I design buildings for a living and I'm having a real hard time deciphering what actual point your attempting to make here. The bolded portion in particular makes very little sense. The horizontal beams do not carry the vertical loads in a building, they "transfer" the load to the vertical supports and provide lateral support. The weight of these members is also, obviously, calculated as part of the dead load of the building as well.
I didn't say the horizontal beams carry the vertical load of the building. They do keep long vertical components from bending and thereby enhancing their strength. But for a collapse to occur the mass of the horizontal components would have to be accelerated downward from above and the conservation of momentum would be affected by that mass. So if there is more than twice as much horizontal mass as vertical then knowing the amount is relevant. People who design buildings are supposed to make them strong enough to stay up and need not concern themselves with the physics of a collapse. But we are supposed to believe a top down collapse is what happened to the WTC. Where is the conservation of momentum involved in building design? psik
Psikeyhackr has spent the last few years on the internet arguing that his high school level understanding of the problem trumps the knowledge and research of those who have spent their lives studying the topic. His basic premise is as follows: 1. The floors of tall buildings must get less massive as the building increases in height. 2. Buildings must hold themselves up. 3. Due to the conservation of momentum, the inertia of the mass below the point of collapse should be enough to absorb the Ek of the mass falling from above the point of collapse. 4. A model made out of paper loops and steel washers confirms this theory. It has been pointed out to him countless times in countless forums that his assumptions about the structural engineering and capabilities of buildings are false, His understanding of the difference between static and dynamic pressure is false, his fundamental premise regarding the conservation of momentum does not apply, and that his understanding of square cube law and the physical properties of materials is flat out wrong. If you are confused as to his argument, it's because he too is confused as to his argument. (the majority of which consists of demanding the distribution of mass within the building in all capital letters.) He's been asked what he would do with those figures countless times and he's always fallen short of providing his mathematical model to define the collapse using the precise distribution of mass he demands.
So FB you come in hear and LIE in your very first post. I never said the conservation of momentum did any such thing. It does slow the falling mass down but that is all. It is the energy required to crush the supports that make the falling mass come to a stop. Now #1 presents a point of linguistic ambiguity. I have long made a point of distinguishing FLOORS and LEVELS. By LEVEL in the WTC I mean a 12 foot high section of the building which would include the FLOOR assembly outside the core and the steel in the core and on the perimeter. Since the columns did get thicker down the building the TONS of STEEL per LEVEL had to increase even though the FLOORS were the same. Are you implying that buildings do not have to hold themselves up? That would be a good trick. So it is certainly curious that in NINE YEARS the physics experts have not been demanding data on the TONS of STEEL and TONS of CONCRETE that were on every level of the towers. Where are the thousands of physics people that should be siding with you if I am wrong? The model with paper loops demonstrates the absorption of energy by components strong enough to support the STATIC LOAD. Just like the crush zones in an automobiles. Why can't you brilliant physicists build a self supporting model that can completely collapse if that is what happened to the WTC? [ame="http://www.youtube.com/watch?v=ZT4BXIpdIdo"]YouTube - WTC Modeling Instruction & Testing in the Real World[/ame] Distribution of mass is important to the building's response to sheer forces also. [ame="http://www.youtube.com/watch?v=z0kUICwO93Q"]YouTube - WTC Impact Model - MIT[/ame] This grade school physics is SO DIFFICULT. [ame="http://www.youtube.com/watch?v=oQLCYR9iROs"]YouTube - 9 11 Mysteries - Full Length[/ame] psik PS - You know fangbeer you are starting to remind me of someone who named himself Timgar Posse after an old handle of mine. http://jollyroger.com/zz/ybusinessd/TheNewEconomyhall/mobydick.html http://fravia.frame4.com/creditca.htm http://www.spectacle.org/1199/wargame.html Economists ignoring the depreciation of all of the automobiles purchased by consumers is more important than 9/11. Look at what has happened to the economy since 1999. But cars wearing out has something to do with physics doesn't it? When do physicists talk about Planned Obsolescence?
If given the values of mass you require, show how you would calculate this. All the engineers that I know agree with me. The hundreds of contributors to the NIST report agree with me. Engineers at Purdue and other colleges that conducted studies agree with me. They're not all that hard to find. I think the better question is, where are the thousands of educated "physics people" that agree with you?
Well, whadya know, you were right !!! The response ... spamming his silly little models (again), must be desperate to up the viewing numbers or something. Welcome aboard Fangbeer ... it's fun, hope you stick around.
Yes. Yes, that info is in the report. The point here is that Psikey has not read the report (he has only searched it for key words that he assumes should appear) and that Psikey doesn't really know what to do with the data he's asking for. He claims that the inertia of the lower portion of the building should slow the rate of decent of the upper mass (which is in fact true and did happen on Sept 11th) and he also claims that the act of breaking the lower mass should have taken enough energy to arrest the collapse. It's that second part of the claim that he's fuzzy on so he built a model out of paper loops and washers because he doesn't understand the math involved in actually calculating the forces involved in buckling. When it's pointed out to him that his paper loops and washers are not scaled to the towers in any significant way he either backs out of his claim saying that the model is only meant to demonstrate the principal of the conservation of momentum (in which case the mass should only have slowed, and not arrested) or he makes the unsupported claim that his paper loops are a material that is "as weak as possible." to support the mass above them. How this is supposed to represent the properties of a steel column he's also a little fuzzy on, other then to say that they are "not as weak as possible." He has remained stubbornly oblivious to the points that the strength of materials does not scale, that gravity does not scale, that the shape of materials contribute to their strength, and that dynamic load is much different then static load. But what can you expect from a guy that, after all this time, still hasn't figured out how to read the report.
