The Physics Profession has not demanded accurate data on the distributions of steel and concrete down the towers. Who cares about Potential Energy and the Conservation of Momentum?
I guess it is time to burn Isaac Newton in effigy.
When any two bodies act upon one another, their total momentum remains constant provided no external forces are acting. In other words, we can say that whenever one body gains momentum, then some other body lose an equal amount of momentum, that is , momentum is never created or destroyed.
@Merlin5by5 {{{ Both the Impactor, and the Impacted, are being CONSTANTLY accelerated DOWN.
That's what WEIGHT IS, your mass accelerated down at 1 g. }}}
What insane physics! Being subjected to a force is not being accelerated by it. Acceleration is change in VELOCITY. If mass is stationary then it is not accelerating. 9.8 m/s^2 is the acceleration caused by gravity IF the mass is free to fall.
These schools sure as fell let people pass with incompetently memorized physics. LOL
A "thought experiment" we can do. Suppose the upper 15% of the north tower starts to collapse. It falls one floor, hitting the floor immediately under the falling part. Just as the falling floor touches the stationary floor, ALL support for the stationary floor disappears. At that instant, the stationary floor starts to fall on its own; in the next instant, the moving floor hits it and they fall together. The process is repeated with each lower floor. How long would it take to hit ground?
@Skeptic121 Thought experiment is not necessary. I already wrote the Python program.
It takes about 12 seconds but it varies with the distribution of mass. Skyscrapers must get heavier toward the bottom. That is why it is so absurd that our EXPERTS have not been demanding the TONS of STEEL and TONS of CONCRETE that were on every level of the towers for NINE YEARS.
You can't compare the ultimate strength of the paper loops in your model with the ultimate strength of the steel in the towers. I explained why to you many times in many other forums. If you can't even do the grade school math to support your grade school physics it's no wonder why you don't understand why the energy of the upper block exceeded the ultimate strength of the lower portion by an order of magnitude no matter what the exact mass was for either.
@psikeyhackr About 12 seconds? That's about the time it actually took, right? So, here is the big question: what took away all that vertical support from the lower part of the tower? You know, the part below where the plane hit. The part below the fire. The part that was undamaged, according to the people who escaped from those floors before the collapse. Undamaged, that is, until some loud explosions happened and the whole thing fell down...
1. Calculate the pound force per square inch imparted to the first impacted "floor" of your model.
2. Calculate what the psi would be scaled up to the full scale of the building. (don't forget that a 10 lb cube scaled up by a factor of 10 weighs 1000 times more then the original cube but only has 100 times the surface area.)
3. Use this data to explain how your paper loop represents the full scale ultimate strength of steel given that ultimate strength doesn't change proportional to scale.
@fangbeer Do it yourself. I don't care if you think math is more important than physics.
How many SQUARE INCHES are there to the edge of a piece of paper 5 inches long? I don't give a damn about trying to compute it. Why don't we have the TONS of STEEL and TONS of CONCRETE on every level after NINE YEARS?
@flanksteak2 So how can the math be done without accurate data to plug into the equations?
Therefore anyone that understands the PHYSICS should be demanding the data before talking about math. So why don't we know the TONS of STEEL and TONS of CONCRETE that were on each and every level of the towers after almost TEN YEARS?
Why hasn't the Physics Profession been demanding that information?
@psikeyhackr You really think you have all this figured out don't you? You, the Youtube flunky, really truly believes he is onto something because you are a batshit crazy shizoid.
@flanksteak2 Some times I get slow days and can stoop to responding to REALLY DUMB STUFF.
I don't look at this video much. There is one with a sound track and intro I stole from Ryan Mackey. I figured out in two weeks that it was ridiculous to think that airlines could destroy buildings 2000 times their mass in less than two hours.
Unfortunately it is hysterically funny that the physics profession has not demanded accurate data on the distributions of steel and concrete in TEN YEARS.
Loops are way stronger (you know that), your indestructible core also adds untold support. Your "weak" structure scaled down is thousands of times stronger than the towers. You can't scale down what happened to the towers with 6 foot crappy models built with your home depot credit card. Youo're attempting to show why a gravitational collapse couldn't have caused the destruction on 1 and 2WTC. You are wrong and this model does nothing to prove your case.
But the problem with your IDIOTIC CLAIM is that the model only costs $30 and anyone that wants to can repeat the experiment for themselves. I can't cheat when people get the materials and do it themselves.
The towers had to be strong enough to support their STATIC LOAD. The DYNAMIC LOAD would still be SLOWED DOWN crushing supports that strong. The north tower destruction due to airliner and fire was IMPOSSIBLE.
@flanksteak2 Regardless of what WORD you want to use for the elimination of support by the columns it still required energy and there was ONLY ONE SOURCE. So the falling mass HAD TO SLOW DOWN.
So why haven't EXPERTS been demanding the TONS of STEEL and TONS of CONCRETE on every level for the last NINE YEARS?
@psikeyhackr Why would it have to slow down? First you claimed it fell at freefall, you were wrong, now you are going to move on and make yet another even more incorrect, fact-ignoring and make yourself look like an even bigger idiot.
What purpose do you take home in making false, ignorant claims?
No amount of explanation gets through to Psikey. When presented with a mathematical model to describe the collapse he called it a bunch of fancy calculus that he didn't understand. He's attempting to describe this collapse through the lens of a high school student who doesn't know anything about the strength of materials, structural mechanics, or even square cube law. In short, he's an idiot who has the gall to blame everyone but himself for his ignorance.
@fangbeer I agree but even in High School, I would have understood that a floor assembly that can only hold 11 floors worth of weight would have collapsed under the weight of 12 floors landing on top of it. (this is an extremely conservative measurement that doesnt' even take into account the weight of the framing or the momentum).
He has to completely ignore the building altogether, and then build a totally irrelevant pretend, non-sequitir model in order to validate his conspiracy leanings
It's more complex then that. WTC floor assemblies didn't hold the weight of the floor above them. They only held their own weight, and transmitted lateral load between inner and outer columns. Just one floor worth of live load hitting from above was enough to damage the connections between the assemblies and the columns of the floor below. This and the fire compromised the lateral strength of the columns in the area of collapse initiation and set off a chain reaction.
It has been NINE YEARS since 9/11. When have we been told the TONS of STEEL and TONS of CONCRETE that were on every level of the towers?
So what objective data can you possibly have about how strong my paper loops are compared to the WTC if you don't have that information any more than I do?
Good luck with trying to help Psikey "get it." After all this time the total sum of his effort to read the 9/11 report (and his primary beef with the report) has been an acrobat search for keywords he expected to find but did not. He hasn't read it.
I attempted many times to explain square cube law to him. Still, he refuses to address the problem of scaled gravity. He claims it doesn't need to be scaled, and simply cannot grasp the concept that gravity cannot be scaled
@UNIVERSITYHI The difference here is Feynman's experiment was a full-scale demonstration of the properties of O-ring material at low temperature. This is dropping washers onto paper. While it certainly isn't necessary to build another WTC to prove the point, any experiment like this needs to account for the structure of the buildings. There is no reason to believe this model is, in any meaningful way, similar to the WTC. Falling in near free-fall does not violate any fundamental laws of physics.
{{ Falling in near free-fall does not violate any fundamental laws of physics. }}
Considering that the buildings were designed to hold themselves up JUST LIKE MY MODEL & they held themselves up for 30 yrs there is a physics problem with the buildings comIng down that fast.
My model is DEAD LOAD ONLY & did not have to withstand the wind. So the WTC towers had additional factors increasing their strength which should have made their chances of coming down less than my models.
One nice thing about that model is that it is VERY CHEAP.
Anyone can duplicate it. There is nothing stopping you from doing so and using something other than PAPER. You can use STEEL and see if that is more likely to collapse. LOL My model is only 3.5 pounds. Some weak material must be used but it must still be strong enough to support the Static Load.
@psikeyhackr The problem is your model is not a model of anything relevant to the WTC. It may be cheap, but it's likely to be invalid. Have you scaled the strength of your materials properly? My bet is you haven't. Once you add an impact load on a compromised structure, your load paths may end up wildly different from design. You're not demonstrating a fundamental physical principal, so you'd need to show similarity if you wish to compare to the WTC.
@roamingcroat {{ Have you scaled the strength of your materials properly? My bet is you haven't. }}
NITWIT! The objective was not to scale the objective was to make the supports AS WEAK AS POSSIBLE. Was the WTC designed to be AS WEAK AS POSSIBLE? My model is DEAD LOAD ONLY! The WTC had to support live load & withstand wind.
So it it won't collapse & is AS WEAK AS POSSIBLE...
"So it it won't collapse & is AS WEAK AS POSSIBLE..."
I first of all doubt that it's as weak as possible. But that's completely irrelevant. What you would need to show is that your model here is either similar to the WTC in some engineering respect (some dimensionless number involving height, weight, material properties, etc.). What you have here is stacked washers.
Physics doesn't care. It won't be forced to make the WTC collapse how you expect it to.
You can doubt it is as weak as possible all you want but the fact of the matter is that you can build it and test it yourself and make any changes you want.
BUT NO! You can come here and TALK and we are supposed to be SO IMPRESSED. What is stopping YOU from building a model that CAN collapse under its own weight? If you can't tell us the distributions of steel and concrete in the WTC how can you complain about ANY MODEL not being to scale? LOL
@psikeyhackr "Like I said the model is CHEAP." And unrelated to the WTC collapse.
"we are supposed to be SO IMPRESSED." You needn't be impressed. I'm stating that I don't find your model to be valid. Is there any reason why your model is somehow more valid than my talk? Or that any model I make is somehow more or less valid than your model? Without some documented similarity to the actual towers, there's really no difference between your video and my written words.
@roamingcroat {{ Or that any model I make is somehow more or less valid than your model? Without some documented similarity to the actual towers, there's really no difference between your video and my written words. }}
Utter Horseshit!
Anyone can CLAIM to be able to build a model that can be collapsed by Its top 15% or less. Doing it brings physics into the picture and not just HOT AIR.
Here was I "think" happened and may explain why we are so confused with what we saw. 1) Planes hit the buildings. 2) the structures were weakend through heat and damage. 3) When the top floors gave, the terrorist blew the buildings. In closing the terrorist damaged and blew the buildings, and for some reason if we detect exsplosives it means the US did it. No...I feel the terroist used explosives and they did it. This is the only thing that I could think of that would answer everything.
Oh what the hell. I did try to build a model from some toothpicks and bits of paper.
Two bits of cardboard placed against each other, two toothpicks planted in either one to support a leaf of paper for a total of some eight "floors".
Results... "Floors" that would heavily sag - but not go down - under certain weight would collapse under said weight dropped from good height, but I could get even one floor below to fail this way, no matter the height.
In fact... Weight that would collapse one floor on its own would sometimes halt mid-collapse.
The sheets of paper sagged, but then unraveled on each other to form a much more sturdier floor, that would resist collapse altogether. Thus, unfortunately this came nowhere close to floors "breaking" from supports. What this does seem to resemble is the "pancaking", however, obviously very crudely.
...Bigger weights, that would collapse the whole structure, would take a good two-three seconds more to reach the ground compared to just dropping them, most noticeably almost halting for a moment on very first impact.
This seems to check out with both intuitive conservation of momentum and known examples of gravitational collapse, as it should.
But, yeah, not a handyman. I'm not sure how to achieve "breaking" supports in this scenario. That is, assuming vertical supports stay in place.
