameras at different angles. Most are digitizations of high speed film, so the frame rate of the source video can't be used directly to determine time in seconds but strobes are visible in many of the clips for synchronization. The F4 and block both have targets to help obtain position data from images.
There's a lot of jitter in these clips. Whatever the transfer process from film to video, it's probably responsible for the movement.
Turns out to be a nice test of one of the methods I've been using on the tower video. I've examined the target on the block wall in Sequence 6 from the time the tail is fully in frame until smoke and debris contamination would render the technique invalid, frames 6730-6880. A plot of x position (increasing values are to the right in frame) by frame number:
http://i21.tinypic.com/ac7axj.png
The nose makes contact around frame 6775. Isn't that obvious?
Here's a view of how the target looks in the video:
QUOTE (shagster+Oct 17 2007, 02:16 AM)
Image for the collapse of WTC1 that I created using Einsteen's approach. This image was made by cropping the video down to the location of the antenna tower. I used the full resolution video from the DVD 'The First 24 Hours'.
http://i134.photobucket.com/albums/q91/sha...c1col1bsmc1.jpg
Is it just me, os is the top section in this image compressing as it falls?
http://i134.photobucket.com/albums/q91/sha...c1col1bsmc1.jpg
Is it just me, os is the top section in this image compressing as it falls?
Sorry Arthur, there were most assuredly modeled results that needed to be compared with reality. Here's one for starters:
The normalized aircraft momentum plots for WTC 1 & 2 as found on pages 206 and 235 of NCSTAR 1-2B.
Since these plots are calculated for the full mass of the aircraft, they represent velocity reduction vs. time plots. And NIST's impact modeling found velocity reductions but failed to validate them!
But in NCSTAR 1-2B NIST state that its objective was to provide an independent assessment of the aircraft impacts USING THE FULL DATABASE OF VIDEO AND PHOTOGRAPHIC EVIDENCE COLLECTED AND MAINTAINED BY NIST.
However, when it comes to the aircraft entering the towers, NIST did not do this. Thus NIST's computer modeling of the aircraft impacts was not validated when it could and should have been.
The normalized aircraft momentum plots for WTC 1 & 2 as found on pages 206 and 235 of NCSTAR 1-2B.
Since these plots are calculated for the full mass of the aircraft, they represent velocity reduction vs. time plots. And NIST's impact modeling found velocity reductions but failed to validate them!
But in NCSTAR 1-2B NIST state that its objective was to provide an independent assessment of the aircraft impacts USING THE FULL DATABASE OF VIDEO AND PHOTOGRAPHIC EVIDENCE COLLECTED AND MAINTAINED BY NIST.
However, when it comes to the aircraft entering the towers, NIST did not do this. Thus NIST's computer modeling of the aircraft impacts was not validated when it could and should have been.
QUOTE (Trippy+Oct 16 2007, 05:25 PM)
Is it just me, os is the top section in this image compressing as it falls?
Tipping, actually. Away from the camera. I'm in the process of using the shortening factor to calculate the tip angle.
Tipping, actually. Away from the camera. I'm in the process of using the shortening factor to calculate the tip angle.
QUOTE (NEU-FONZE+Oct 16 2007, 01:26 PM)
Sorry Arthur, there were most assuredly modeled results that needed to be compared with reality. Here's one for starters:
The normalized aircraft momentum plots for WTC 1 & 2 as found on pages 206 and 235 of NCSTAR 1-2B.
Since these plots are calculated for the full mass of the aircraft, they represent velocity reduction vs. time plots. And NIST's impact modeling found velocity reductions but failed to validate them!
But in NCSTAR 1-2B NIST state that its objective was to provide an independent assessment of the aircraft impacts USING THE FULL DATABASE OF VIDEO AND PHOTOGRAPHIC EVIDENCE COLLECTED AND MAINTAINED BY NIST.
However, when it comes to the aircraft entering the towers, NIST did not do this. Thus NIST's computer modeling of the aircraft impacts was not validated when it could and should have been.
