The Towers did withstand the aircraft impact. They did not withstand the effects of the fire, which brought the structural margins of the columns to zero and resulted in near-simultaneous column failure at that floor and each succeeding floor. I have explained this many times before.
People hearing "explosions" may be grossly mistaken. The air compression from the falling upper stack resulted in blowouts of the windows on the subsequent floors beneath. (Is a balloon popping or a tire blowout the sound of an explosion? Think of scale.) The sound of columns failing in shear can be exceedingly loud.
The timing of the collapse of the North and South towers correlate with how tall the stack above the collision floor was. The taller the stack, the shorter the interval. This is consistent with physical theory, not with a "controlled demolition."
One persistent myth is the belief that jet fuel can melt steel beams. However, this claim is not supported by scientific evidence. Steel melts at a temperature of 2,750 degrees Fahrenheit, while jet fuel burn at temperatures ranging from 800 to 1,500 degrees Fahrenheit.
Steel signify weakens at approx 1000 deg F… but I believe it was a controlled demo…there were people working in the non public spaces for weeks/months prior to this event.
You are consistently wrong on this point. The adiabatic flame temperature of kerosene (jet fuel) is 3801 F. You can look it up. https://en.wikipedia.org/wiki/Adiabatic_flame_temperature How do you think we melt iron in the first place? Foundries use coke (a form of purified coal) that burns at 3,957 F, not far from jet fuel.
But the towers fell straight into their footprints. I don't know how a localized fire in a building can cause all 4 corners to collapse simultaneously. And what about those slanted cut lines on the steel beams that were exposed in the aftermath? I heard that is the way demolition explosives are made to destroy them.
If you can find my response to daedalus001, I explain the collapse process in detail.
A column can fail in either of two ways: in buckling or in shear. In buckling, it would need enough room and plasticity to bend. If there is no freedom to bend or it is too rigid to bend, then it will fail in shear. It turns out that when a column fails in compressive shear, the break is always at 45 degrees. It turns out that is the angle at which the combined force and the bearing area result in the highest shear value. I have no idea whether demolition explosives are configured this way. I suspect it wouldn't matter. If the column is weakened, that is how it would shear anyway.
Melting steel beams from a fire (assuming it would be possible) would never allow a building to collapse into it's own footprint. It would instead compromise a section of the structure and if collapse occurred it certainly would not be uniform.
Watch architect Richard Gage's presentation on 9/11 which is illuminating in many ways, including information about the detection of nano-thermite in the rubble.
You don't understand how a structure responds to catastrophic structural failure. It's not necessary to assume melted steel beams. The mass of the building is supported by an array of columns. They have some failure limit load against which is applied a safety factor. Here comes the airplane smash, which probably compromises at least a few beams. And then along comes a chimney fire as the jet fuel is burned in what amounts to a furnace with an upcoming draft and a chimney outlet. The columns get hotter...and weaker. Their strength goes down and down, to 90%, 70%, 50%, 30% and at some point the entire array of columns is precariously AT the limit load. What happens next? The weakest column fails in compressive shear (producing the 45-degree cuts). Then what happens? The loads are redistributed among the remaining columns. How fast does this take? The speed of sound in iron is about 4000 feet per second and hotter is faster, so if we consider a range of 100 feet, the loads are redistributed in 25 milliseconds (or less). Then what? Since the total load hasn't changed and the previous configuration failed, the configuration with the failed column will also fail, and the next weakest column will fail. Loads are again redistributed in 25 milliseconds (or less). It may not take a radius of 100 feet for the next column to fail. If there are a total of 100 columns, the entire lot will fail within 2.5 seconds (or less). Then what happens? In 2.5 seconds, the mass of the overburden will not have tilted significantly (inertial confinement, high angular inertia), but it will now fall at the acceleration of gravity for about 15-20 feet (whatever the distance between floors would be) and will build up a level of momentum that will greatly increase the loading on the columns of the next floor down. And the process repeats. Each collapsed floor adds to the mass. All the way down.