The flaw in your reasoning is that your washers are only one or two inches apart whereas the floors in the WTC are 14 feet apart. Your video shows a the top part crushing more than one floor and arresting only because the lower "washer floors" at two inches (?) apart and not 14 feet. If they were 14 feet the effect would be quite different. Take the collapsed mass back up to the top and drop it again - and then repeat over and over again. That's the right simulation
@rgsalinger You've never heard of scale tests? Either way, what is shown here is true for any materials at any heights and does not require a thousand foot tall model to demonstrate such.
@ryinski2 sure I've heard of scale models, but you cannot simulate the second drop this way. Each drop was somewhere between 12 and 14 feet and your drops are only what - two inches. In the WTC, after the first floor breaks the remaining mass has another 12-14 feet to gather energy/momentum. You have proven exactly what you set out not to prove.
Here the "floors" are also allowed similar distance to "fall" through when their supports are shattered as there would be between WTC floors.
It's an illustration of already known principle of conservation of momentum: one way or another, 90% of the building offers more resistance than 10% of it, as illustrated above.
@SexyMelon Thanks the laws of physics require that any model like this have the same distance between the floors as existed in the WTC towers or it is NOT to scale in terms of the physics. Find a local physics professor and show him the model and ask him if it will scale correctly, it won't. Once the first floor "breaks" you now have an even greater accelerating mass, so the next floor MUST break.
@rgsalinger "Once the first floor "breaks" you now have an even greater accelerating mass, so the next floor MUST break."
Err, no.
Look up conservation of momentum: if a falling mass comes in contact with another, it DE-celerates, no otherwise. The total momentum is shared - lessened - with each collision, as the above model illustrates.
The mass does not get "bigger" either, since all bottom floors in the building have to support the above mass by definition.
@SexyMelon Conservation of momentum is only correct when you have a closed system. In the WTC collapses once the top of the building begins to accelerate you have the force of gravity as well as the velocity of the moving mass to contend with. Look it up yourself - "closed system" - the mass keeps accelerating and it's getting heavier.
@rgsalinger "Conservation of momentum is only correct when you have a closed system."
The heck? Of course not. Physical laws act on any scale, you're confusing outside factors for whether laws still apply.
"In the WTC collapses once the top of the building begins to accelerate you have the force of gravity as well as the velocity of the moving mass to contend with."
@rgsalinger "the mass keeps accelerating and it's getting heavier"
Again, no. Conservation of momentum dictates sharing of momentum slows down the overall mass. There can never be acceleration on impact under influence of only gravity: force of gravity can either be expended on motion OR crushing the structure, you can't have both be equally strong at the same time.
The experiment above confirms that. If you what you said were to be true, this "bigger accelerating mass" would collapse it.
@SexyMelon I didn't say that there was an acceleration under impact, I said that the velocity will continue to increase under impact. Unless the collapse was completely arrested by impact with the first floor, the new starting velocity is greater than the original zero velocity. So, you have more mass and move V when the next impact occurs. Therefore, if the first impacted floor failed then the next one is certain to.
@SexyMelon Sorry that wasn't clear. The impact reduces the acceleration of the upper mass, it doesn't actually slow it down. The acceleration can reduce from (say) .6 to .1 and velocity still increases. Your mental model of the collapse leaves out gravity. If we were talking about a collapse in the absence of gravity then you'd be correct.
@rgsalinger "Your mental model of the collapse leaves out gravity."
It's not a mental model, it's a physical experiment provided above...
And no, of course it doesn't leave out gravity. In fact it's the foundation of the objection to it: gravity is uniform across all weights and dimensions, and provides a constant force throughout; in a gravitational collapse, energy which is used to crush the structure cannot be used to also accelerate it downward all the same. This is not true for WTC.
@SexyMelon Actually the structure of the WTC towers puts up enormous resistance to the collapse, that's why it takes longer than what free fall would predict.
There are two simultaneous factors involved in arresting the falling mass. The conservation of momentum slows things down but energy is lost in the process of crushing the paper loops. Since the only energy source is the kinetic energy of the falling mass the crushing of the loops slows things down more.
The bending and dislocation of core columns and beams would have slowed down the WTC.
Other than the experiment above... Do you think there is any intuitive way to express just how much energy would be expended on such work (crushing, bending)?..
Conservation of momentum alone seems hard enough to explain somehow. But this may be more important, I understand it's the reason we use explosives rather than wrecking balls to bring down steel-frames in the first place?..
@SexyMelon Well that is one problem with the WTC. The columns get thicker all of the way down the building. So the amount of energy required should increase level by level. But we are not even told the tons of steel at every level. So we have spent years listening to EXPERTS who have not been demanding the information required to solve the problem.
Very curious country we have here.
Are we sure they were smart enough to put men on the Moon 41 years ago? LOL
@psikeyhackr "So we have spent years listening to EXPERTS who have not been demanding the information required to solve the problem."
Hit the nail on the head there.
How can we pretend to have solved the problem without any meaningful investigation? Why do people think there's any evidence to support the official conspiracy when pressed for it they can only name NIST investigations and such, who have not collected any evidence?
Everyone just sort of assumes... What the TV told them... Oh.
@psikeyhackr The increasing mass of steel further down might not phase someone who thinks it has consistency of paper in the first place - that's really the major problem of understanding there - but it would at the very least signal that there *must* have been some form of deceleration.
Then again, even free-fall (Chandler, WTC7) doesn't seem to phase some people.
"Are we sure they were smart enough to put men on the Moon 41 years ago? LOL"
@rgsalinger "Actually the structure of the WTC towers puts up enormous resistance to the collapse, that's why it takes longer than what free fall would predict."
NIST says it took tower two 11 seconds to reach the ground. Estimated free-fall time for it is 9 seconds. Two more seconds hardly even accounts for resistance of thin air.
Most controlled demolitions occur at upwards of 200% of free-fall. Gravitational at upwards of 300%. WTC? 110%.
@SexyMelon I'd like to see your source on the speed of controlled demolitions. If your point is that they take much longer than WTC, then how can you argue for CD at WTC? On the other hand, just do the math to calculate the actual resistance necessary to reduce the acceleration from 1g to .6g for a mass of 30000 tons and you'll see the point..
@rgsalinger "If your point is that they take much longer than WTC, then how can you argue for CD at WTC?"
Because it's the closest thing, of course, and the only known possibility as it places possibility of gravitational collapse into territory of ludicrous by default.
@rgsalinger "On the other hand, just do the math to calculate the actual resistance necessary to reduce the acceleration from 1g to .6g for a mass of 30000 tons and you'll see the point."
Err... Approximately 15,000 tons?..
If you're going to calculate it like that, by taking masses as a whole, the upper block would have stopped on impact. Watch the video above: the mass is not structurally integral, so some of it is crushed, while other parts stay undamaged (note, on both ends).
@SexyMelon The problem with the video is simple, if the first drop is 12 feet then the next drop has to be 12 feet or the model is flawed. You cannot simply scale up one portion and leave the other intact, it's not a model to scale. You need to have each collision taking place at the speed achieved by a 1 g acceleration over a span of 12 (or 14 feet). Otherwise the momentum transfer is only about .01 of what it needs to because there is only a two inch fall.
@rgsalinger "The problem with the video is simple, if the first drop is 12 feet then the next drop has to be 12 feet or the model is flawed."
Why is this an issue? The model is scaled: what are gigantic floor slabs at WTC are are small metal planes here, and what is 12-foot drop there is a few inches here. It's scaled. If the model had 12-foot drops, it would scale to a building the top of which would hover in outer space.
@SexyMelon You need to read up on how scale models work and then maybe you will understand. The massive concrete floors are 4 inches thick. They are not made to hold up 10 times their own weight so when they are hit by 30k tons, they are disconnected from the columns. And, this is such a chaotic event that a simple model like this, even with the correct spacing, cannot do it justice or show us anything probitive.
@rgsalinger "You need to read up on how scale models work and then maybe you will understand."
I don't believe I ever tired to remind you that this IS a scale model, and thus - obviously? - the distance between floors also has to be to scale. I do not know why you want it otherwise.
"And, this is such a chaotic event"
A chaotic event would not bring the buildings down straight into their own basement. This is why we demolish buildings instead of setting fires to them.
@rgsalinger "a simple model like this, even with the correct spacing, cannot do it justice or show us anything probitive"
Why not? What is the crucial detail that would alter the outcome of the experiment? Obviously models do work, and we do use them to test real-world conditions. Models not being "complex enough" is not an objection in itself. What's missing exactly?
@SexyMelon What's missing is 12 feet between floors as well as a steel and concrete structure. What's also missing is the tilt that makes the columns not impact each other and obviates the idea that steel needs to be "shattered" or crushed for the building to collapse.
@rgsalinger "What's also missing is the tilt that makes the columns not impact each other"
How does that work? How can tilt displace columns? Most buildings tilt during controlled demolitions - inevitably, sometimes inward on purpose - and it accomplishes no such thing.
@SexyMelon The top of each tower falls by tilting around a fulcrum formed by its stronger side. Therefore, when the first lower floor is impacted, the columns are not aligned either on the perimeter or in the core. So, it's not necessary to crush steel to achieve a failure of a floor.
@rgsalinger "Therefore, when the first lower floor is impacted, the columns are not aligned either on the perimeter or in the core."
That makes no sense. Tilt can only misplace columns at the tip of the tilt, those at the axis, by definition, remain in place.
Again, most demolition occur at a tilt, and no such displacement occurs. If this were a known effect, don't you think the million-dollar-industry would be clued in on it?
@rgsalinger I guess the question is... What kind of experiment can you do where the factors you outline alter the outcome so dramatically?.. Should you really believe it when it has never been tested?..
Actually I think you can replicate at least one of those conditions with an assembly akin to those silly cabinets you can get at IKEA, where the boards are supported by tiny wooden bolts... Wish I was a handyman, this is actually interesting.
@SexyMelon I think that I understand why we don't see this the same. You think that the steel columns had to be "crushed" - fail for the collapse to continue. Based on my observations and reading, the connections came apart, the columns are seen to be largely intact with broken bolts and sheared connections. Hence, I see each floor destroyed, the debris from it accumulating and no resistance to speak of for another 12 feet. You see it differently for some reason.
@rgsalinger "Based on my observations and reading, the connections came apart, the columns are seen to be largely intact with broken bolts and sheared connections."
Well, that's quite simply not true - and indeed not advocated by the "official" investigations, see NIST FAQ on WTC investigations - quite glaringly, the core steel structure collapsed along with the concrete one. In fact the very scarce photographic evidence also documents connections being intact.
@SexyMelon i don't think that I cited any "official" explanations. I told you what I saw and the reading I have done is in no way "official". What I've read are various peer reviewed articles published in recognized journals. It's clear that the steel was not "crushed" in the collapse. That only happened during the collapse initiation phase. You're using the term collapse loosely. Just look at pictures and you can see what I mean - the structure comes apart at its connections, there is no crush.
@rgsalinger "i don't think that I cited any "official" explanations."
I believe the mechanism of collapse you're referring too with "falling" floors and "severed connections" describes what is officially known as "pancake theory".
Again, it is rejected by advocates of the official story due to both physical impossibility and glaring contradiction with observed facts.
@rgsalinger The official story - one of them anyway - to date is that the floor trusses sagged in the fires, initiating the collapse through progressive sagging and pulling the core columns they're attached to with them.
It is, of course, also physically impossible. You may notice that, not only is there nothing "falling" in that model, but the strongest part of the building has to be literally torn to shreds by the weakest one.
@SexyMelon Look some more, please. I think that the original FEMA study has some good shots if you can find them or just peer a bit into some hi-res photos of the pile taken soon after the collapses and you'll see what I mean - no shredded steel. Finally, the guys who examined the steel in the waste sites reported no shredding or other evidence of explosives (if that matters).
