Can't find any descriptions by any people in the buildings of impacts/oscillations at the links. Can you be more precise!
Hardfire: Physics of 9/11
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Can't find any descriptions by any people in the buildings of impacts/oscillations at the links. Can you be more precise!
bill smith
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Heiwa this is a hypothetical situation but is it a valid one ?
Suppose you took the 767 that hit WTC1 and suspended it on a string and then flew the buliding into it at 590 mph would the building smash the plane or would the plane slide seamlssly into the building ? Are the impact physics the same ?
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You really expect buildings to sway that much
I think you have been wachting too many comics.
Dont take physics lessons from roadrunner.
Looking at Billys youtube link I found this:-
This is the funniest Truther WTC model I've seen. Highly recommended.
BV
bill smith
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Pretty impressive stuff. I'll save that one for another occasion. Thanks
A W Smith
Philosopher
go read the book,
heres more accounts, most of them are duplicated in the book
http://911stories.googlepages.com/insidethenorthtower:witnessaccounts91-60
[FONT=arial,sans-serif]85th floor
"Marvin W. Pickrum,...85th floor inside Tower One....It felt like the building leaned, like standing with your back to the waves in the ocean."
[/FONT][FONT=arial,sans-serif]85th floor
Timothy Snyder and two other employees of Thermo Electron were in their 85th floor office in the North Tower of the World Trade Center when the plane hit three floors above them. They didn’t know it was a plane; Mr. Snyder believed it was a bomb.
“We were just working,” he says. “All of a sudden, we heard this slamming sound that was so loud. The debris started falling outside the windows, and the door to the office blew open. The building started swaying, and it was hard to say if the building would remain standing. I was in my chair, and I just grabbed onto my desk.
“After five or 10 seconds, the building stopped moving, and we knew we had to leave. We all grabbed our bags and headed out.” They walked down to the 78th floor where they were guided to another stairwell, crossing a lobby with a bank of elevators. The marble walls of the lobby were buckled.
[/FONT][FONT=arial,sans-serif]85th floor
Corky Adams: I begin preparing reports for another day of trading at the NYMEX,... horrific explosion. An immediate change in the air pressure. A ghostly column of air shoots like a canon into the office. The front door slams shut. Papers are whipped into the air. I’m thrown off my chair and to the ground. My boss jumps out of his office a second prior to the explosion. He had watched, in horrific disbelief, the entire event as the plane narrowly missed the empire state building and set a direct course for our building. The explosion sends the tower shaking furiously, lurching back and forth with sickening vengeance for maybe five or ten seconds. I think we may die. The building may topple over, or crumble. Finally it stops. The building is still standing. Everybody stares at each other, no idea of what happened or what to say. Speculations about an explosion, a bomb. No, it was a plane, our boss says. A commercial jet.
[/FONT][FONT=arial,sans-serif]83rd floor
Allen ran computer operations at Lava Trading, on the 83rd floor of the North Tower. Allen was also a licensed pilot and a ham radio operator. When he saw a plane flying low south along the Hudson
River about 8:45 AM, he was surprised, but supposed that it was approaching Newark Airport. A moment later, however, he noticed the familiar sound of a pilot gunning the aircraft’s engine, then heard a
roar as the plane hit the building thirteen floors above him. The building started shuddering, debris began falling, and fires fed by cascading airplane fuel broke out. http://press.princeton.edu/chapters/s8136.html
[/FONT][FONT=arial,sans-serif]82nd floor
"...they heard the boom. The building swayed so severely that it nearly knocked them off their feet. Pieces of the facade started raining outside the window. Patrice Yepez, a co-worker, ran in screaming that a fireball had blown out the elevators. Borst ran into the main corridor and found it destroyed....” http://www.newsday.com/ny-lisave172418919oct17.story
[/FONT][FONT=arial,sans-serif]81st floor, didn't hear impact.