To your first claim:
Its not clear that the speed accuracy of the video (range of 48 mph) was sufficient for that purpose.
BUT
NIST details many other ways they validated the impact modeling. They just didn't do the one that Omika did. And by the way, you do have access to Omika's study, but I notice you haven't posted anything that contradicts NIST's aircraft momentum plots for WTC 1 & 2 as found in NCSTAR 1-2B.
As to the last claim, apparently you can't read that well.
The objective of the VIDEO analysis was to determine the INITIAL impact conditions.
See NIST 1-2B - Section 7-4 pg 172 for the ACTUAL WORDING that Neu got wrong.
Arthur
The normalized aircraft momentum plots for WTC 1 & 2 as found on pages 206 and 235 of NCSTAR 1-2B.
Since these plots are calculated for the full mass of the aircraft, they represent velocity reduction vs. time plots. And NIST's impact modeling found velocity reductions but failed to validate them!
But in NCSTAR 1-2B NIST state that its objective was to provide an independent assessment of the aircraft impacts USING THE FULL DATABASE OF VIDEO AND PHOTOGRAPHIC EVIDENCE COLLECTED AND MAINTAINED BY NIST.
However, when it comes to the aircraft entering the towers, NIST did not do this. Thus NIST's computer modeling of the aircraft impacts was not validated when it could and should have been.
To your first claim:
Its not clear that the speed accuracy of the video (range of 48 mph) was sufficient for that purpose.
BUT
NIST details many other ways they validated the impact modeling. They just didn't do the one that Omika did. And by the way, you do have access to Omika's study, but I notice you haven't posted anything that contradicts NIST's aircraft momentum plots for WTC 1 & 2 as found in NCSTAR 1-2B.
As to the last claim, apparently you can't read that well.
The objective of the VIDEO analysis was to determine the INITIAL impact conditions.
See NIST 1-2B - Section 7-4 pg 172 for the ACTUAL WORDING that Neu got wrong.
Arthur
The values for N-F:
Here is the video source used:
http://www.911archive.info/video/WTC2/WTC2...%20-%20east.avi
again the png file:
http://i23.tinypic.com/2jxio.png
25 fps, one frame is about 0.04 seconds
width 51 pixels is 64 meter
There are about 4-5 frames available where the plane makes contact with the building before it disappears
In 8 frames the plane moves about 56 pixels, therefore the velocity of the
plane was (assuming the velocity vector is perpendicular) about
(56*64/51)/(8*0.04)=219.6 m/s
assuming an error of two pixels (I take two because if you take the difference between two points the error doubles) we get a value between
203.8 m/s < v < 236.7 m/s
The highest value differs from 242 m/s value a factor 1.022, a framerate conversion from 29.97 to 25 (NTSC:PAL) cannot explain this difference, but if we look at the low resolution of the video this is a very acceptable value, especially because it is assumed to be perpendicular, in reality it isn't then the value will be a 1/cos() higher.
Shagster,
Great pictures, finally there is a professional to peer-review the methods... :-)
Here is the video source used:
http://www.911archive.info/video/WTC2/WTC2...%20-%20east.avi
again the png file:
http://i23.tinypic.com/2jxio.png
25 fps, one frame is about 0.04 seconds
width 51 pixels is 64 meter
There are about 4-5 frames available where the plane makes contact with the building before it disappears
In 8 frames the plane moves about 56 pixels, therefore the velocity of the
plane was (assuming the velocity vector is perpendicular) about
(56*64/51)/(8*0.04)=219.6 m/s
assuming an error of two pixels (I take two because if you take the difference between two points the error doubles) we get a value between
203.8 m/s < v < 236.7 m/s
The highest value differs from 242 m/s value a factor 1.022, a framerate conversion from 29.97 to 25 (NTSC:PAL) cannot explain this difference, but if we look at the low resolution of the video this is a very acceptable value, especially because it is assumed to be perpendicular, in reality it isn't then the value will be a 1/cos() higher.
Shagster,
Great pictures, finally there is a professional to peer-review the methods... :-)
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