That's not helping. Like I said, I remember dozens of photos that show connections intact, I'll tell you if I can find them...
"Finally, the guys who examined the steel in the waste sites reported no shredding or other evidence of explosives (if that matters)."
No search for evidence of any kind of explosives or incendiaries was ever conducted - not to mention most of the steel was outright destroyed - so that's a bold-faced lie on their part.
@rgsalinger I've heard about the "tilt" before, and I see where it's coming from: given enough falling distance, it can make some of the columns "miss, but most will remain in place by definition (the axis).
Again, most saliently, it doesn't work in reality: most demolitions occur at a tilt, and the effect is never observed in any of them, nor in any true chaotic collapses.
And even then, crushing through floor assemblies of a sky-scraper is hardly comparable to no resistance at all.
@rgsalinger This is generally what WTC core was like:
/watch?v=BVzg5qlcYBY
A solid mesh of steel on the inside, surrounded by big floor space with no columns, with a final single layer of columns on the outside.
This is the kind of structure that would not only stand on its own but, by definition, would stand on its own AND hold up the floors of the building in the first place. If you break the connections somehow, you free the core of the load.
@SexyMelon I mean that you can find video of the core standing if you look around. After a few seconds, it falls apart. That shows me that the core, while strong as part of the overall structure is not strong once its on it's own. That's the real point - the building is a complex structure, not a pizza box or a wood block. Once it's structural integrity is initially breached it can be induced to fail.
@rgsalinger Short version, if you're not crushing the core structure... You're not crushing the core structure. It would stay intact. It did not.
Again, look it up. Pancake theory has been dismissed by champions of the official story just as "core meltdown" (that's where the steel was meant to be literally melted by fires) was, for likewise glaringly obvious reasons of impossibility.
It still sticks to the "debris mass" thing in spite of that... It just doesn't make sense either.
@SexyMelon Actually part of the core did stay intact but then a few seconds later it falls. Again, it comes apart at its connections, it doesn't crush. You don't have to crush any complex structure to make it come apart under load. It will break at its weakest points - in the case its connections. I have no idea what the "pancake" theory is or isn't and it doesn't matter to me. Those buildings don't come apart by having the columns crushed.
@rgsalinger "It will break at its weakest points - in the case its connections."
If the connections broke, by definition, the structure they were separated from would not be destroyed. It was. In fact, the floor truss connections appear to have remained intact.
Of course, crushing connections would still take a tremendous amount of energy. Or at least something greater than what could be mistaken for thin air.
@SexyMelon No they didn't remain intact. They are clearly severed in all the pictures I've seen of the debris. You can see several floors worth of columns coming down separated at their connections. There are no pictures of "shredded" steel at all or even buckled columns. The only columns which buckled are the ones which failed in the initiation sequence of the collapses. After that the mechanism is different.
@SexyMelon This is where we differ - as each floor breaks up, there is no resistance below that floor - that's what is "broken", hence the mass (which is now bigger) will continue to fall another 12 feet. You cannot simply scale that down. No one builds scale models of buildings to test their structure because the scaling is not a simple linear function.
@rgsalinger "This is where we differ - as each floor breaks up, there is no resistance below that floor "
What? Breaking supports would produce positively massive amount of resistance.
But, as aforementioned, this is not an option: not only are connections solid metal, if they were indeed destroyed, parts of the building would, by definition, stay intact.
@rgsalinger Again, if the collapse built momentum as opposed to expend it... Why doesn't it work in the video above?
The "floors" crush, the "mass" increases, and yet it decelerates, slows down and halts; indeed all known gravitational collapses do. It just doesn't appear to be possible.
Heck, even explosive demolitions halt just because of a second-off timing in the explosions: /watch?v=UsePUn5-88c
@SexyMelon It doesn't work in the video because he's not allowing the initial collapsed material to go another 12 feet. If he did he must get the same result - another two "floors" collapsed. Your use of Newton's second law is incorrect because there is a force acting on the falling mass.
@rgsalinger Errata: obviously gravitation does depend on mass, it's just that any mass here is insignificant to Earth's.
"It doesn't work in the video because he's not allowing the initial collapsed material to go another 12 feet."
This would be completely out of scale?.. Why?..
If the tower had this large spacing between floors, it would actually halt sooner because supports would have to be sturdier to hold it up in the first place...
@rgsalinger "Your use of Newton's second law is incorrect because there is a force acting on the falling mass."
Newton's second law concerns only gravity - it being the only force at play here versus elastic resistance - in the first place, so how could it possibly be incorrect?..
Also, it's not entirely accurate to describe it as "falling" mass: the building is a solid mesh of steel and concrete, and one way or another the collapse has to crush through them.
@SexyMelon The 2nd law is not about gravity it's about momentum and it holds only in a closed system. It's your use of it which is incorrect. I don't understand your other point but I agree that the collapse proceeds roughly through the center of mass of the building but that's because there is not enough torque for anything else to happen. Sorry if I'm not following your argument
@SexyMelon Newtons second law concerns momentum within a closed system. it has nothing whatsoever to do with gravity. Newton also discovered gravity but that's a separate law from the laws of motion. That's where you are getting confused. Momentum in an open system (with a force acting upon it) allows for a momentum transfer without a decrease in velocity through deceleration.
@rgsalinger "Newtons second law concerns momentum within a closed system. it has nothing whatsoever to do with gravity."
I said I know two times... It concerns gravity here because gravity is the only force allowed in play, allowed to act on the structure. F=ma -> a=F(g)/m
What this alone does not account for is the elastic force of the structure itself, and this is the question.
@rgsalinger "Momentum in an open system (with a force acting upon it) allows for a momentum transfer without a decrease in velocity through deceleration."
To have constant acceleration in this system would require either floors having same amount of resistance as thin air between them, or be rocket-propelled.
Well, there's no space for anything to "fall" in the structure. Just like the model above, it is solid. It's a mesh of steel. The reason anything can "fall" in demolition is because said supports are physically destroyed and, unlike concrete, steel cannot shatter on impact. Its tensile strength is immense.
"that's because there is not enough torque for anything else to happen"
Collapsing at an angle would supply tilt by default, wouldn't it?
@SexyMelon The upper part of the tower and the accreted material from the first lower floor that fails falls another 12 feet under acceleration from gravity. Then it encounters the next floor with even more accreted material so the total momentum keeps increasing as both the mass and the velocity are greater than they were when the first floor impacted was destroyed. As each floor loses its structural integrity it provides minimal resistance. When the next floor is hit it resists momentarily.
@rgsalinger "The upper part of the tower and the accreted material from the first lower floor that fails falls another 12 feet under acceleration from gravity."
That's the first problem: it doesn't "fall". By definition, it has to crush the structure that supports the towers.
"Then it encounters the next floor with even more accreted material so the total momentum keeps increasing"
No. Total momentum decreases on impact, not increases.
Again, if that were true, why doesn't it actually work?..
@SexyMelon "Total momentum decreases on impact, not increases."
To clarify...
Of course total momentum stays the same. I mean in the context of the collapse, collision of falling mass with stationary one would slow down the one in motion, not add more speed or force: the only allowed force at play is gravity, and that is constant, G.
Assuming the floor gives, some of the gravitational force has been expended on combating resistance, and thus cannot work towards moving it forward.
@SexyMelon As you increase mass, you decrease acceleration (I wish I could conjure a proper formula to express this with all involved factors).
I believe you already know this, and said this should occur, I'm reiterating it because it's the whole point: it does not occur. The acceleration remains uniform throughout the collapse, indicating lack of resistance, or rather lack of resistance of floors - trusses, hat trusses, core columns, sky-lobbies - compared to thin air between them.
@SexyMelon Much better argument - that constant acceleration is suspicious. We should see a reduction in acceleration each time a floor is destroyed. How much should we see? How visible would it be? What I've seen is a broad brush approach - using smoothed data to prove the point. I have never seen anyone demonstrate that the acceleration changes would be visible in a video, which is all we have to go on.
@rgsalinger "How much should we see? How visible would it be?"
Difficult question made easier by gross disproportion of the collapsing mass in comparison to collapsed one: at least after 10 floors.
It's not necessary to graph out reduction as per impact with one floor - approximately 0,4m/s, see calculations below - when you can judge the collapse as a whole.
The acceleration is uniform throughout. So neither at the start, nor even after 100 floors, there is no reduction at all.
@rgsalinger "How much should we see? How visible would it be?"
Oh. Actually there's an easier way to see that, even with your naked eye:
/watch?v=3GNhEpHfgfI
This is a true gravitational collapse. It has acceleration of near-free-fall when the initial supports are removed, it visibly slows down when first floor is impacted, and it visibly slows down as the crush is proceeded, visibly halting just before the smoke cloud engulfs the scene.
@rgsalinger Another things to note about Verinage is that it has crush-up simulate-nous with crush-down, produces no explosive ejection of debris, occurs at upwards of 300% of free-fall, cannot be used for steel-frame structures... Actually I left a few comments on that video if you can be bothered
(The author has since blocked me so I can't raise a final contrary argument... No comment, heh.)
Again, compare to WTC. Maybe play them side by side, I don't know. See for yourself, what you think.
@SexyMelon ...Also, note, Verinage demolitions always make the cut at the center of the building? Why is that?.. Well, a brief look at what is left of the top structure and its total speed by the time collapse reached the ground should explain that...
(Spoiler: the upper mass is completely destroyed along with bottom one, and collapse grinds to a virtual halt even before it hits the ground. If you made the cut anywhere else, some of the building would be left standing: /watch?v=UsePUn5-88c )
@SexyMelon That's right, SOME of the force. Unless the resistance of the first floor impacted is equal or greater than gravity times at least ten then acceleration - positive change in velocity will occur. Given that the upper block is time times the weight of the floor impacted, you're going to get only a reduction in acceleration, not velocity, at best.
Yes, thank you. And the acceleration measurement of the descent would suggest all of it went into accelerating the structure instead (as it's uniform and near-free-fall).
"Unless the resistance of the first floor impacted is equal or greater than gravity times at least ten then acceleration - positive change in velocity will occur."
Obviously it is greater than gravity considering the building had to stand up in the first place.
@SexyMelon No, it's not free fall. Each floor shows considerable resistance. Sure the floor stood up but it was part of a structure, not on it's own and it certainly wasn't designed to hold up the rest of the building - 10 floors - with its columns removed.
This is not true, as the acceleration of the collapse is uniform throughout the event, and differs from acceleration of free-fall by only a miniscule amount (0,2ms), which is comparable to if not less than resistance of thin air, the air between floors themselves. Resistance comparable to that of thin air is not nearly "considerable" in any case.
@rgs "it certainly wasn't designed to hold up the rest of the building - 10 floors - with its columns removed."
That is unknown to make judgment like that. Whether one floor was enough or not, further ten, and more so further hundred, should be more than enough by conservation of momentum.
What was designed to hold the weight of the floors collapsing were two reinforced concrete sky-lobbies. These were specifically designed to limit collapse of *any* third of the building to that part only.
@rgsalinger "Given that the upper block is time times the weight of the floor impacted..."
You can't think that way. If you judge the falling structure as one contingent block, then the one below it is simply a nine times bigger block. The collisions themselves are inelastic, they occur between individual floors, which is why individual floors are crushed (both up and down).
What you want are collisions between individual floors but across the total number of floors.
@SexyMelon Prove that I am wrong then, if you can, otherwise we will just disagree. The impact event is not inelastic in any sense of the word unless you greatly simplify it to the point of not resembling what happened as has been done here.
@rgsalinger "Prove that I am wrong then, if you can, otherwise we will just disagree."
