[Closed] 9/11 documentary

You mean the lower structure was unable to provide any resistance? None at all?

Of course it provided resistance, but it was so minimal in its effect it may as well be none. Certainly wouldn’t be enough to show any visible signs of deceleration.

therefore unless additional energy is introduced to accelerate the upper portion

It was about me , some folk on here and the pope - Not sure how you missed that as normally you have such a great understanding of things

You and the Pope eh, two wonderfully well informed patriarchs 😉

It is important only to invoke science if you understand it.

You can say that again.

you could if you used thirty ton tea bags

Precisely!!! I’d need a thirty ton tea bag to stand any chance of hammering in a nail. Why?

it really is pointless I have more chance of persuading the pope there is no god as his belief is more rational than this guff

Indeed; but would it require a controlled explosion to make 000s of unconnected blocks collapse into a pile? Would the same thing happen if all the blocks were glued to their adjacent blocks?

If we took the top glass from a stack of pint glasss and dropped it back in from, say, 50cm*, will it a) fall to earth, breaking all the other glasses before breaking itself, or b) break some glasses and possibly itself before coming to a halt? If we took a steel-framed tower construction, damaged fewer than 20% of supporting columns across less than 5% of its height, would you expect the portion above the damage to fall symmetrically vertical and destroy the entire structure below it [u]before[/u] then destroying itself?

*relatively, way further than the tops of the towers descended

Ok, i say we all agree with Three_braincells that it was a conspiracy, and it was blown up by the US government.

So, now what you gonna moan about Three now that we are all agreed you are right?? 😉

No need to be a dick, maxtorque. And I didn’t say that anything was blown up by the US Government; Congress would never allow it Shirley.

Ok three fish. Imagine you have a building 22 floors high. I remove the 2nd floor, do you agree that the 20 floors above will squash the 1st floor below.?

It’s not in any way a direct comparison, but I’ll go along.

Yes, in your example the first floor would probably be crushed. Also, the third floor would probably exhibit considerable damage. Damage (distortion) would diminish rapidly from this point, though it’s possible that the tower would actually topple over.

I chose this for the soundtrack; other videos are available:

that's his 2nd law f=ma

Erm... Not really.

I only really said the documentary was compelling - not true.

[img] [/img]

^^^ look at me! Look a me!!

- ie that thousands of government employees conducted massively destructed and invasive pre-demolition prep on the twin towers which would easily have taken 6 months to a year and no one noticed. No one questioned anything. None of the survivors recall seeing strange men drilling strange holes

Why would it have taken such a massive team? And so long?

Why would it have taken such a massive team? And so long?

They were really big?

Is that a question? Or an answer? It doesn't really explain anything.

Yes, in your example the first floor would probably be crushed. Also, the third floor would probably exhibit considerable damage

Now lets move the system on.

Do you accept that if the there was a floor below this system we described, then the 22 floors, lets assume the bottom 3 of them are now mobile debris, have mass and are moving at some velocity v? IE the 22 floors have not stopped, and the mass of moving material has increased by the mass equal to 1 floor?

Hmmm. Makes you think...

IE the 22 floors have not stopped, and the mass of moving material has increased by the mass equal to 1 floor?

Has the momentum changed?

Has the momentum changed?

Well the mass has increased and it has been accelerated by gravity. so both v and m are increased, so yes.

[quote=CharlieMungus ]Is that a question? Or an answer? It doesn't really explain anything.

YOU used to use your intelligence for things other than shit blatant trolling

Ok, so F=ma stops working, carry on.

That's pretty much the whole point, its a variable mass system and is hence not closed.
Also F depends on where you measure it..

YOU used to use your intelligence for things other than shit blatant trolling

Not trolling, just keeping the science on track and applying a slightly critical eye to some of the statements being made.

Also, "because they are big" is a bit of a crap answer really isn't it?

applying a slightly critical eye to some of the statements being made.

Also F depends on where you measure it..