As for "nano-thermite," I don't give that any credibility at all, ever since I first heard it, years ago. If you go back to the fire environment, with flame temperatures near 3,800 F, the aluminum fuselage of the 767 is bound to melt (at a temperature of 1,220 F). (I've seen photos of the wreckage of aircraft that burned after impact. Conspicuous outpours of once-molten aluminum.) Liquid aluminum, like liquid water, will evaporate below its boiling point (non-zero vapor pressure). Aluminum vapor is an excellent fuel (it is the major constituent of solid rocket propellant used in space launch vehicles) and it produces aluminum oxide ash: "Evidence of 'nano-thermite'." This combustion occurs in the neighborhood of 6,000-7,000 F. Molten iron? No surprise. The thermite process is only the combustion of aluminum for the purpose of melting iron. So, the allegation that thermite was involved comes from someone with no idea of the combustion environment. (One of my background specialties is jet and rocket engine combustion chemistry.)
By the way, I have NOT read any official reports on the Twin Towers collapse. This is intentional, because I don't want to give anyone the satisfaction of accusing me of repeating "the narrative." I actually do not know what "the narrative" is, but I would be gratified if it backed me up.
With regard to the Twin Towers, they effectively assume the non-existence of many tons of aluminum in the form of the airplane fuselage and wings, subject to melting, evaporation, leading to combustion or condensation. Nano-scale spheres of aluminum would be expected to condense from aluminum vapor. And iron is known to oxidize at environmental temperatures, let alone combustion temperatures (e.g., as the fuel in "orange" sparkler fireworks). It's all the same chemistry.
The Towers did withstand the aircraft impact. They did not withstand the effects of the fire, which brought the structural margins of the columns to zero and resulted in near-simultaneous column failure at that floor and each succeeding floor. I have explained this many times before.
People hearing "explosions" may be grossly mistaken. The air compression from the falling upper stack resulted in blowouts of the windows on the subsequent floors beneath. (Is a balloon popping or a tire blowout the sound of an explosion? Think of scale.) The sound of columns failing in shear can be exceedingly loud.
The timing of the collapse of the North and South towers correlate with how tall the stack above the collision floor was. The taller the stack, the shorter the interval. This is consistent with physical theory, not with a "controlled demolition."
One persistent myth is the belief that jet fuel can melt steel beams. However, this claim is not supported by scientific evidence. Steel melts at a temperature of 2,750 degrees Fahrenheit, while jet fuel burn at temperatures ranging from 800 to 1,500 degrees Fahrenheit.
Steel signify weakens at approx 1000 deg F… but I believe it was a controlled demo…there were people working in the non public spaces for weeks/months prior to this event.
You are consistently wrong on this point. The adiabatic flame temperature of kerosene (jet fuel) is 3801 F. You can look it up. https://en.wikipedia.org/wiki/Adiabatic_flame_temperature How do you think we melt iron in the first place? Foundries use coke (a form of purified coal) that burns at 3,957 F, not far from jet fuel.
And it is not necessary to melt steel, when structural steel loses 70% of its strength at a temperature of 1,112 F (sloping downward at higher temperatures). https://www.engineeringtoolbox.com/metal-temperature-strength-d_1353.html
The only persistent "myth" in this case is what you are believing in. Especially under the further myth that it is scientific.
But the towers fell straight into their footprints. I don't know how a localized fire in a building can cause all 4 corners to collapse simultaneously. And what about those slanted cut lines on the steel beams that were exposed in the aftermath? I heard that is the way demolition explosives are made to destroy them.
Also the thermite that was found.
If you can find my response to daedalus001, I explain the collapse process in detail.
