What is the effect of QUANTITY and CONDUCTIVITY on the TIME it takes
The amount of time at which structural steel will fail is entirely dependent on the amount of energy released by the crash.
to raise the CORE temperature of the steel?
What do you mean by core? The correct formulation of the question is this:
How much energy is required to cause (name the type of steel structural member)
to fail?
The steel on the 81st floor of the south tower had to be strong enough to support another 29 stories.
Steel loses its strength when it gets hot.
So how thick was the steel? How many tons of steel were there?
It wasn't only steel that failed. The concrete did, too. The structure failed. It was a network of individually inadequate members which only could support the load when acting in tandem. You need to understand network analysis to try to address this. It requires competency in linear algebra and calculus. Not you strong points.
How did conductivity affect this heating?
Conductivity didn't cause the heating. Energy from the crash did. At half the thermal conductivity, twice as much energy will be conducted in the same amount of time. You need a course in freshman physics to grasp this.
Even if the fire reached 1100 degrees F how long would it take the steel to weaken?
You are still failing to understand freshman concepts. Temperature does not bend steel. Energy does. I can expose a steel paper clip to a million degrees without affecting it. For example, I can shoot an extremely hot atom into it with no affect at all. On the other hand, if I dip it into a room-sized vat of molten steel, the paper clip will rapidly liquefy. Explain this and you will begin to understand the difference between temperature and energy. Again, this is freshman science.
And why didn't this heating steel sag and slowly lower the structure above rather than suddenly give way?
See the answers above, and see if you can now answer your own question.
People who have decided to BELIEVE in collapse can simply ignore such obvious questions.
People who believe in their own spurious assumptions simply ignore the laws of nature. Now: which one are you going to run with? Therein lies the rub.
The south tower came down less than one hour after impact so why isn't everyone wondering how the steel heated so fast?
Because they either studied science, and know what you don't know, or else they are illiterate in science, but rely on people who studied it. Then there's you. You are neither able to address the fundamental concepts, nor are you able to accept the correct answers to questions about fundamental concepts. And along the way you've convinced yourself that you actually know something about a subject in which you could not pass the freshman exams. In spite of this, you are vociferously arguing with science professionals, academics and people with advanced science degrees, who are on same page because they understand and/or master the fundamentals.
And that does not even raise the issue of how the top 29 stories tilted 22 degrees so quickly.
Calling something you don't understand an issue doesn't make it an issue. It simply remains a principle of science that you have no experience with. You are reacting with skepticism to a question that requires the application of freshman math and science. Without it, you're jumping to conclusions without any valid basis for doing so.
And then they don't ask about the center of gravity at all.
...And then you ask about CG for no reason at all. Until you can demonstrate how to apply CG in an equation, what good is it? What if I said the CG was 1, a million or a trillion? Would you even know what to say to me?
See if you can pass the freshman exams, and get back with me, and let's see if we can decide who's the idiot.
No I was not. I never said where the center of rotation was. Grumpy said the center of rotation was at the center of gravity. But he has never specified where the center of gravity was along the height of the tilted top 29 stories. Here is a video supposedly demonstrating the center of rotation.
You're ignoring the heterogeneous distribution of reactions in the network. It's a bad assumption, as is the failure to recognize the structure as a network in the first place, something that would be hard to model under static conditions, much less the complexity of modeling the effect of a plane crashing into the structure. One of the quintessential aspects of a novice is the tendency to oversimplify. This is your most obvious shortcoming. You're simply unqualified to comment on structural engineering, strength of materials and physics--all of which are prerequisites to an intelligent discussion on this subject.
It says nothing about the center of gravity.
So what is the center of gravity of a homogeneous rectangular prism? When you figure that out, explain how the prism can be caused to twist or rotate under failure, and how it can be prevented from twisting or rotating under failure.
But the moment of inertia does not explain how all of the columns could be sheared regardless of where the center of rotation and center of gravity were.
The way you tell it. You were the one advocating against any twisting or rotating during collapse. In order to prove it, you would need to apply the moment of inertia. You would need to prove that the amount of torque to overcome the inertia was not present. Now let's say you can find the CG and moment of inertia for one of the towers. The question is: do you even know how to apply these parameters to answer what I asked immediately above?
You are obviously confusing CG and moment of inertia, temperature and energy, statics and dynamics, idealizations and complex real world systems, and science and bogus assumptions. Worse, you are confusing knowledge and fear of the unknown, as you are confusing the integrity of hard work (like buckling down and cracking the books) vs the dishonesty of skipping the work, and pretending to understand it as a matter of uneducated guesswork --and of runaway fantasies about cause and effect.