Sure, it's a problem there is some elasticity in the building, more the higher you are. But I think for now we could consider the force at the interface between the falling bit and the bit underneath. So we have the force crushing the floor below and at the same time slowing the mass above, or at least reducing its momentum.

Sure, sounds reasonable.
I have a statement on the relationship between this force you have defined and the reduction of the momentum etc.
But I was hoping to keep three fish in the discussion and see if he or I can pick holes in each others story. So I kind of want his comments before moving it on too far, is that fair enough?

A simple experiment.

Take a raw egg and place in an egg-cup. Now take a 1Kg weight such as that from a set of old fashioned weighing scales and balance it on top of the egg. It will be supported no problem. Now lift the weight a couple of cm and drop it. The egg will crack and break into pieces.

That's the difference between a static and dynamic system.

The lower 85% of the tower was only designed to hold up the mass of top bit "statically". There's some redundancy in the design to allow for excess load but that's usually in the order of a few percent.

It's highly unlikely either top section of the towers would have fallen over. The towers were approximately 70mx70m in cross section so the centre of mass would have had to move at least 35 metres to lie outside the building walls. Each floor of the towers was just under 4m in height. The north tower was hit between the 93rd and 99th floor so there'd only be 11 to 17 floors of material, i.e. a maximum of 68 metres meaning its CofG would be around 35m above the impact. So for it to fall over that point would have to move 35m horizontally. Similar quick calc for the south tower gives a CofG for the section above the impact zone of 60m.

Look at video of the tops of the towers as they begin to fall, they wobble by a few degrees but nowhere near the amount needed for them to topple over. The path of least resistance for the falling mass was through the structure below.

5plusn8, you are completely ignoring resistance. Even if the lower part of the building were just a pile of steel and concrete, there’s going to be resistance, which is why the domino pyramid is actually quite useful - notice how it takes quite some time to overcome what little resistance is present in its system.

The lower 85% of the tower was only designed to hold up the mass of top bit "statically". There's some redundancy in the design to allow for excess load but that's usually in the order of a few percent.

Skyscrapers are designed to transfer force from the top of the structure to the bottom, it’s how they remain stable in high winds. To say they are only designed for static force is not true. With your eggsperiment, try it again with another egg instead of a 1kg weight. The object that fell into the WTC was also WTC, not something materially or structurally different.

The path of least resistance for the falling mass was through the structure below.

The path of least resistance was 80-something floors of solid steel and concrete?

I'm not, I want to get to resistance in a minute, will you answer my question?

Do you accept that if the there was a floor below this system we described, then the 22 floors, lets assume the bottom 3 of them are now mobile debris, have mass and are moving at some velocity v? IE the 22 floors have not stopped, and the mass of moving material has increased by the mass equal to 1 floor?

Demolition of these towers sounds like a piece of piss. Take a floor out (top or bottom, doesn't seem to matter) and it collapses into the basement, sure as eggs is eggs.

But it can't have been a controlled demolition because that would have taken thousands of people and weeks of preparation.

So is it hard or is it easy? I'm confused.

Also, "because they are big" is a bit of a crap answer really isn't it?

You asked why it would take a long time with lots of people. I suggested it was because it was big. Big buildings take lots of time and lots of people to rig for demolition.

Unless you know a quick way. Like fly a plane into it...

Demolition of these towers sounds like a piece of piss. Take a floor out (top or bottom, doesn't seem to matter) and it collapses into the basement, sure as eggs is eggs.

Why would it have taken such a massive team? And so long?

Unless you know a quick way. Like fly a plane into it...

In fact, maybe they designed a inherent weakness into the tower so they could easily demolish them without anyone suspecting a thing. Maybe that’s no-one noticed them being rigged for demolition.

I could get into this conspiracy thing.

[quote="Three_Fish"]The path of least resistance was 80-something floors of solid steel and concrete?Except for most skyscrapers, or even large buildings, they have far more in common with the eggshell example that keeps cropping up.

The path of least resistance was 80-something floors of solid steel and concrete?

It wasn't solid steel and concrete, it was mostly air otherwise they wouldn't have been able to fit offices into it. It was designed as the lightest framework possible to get the most space. It wasn't designed for a dynamic force of the mass of many floors dropping due to a failure of the supporting structure.

