Gam is quick to point out that the penthouse collapsed 'before' the main WTC-7 structure. Okay. Fine. So how does that happen when WTC-7 is 350 feet away and we can see that nothing struck the upper floors of the 47-story skyscraper?
I'll make this as simple as I can Terral. Let's discuss one aspect of a the structural system of a building. Do you understand what loads are? Do you understand how loads are distributed throughout a structure so that the weight load is not carried by one individual columns or beam, but by ALL the columns and beams?
Here's an example. Do you know how some companies have team building exercises? Some of them have one person lay on their backs on the ground and have, for example, 10 people surround that person, put two fingers from each hand underneath them and then lift them up? After that, let's knock that number down to five people and try it again. Do you think that each of the five people will have to lift more weight per person than when they had 10 people? Let's get only one person. What then?
Now, if you have columns connected by beams, this helps distribute the load to the other columns. If you start breaking connections of those beam to other columns, you start to overload single columns.
Now throw in the fact the the column/s are being heated from the office fires. They don't have to be heated to melting to be affected. Steel starts to lose it's strength at 650F. As the temperature rises, the steel continues to lose more of it's strength.
So through thermal expansion of the fires breaking connections throughout the system, fires lessening the support strength of the steel columns, what do you expect to happen?
If a steel column loses 80%-90% of it's strength at 1000F, what happens as it tried to support the load it was designed for? You said yourself that office fires reach temps of 800F-1000F. So steel does NOT need to melt to fail.
If the building was NOT on fire, where was all the smoke coming from?
Your claim that heat races to colder parts of the structure meaning that no steel beam or column would reach strength-lessening temperatures is completely stupid because there was a CONSTANT heat source in the office fire. If your statement were true then things I've seen in steel mills never happened. I have never seen a crane clamp lifting a bright red steel slab fresh from a furnace, turn red due to your "FAST HEAT CONDUCTION" crap. I have never seen rollers in a slab mill turn red due to your "FAST HEAT CONDUCTION" crap.
If you apply a constant heat source to one area of steel, it's going to heat up. It's not going to quickly dissipate. That's why they INSULATE STEEL to begin with.
Even if that DID insulate the steel, did the also insulate the connections to make sure those weren't affected by heat?
Tell me why, based on your HEAT CONDUCTION crap, this crane clamp isn't red by now if heat transfers as quick as you say.