That's what the video above is about, isn't it?..
If what you say were true, it should have collapsed.
That's the whole point, isn't it?.. There's an experiment, and it doesn't work. There are videos of true gravitational collapses, and they "don't work" either. There's knowledge that steel-frame buildings cannot be demolished via gravitational collapse alone.
@SexyMelon You keep saying "slow down" which is not the case when a force is acting (gravity) unless the resistance is greater than some calculated value.
@rgsalinger "You keep saying "slow down" which is not the case when a force is acting (gravity) unless the resistance is greater than some calculated value."
Sorry for being vague, "slow down" as in reduction in acceleration as well as reduction in velocity if acceleration is zero.
"Much better argument - that constant acceleration is suspicious. We should see a reduction in acceleration each time a floor is destroyed."
Absolutely! Indeed that is the argument, or at least big part of it.
@SexyMelon First of all total momentum must be conserved at the moment of impact. Second, as soon as the floor loses its integrity it just adds its mass to the 10 floors already descending. There is NO NEED to "crush" the steel and the pictures at ground zero prove that crushing in that sense never happened. Instead connections between the floors and columns were severed. There was no crush, there was catastrophic failure. If it collapses like an accordion, you would be more or less right.
@rgsalinger "If it collapses like an accordion, you would be more or less right."
"Accordion" collapse - the actual name for it is "pancake theory", I believe, and you might be interested to know it is official rejected as explanation for the collapse by NIST - is presented in the video above, and it just doesn't work.
@rgsalinger "When the next floor is hit it resists momentarily."
That does not occur. The acceleration of collapse wake is uniform even throughout reinforced concrete skylobbies.
"I'd like to see your source on the speed of controlled demolitions."
I don't think there can be any particular source, but you can check for yourself using any known video of explosive/gravitational demolition: /watch?v=dgZLXI3whGA
@rgsalinger " Sorry if I'm not following your argument."
Sorry, I am rather long-winded. Is there anything I can explain specifically, or summarize?..
The important part, I think, remains that: if the momentum-building or whatever you call the event to have collapsed WTC, is a real thing... Why doesn't it work for the video above?
That's the whole point of that experiment. To see if the hypothesis works. It doesn't appear to.
@SexyMelon The total amount of mass is increasing as each collapsed floor adds itself to the previous floors. Deceleration is not reduction in velocity, it is reduction in acceleration so total momentum (MV) is still increasing. So when the next floor is impacted the overall force is greater.
@rgsalinger "The total amount of mass is increasing as each collapsed floor adds itself to the previous floors."
Then why did this "increasing mass" did not collapse the model in the video above? Does the principle only apply to WTC?..
The fact is, there is no "increasing mass" - nothing is added, the only time mass was added into equation is when a plane crashed into it - and there is definitely no "increasing speed" as collisions always slow down the moving object. Not accelerate it.
@SexyMelon The increasing mass would do exactly as I said if you just let it fall another twelve feet. As each floor in the WTC loses its structural integrity, it effectively cannot provide any resistance. Of course the actual events are much more complicated, we see connected columns multi stories high breaking off, for example. However, we're just talking about how this model contradicts the idea that there wasn't enough gravitational energy to bring about the collapses alone. Send me a PM.
@rgsalinger "The increasing mass would do exactly as I said if you just let it fall another twelve feet."
But then the model would be ludicrously out of scale...What? And why do you think it would perform better exactly, when the strength of supports needed to hold such a structure up in the first place would provide more resistance than normal-sized ones?
"As each floor in the WTC loses its structural integrity"
Not likely. Steel does not shatter on impact. It's tensile strength is immense.
@rgsalinger "We're just talking about how this model contradicts the idea that there wasn't enough gravitational energy to bring about the collapses alone."
Good.
So how does it contradict it?.. I understand you're saying it should have allowed a fall of 12 feet, but the model is obviously scaled, so what gives?.. This would more likely halt it sooner.
"Send me a PM."
If this would be more convenient for you, feel free to fire one off to me. Until then I'll reply here if you don't mind?..
Well, it's that day. TEN YEARS of Bad Physics!
The Physics Profession has not demanded accurate data on the distributions of steel and concrete down the towers. Who cares about Potential Energy and the Conservation of Momentum?
I guess it is time to burn Isaac Newton in effigy.
psikeyhackr 5 months ago in playlist More videos from psikeyhackr
When any two bodies act upon one another, their total momentum remains constant provided no external forces are acting. In other words, we can say that whenever one body gains momentum, then some other body lose an equal amount of momentum, that is , momentum is never created or destroyed.
naziballs 1 year ago
@naziballs
LMAO, since when? Total Momentum is added to in a gravity field.
Both the Impactor, and the Impacted, are being CONSTANTLY accelerated DOWN.
That's what WEIGHT IS, your mass accelerated down at 1 g.
That's what CONSTANTLY compresses the springs in a weight scale.
There is a constant acceleration in a gravity field, and there is practically
no place in the universe without a gravity field, even between giant
galaxie clusters separated by millions of light years.
Merlin5by5 6 months ago
@Merlin5by5 {{{ Both the Impactor, and the Impacted, are being CONSTANTLY accelerated DOWN.
That's what WEIGHT IS, your mass accelerated down at 1 g. }}}
What insane physics! Being subjected to a force is not being accelerated by it. Acceleration is change in VELOCITY. If mass is stationary then it is not accelerating. 9.8 m/s^2 is the acceleration caused by gravity IF the mass is free to fall.
These schools sure as fell let people pass with incompetently memorized physics. LOL
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psikeyhackr 6 months ago
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@psikeyhackr
That's actual Physics, dumbshit. You don't have to have a velocity at all,
in order to be accelerated down in a gravity field. SO, you say 9.8 m/s^2
is the acceleration caused by gravity?
The SI units for acceleration are m / s^2 (meters per second squared)
Do you see your problem yet, Super-Genius?
Merlin5by5 6 months ago
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@psikeyhackr
EVEN a grade school teacher will tell you gravity is PRESSING you against
the earth, and that you would fly off it, if not HELD DOWN by gravity.
What did you think that PRESSING DOWN was?
Watching Truthers learn physics is like watching Cats being herded.
Dumb, obstinate, and full of ADHD diversions.
Merlin5by5 6 months ago
A "thought experiment" we can do. Suppose the upper 15% of the north tower starts to collapse. It falls one floor, hitting the floor immediately under the falling part. Just as the falling floor touches the stationary floor, ALL support for the stationary floor disappears. At that instant, the stationary floor starts to fall on its own; in the next instant, the moving floor hits it and they fall together. The process is repeated with each lower floor. How long would it take to hit ground?
Skeptic121 1 year ago
@Skeptic121 Thought experiment is not necessary. I already wrote the Python program.
It takes about 12 seconds but it varies with the distribution of mass. Skyscrapers must get heavier toward the bottom. That is why it is so absurd that our EXPERTS have not been demanding the TONS of STEEL and TONS of CONCRETE that were on every level of the towers for NINE YEARS.
the911forum (DOT) freeforums (DOT) org/post11173.html#p11173
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psikeyhackr 1 year ago
@psikeyhackr
You can't compare the ultimate strength of the paper loops in your model with the ultimate strength of the steel in the towers. I explained why to you many times in many other forums. If you can't even do the grade school math to support your grade school physics it's no wonder why you don't understand why the energy of the upper block exceeded the ultimate strength of the lower portion by an order of magnitude no matter what the exact mass was for either.
fangbeer 1 year ago
@psikeyhackr About 12 seconds? That's about the time it actually took, right? So, here is the big question: what took away all that vertical support from the lower part of the tower? You know, the part below where the plane hit. The part below the fire. The part that was undamaged, according to the people who escaped from those floors before the collapse. Undamaged, that is, until some loud explosions happened and the whole thing fell down...
Skeptic121 1 year ago
@Skeptic121 He's a 911 Truther like you ya Dumbass
flanksteak2 1 year ago
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@flanksteak2 "He's a 911 Truther like you ya Dumbass" and your point is?
Skeptic121 1 year ago
1. Calculate the pound force per square inch imparted to the first impacted "floor" of your model.
2. Calculate what the psi would be scaled up to the full scale of the building. (don't forget that a 10 lb cube scaled up by a factor of 10 weighs 1000 times more then the original cube but only has 100 times the surface area.)
3. Use this data to explain how your paper loop represents the full scale ultimate strength of steel given that ultimate strength doesn't change proportional to scale.
fangbeer 1 year ago
@fangbeer Do it yourself. I don't care if you think math is more important than physics.
How many SQUARE INCHES are there to the edge of a piece of paper 5 inches long? I don't give a damn about trying to compute it. Why don't we have the TONS of STEEL and TONS of CONCRETE on every level after NINE YEARS?
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psikeyhackr 1 year ago
@psikeyhackr
You don't give a damn about math? Seriously? It's no wonder you didn't move beyond grade school physics.
fangbeer 1 year ago
@psikeyhackr "I don't care if you think math is more important than physics."
Physical principles can not be accurately calculated without the use of math.
You know that we know that you know that we know that you have ZERO training in ANY sort of physics, chemistry or engineering.
flanksteak2 1 year ago
@flanksteak2 So how can the math be done without accurate data to plug into the equations?
Therefore anyone that understands the PHYSICS should be demanding the data before talking about math. So why don't we know the TONS of STEEL and TONS of CONCRETE that were on each and every level of the towers after almost TEN YEARS?
Why hasn't the Physics Profession been demanding that information?
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psikeyhackr 6 months ago
@psikeyhackr You really think you have all this figured out don't you? You, the Youtube flunky, really truly believes he is onto something because you are a batshit crazy shizoid.
7 months later.......LOL
flanksteak2 6 months ago
@flanksteak2 Some times I get slow days and can stoop to responding to REALLY DUMB STUFF.
I don't look at this video much. There is one with a sound track and intro I stole from Ryan Mackey. I figured out in two weeks that it was ridiculous to think that airlines could destroy buildings 2000 times their mass in less than two hours.
Unfortunately it is hysterically funny that the physics profession has not demanded accurate data on the distributions of steel and concrete in TEN YEARS.
psikeyhackr 6 months ago
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@psikeyhackr The only funny thing here is the fact that you think you know what you are talking about.
And that's not really funny.
flanksteak2 6 months ago
Scaling would make your model much stronger than the towers.
All this time and you still don't get that?
justin39640 1 year ago
@justin39640
Where did I claim to be scaling anything? The paper loops were selected to be as weak as possible to support the static load?
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psikeyhackr 1 year ago
@psikeyhackr
Loops are way stronger (you know that), your indestructible core also adds untold support. Your "weak" structure scaled down is thousands of times stronger than the towers. You can't scale down what happened to the towers with 6 foot crappy models built with your home depot credit card. Youo're attempting to show why a gravitational collapse couldn't have caused the destruction on 1 and 2WTC. You are wrong and this model does nothing to prove your case.
Thank you, goodnight
justin39640 1 year ago
@justin39640
Obviously videos can't really PROVE anything.
But the problem with your IDIOTIC CLAIM is that the model only costs $30 and anyone that wants to can repeat the experiment for themselves. I can't cheat when people get the materials and do it themselves.
The towers had to be strong enough to support their STATIC LOAD. The DYNAMIC LOAD would still be SLOWED DOWN crushing supports that strong. The north tower destruction due to airliner and fire was IMPOSSIBLE.
Build it yourself.
psikeyhackr 1 year ago
@psikeyhackr Tissue paper is weaker than the paper you used so clearly you did not make the model as weak as possible.
flanksteak2 1 year ago
@flanksteak2 So obviously you are too dumb to know what As Weak As POSSIBLE means.