The mechanism has been explained to you in several different ways. If you are unable to understand them then admit it rather than come up with ever more spurious assertions that merely show up your lack of understanding.

80-something floors of solid steel and concrete?

No, it was 80 something floors of steel spanning structures that got thinner the higher up it went, no structural concrete at all.

Twin towers were mostly empty space

Three fish, ignore them, answer my question.

will you answer my question?

I already told you, your example is not comparable. Why are you going to add resistance later? Just put it where it’s meant to be. And why not stick to an example where we can observe hypothesis (or lack of)? I’m busy, I’ve a load of work to do and, to be honest, considering pointless examples of incomplete equations is pretty much bottom of my list of priorities. If I’m missing something, you’re going to have to less obscure.

5plusn8, you are completely ignoring resistance. Even if the lower part of the building were just a pile of steel and concrete, there’s going to be resistance,

The resistance was overcome. Like a lot of things, if the system is intact it is very strong, as soon as you start removing key parts of the system it becomes very weak. Forces start acting in directions that the original design was not designed to cope with, forces and the distribution of forces are upset and parts of the structure over-stressed. After than you're doomed and the structure can only collapse.

Another analogy is a Karate person karate chopping breeze blocks in half. Take 4 breeze blocks and stack them on top of eachother then they have no chance of karate chopping through them. Put a half inch gap between the blocks and they cut through them with ease - you only need to break the first block and the momentum of that first break does the rest. The structure of breeze blocks with a gap between each layer is effectively what you've got with a building. The momentum due to the small amount of speed built up from the floor above collapsing generates forces that are orders of magnitude greater than the forces the structure was designed to cope with.

I already told you, your example is not comparable. Why are you going to add resistance later? Just put it where it’s meant to be. And why not stick to an example where we can observe hypothesis (or lack of)? I’m busy, I’ve a load of work to do and, to be honest, considering pointless examples of incomplete equations is pretty much bottom of my list of priorities. If I’m missing something, you’re going to have to less obscure.

Its a model. Resistance is my next question. This is what we call a discussion. It's a shame you want to withdraw now.
I wanted to ask you how the resistance effects the very first failure. There is an interesting discussion to be had about that. But we need to establish a few agreed facts first.so please answer the question?

[quote=CharlieMungus ]It doesn't really explain anything.

Just like most conspiracy theories, including this one.

Which is quite an important point - because to suggest that it couldn't have been caused by the planes because of the way it fell is to ignore that the fundamental physics involved in a controlled demolition is much the same. I like how 3fish's video ruins his theory by demonstrating that controlled demolitions only involve removing a small part of the structure, in the same way the planes did.

But conspiracy theorists will conspiracy theory.

What did conspiracy theorists do before YouTube?

Enormous mass falls, converting PE to KE.

Enormous mass encounters barrier (floor below) and VERY slightly (probably imperceptibly) slows as it ploughs through it.
Enormous mass continues to convert PE to KE by falling under gravity, but is now a bit more enormous.

Enormous (+ 1xfloor) mass encounters barrier (next floor below) and VERY slightly (probably even more imperceptibly) slows as it ploughs through it.
Enormous (+ 2xfloor) mass continues to convert PE to KE by falling under gravity.

Enormous (+ 2xfloor) mass encounters barrier (next floor below) and VERY slightly (probably even more imperceptibly) slows as it ploughs through it.
Enormous (+ 3x floor) mass continues to convert PE to KE by falling under gravity.

Enormous (+ 3xfloor) mass encounters barrier (next floor below) and VERY slightly (probably even more imperceptibly) slows as it ploughs through it.

Etc.

Resistance (of the floor) is futile.
Basically, in the case of the towers collapsing, loss of momentum caused by encountering a floor<<<gain in momentum, as a result of free falling between floors; hence the entire building collapsed.

Had the structure been stronger/the damage not so great/impact occurred higher up, the buildings would probably not have collapsed.

