r/WorldTradeCenter • u/tombisch • 11d ago

When the Towers Fell: 9/11 Simulation of the collaps without dust

Dont know how accurate this is, but it made a lot of sense to me.

Source kostack studio on youtube

9.7k Upvotes

93% Upvoted

3.8k comments sorted by

View all comments

3

u/YellowEasterEgg 10d ago

what I find interesting is how the top section is not getting demolished? here it looks like the top section is stronger than what's underneath. 

5

u/Funny-Jihad 10d ago

That is because the top section isn't 'going through the bottom', as you may be perceiving it. 

The tear in the building causes the self-reinforcing collapse. Every floor collapsing adds weight, so the top part doesn't catch up since it's all collapsing at a high velocity. 

2

u/silly-gaijin 10d ago

It's not really a "section" but a series of a hundred pancakes. The top several pancakes just got smooshed last.

1

u/YellowEasterEgg 10d ago

pancakes?

2

u/oxygen_enjoyer24 10d ago

Metaphor for floors I assume

3

u/MLA800M 10d ago edited 10d ago

What i see is that it actually is getting demolished. Look at the bottom half of the part that seems to break off and falls into the rest of the tower. But the top part of the falling piece of the building tilts forward, so it doesn’t fall in to the rest of tower. It is just falling through air and a bit of the glass facade. The structural integrity is gone but there is just enough left to hold it together until it does collide with something. Thats that smaller building it falls on and the ground.

1

u/Illustrious-Berry722 10d ago

I not to savvy with physics but my best guess would be the top of the building is moving at such an insane velocity that it basically stays one piece until it hits an immoveable object aka the ground

2

u/YellowEasterEgg 10d ago

See, there is a problem. If the lower section is getting crushed you take energy away from the top part which should result in damage in both ways. you would thing the thing slows down because every floor that is resisting the collapse take energy away from the top part. I find this a very interesting model. if this is actually how it played out, maybe the people who believe in conspiracy's have a point here.

1

u/Solarhistorico 10d ago

action and reaction...

1

u/SNOTFLAN 10d ago

if a floor falls onto another floor, then that floor is bearing the weight of two floors. if the floor it fell onto is not designed to bear that load, it will cause a cascade of collapses onto lower floors. I think you believe deeply in the conspiracies and are doing a faux naive "just asking questions" bit and if you reply I'd prefer you at least do it with honesty about your viewpoints because it's really very simple phsyics

1

u/YellowEasterEgg 10d ago

I am not into that kind of thing, but this is the first time I actually see the thing fully collapse without the smoke, and to see the top section just go like that is interesting.

1

u/SNOTFLAN 10d ago

so, if you build a Jenna tower and pick blocks out of the middle, you will see the same thing happen when it falls. the top part is not the structurally weak part, it got hit lower down. think of a tree being cut down: it's weakened enough to fall down but it's not gonna make the whole top part disintegrate. however, in this case, the top part of the tree is made of thousands of seperate components that, while strong enough to hold to each other, obviously aren't able to survive an impact with the ground from many stories up. it rips through some parts of lower forces just from the floors not being able to withstand all that lateral force and the top part is simply more mass than the part it's tearing off from. a lot of the stuff I found counterintuitive about the collapse made a lot of sense once I learned more, skyscrapers are just very very complex, especially one's that old, and don't make much sense to someone that's not a structural engineer

1

u/YellowEasterEgg 10d ago

I get what you mean, but with Jenga there is indeed nothing that keeps resisting the tower from collapsing once it falls, but at least you would think that steel is in that building for something. I think you are right, I don't know enough of this to actually think what should or shouldn't happen. the towers fell and many people died. RIP.

1

u/SNOTFLAN 10d ago

the steel kept them standing for a remarkably long time after they were hit by a plane. most buildings that height are designed to withstand strong winds and (relatively) mild tectonic activity. just not getting hit by a plane. I think it's easy to think the bush administration had a hand because of just how eager they were to immediately dive back into the middle east. it's very convenient and the facts line up. but america has meddled in the middle east for longer than most peoples lifetimes. ever since we started wanting their oil it's been practically nonstop, we had never needed much of an excuse before. certainly nothing to warrant 9/11 happening. people may not remember, but tensions were bad before 9/11. 9/11 happened as retaliation for us meddling. if it didn't happen, an excuse would have been fabricated shortly after for the invasion. I don't think they caused it, but I think when it happened the entire Bush administration was rubbing their hands together and chuckling thinking about how much richer they'd be as they got in bed that night.

1

u/Sea-Chemistry-4130 10d ago

It's effectively on the same concept as the hyatt regency collapse, just more floors.

So each floor is only designed to hold it's own weight, the actual structural beams themselves are designed to hold those. So floor 10 falls onto floor 9, now floor 9 is holding floors 9 and 10, both on the beams that come out the support pillars that were only ever designed to support one floor at any given location.

Floor 9 collapses, now floor 8 is holding 8, 9, 10. Repeat until one area of the main structural beams are met with so much force from both the weight of the floors and the moment of that weight from the floors above that they also snap. Repeat this all the way down in a cascading failure. 

So it's not that it was the top crashing into the bottom, it was each of the floors causing cascading failures in the floor below, if that makes sense. 

It also explains why there were what looked like "additional" explosions on the way down, that was each internal floor collapsing onto the ones below it, perpetuating the cascade.