The structure had to support its own weight. I left it standing for 3 days before I did the drop.
Tissue paper could not support the weight of a single washer. I tried it.
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psikeyhackr 1 year ago
@psikeyhackr "as weak as possible"
It's non-sequitir because you are still under the mistaken impression that the falling mass was "crushing" the columns.
This incorrect assumption is the basis for the entire Truther "explosives did it" fantasy.
You're no different than any other truther in regards to this false belief.
flanksteak2 1 year ago
@flanksteak2 Regardless of what WORD you want to use for the elimination of support by the columns it still required energy and there was ONLY ONE SOURCE. So the falling mass HAD TO SLOW DOWN.
So why haven't EXPERTS been demanding the TONS of STEEL and TONS of CONCRETE on every level for the last NINE YEARS?
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psikeyhackr 1 year ago
@psikeyhackr Why would it have to slow down? First you claimed it fell at freefall, you were wrong, now you are going to move on and make yet another even more incorrect, fact-ignoring and make yourself look like an even bigger idiot.
What purpose do you take home in making false, ignorant claims?
flanksteak2 1 year ago
@flanksteak2
No amount of explanation gets through to Psikey. When presented with a mathematical model to describe the collapse he called it a bunch of fancy calculus that he didn't understand. He's attempting to describe this collapse through the lens of a high school student who doesn't know anything about the strength of materials, structural mechanics, or even square cube law. In short, he's an idiot who has the gall to blame everyone but himself for his ignorance.
fangbeer 1 year ago
@fangbeer I agree but even in High School, I would have understood that a floor assembly that can only hold 11 floors worth of weight would have collapsed under the weight of 12 floors landing on top of it. (this is an extremely conservative measurement that doesnt' even take into account the weight of the framing or the momentum).
He has to completely ignore the building altogether, and then build a totally irrelevant pretend, non-sequitir model in order to validate his conspiracy leanings
flanksteak2 1 year ago
@flanksteak2
It's more complex then that. WTC floor assemblies didn't hold the weight of the floor above them. They only held their own weight, and transmitted lateral load between inner and outer columns. Just one floor worth of live load hitting from above was enough to damage the connections between the assemblies and the columns of the floor below. This and the fire compromised the lateral strength of the columns in the area of collapse initiation and set off a chain reaction.
fangbeer 1 year ago
@justin39640
It has been NINE YEARS since 9/11. When have we been told the TONS of STEEL and TONS of CONCRETE that were on every level of the towers?
So what objective data can you possibly have about how strong my paper loops are compared to the WTC if you don't have that information any more than I do?
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psikeyhackr 1 year ago
@justin39640
Good luck with trying to help Psikey "get it." After all this time the total sum of his effort to read the 9/11 report (and his primary beef with the report) has been an acrobat search for keywords he expected to find but did not. He hasn't read it.
I attempted many times to explain square cube law to him. Still, he refuses to address the problem of scaled gravity. He claims it doesn't need to be scaled, and simply cannot grasp the concept that gravity cannot be scaled
fangbeer 1 year ago
@fangbeer The only thing to get is that it is a SNOW JOB to confuse the ignorant and keep them that way.
They can specify the total for the steel in three places but never the total for the concrete and then can't do the distribution for the steel.
So they now need to keep grade school physics confusing FOREVER.
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psikeyhackr 1 year ago
This experiment is as elegant as Richard Feynman's ice water test on Space Shuttle O-Rings. You are to be commended on this.
UNIVERSITYHI 1 year ago
@UNIVERSITYHI The difference here is Feynman's experiment was a full-scale demonstration of the properties of O-ring material at low temperature. This is dropping washers onto paper. While it certainly isn't necessary to build another WTC to prove the point, any experiment like this needs to account for the structure of the buildings. There is no reason to believe this model is, in any meaningful way, similar to the WTC. Falling in near free-fall does not violate any fundamental laws of physics.
roamingcroat 1 year ago
@roamingcroat
{{ Falling in near free-fall does not violate any fundamental laws of physics. }}
Considering that the buildings were designed to hold themselves up JUST LIKE MY MODEL & they held themselves up for 30 yrs there is a physics problem with the buildings comIng down that fast.
My model is DEAD LOAD ONLY & did not have to withstand the wind. So the WTC towers had additional factors increasing their strength which should have made their chances of coming down less than my models.
psikeyhackr 1 year ago
@roamingcroat
{{{ This is dropping washers onto paper. }}}
One nice thing about that model is that it is VERY CHEAP.
Anyone can duplicate it. There is nothing stopping you from doing so and using something other than PAPER. You can use STEEL and see if that is more likely to collapse. LOL My model is only 3.5 pounds. Some weak material must be used but it must still be strong enough to support the Static Load.
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psikeyhackr 1 year ago
@psikeyhackr The problem is your model is not a model of anything relevant to the WTC. It may be cheap, but it's likely to be invalid. Have you scaled the strength of your materials properly? My bet is you haven't. Once you add an impact load on a compromised structure, your load paths may end up wildly different from design. You're not demonstrating a fundamental physical principal, so you'd need to show similarity if you wish to compare to the WTC.
roamingcroat 1 year ago
@roamingcroat {{ Have you scaled the strength of your materials properly? My bet is you haven't. }}
NITWIT! The objective was not to scale the objective was to make the supports AS WEAK AS POSSIBLE. Was the WTC designed to be AS WEAK AS POSSIBLE? My model is DEAD LOAD ONLY! The WTC had to support live load & withstand wind.
So it it won't collapse & is AS WEAK AS POSSIBLE...
Some people can't figure out the obvious.
They have decided what they prefer to BELIEVE.
Physics does not care!
psikeyhackr 1 year ago
@psikeyhackr "NITWIT!" There we go.
"So it it won't collapse & is AS WEAK AS POSSIBLE..."
I first of all doubt that it's as weak as possible. But that's completely irrelevant. What you would need to show is that your model here is either similar to the WTC in some engineering respect (some dimensionless number involving height, weight, material properties, etc.). What you have here is stacked washers.
Physics doesn't care. It won't be forced to make the WTC collapse how you expect it to.
roamingcroat 1 year ago
@roamingcroat
Like I said the model is CHEAP.
You can doubt it is as weak as possible all you want but the fact of the matter is that you can build it and test it yourself and make any changes you want.
BUT NO! You can come here and TALK and we are supposed to be SO IMPRESSED. What is stopping YOU from building a model that CAN collapse under its own weight? If you can't tell us the distributions of steel and concrete in the WTC how can you complain about ANY MODEL not being to scale? LOL
psikeyhackr 1 year ago
@psikeyhackr "Like I said the model is CHEAP." And unrelated to the WTC collapse.
"we are supposed to be SO IMPRESSED." You needn't be impressed. I'm stating that I don't find your model to be valid. Is there any reason why your model is somehow more valid than my talk? Or that any model I make is somehow more or less valid than your model? Without some documented similarity to the actual towers, there's really no difference between your video and my written words.
roamingcroat 1 year ago
@roamingcroat {{ Or that any model I make is somehow more or less valid than your model? Without some documented similarity to the actual towers, there's really no difference between your video and my written words. }}
Utter Horseshit!
Anyone can CLAIM to be able to build a model that can be collapsed by Its top 15% or less. Doing it brings physics into the picture and not just HOT AIR.
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psikeyhackr 1 year ago
This is quite elegant.
UNIVERSITYHI 1 year ago
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Here was I "think" happened and may explain why we are so confused with what we saw. 1) Planes hit the buildings. 2) the structures were weakend through heat and damage. 3) When the top floors gave, the terrorist blew the buildings. In closing the terrorist damaged and blew the buildings, and for some reason if we detect exsplosives it means the US did it. No...I feel the terroist used explosives and they did it. This is the only thing that I could think of that would answer everything.
JimmyGunXD556 1 year ago
Dude, youre awesome. Thanks for this video.
Seigu007 1 year ago
Oh what the hell. I did try to build a model from some toothpicks and bits of paper.
Two bits of cardboard placed against each other, two toothpicks planted in either one to support a leaf of paper for a total of some eight "floors".
Results... "Floors" that would heavily sag - but not go down - under certain weight would collapse under said weight dropped from good height, but I could get even one floor below to fail this way, no matter the height.
SexyMelon 1 year ago
In fact... Weight that would collapse one floor on its own would sometimes halt mid-collapse.
The sheets of paper sagged, but then unraveled on each other to form a much more sturdier floor, that would resist collapse altogether. Thus, unfortunately this came nowhere close to floors "breaking" from supports. What this does seem to resemble is the "pancaking", however, obviously very crudely.
SexyMelon 1 year ago
...Bigger weights, that would collapse the whole structure, would take a good two-three seconds more to reach the ground compared to just dropping them, most noticeably almost halting for a moment on very first impact.
This seems to check out with both intuitive conservation of momentum and known examples of gravitational collapse, as it should.
But, yeah, not a handyman. I'm not sure how to achieve "breaking" supports in this scenario. That is, assuming vertical supports stay in place.
SexyMelon 1 year ago
The flaw in your reasoning is that your washers are only one or two inches apart whereas the floors in the WTC are 14 feet apart. Your video shows a the top part crushing more than one floor and arresting only because the lower "washer floors" at two inches (?) apart and not 14 feet. If they were 14 feet the effect would be quite different. Take the collapsed mass back up to the top and drop it again - and then repeat over and over again. That's the right simulation
rgsalinger 1 year ago
@rgsalinger You've never heard of scale tests? Either way, what is shown here is true for any materials at any heights and does not require a thousand foot tall model to demonstrate such.
ryinski2 1 year ago
@ryinski2 sure I've heard of scale models, but you cannot simulate the second drop this way. Each drop was somewhere between 12 and 14 feet and your drops are only what - two inches. In the WTC, after the first floor breaks the remaining mass has another 12-14 feet to gather energy/momentum. You have proven exactly what you set out not to prove.
rgsalinger 1 year ago
@rgsalinger The model is scaled, obviously.
Here the "floors" are also allowed similar distance to "fall" through when their supports are shattered as there would be between WTC floors.
It's an illustration of already known principle of conservation of momentum: one way or another, 90% of the building offers more resistance than 10% of it, as illustrated above.
SexyMelon 1 year ago
@SexyMelon Thanks the laws of physics require that any model like this have the same distance between the floors as existed in the WTC towers or it is NOT to scale in terms of the physics. Find a local physics professor and show him the model and ask him if it will scale correctly, it won't. Once the first floor "breaks" you now have an even greater accelerating mass, so the next floor MUST break.
rgsalinger 1 year ago
@rgsalinger "Once the first floor "breaks" you now have an even greater accelerating mass, so the next floor MUST break."
Err, no.
Look up conservation of momentum: if a falling mass comes in contact with another, it DE-celerates, no otherwise. The total momentum is shared - lessened - with each collision, as the above model illustrates.
The mass does not get "bigger" either, since all bottom floors in the building have to support the above mass by definition.
SexyMelon 1 year ago
@SexyMelon Conservation of momentum is only correct when you have a closed system. In the WTC collapses once the top of the building begins to accelerate you have the force of gravity as well as the velocity of the moving mass to contend with. Look it up yourself - "closed system" - the mass keeps accelerating and it's getting heavier.
rgsalinger 1 year ago
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@rgsalinger "Conservation of momentum is only correct when you have a closed system."
The heck? Of course not. Physical laws act on any scale, you're confusing outside factors for whether laws still apply.
"In the WTC collapses once the top of the building begins to accelerate you have the force of gravity as well as the velocity of the moving mass to contend with."
That's true, of course.