Controlled demolition of the towers is conjecture... there's been compelling arguments for both sides.

I'd like to hear people's theories on why the collapse was so uniform in comparison to how severely the top of the tower was tilting:

[img] [/img]

[img] [/img]

Imagine suspending a 20 storey building and dropping it 4m onto a single storey building, what do you think would happen?

Another thing, as has been noted, rigging two of the largest office buildings in the world for demolition would be a large undertaking, a major project indeed. The paper trail would be massive, construction permits, inspections, works singled , delivery to site forms, it goes on and on. So presumably this paper trail exists, something like a major retiring project for both the towers? There would be whitnesses who observed all this construction going on in the building for months.

I'd like to hear people's theories on why the collapse was so uniform in comparison to how severely the top of the tower was tilting

Because gravity tends to work in this direction:
[img] [/img]
?

So stuff tends to fall down, not across.

.. there's been compelling arguments for both sides.

Honestly there hasn't 😆

[url= https://www.nist.gov/engineering-laboratory/final-reports-nist-world-trade-center-disaster-investigation ]Final Reports on WTC collapse[/url]

I'd like to hear people's theories on why the collapse was so uniform in comparison to how severely the top of the tower was tilting:

I'm curious - if the official explanation was controlled demolition, would that be sufficient for the conspiracy theorists to believe that it was caused by planes smashing into them?

someone earlier rated this thread as a 3/10, the big red arrow demonstrating the direction of gravity just jacked this up to a 8/10 for me!

This thread is an eye opener.... 😯

Question for the "It can't fall like that naturally" people.

Start with the statement:

"I don't understand how it could fall like that naturally"

There are two possible outcomes from this

1> I don't understand => I need to improve my understanding
2> It didn't fall Naturally => And I can prove it thusly

However, if 2 were true you'd need a full and complete understanding of the physics to prove it. Which means your original statement should have been:

"I completely understand the physics of building collapse and it [i]cannot [/i]have fallen like that naturally, and here is why..."

So...

1> Are you sure of your opinion because you think you have a full understanding of the physics and are using it to explain how this building couldn't have collapsed naturally in the way observed.

Or

2> Are you trying to explain your opinion of how this building collapsed using your current understanding of the physics of it?

the two things are different...

1 Assumes nothing about the cause, but uses physics to describe the mechanism of collapse

2 Assumes a cause of the collapse and then attempts to explain the mechanism of it.

Have a think about it...are you sure your understanding is sufficient? If someone asked you to come and consult on some pending demolition work or Skyscraper building would you feel capable enough to do the job?

Reckon you could walk into a degree level (or even A level) classical Newtonian Physics exam tomorrow and pass?

If any of the above answers are 'no' then perhaps you need to think about whether it's your understanding that's lacking rather than the explanations.

Admitting that your understanding is incomplete is not a bad thing, and it doesn't mean you're incapable of improving your understanding. But arguing that other people are wrong and then trying to make it fit based on your current [b]mis[/b]understanding is never going to end well, especially when people can poke holes in your explanation.

If on the other hand you can answer yes to those questions and are sure you're a physics whizz then I invite you to write a paper detailing the impossibility of the observed collapse and its contradiction of Newtonian physics, submit it for peer review and see what happens. If you're correct then you should get a lot of Physicists on your side...not to mention a few job offers in construction or demolition depending on if you're a glass half full or half empty kinda guy 😉

*FWIW I have a Masters degree in Physics, I'd still answer 'no' to all of those questions, maybe the A Level paper but I'd still probably need to do some revision 😉

amedias, yup, 8 pages of shonky misremembered school physics arguments, assumptions and insults is going nowhere fast.

One more page and this will equal my "End Halal Petition" thread 🙂

misremembered school physics

oi mine is a google backed I'll have you know.

I'd like to hear people's theories on why the collapse was so uniform in comparison to how severely the top of the tower was tilting

My theory is this.... That’s [b]exactly[/b] what happens when that particular building gets hit by that particular plane in that particular way on that particular day.

But we would all love to hear what your theory is I’m sure.... the floor is yours.