Michael Wright: "All of a sudden there was this shift of an earthquake. People ask, "Did you hear a boom?" No, the way I can best describe it is that every joint in the building jolted...we all got knocked off balance...the flex caused the marble walls in the bathroom to crack.
[/FONT][FONT=arial,sans-serif]72nd floor
Frank Lombardi, Port Authority Chief Engineer
Lombardi was at his desk. He heard nothing, but felt the tower sway, and saw people in the hallway go airborne before they fell. His first thought was that New York was experiencing an earthquake. [/FONT][FONT=arial,sans-serif]William Langewiesche. American Ground. New York: North Point Press, 2002. p.47
[/FONT][FONT=arial,sans-serif]70th floor
Kim King: When the plane entered the World Trade Tower One, the impact was enormously overwhelming. For a couple of seconds I didn’t breathe, my body was frozen, my eyes were open wide but yet I couldn’t see what was happening, and my mind went totally blank. Mentally I couldn’t even begin to register what was happening. The sound of the impact was so massive; my body just trembled with fear, sadness, horror, and panic. The sound of impact was so loud I was truly disorientated. Tower One instantaneously rocked from side to side. It must have rocked at least 15 to 20 degrees in each direction, to the point that it made you loose your balance, however, it felt like my feet were glued to the floor. The floor shook so much your knees buckled, you could see the ceiling trembling above you, the windows were actually shaking and you could hear the sounds of Tower cracking apart. The cracking sounds of the Tower were dreadfully unnatural. My heart was about to beat out of my chest and my body was shaking from fear. The horrifying thing now, was that this was only the beginning of the nightmare.
[/FONT][FONT=arial,sans-serif]68th floor
Greg Trevor: I was nearly knocked to the floor by the impact of the first plane, which slammed into the north side of Tower One more than 20 floors above me. I heard a loud thud, followed by an explosion. The building felt like it swayed about 10 feet to the south. It shuddered back to the north, then shimmied back and forth.
[/FONT][FONT=arial,sans-serif]62nd floor
Daniel T. Duffy: I heard no sound - no crash, no explosion, no screams, but I felt that fortress of steel and glass wobble back and forth like it was a cheap card table, nearly knocking me off my feet. It felt for a moment as if the entire building would go toppling over onto Church Street.
[/FONT][FONT=arial,sans-serif]Below 53rd floor
Kenton Beerman, 24, was also sending e-mail at work when an explosion rocked 1 World Trade Center, making it sway back and forth for 10 seconds.
At first, Beerman thought the building would fall into the Hudson River. Then he realized it had stopped moving and saw thousands of pieces of paper fluttering outside.
[/FONT]
Mr.Herbert
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If anyone is interested. "D-Mole" (i believe that his name is short for human papilloma virus) at the PFFT, claims to have found "more flaws" in Ryan's lecture. Funny how they post it on their site, but don't e-mail him.
http://pilotsfor911truth.org/forum//index.php?s=&showtopic=16647&view=findpost&p=10768761
in part:
http://pilotsfor911truth.org/forum//index.php?s=&showtopic=16647&view=findpost&p=10768761
in part:
Di**Mole said:
ktesibios
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Oh for the love of Levy's Rye Bread!
bill, if you had bothered to inform yourself minimally about the investigations into the destruction of the Towers, you would know that not only was shock and oscillation caught on tape, but that it was sufficiently caught to allow the period and amplitude of the swaying caused by the impact to be measured.
NIST was interested in the oscillatory behavior of the buildings because the natural periods of the different modes of oscillation could be predicted from the structural model they constructed to analyze the airplane impacts, and that prediction could be compared with real-world measured values as a check on the accuracy of the model. Data on the Towers' swaying in the wind already existed, having been gathered by accelerometers installed in the Towers to monitor their swaying (of interest to PANYNJ because it directly impacted tenants' comfort). As it turned out, the measured periods of oscillation agreed nicely with the model predictions.