SexyMelon 1 year ago
@rgsalinger "the mass keeps accelerating and it's getting heavier"
Again, no. Conservation of momentum dictates sharing of momentum slows down the overall mass. There can never be acceleration on impact under influence of only gravity: force of gravity can either be expended on motion OR crushing the structure, you can't have both be equally strong at the same time.
The experiment above confirms that. If you what you said were to be true, this "bigger accelerating mass" would collapse it.
SexyMelon 1 year ago
@SexyMelon I didn't say that there was an acceleration under impact, I said that the velocity will continue to increase under impact. Unless the collapse was completely arrested by impact with the first floor, the new starting velocity is greater than the original zero velocity. So, you have more mass and move V when the next impact occurs. Therefore, if the first impacted floor failed then the next one is certain to.
rgsalinger 1 year ago
@rgsalinger "I didn't say that there was an acceleration under impact, I said that the velocity will continue to increase under impact."
That's... That's the same thing... Acceleration is increase in velocity.
"Unless the collapse was completely arrested by impact with the first floor, the new starting velocity is greater than the original zero velocity."
No it's not. Impact with a stationary object always slows down moving one.
And it is acceleration by definition also.
SexyMelon 1 year ago
@SexyMelon Sorry that wasn't clear. The impact reduces the acceleration of the upper mass, it doesn't actually slow it down. The acceleration can reduce from (say) .6 to .1 and velocity still increases. Your mental model of the collapse leaves out gravity. If we were talking about a collapse in the absence of gravity then you'd be correct.
rgsalinger 1 year ago
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@rgsalinger "The impact reduces the acceleration of the upper mass, it doesn't actually slow it down."
Like I said, that's the problem, it doesn't, the acceleration remains constant: /watch?v=k7c0Gtq4sYY
And, of course, if it did reduce it, it would - assuming not halting completely as it would - be pretty noticeable after 100 floors or so, no?..
SexyMelon 1 year ago
@rgsalinger "Your mental model of the collapse leaves out gravity."
It's not a mental model, it's a physical experiment provided above...
And no, of course it doesn't leave out gravity. In fact it's the foundation of the objection to it: gravity is uniform across all weights and dimensions, and provides a constant force throughout; in a gravitational collapse, energy which is used to crush the structure cannot be used to also accelerate it downward all the same. This is not true for WTC.
SexyMelon 1 year ago
@SexyMelon Actually the structure of the WTC towers puts up enormous resistance to the collapse, that's why it takes longer than what free fall would predict.
rgsalinger 1 year ago
@SexyMelon & @rgsalinger
There are two simultaneous factors involved in arresting the falling mass. The conservation of momentum slows things down but energy is lost in the process of crushing the paper loops. Since the only energy source is the kinetic energy of the falling mass the crushing of the loops slows things down more.
The bending and dislocation of core columns and beams would have slowed down the WTC.
psikeyhackr 1 year ago 7
@psikeyhackr Exactly, thank you.
Other than the experiment above... Do you think there is any intuitive way to express just how much energy would be expended on such work (crushing, bending)?..
Conservation of momentum alone seems hard enough to explain somehow. But this may be more important, I understand it's the reason we use explosives rather than wrecking balls to bring down steel-frames in the first place?..
SexyMelon 1 year ago
@SexyMelon Well that is one problem with the WTC. The columns get thicker all of the way down the building. So the amount of energy required should increase level by level. But we are not even told the tons of steel at every level. So we have spent years listening to EXPERTS who have not been demanding the information required to solve the problem.
Very curious country we have here.
Are we sure they were smart enough to put men on the Moon 41 years ago? LOL
psikeyhackr 1 year ago 2
@psikeyhackr "So we have spent years listening to EXPERTS who have not been demanding the information required to solve the problem."
Hit the nail on the head there.
How can we pretend to have solved the problem without any meaningful investigation? Why do people think there's any evidence to support the official conspiracy when pressed for it they can only name NIST investigations and such, who have not collected any evidence?
Everyone just sort of assumes... What the TV told them... Oh.
SexyMelon 1 year ago
@psikeyhackr The increasing mass of steel further down might not phase someone who thinks it has consistency of paper in the first place - that's really the major problem of understanding there - but it would at the very least signal that there *must* have been some form of deceleration.
Then again, even free-fall (Chandler, WTC7) doesn't seem to phase some people.
"Are we sure they were smart enough to put men on the Moon 41 years ago? LOL"
Oh god. Sadly, with what you said, good point. :/
SexyMelon 1 year ago
@rgsalinger "Actually the structure of the WTC towers puts up enormous resistance to the collapse, that's why it takes longer than what free fall would predict."
NIST says it took tower two 11 seconds to reach the ground. Estimated free-fall time for it is 9 seconds. Two more seconds hardly even accounts for resistance of thin air.
Most controlled demolitions occur at upwards of 200% of free-fall. Gravitational at upwards of 300%. WTC? 110%.
SexyMelon 1 year ago
@SexyMelon I'd like to see your source on the speed of controlled demolitions. If your point is that they take much longer than WTC, then how can you argue for CD at WTC? On the other hand, just do the math to calculate the actual resistance necessary to reduce the acceleration from 1g to .6g for a mass of 30000 tons and you'll see the point..
rgsalinger 1 year ago
@rgsalinger "If your point is that they take much longer than WTC, then how can you argue for CD at WTC?"
Because it's the closest thing, of course, and the only known possibility as it places possibility of gravitational collapse into territory of ludicrous by default.
SexyMelon 1 year ago
@rgsalinger "On the other hand, just do the math to calculate the actual resistance necessary to reduce the acceleration from 1g to .6g for a mass of 30000 tons and you'll see the point."
Err... Approximately 15,000 tons?..
If you're going to calculate it like that, by taking masses as a whole, the upper block would have stopped on impact. Watch the video above: the mass is not structurally integral, so some of it is crushed, while other parts stay undamaged (note, on both ends).
SexyMelon 1 year ago
@SexyMelon The problem with the video is simple, if the first drop is 12 feet then the next drop has to be 12 feet or the model is flawed. You cannot simply scale up one portion and leave the other intact, it's not a model to scale. You need to have each collision taking place at the speed achieved by a 1 g acceleration over a span of 12 (or 14 feet). Otherwise the momentum transfer is only about .01 of what it needs to because there is only a two inch fall.
rgsalinger 1 year ago
@rgsalinger "The problem with the video is simple, if the first drop is 12 feet then the next drop has to be 12 feet or the model is flawed."
Why is this an issue? The model is scaled: what are gigantic floor slabs at WTC are are small metal planes here, and what is 12-foot drop there is a few inches here. It's scaled. If the model had 12-foot drops, it would scale to a building the top of which would hover in outer space.
What?..
SexyMelon 1 year ago
@SexyMelon You need to read up on how scale models work and then maybe you will understand. The massive concrete floors are 4 inches thick. They are not made to hold up 10 times their own weight so when they are hit by 30k tons, they are disconnected from the columns. And, this is such a chaotic event that a simple model like this, even with the correct spacing, cannot do it justice or show us anything probitive.
rgsalinger 1 year ago
@rgsalinger "You need to read up on how scale models work and then maybe you will understand."
I don't believe I ever tired to remind you that this IS a scale model, and thus - obviously? - the distance between floors also has to be to scale. I do not know why you want it otherwise.
"And, this is such a chaotic event"
A chaotic event would not bring the buildings down straight into their own basement. This is why we demolish buildings instead of setting fires to them.
SexyMelon 1 year ago
@rgsalinger "a simple model like this, even with the correct spacing, cannot do it justice or show us anything probitive"
Why not? What is the crucial detail that would alter the outcome of the experiment? Obviously models do work, and we do use them to test real-world conditions. Models not being "complex enough" is not an objection in itself. What's missing exactly?
SexyMelon 1 year ago
@SexyMelon What's missing is 12 feet between floors as well as a steel and concrete structure. What's also missing is the tilt that makes the columns not impact each other and obviates the idea that steel needs to be "shattered" or crushed for the building to collapse.
rgsalinger 1 year ago
@rgsalinger "What's also missing is the tilt that makes the columns not impact each other"
How does that work? How can tilt displace columns? Most buildings tilt during controlled demolitions - inevitably, sometimes inward on purpose - and it accomplishes no such thing.
But thank you for outlining the actual faults.
SexyMelon 1 year ago
@SexyMelon The top of each tower falls by tilting around a fulcrum formed by its stronger side. Therefore, when the first lower floor is impacted, the columns are not aligned either on the perimeter or in the core. So, it's not necessary to crush steel to achieve a failure of a floor.
rgsalinger 1 year ago
@rgsalinger "The top of each tower falls by tilting around a fulcrum formed by its stronger side."
The problem with that that there is no "stronger" side. The tilt stops mid-air, too.
SexyMelon 1 year ago
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@rgsalinger "Therefore, when the first lower floor is impacted, the columns are not aligned either on the perimeter or in the core."
That makes no sense. Tilt can only misplace columns at the tip of the tilt, those at the axis, by definition, remain in place.
Again, most demolition occur at a tilt, and no such displacement occurs. If this were a known effect, don't you think the million-dollar-industry would be clued in on it?
SexyMelon 1 year ago
@rgsalinger I guess the question is... What kind of experiment can you do where the factors you outline alter the outcome so dramatically?.. Should you really believe it when it has never been tested?..
Actually I think you can replicate at least one of those conditions with an assembly akin to those silly cabinets you can get at IKEA, where the boards are supported by tiny wooden bolts... Wish I was a handyman, this is actually interesting.
SexyMelon 1 year ago
@rgsalinger "You cannot simply scale up one portion and leave the other intact, it's not a model to scale."
Exactly?.. Which is why you can't have the model have 12-foot drops here, it wouldn't be to scale?..
"You need to have each collision taking place at the speed achieved by a 1 g acceleration over a span of 12 (or 14 feet)."
1G acceleration cannot occur in anything other than free-fall.
And, again, this would be completely out of scale, what gives?
SexyMelon 1 year ago
@SexyMelon I think that I understand why we don't see this the same. You think that the steel columns had to be "crushed" - fail for the collapse to continue. Based on my observations and reading, the connections came apart, the columns are seen to be largely intact with broken bolts and sheared connections. Hence, I see each floor destroyed, the debris from it accumulating and no resistance to speak of for another 12 feet. You see it differently for some reason.
rgsalinger 1 year ago
@rgsalinger "Based on my observations and reading, the connections came apart, the columns are seen to be largely intact with broken bolts and sheared connections."
Well, that's quite simply not true - and indeed not advocated by the "official" investigations, see NIST FAQ on WTC investigations - quite glaringly, the core steel structure collapsed along with the concrete one. In fact the very scarce photographic evidence also documents connections being intact.
SexyMelon 1 year ago
@SexyMelon i don't think that I cited any "official" explanations. I told you what I saw and the reading I have done is in no way "official". What I've read are various peer reviewed articles published in recognized journals. It's clear that the steel was not "crushed" in the collapse. That only happened during the collapse initiation phase. You're using the term collapse loosely. Just look at pictures and you can see what I mean - the structure comes apart at its connections, there is no crush.
rgsalinger 1 year ago
@rgsalinger "i don't think that I cited any "official" explanations."
I believe the mechanism of collapse you're referring too with "falling" floors and "severed connections" describes what is officially known as "pancake theory".
Again, it is rejected by advocates of the official story due to both physical impossibility and glaring contradiction with observed facts.
SexyMelon 1 year ago
@rgsalinger The official story - one of them anyway - to date is that the floor trusses sagged in the fires, initiating the collapse through progressive sagging and pulling the core columns they're attached to with them.