Your theory is "because it did", neal? 😕

CharlieMungus - Member

- ie that thousands of government employees conducted massively destructive and invasive pre-demolition prep on the twin towers which would easily have taken 6 months to a year and no one noticed. No one questioned anything. None of the survivors recall seeing strange men drilling strange holes

Why would it have taken such a massive team? And so long?

Because controlled demolitions take a long time. You should probably read about them. For example one of the largest controlled demolitions ever the [url= https://en.wikipedia.org/wiki/AfE-Turm#Demolition ]Afe Tower[/url] took 6 months to prep for demolition. It was 381ft tall. [b]381ft[/b]. The Twin towers were [b]1362ft[/b] and [b]1368ft[/b], so a massively more complicated job.

Keep in mind that that 6 month prep is with complete uninhibited and unrestricted access to the building where they rip the insides to pieces and drill thousands of holes.

[url= http://www.controlled-demolition.com/seattle-kingdome ]Controlled Demolition inc[/url] go into some detail about their jobs. For instances when demoliting the Seatle "Kingdome" they

drilled [b]5,905[/b] holes for CDI’s explosive placements in the tension and compression rings, roof ribs, columns and support structure under the Kingdome. During loading operations, CDI laid [b]21.6 miles of detonating cord[/b] and placed more than [b]4,700 lb. of explosives[/b] in critical locations to control the fall of the structure and reduce vibration. The explosives detonation sequence utilized over 900 delays both to control the fall of the structure, mitigate air overpressure and to enhance fragmentation of resultant debris.

They also destroyed one of the worlds largest department stores (still tiny compared to the WTC and it took them almost a year from start to finish - again, in daylight, all day every day. And conspiracy theorists are suggesting that this was done either at night, in the dark or somehow without knowledge or witness of any of the thousands of people who worked in the WTC.

It would have taken years of work, hundreds if not thousands of workers (which means tens of thousands of conspirators), tens of thousands of tons of explosives and hundreds of miles of detcord.

^^^

See, it was because they were big...

^ Thing is though, they'll read that and instead of going [i]"oh yeah, well I guess that's that theory out the window then!"
[/i]

They'll think [i]"Flippin heck, they must have been [b]really [/b]good at covering it up"[/i] 🙄

You should probably read about them. For example one of the largest controlled demolitions ever the Afe Tower took 6 months to prep for demolition.

Trucks were arriving every night at the WTC from about August 23rd according to this CIA insider :

CharlieMungus - Member

- ie that thousands of government employees conducted massively destructive and invasive pre-demolition prep on the twin towers which would easily have taken 6 months to a year and no one noticed. No one questioned anything. None of the survivors recall seeing strange men drilling strange holes

Why would it have taken such a massive team? And so long?

Think of your own place of work. Do you believe that someone could for example re wire that or run new network cables in completely secrecy and without being discovered by anyone?

And that's an entire order of magnitude less than running demolition charges on a massive scale never before seen.

And this is the problem with all this truther stuff. You have to suspend your critical thinking to subscribe to it, whilst pretending you are doing the opposite.

So it only took them [b]19 days[/b] to rig both towers for demolition? These so-called demolition experts would appear to be taking the urine with how long they take to do it.

TurnerGuy - Member

Trucks were arriving every night at the WTC from about August 23rd according to this CIA insider :

www.youtube.com/watch?v=i6eMq5Rit1w

an unnamed, unverified female says that. Doesn't make it fact. Doesn't make it even close to fact.

Again, critical thinking suspended.

go find multiple verified eye witness accounts, provide links to their unedited testimony. correlate that with traffic camera footage etc. identify the drivers of the vehicles, where the vehicles were rented, purchased etc.

Actually find me a truck driver testimony, that would be the first whistleblower. You'd be fanous

- ie that thousands of government employees conducted massively destructive and invasive pre-demolition prep on the twin towers which would easily have taken 6 months to a year and no one noticed. No one questioned anything. None of the survivors recall seeing strange men drilling strange holes

Plus *if* the fact the towers collapsed downwards in a relatively self contained fashion is the giveaway that it was controlled demolition, the demolition guys would have rigged it so it collapsed to one side or t'other.