A column can fail in either of two ways: in buckling or in shear. In buckling, it would need enough room and plasticity to bend. If there is no freedom to bend or it is too rigid to bend, then it will fail in shear. It turns out that when a column fails in compressive shear, the break is always at 45 degrees. It turns out that is the angle at which the combined force and the bearing area result in the highest shear value. I have no idea whether demolition explosives are configured this way. I suspect it wouldn't matter. If the column is weakened, that is how it would shear anyway.
Melting steel beams from a fire (assuming it would be possible) would never allow a building to collapse into it's own footprint. It would instead compromise a section of the structure and if collapse occurred it certainly would not be uniform.
Watch architect Richard Gage's presentation on 9/11 which is illuminating in many ways, including information about the detection of nano-thermite in the rubble.
https://www.youtube.com/watch?v=wml_NCZ7ROg
You don't understand how a structure responds to catastrophic structural failure. It's not necessary to assume melted steel beams. The mass of the building is supported by an array of columns. They have some failure limit load against which is applied a safety factor. Here comes the airplane smash, which probably compromises at least a few beams. And then along comes a chimney fire as the jet fuel is burned in what amounts to a furnace with an upcoming draft and a chimney outlet. The columns get hotter...and weaker. Their strength goes down and down, to 90%, 70%, 50%, 30% and at some point the entire array of columns is precariously AT the limit load. What happens next? The weakest column fails in compressive shear (producing the 45-degree cuts). Then what happens? The loads are redistributed among the remaining columns. How fast does this take? The speed of sound in iron is about 4000 feet per second and hotter is faster, so if we consider a range of 100 feet, the loads are redistributed in 25 milliseconds (or less). Then what? Since the total load hasn't changed and the previous configuration failed, the configuration with the failed column will also fail, and the next weakest column will fail. Loads are again redistributed in 25 milliseconds (or less). It may not take a radius of 100 feet for the next column to fail. If there are a total of 100 columns, the entire lot will fail within 2.5 seconds (or less). Then what happens? In 2.5 seconds, the mass of the overburden will not have tilted significantly (inertial confinement, high angular inertia), but it will now fall at the acceleration of gravity for about 15-20 feet (whatever the distance between floors would be) and will build up a level of momentum that will greatly increase the loading on the columns of the next floor down. And the process repeats. Each collapsed floor adds to the mass. All the way down.
As for "nano-thermite," I don't give that any credibility at all, ever since I first heard it, years ago. If you go back to the fire environment, with flame temperatures near 3,800 F, the aluminum fuselage of the 767 is bound to melt (at a temperature of 1,220 F). (I've seen photos of the wreckage of aircraft that burned after impact. Conspicuous outpours of once-molten aluminum.) Liquid aluminum, like liquid water, will evaporate below its boiling point (non-zero vapor pressure). Aluminum vapor is an excellent fuel (it is the major constituent of solid rocket propellant used in space launch vehicles) and it produces aluminum oxide ash: "Evidence of 'nano-thermite'." This combustion occurs in the neighborhood of 6,000-7,000 F. Molten iron? No surprise. The thermite process is only the combustion of aluminum for the purpose of melting iron. So, the allegation that thermite was involved comes from someone with no idea of the combustion environment. (One of my background specialties is jet and rocket engine combustion chemistry.)
By the way, I have NOT read any official reports on the Twin Towers collapse. This is intentional, because I don't want to give anyone the satisfaction of accusing me of repeating "the narrative." I actually do not know what "the narrative" is, but I would be gratified if it backed me up.
There's plenty of evidence of nano-thermite or some other non-fuel related fuckery.
For example, watch from this point - https://youtu.be/wml_NCZ7ROg?si=dfnzCvchVjdzDpk_&t=2036
With regard to the Twin Towers, they effectively assume the non-existence of many tons of aluminum in the form of the airplane fuselage and wings, subject to melting, evaporation, leading to combustion or condensation. Nano-scale spheres of aluminum would be expected to condense from aluminum vapor. And iron is known to oxidize at environmental temperatures, let alone combustion temperatures (e.g., as the fuel in "orange" sparkler fireworks). It's all the same chemistry.