Measuring the amplitude of the oscillations induced by the airplane impacts was useful because this data could be used to refine the estimates of airplane velocity generated by analysis of the videos of the impact.*
This might be of interest:
NIST NCSTAR 1-2 said:
Lessee... 27 inches of displacement at the roofline, of a building that was 207 feet on a side... about 1% of the buildings width...
(FYI, the maximum displacement under maximum wind loading was about 65 inches)
yeah that's surely gonna be obvious to people peering at @#$%^ YouTube videos!
Actually, it wasn't. Deriving quantitative information about the building's motion from the video record required a bit more sophistication than that. The process is described in NIST NCSTAR 1-5
Section 2.3.3 Determination of Primary Oscillation Period (p.24 (pdf p. 78)
and NIST NCSTAR 1-5A
Section 7.3.2 Determination of the Primary Oscillation Period of WTC 2 using a Simple Image Analysis Approach
p.100 (pdf p.196)
Section 7.3.3 Moiré Analysis of Primary Frequencies and Time-Dependent Oscillation Amplitude Following the Aircraft Impact
p. 102 (pdf p.198)
The text quoted above is from NIST NCSTAR 1-2, p. 28 (pdf p.142).
Go and do your reading, bill, and perhaps you might learn why your uninformed expectations are no standard by which to evaluate reality.
*One of the fascinating things about the entire suite of NCSTAR reports is the amount of them that is spent in describing the ways NIST found to test and validate their models by comparing their predictions to real-world data. These guys really liked to torture-test their tools.
I have only been in office buildings in Yokohama, Japan, subject to fairly heavy earthquakes a bit away (not below). Building is swaying sideways, loose things may move. Hanging lamps swing, etc. It can last several minutes. Time to grab your survival bag and get out. Haneda airport was only 20 kms away but no airplane ever touched any buildings.
bill smith
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Do you have a copy of those videos or know where I can find them ?
bill smith
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You are being a bit cryptic Heiwa. Is this an answer to my post or did you answer another by mistake ?
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ktesibios
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Go and do the Zarquon-fetch-it reading first. Then, if you really want to find the primary source material, you can try this:
The sections of NCSTAR 1-5A I cited show the frames used in the analysis. By comparing those to the stills from some of the video sources shown in Appendix E of NCSTAR 1-2, you may be able to determine which ones were used in the image analysis.
NIST was quite conscientious about marking all reproduced images with proper copyright notice, which will provide the names of the people who recorded the originals. You could then try contacting these sources to see if you can obtain copies.
You will need high-quality copies (compressed digital video formats just aren't going to cut it). You will also need the appropriate equipment to do the subtractive process outlined in Section 7.3.2 of NCSTAR 1-5A, or if you want to attempt to replicate the Moiré analysis, you'll need the appropriate equipment to capture freeze-frames and count pixels and a good understanding of the principles involved and the mathematics of deriving displacement information from the interaction of the column lines with the columnar arrangement of pixel sensors in the camera.
Oh, BTW, you'll also need detailed information about the image sensors in the cameras involved.
Since you have never given any sign that you have any knowledge whatsoever of image analysis, I think that the likelihood of your doing this work successfully is about the same as the likelihood of my finding my Honda miraculously transformed into a Porsche when I leave work this afternoon.
Jay Windley described the fundamental problem of conspiracist "analysts" perfectly:
"We do not require the universe to operate according to the expectations of the ignorant."
Ya dig whatimsaying?
bill smith
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Let's assume that the building that moved 27 inches at he roofline was WTC1. Under maximum windloading it would move 65 inches. So the 27 inches would represent the force applied by about 40% of maximun windloading . This had to have been caused by the impact of the plane.
We know the velocity, weight, and angle of attack of the plane so it's kinetic energy can be worked out. Are there enough details there to work out the force of the impact ?
We know the velocity, weight, and angle of attack of the plane so it's kinetic energy can be worked out. Are there enough details there to work out the force of the impact ?
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psikeyhackr
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Now ain't all of that very interesting.
