it wasn't controlled demolition. heat weakens steel. steel doesn't have to melt to be weakened.
heat from the building/fuel fire caused by impact weakened the structure that was already weakened by impact. once one floor fails, the rest collapse.
if you don't believe me, here's an experiment: go take a cinder block, put a Coke can on it, balance another cinder block top of the can. repeat for three stories or so, then drop a cinder block on top. it'll all collapse at once.
WTC7 wasn't hit by an airplane. Office fire cannot significantly weakened steel to the point all the steel beams would fell straight in their own footprint through the path of most resistance.
Heat from the fire affecting the steel beam would have dissipate through the steel beams and wouldn't have weakened them equally everywhere making all steel beams to fall at the same rate all through out the whole building the way they did.
Watch the first 2 video I mention above if you care to learn more about why your assumption are wrong and learn about how they have been proven wrong.
As you can see it's very easy for an office fire to weaken steel.
The whole structures of the 3 towers hold on until point of collapse then all of the steel beam collapsed onto themselves through the path of most resistance like the video demonstrate.
I said, office fire cannot significantly weakened steel to the point all the steel beams would fell straight in their own footprint through the path of most resistance.
Even if the Steel would have been weaken by any amount of %, the way the towers felt straight through the past of most resistance defies the laws of physics if we are to believe the official version.
Your comment in noway refute what I said.
Welcome on Steemit as this seems your very first comment ever, after just receiving your account today.
Also, ignore the fact that on the video, with careful observation, you can clearly see that the center columns collapsed first. They were not damaged by "isolated fires." That building was demolished. Period. Next question please...
wtc 7 was hit by a piece of the other buildings that flew from their collapse.
If that made the building collapse, why did the center columns collapse first?
To melt steel, a basic office fire is far the temperatures required. It would need a metric tonne of thermite on every floor igniting perfectly at the exact same time to have that kind of effect.
How can you be soooo naive !!
What's naive about it?
Not a valid engineering comparison example.
What dropped on TOP of the building to crush it like you say ?
The plane flew into it from the SIDE.
Using your logic is should have fallen sideways.. by a measurable smidgen at least.
Please explain to this lowly test engineer your logic .. im keen :)
what dropped on top was those many floors ABOVE the failing column. dropped all at once, massive impact. buildings aren't designed to withstand that.
it fell mostly level because the support was central. try my experiment, and you'll see that the cinder blocks fall mostly level.
I don't know if you truly believe what your comments on this tread transpire but if you do I have sympathy for you and I recommend you watch the 2 movies above as I had already said.
May people recognize my first comment I made on this tread as true or at least intriguing enough to learn more on the subject.
They could save a lot of time and agony by watching these videos instead:
Oh dear .. armchair engineering alert.
Actually the buildings I have been involved with all got heavily modeled for exactly the physics you describe.
I suggest you read more Physics 101 because what you are saying does not fit with reality and its making you look a little silly.
Be brave and boogie on baby :)
Could you be more specific? I hold a master's in mathematics, and I've aced every physics and engineering class. Bring it.
Lol, really :) Love ya vigour.
thank you. is that it?
Pretty much.
Keep up the studies, good luck in the exams :)
What the hell are you talking about, @lostinthesauce?
Balance some blocks on some loose drinks tins?
Balance? Just balance?
Have you actually seen photos of the Twin Towers before their controlled demolition?
The strongest, the most dense, the most concentrated network of the thickest steel girders, forming an actual, vast, thick cage around the whole outside of the building, with similar steel interior suport in the core of the building.
With foundations going down 10 floors worth of space underground.
There were no buildings on earth like them, before or during their time or since their demise.
You want to compare that to balancing concrete blocks on drinks cans in a fragile way and then trying to make skittles out of what are already essentially nothing but skittles anyway?
You insult peoples' basic intelligence.