It is, of course, also physically impossible. You may notice that, not only is there nothing "falling" in that model, but the strongest part of the building has to be literally torn to shreds by the weakest one.
SexyMelon 1 year ago
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@rgsalinger "I told you what I saw and the reading I have done is in no way "official"."
Good. I'm glad you can think for yourself.
"What I've read are various peer reviewed articles published in recognized journals. "
And that's even better.
"Just look at pictures and you can see what I mean - the structure comes apart at its connections, there is no crush."
I'm not aware of any evidence to suggest that. Indeed I remember a dozen pictures showing connections still intact.
SexyMelon 1 year ago
@SexyMelon Look some more, please. I think that the original FEMA study has some good shots if you can find them or just peer a bit into some hi-res photos of the pile taken soon after the collapses and you'll see what I mean - no shredded steel. Finally, the guys who examined the steel in the waste sites reported no shredding or other evidence of explosives (if that matters).
rgsalinger 1 year ago
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@rgsalinger "Look some more, please."
That's not helping. Like I said, I remember dozens of photos that show connections intact, I'll tell you if I can find them...
"Finally, the guys who examined the steel in the waste sites reported no shredding or other evidence of explosives (if that matters)."
No search for evidence of any kind of explosives or incendiaries was ever conducted - not to mention most of the steel was outright destroyed - so that's a bold-faced lie on their part.
SexyMelon 1 year ago
@rgsalinger I've heard about the "tilt" before, and I see where it's coming from: given enough falling distance, it can make some of the columns "miss, but most will remain in place by definition (the axis).
Again, most saliently, it doesn't work in reality: most demolitions occur at a tilt, and the effect is never observed in any of them, nor in any true chaotic collapses.
And even then, crushing through floor assemblies of a sky-scraper is hardly comparable to no resistance at all.
SexyMelon 1 year ago
@rgsalinger This is generally what WTC core was like:
/watch?v=BVzg5qlcYBY
A solid mesh of steel on the inside, surrounded by big floor space with no columns, with a final single layer of columns on the outside.
This is the kind of structure that would not only stand on its own but, by definition, would stand on its own AND hold up the floors of the building in the first place. If you break the connections somehow, you free the core of the load.
One way or another, it has to be destroyed.
SexyMelon 1 year ago
@rgsalinger "You're using the term collapse loosely."
Yes, sorry. I am referring to the grand sum of events starting before 11-16 seconds it took top of the towers to reach ground level.
"Actually part of the core did stay intact but then a few seconds later it falls."
Outside columns. And even those were completely shredded. While technically "a" core, it's not "the" core, as one should be obvious in case of WTC.
SexyMelon 1 year ago
@SexyMelon I mean that you can find video of the core standing if you look around. After a few seconds, it falls apart. That shows me that the core, while strong as part of the overall structure is not strong once its on it's own. That's the real point - the building is a complex structure, not a pizza box or a wood block. Once it's structural integrity is initially breached it can be induced to fail.
rgsalinger 1 year ago
@rgsalinger "I mean that you can find video of the core standing if you look around."
Like I said, it's not the core. It's the outer perimeter columns.
Core is a solid cross-braced 3D mesh. Outer columns are a single 2D layer.
SexyMelon 1 year ago
@rgsalinger "That shows me that the core, while strong as part of the overall structure is not strong once its on it's own."
That'd be wrong, the core alone was predicted to withstand high hurricanes when separated from all the floors - and thus most of the load.
Core is what held the structure up in the first place, separating it from floors' load would make it stronger, not weaker.
SexyMelon 1 year ago
@rgsalinger "That's the real point - the building is a complex structure, not a pizza box or a wood block."
That's not a point at all. Just because something is complex doesn't automatically mean your argument is the right one.
"Once it's structural integrity is initially breached it can be induced to fail."
There are thousands of cases of partial collapses in various buildings. Not one in steel-frame ones has ever induced a total one.
Scratching something is different from destroying it.
SexyMelon 1 year ago
@rgsalinger Short version, if you're not crushing the core structure... You're not crushing the core structure. It would stay intact. It did not.
Again, look it up. Pancake theory has been dismissed by champions of the official story just as "core meltdown" (that's where the steel was meant to be literally melted by fires) was, for likewise glaringly obvious reasons of impossibility.
It still sticks to the "debris mass" thing in spite of that... It just doesn't make sense either.
SexyMelon 1 year ago
@SexyMelon Actually part of the core did stay intact but then a few seconds later it falls. Again, it comes apart at its connections, it doesn't crush. You don't have to crush any complex structure to make it come apart under load. It will break at its weakest points - in the case its connections. I have no idea what the "pancake" theory is or isn't and it doesn't matter to me. Those buildings don't come apart by having the columns crushed.
rgsalinger 1 year ago
@rgsalinger "It will break at its weakest points - in the case its connections."
If the connections broke, by definition, the structure they were separated from would not be destroyed. It was. In fact, the floor truss connections appear to have remained intact.
Of course, crushing connections would still take a tremendous amount of energy. Or at least something greater than what could be mistaken for thin air.
SexyMelon 1 year ago
@SexyMelon No they didn't remain intact. They are clearly severed in all the pictures I've seen of the debris. You can see several floors worth of columns coming down separated at their connections. There are no pictures of "shredded" steel at all or even buckled columns. The only columns which buckled are the ones which failed in the initiation sequence of the collapses. After that the mechanism is different.
rgsalinger 1 year ago
@rgsalinger "I have no idea what the "pancake" theory is or isn't and it doesn't matter to me."
I'll probably note again I deeply admire independent thinking. It's more important that anyone's opinion on this issue one way or another.
"What's missing is 12 feet between floors"
Why do you keep requesting that? Don't you understand this would break the actual scale of the model?
SexyMelon 1 year ago
@SexyMelon This is where we differ - as each floor breaks up, there is no resistance below that floor - that's what is "broken", hence the mass (which is now bigger) will continue to fall another 12 feet. You cannot simply scale that down. No one builds scale models of buildings to test their structure because the scaling is not a simple linear function.
rgsalinger 1 year ago
@rgsalinger "This is where we differ - as each floor breaks up, there is no resistance below that floor "
What? Breaking supports would produce positively massive amount of resistance.
But, as aforementioned, this is not an option: not only are connections solid metal, if they were indeed destroyed, parts of the building would, by definition, stay intact.
SexyMelon 1 year ago
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@rgsalinger "No one builds scale models of buildings to test their structure because the scaling is not a simple linear function."
Yes, scaling IS a simple linear function...
Scale models of floor assemblies are mandatory tested before any building goes up. WTC's floors were certified to ASTM E119 per se.
"No they didn't remain intact. They are clearly severed in all the pictures I've seen of the debris."
Not going by the photos I remember.
SexyMelon 1 year ago
@rgsalinger Again, if the collapse built momentum as opposed to expend it... Why doesn't it work in the video above?
The "floors" crush, the "mass" increases, and yet it decelerates, slows down and halts; indeed all known gravitational collapses do. It just doesn't appear to be possible.
Heck, even explosive demolitions halt just because of a second-off timing in the explosions: /watch?v=UsePUn5-88c
SexyMelon 1 year ago
@SexyMelon It doesn't work in the video because he's not allowing the initial collapsed material to go another 12 feet. If he did he must get the same result - another two "floors" collapsed. Your use of Newton's second law is incorrect because there is a force acting on the falling mass.
rgsalinger 1 year ago
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@rgsalinger Errata: obviously gravitation does depend on mass, it's just that any mass here is insignificant to Earth's.
"It doesn't work in the video because he's not allowing the initial collapsed material to go another 12 feet."
This would be completely out of scale?.. Why?..
If the tower had this large spacing between floors, it would actually halt sooner because supports would have to be sturdier to hold it up in the first place...
SexyMelon 1 year ago
@rgsalinger "Your use of Newton's second law is incorrect because there is a force acting on the falling mass."
Newton's second law concerns only gravity - it being the only force at play here versus elastic resistance - in the first place, so how could it possibly be incorrect?..
Also, it's not entirely accurate to describe it as "falling" mass: the building is a solid mesh of steel and concrete, and one way or another the collapse has to crush through them.
SexyMelon 1 year ago
@SexyMelon The 2nd law is not about gravity it's about momentum and it holds only in a closed system. It's your use of it which is incorrect. I don't understand your other point but I agree that the collapse proceeds roughly through the center of mass of the building but that's because there is not enough torque for anything else to happen. Sorry if I'm not following your argument
rgsalinger 1 year ago
@rgsalinger And if it is indeed "enormous" resistance... Well, why the hell did it collapse?..
"The 2nd law is not about gravity it's about momentum and it holds only in a closed system."
Yes, and the only force allowed in gravitational collapse is gravity. Of course it functions outside of closed systems... It's the law of physics.
...
Again, if this "building mass" can happen, why doesn't it happen in the model above?
SexyMelon 1 year ago
@SexyMelon Newtons second law concerns momentum within a closed system. it has nothing whatsoever to do with gravity. Newton also discovered gravity but that's a separate law from the laws of motion. That's where you are getting confused. Momentum in an open system (with a force acting upon it) allows for a momentum transfer without a decrease in velocity through deceleration.
rgsalinger 1 year ago
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@rgsalinger "Newtons second law concerns momentum within a closed system. it has nothing whatsoever to do with gravity."
I said I know two times... It concerns gravity here because gravity is the only force allowed in play, allowed to act on the structure. F=ma -> a=F(g)/m
What this alone does not account for is the elastic force of the structure itself, and this is the question.
What are you saying with this exactly?
SexyMelon 1 year ago
@rgsalinger "Momentum in an open system (with a force acting upon it) allows for a momentum transfer without a decrease in velocity through deceleration."
A(collapse) = F(gravity) - F(resistance) / M(debris)
To have constant acceleration in this system would require either floors having same amount of resistance as thin air between them, or be rocket-propelled.
And that's kinda the whole point.
SexyMelon 1 year ago
@rgsalinger "don't understand your other point"
Well, there's no space for anything to "fall" in the structure. Just like the model above, it is solid. It's a mesh of steel. The reason anything can "fall" in demolition is because said supports are physically destroyed and, unlike concrete, steel cannot shatter on impact. Its tensile strength is immense.
"that's because there is not enough torque for anything else to happen"
Collapsing at an angle would supply tilt by default, wouldn't it?
SexyMelon 1 year ago
@SexyMelon The upper part of the tower and the accreted material from the first lower floor that fails falls another 12 feet under acceleration from gravity. Then it encounters the next floor with even more accreted material so the total momentum keeps increasing as both the mass and the velocity are greater than they were when the first floor impacted was destroyed. As each floor loses its structural integrity it provides minimal resistance. When the next floor is hit it resists momentarily.
rgsalinger 1 year ago
@rgsalinger "The upper part of the tower and the accreted material from the first lower floor that fails falls another 12 feet under acceleration from gravity."
That's the first problem: it doesn't "fall". By definition, it has to crush the structure that supports the towers.
"Then it encounters the next floor with even more accreted material so the total momentum keeps increasing"
No. Total momentum decreases on impact, not increases.
Again, if that were true, why doesn't it actually work?..
SexyMelon 1 year ago
@SexyMelon "Total momentum decreases on impact, not increases."
To clarify...
Of course total momentum stays the same. I mean in the context of the collapse, collision of falling mass with stationary one would slow down the one in motion, not add more speed or force: the only allowed force at play is gravity, and that is constant, G.
Assuming the floor gives, some of the gravitational force has been expended on combating resistance, and thus cannot work towards moving it forward.