But don't you need the distribution of mass of the tower to figure out how much of the planes kinetic energy went into shaking the tower? And don't you need to subtract that to compute how much of the energy did structural damage?
So where did the NIST do these calculations?
psik
A W Smith
Philosopher
one note psikey
Is that all you know is one chord? Can ya play anything else? Whine a different tune once in awhile? The column cross sections are documented. the floor slab thickness is a known. Figure it out. and its not even relevant
Is that all you know is one chord? Can ya play anything else? Whine a different tune once in awhile? The column cross sections are documented. the floor slab thickness is a known. Figure it out. and its not even relevant
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psikeyhackr
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So why do we have some sites saying there were 90,000 tons of concrete per tower
and
other sites saying that both towers had 425,000 cubic yards.
Now the sites that say 425,000 cubic yards also say 200,000 tons of steel which matches the NCSTAR1 report but that report NEVER SPECIFIES A TOTAL for the concrete.
But if you convert those cubic yards to tons it comes to 300,000 tons per building. So there appears to be a bit of a discrepancy. You JREFers are real good at not noticing discrepancies.
R. Mackey talked about that model in 2-6 and 2-7 in his 3rd Hardfire video but I didn't notice any mention of a need for variations in mass for the different levels of the model.
But EVERYBODY HERE says MacKey did a Fantastic job. LOL
psik
A W Smith
Philosopher
You keep trotting out this concrete and steel mass per level likes its some holy grail or smoking gun. lemme tell you something genius. It is irrelevant. Know why? You cannot isolate the mass alone to determine what dampening it would have on impact or wind loading. You don't design skyscrapers by just portioning out weights of steel and concrete on a scale next to a cauldron like your making a witches brew. it ain't that simple. You predict the loads and work back from there. In the case of the towers you come up with a concept of a tube in tube. You calculate what you need for column cross sections for dead and live loads. You calculate what you need for spandrels to act as a vierendeel truss to distribute wind loads. you add viscoelastic dampers to further dampen movement during wind loads. You create a composite floor system with the truss knuckles embedded in the concrete slab to act as a composite.
You are trying to treat the wtc like some upside down mass dampened tuning fork. and it simply is irrelevant and wont work. Its as silly as,, well.. toothpicks and washers. it does not apply. You are ignoring the complexity of the design itself.
You are trying to treat the wtc like some upside down mass dampened tuning fork. and it simply is irrelevant and wont work. Its as silly as,, well.. toothpicks and washers. it does not apply. You are ignoring the complexity of the design itself.
psikeyhackr
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I never said anything about "isolating the mass" whatever you think that means. A 12 foot length of a 36 foot column going through any level is going to have some mass just like every other column going through that level. The people who designed the building had to make the building support itself so they figured all of that out along with wind loading. I am simply asking for data that was already figured out before the hole for the foundation was dug.
Human beings have been building complex structures on the planet for thousands of years. You would think that structural engineering is supposed to be impressive or something. It is just big and expensive. The Empire State Building was completed before the first transistor was inverted. A $50 microprocessor is more impressive than the World Trade Center. It is ridiculous that this problem has dragged on this long.
My toothpicks and washers demonstrated that MASS affected the collapse distance.
My impact experiment demonstrated that mass and its distribution affected the oscillation.
So why doesn't an OFFICIAL US GOVERNMENT SOURCE tell everyone the distribution of steel and concrete in the towers in human readable form? Why should any JREFer have a problem with that?
psik
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psikeyhackr
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There is a difference between a demonstration of principle and a PROOF.
Where did I claim to PROVE something?
Of course I can't expect people that play word games and bring up irrelevant analogies to be very rigorous in their meaning, now can I? Was the gravity I used different from the gravity in New York on 9/11? I wasn't doing any heat testing but then then the NIST can't prove the fireproofing came off the trusses, now can they?
I guess PROOF doesn't mean much to you people anyway.
psik