No shyte on the bolded. I've lost track of how many Truther working the "I know physics" angle seem to have a blind spot on this front. I've even posted a simple formula (multiple times) who's acronym should be a massive cluebrick.
Sure, static and dynamic are so difficult to understand. Whatever material supports the static load has to have some resistance to the dynamic load. But I also did a Python program with magical floating masses and no supports. The Conservation of momentum alone causes the collapse to take about 12 seconds. So any supports had to slow things down further. So how did the buildings come down so quickly oh physics geniuses? So the people that claim the buildings could collapse can't build a model that can but then they don't want accurate data on the distributions of steel and concrete in the towers either. Even though the NIST admitted the information was necessary to analyze the south tower impact. And then Purdue makes a SCIENTIFIC SIMULATION of the north tower impact where the core columns don't move even though the NIST admits to empirical evidence of the south tower deflecting 15 inches due to the impact. The nation that put men on the Moon can't tell the entire world the TONS of STEEL and TONS of CONCRETE that were on every level of buildings designed before 1969. Great SCIENCE from the leader of the FREE WORLD. 9/11 is the Piltdown Man incident of the 21st century. psik
And so goes Psikeyhackr; round and round without addressing a single of his own flaws. Futile as it is, I'll respond anyway. 1. The building did take longer than 12 seconds to collapse. If the time it took to collapse is wrong, what is your calculation showing the time the building should have taken to collapse? I have never seen you talk about this because you don't know how to calculate this. Ironically, however, you are quite certain that the people who do know how to do this are wrong because you have a high school education and a model made out of paper and washers. 2. The building did not collapse in levels like your Python model suggests. How do you suggest we account for the fact that floors failed first, then outer columns, and then core columns? Shouldn't we subtract the appropriate amount of mass from "levels" in which core steel can still be seen standing after outer columns and floor trusses have collapsed? What is the appropriate amount of mass to subtract for the collapse of the floor trusses that preceded the collapse of the outer columns? What is the appropriate amount of mass to subtract to account for outer columns below the plane of collapse that buckled outward rather than inward? Once the outer column sections were no longer pinned by floor sections, wouldn't they be expected to buckle under their own instability due to an extremely high slenderness ratio?
So compute how much energy was required to crush each level of the core in the north tower. But then you don't even want to know how much steel was on each level in the core of the north tower so you can't compute the energy. So how can we compute how much it SHOULD HAVE SLOWED the collapse down? 50% of gravitational acceleration would have made it 18 seconds. Most sources specify less time than that. In fact my Python program based SOLELY ON THE CONSERVATION of momentum gives about 12 SECONDS. So any crush energy at all should have taken it over 12 seconds but Dr. Sunder of the NIST says 11. So our engineering schools still have a physics problem that they can only deal with by ignoring. Physics is NEVER going to change so how many decades can they go along with this nonsense? [ame="http://www.youtube.com/watch?v=ZT4BXIpdIdo"]YouTube - WTC Modeling Instruction & Testing in the Real World[/ame] 9/11 is the Piltdown Man incident of the 21st century. psik
The Python model does not suggest a collapse. The Python program is "magical". It can only happen in a computer. There are no supports for the suspended masses. It is just a computerized thought experiment to come up with a minimum possible collapse time. But there are sources that say the north tower cm down in less than 12 seconds. Like Dr. Sunder of the NIST. He said 11 seconds in a PBS podcast. http://www.pbs.org/wgbh/nova/tech/debunking-9-11-bomb-theories.html The physics model shows what should have happened. Where is the energy computed for that buckling in the video you linked to. It is the energy to crush the levels that slows down the falling mass and causes it to arrest. So where are the calculations for the energy to collapse each level of the core? [ame="http://www.youtube.com/watch?v=wrdO8hPJGyg"]YouTube - Buckling of a Thin Column.MP4[/ame] Oh d(*)m(*), that's right. You don't even want to know how much steel was on each level of the core so how can you possibly compute the energy required to collapse it? psik
Quit your semantics. If the building didn't collapse in levels then your Python model can not suggest a minimum collapse time, can it, bone head? For the Python model to have meaning, the assumption has to be made that the building collapsed in levels. That assumption is false. There are sources that say all sorts of odd things. In the case of Dr. Sunder he is paraphrasing the official report for the sake of brevity. If you would have read it, (which you still haven't) you would know the entire context. They say: http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm Therefore the time it took the top portion of the building to hit the ground, is approximately 11 seconds. The time it took the entire building to collapse > 25 seconds. This bears out the lie that knowing exact mass distribution on every level would somehow help us describe the collapse. Not only would you need to know the mass on every level, but you'd also have to be able to measure the amount of mass the remained standing after the initial collapse. Do you have a way to measure that? Obviously you know some different way to do it. Why don't you tell us how you would calculate buckling.
Calculating the time for dropping a mass from 1360 feet through empty space should give the minimum possible time the fall could occur, 9.2 seconds. But we know there was not empty space there. So the people CLAIMING it was a collapse are saying the mass above the impact zone forced the mass below the impact zone down. So just doing calculations on mass alone with the conservation of momentum should result in a LARGER MINIMUM. So any kind of straight down collapse SHOULD TAKE LONGER. So since my "magical" collapse takes 12 seconds and there are claimed figures for the real event of less than 12 seconds then even a retarded physicist like yourself should find that odd. The point of the program is simply to show the absurdity of what we are SUPPOSED TO BELIEVE. You can of course write your own program and try to get different numbers. Isn't the conservation of momentum, physics and not semantics? Don't you want EVERYONE to understand simple physics? psik
you never read the omission commission report either huh. so why are you here arguing if you do not know the subject matter or where the data is.
They had to come up with the numbers somewhere. Creating an imaginary set of parameters was easier than trying to circumvent physics. What's a shill to do? LOL