SexyMelon 1 year ago
@SexyMelon As you increase mass, you decrease acceleration (I wish I could conjure a proper formula to express this with all involved factors).
I believe you already know this, and said this should occur, I'm reiterating it because it's the whole point: it does not occur. The acceleration remains uniform throughout the collapse, indicating lack of resistance, or rather lack of resistance of floors - trusses, hat trusses, core columns, sky-lobbies - compared to thin air between them.
SexyMelon 1 year ago
@SexyMelon Much better argument - that constant acceleration is suspicious. We should see a reduction in acceleration each time a floor is destroyed. How much should we see? How visible would it be? What I've seen is a broad brush approach - using smoothed data to prove the point. I have never seen anyone demonstrate that the acceleration changes would be visible in a video, which is all we have to go on.
rgsalinger 1 year ago
@rgsalinger "How much should we see? How visible would it be?"
Difficult question made easier by gross disproportion of the collapsing mass in comparison to collapsed one: at least after 10 floors.
It's not necessary to graph out reduction as per impact with one floor - approximately 0,4m/s, see calculations below - when you can judge the collapse as a whole.
The acceleration is uniform throughout. So neither at the start, nor even after 100 floors, there is no reduction at all.
SexyMelon 1 year ago
@rgsalinger "How much should we see? How visible would it be?"
Oh. Actually there's an easier way to see that, even with your naked eye:
/watch?v=3GNhEpHfgfI
This is a true gravitational collapse. It has acceleration of near-free-fall when the initial supports are removed, it visibly slows down when first floor is impacted, and it visibly slows down as the crush is proceeded, visibly halting just before the smoke cloud engulfs the scene.
Compare that to how WTCs behaved.
SexyMelon 1 year ago
@rgsalinger Another things to note about Verinage is that it has crush-up simulate-nous with crush-down, produces no explosive ejection of debris, occurs at upwards of 300% of free-fall, cannot be used for steel-frame structures... Actually I left a few comments on that video if you can be bothered
(The author has since blocked me so I can't raise a final contrary argument... No comment, heh.)
Again, compare to WTC. Maybe play them side by side, I don't know. See for yourself, what you think.
SexyMelon 1 year ago
@SexyMelon ...Also, note, Verinage demolitions always make the cut at the center of the building? Why is that?.. Well, a brief look at what is left of the top structure and its total speed by the time collapse reached the ground should explain that...
(Spoiler: the upper mass is completely destroyed along with bottom one, and collapse grinds to a virtual halt even before it hits the ground. If you made the cut anywhere else, some of the building would be left standing: /watch?v=UsePUn5-88c )
SexyMelon 1 year ago
@SexyMelon That's right, SOME of the force. Unless the resistance of the first floor impacted is equal or greater than gravity times at least ten then acceleration - positive change in velocity will occur. Given that the upper block is time times the weight of the floor impacted, you're going to get only a reduction in acceleration, not velocity, at best.
rgsalinger 1 year ago
@rgsalinger "That's right, SOME of the force."
Yes, thank you. And the acceleration measurement of the descent would suggest all of it went into accelerating the structure instead (as it's uniform and near-free-fall).
"Unless the resistance of the first floor impacted is equal or greater than gravity times at least ten then acceleration - positive change in velocity will occur."
Obviously it is greater than gravity considering the building had to stand up in the first place.
SexyMelon 1 year ago
@SexyMelon No, it's not free fall. Each floor shows considerable resistance. Sure the floor stood up but it was part of a structure, not on it's own and it certainly wasn't designed to hold up the rest of the building - 10 floors - with its columns removed.
rgsalinger 1 year ago
@rgsalinger "No, it's not free fall."
It's 110-160% of free-fall by various estimates.
"Each floor shows considerable resistance."
This is not true, as the acceleration of the collapse is uniform throughout the event, and differs from acceleration of free-fall by only a miniscule amount (0,2ms), which is comparable to if not less than resistance of thin air, the air between floors themselves. Resistance comparable to that of thin air is not nearly "considerable" in any case.
SexyMelon 1 year ago
@rgs "it certainly wasn't designed to hold up the rest of the building - 10 floors - with its columns removed."
That is unknown to make judgment like that. Whether one floor was enough or not, further ten, and more so further hundred, should be more than enough by conservation of momentum.
What was designed to hold the weight of the floors collapsing were two reinforced concrete sky-lobbies. These were specifically designed to limit collapse of *any* third of the building to that part only.
SexyMelon 1 year ago
@rgsalinger "Given that the upper block is time times the weight of the floor impacted..."
You can't think that way. If you judge the falling structure as one contingent block, then the one below it is simply a nine times bigger block. The collisions themselves are inelastic, they occur between individual floors, which is why individual floors are crushed (both up and down).
What you want are collisions between individual floors but across the total number of floors.
SexyMelon 1 year ago
@SexyMelon Prove that I am wrong then, if you can, otherwise we will just disagree. The impact event is not inelastic in any sense of the word unless you greatly simplify it to the point of not resembling what happened as has been done here.
rgsalinger 1 year ago
@rgsalinger "The impact event is not inelastic in any sense of the word."
This would mean the falling mass did not accumulate as a whole. Inelastic = "Sticky".
SexyMelon 1 year ago
@rgsalinger "Prove that I am wrong then, if you can, otherwise we will just disagree."
That's what the video above is about, isn't it?..
If what you say were true, it should have collapsed.
That's the whole point, isn't it?.. There's an experiment, and it doesn't work. There are videos of true gravitational collapses, and they "don't work" either. There's knowledge that steel-frame buildings cannot be demolished via gravitational collapse alone.
So... It just appears not to work. Well?..
SexyMelon 1 year ago
@rgsalinger "you're going to get only a reduction in acceleration, not velocity, at best."
Once again, this is just not what is observed: the acceleration is uniform throughout the collapse. It stays the same, at approximately 8,9m/s.
"You seem to be ignoring the fact that as each floor is destroyed some portion of it is added to the descending mass of the upper block."
I don't believe I have. I disagree about momentum being added, which it can't be in such collision, and is not in video above.
SexyMelon 1 year ago
@SexyMelon You keep saying "slow down" which is not the case when a force is acting (gravity) unless the resistance is greater than some calculated value.
rgsalinger 1 year ago
@rgsalinger "You keep saying "slow down" which is not the case when a force is acting (gravity) unless the resistance is greater than some calculated value."
Sorry for being vague, "slow down" as in reduction in acceleration as well as reduction in velocity if acceleration is zero.
"Much better argument - that constant acceleration is suspicious. We should see a reduction in acceleration each time a floor is destroyed."
Absolutely! Indeed that is the argument, or at least big part of it.
SexyMelon 1 year ago
@SexyMelon First of all total momentum must be conserved at the moment of impact. Second, as soon as the floor loses its integrity it just adds its mass to the 10 floors already descending. There is NO NEED to "crush" the steel and the pictures at ground zero prove that crushing in that sense never happened. Instead connections between the floors and columns were severed. There was no crush, there was catastrophic failure. If it collapses like an accordion, you would be more or less right.
rgsalinger 1 year ago
@rgsalinger "First of all total momentum must be conserved at the moment of impact."
Yes, I believe I corrected myself. Total acceleration is what goes down as momentum is shared.
"Second, as soon as the floor loses its integrity"
Steel-frame structures do not crumble on impact, so that's just not possible.
"Instead connections between the floors and columns were severed."
This would leave the steel core structure intact after the collapse, making it internal. This obviously did not occur.
SexyMelon 1 year ago
@rgsalinger "If it collapses like an accordion, you would be more or less right."
"Accordion" collapse - the actual name for it is "pancake theory", I believe, and you might be interested to know it is official rejected as explanation for the collapse by NIST - is presented in the video above, and it just doesn't work.
SexyMelon 1 year ago
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@rgsalinger "When the next floor is hit it resists momentarily."
That does not occur. The acceleration of collapse wake is uniform even throughout reinforced concrete skylobbies.
"I'd like to see your source on the speed of controlled demolitions."
I don't think there can be any particular source, but you can check for yourself using any known video of explosive/gravitational demolition: /watch?v=dgZLXI3whGA
SexyMelon 1 year ago
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@rgsalinger " Sorry if I'm not following your argument."
Sorry, I am rather long-winded. Is there anything I can explain specifically, or summarize?..
The important part, I think, remains that: if the momentum-building or whatever you call the event to have collapsed WTC, is a real thing... Why doesn't it work for the video above?
That's the whole point of that experiment. To see if the hypothesis works. It doesn't appear to.
SexyMelon 1 year ago
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@rgsalinger "Therefore, if the first impacted floor failed then the next one is certain to."
Again, then why doesn't it work for the video above?..
"I have no views on bowling balls and China."
You should. Please do form a personal opinion, it's very important.
"I do know that an impact from 12 feet is much greater than an impact from two inches."
The model is scaled...
"Deceleration doesn't always result in a decrease in velocity."
Never argued otherwise. The collapse does not decelerate.
SexyMelon 1 year ago
@SexyMelon The total amount of mass is increasing as each collapsed floor adds itself to the previous floors. Deceleration is not reduction in velocity, it is reduction in acceleration so total momentum (MV) is still increasing. So when the next floor is impacted the overall force is greater.
rgsalinger 1 year ago
@rgsalinger "The total amount of mass is increasing as each collapsed floor adds itself to the previous floors."
Then why did this "increasing mass" did not collapse the model in the video above? Does the principle only apply to WTC?..
The fact is, there is no "increasing mass" - nothing is added, the only time mass was added into equation is when a plane crashed into it - and there is definitely no "increasing speed" as collisions always slow down the moving object. Not accelerate it.
SexyMelon 1 year ago
@SexyMelon The increasing mass would do exactly as I said if you just let it fall another twelve feet. As each floor in the WTC loses its structural integrity, it effectively cannot provide any resistance. Of course the actual events are much more complicated, we see connected columns multi stories high breaking off, for example. However, we're just talking about how this model contradicts the idea that there wasn't enough gravitational energy to bring about the collapses alone. Send me a PM.
rgsalinger 1 year ago
@rgsalinger "The increasing mass would do exactly as I said if you just let it fall another twelve feet."
But then the model would be ludicrously out of scale...What? And why do you think it would perform better exactly, when the strength of supports needed to hold such a structure up in the first place would provide more resistance than normal-sized ones?
"As each floor in the WTC loses its structural integrity"
Not likely. Steel does not shatter on impact. It's tensile strength is immense.
SexyMelon 1 year ago
@rgsalinger "We're just talking about how this model contradicts the idea that there wasn't enough gravitational energy to bring about the collapses alone."
Good.
So how does it contradict it?.. I understand you're saying it should have allowed a fall of 12 feet, but the model is obviously scaled, so what gives?.. This would more likely halt it sooner.
"Send me a PM."
If this would be more convenient for you, feel free to fire one off to me. Until then I'll reply here if you don't mind?..
SexyMelon 1 year ago
@rgsalinger Momentum here is relatively easy to calculate excluding force of gravity and elastic force both...
P = M(floor 1) * V
Assuming individual floor weight of 10,000 kg and initial velocity of 10m/s...
P(total) = 300,000 * 10 + 10,000 * 0 = 310,000 * X
X = 9,6
Drops below 1m/s after about 70 floors if I remember correctly. No resistance or gravity involved, of course, so not too applicable.
SexyMelon 1 year ago
@SexyMelon ...Or other laws of motion involved for that matter.
Again, shorthand, if there were to be "building of momentum" in collapse and such, why doesn't it work for the video above?..
Why doesn't it work for any known collapse?.. For any known experiment?.. Why does it seem to contradict basic conservation of momentum?..
SexyMelon 1 year ago