Your theory is "because it did", neal?

Yup.

My theory is that some planes flew into some buildings.
Those buildings, and one other, collapsed due to the damage caused.

I await with baited breath an alternate theory that holds up to even the mildest scrutiny.

Can posting links to you tube videos be disabled on this thread?

If some of the contributors have to articulate their responses they might take more time considering the validity of their argument....

I think a building with several thousand workers in it would require several trucks a day to visit it just for normal operation. Americans aren't exactly shy when it comes to producing trash, there'd be several garbage trucks plus lots of delivery vehicles plus parcel delivery and pickup. Not even got to maintenance yet.

they might take more time considering the validity of their argument....

I remain doubtful

I think a building with several thousand workers in it would require several trucks a day to visit it just for normal operation. Americans aren't exactly shy when it comes to producing trash, there'd be several garbage trucks plus lots of delivery vehicles plus parcel delivery and pickup. Not even got to maintenance yet

And .... ?

keep WT7 in mind.

The only ever hi-rise building to ever collapse at near free fall speed, straight down, from minor damage and office fires.

If you'd showed the video of it collapsing to everyone on earth a day before the event, every single one of them would have said that is a controlled demolition.

I'm not convinced many people have seen a tower block collapse without it being a controlled demolition. You'd be showing them a video of a building falling down. "yes, that looks just like a building falling down"

keep WT7 in mind.

How and why?

Can we agree that a controlled demolition takes a LOT of preparation and it would e very difficult to do this without being noticed?

Why would they want to do it? The horror achieved by the planes crashing into the Towers was easily enough. In fact I can't even remember hearing about WT7 on the day. I can remember exactly where I was when I saw the footage of the aircraft.

If you'd showed the video of it collapsing to everyone on earth a day before the event, every single one of them would have said that is a controlled demolition.

How many videos of buildings falling down from other causes have people seen?

The only ever hi-rise building to ever collapse at near free fall speed, straight down, from minor damage and office fires.

The 'free-fall' nonsense is just that, nonsense. So that leaves 'straight down' bit, but that's the direction gravity tends to work in so no surprises there, so that leaves 'minor damage', well I think it was actually hit by rather a lot of debris wasn't it? It wasn't just a few pebbles landing on the roof...So, office fires, well they can get pretty bad if left unchecked, which they pretty much were, and other buildings have suffered structural failure due to fire.

But, let's assume it did fall at a bizarre speed, in a funny direction, after minor damage and couple of waste paper baskets caught fire. What's the next step?

How do you leap from "Hmm, that looks a bit unusual, I wonder what happened there" to assuming it was a conspired and secret controlled demolition (for $reasons). Could it not be that there's more info than you have? Or a mechanism at work you don't understand? Could it even have been incompetent construction?

But I realise this is all futile, you've already decided on your opinion and only information that supports it will be relevant.

"If you'd showed the video of it collapsing to everyone on earth a day before the event, every single one of them would have said that is a controlled demolition."
...and if you told them that the two biggest buildings in the world had just fallen down and smashed into the ground right next door causing a massive shock and raining debris on the building that also caught fire?

What a great thread for outing the fragility of belief systems... 😆

There's a big contradiction here: on one hand you have an argument that collapsing a building into its own footprint by controlled demolition is an incredibly tricky, lengthy, precise job, but on the other hand the results can be replicated exactly by smacking it on one side with a big heavy thing and setting it on fire. Doesn't matter if it's central strike or not. Or you can just throw rubble at it and set it on fire. Same result. Are these so called "demolition experts" having a laugh - years to set up? Why?

If the structures of these building allowed them all to collapse neatly under such a variety of imprecise impacts, loads and fires, then a deliberate demolition could have been done in a variety of imprecise and localised methods as well.

Either it's easy to do this, or it's hard. Which is it?

The only ever hi-rise building to ever collapse at near free fall speed, straight down, from [b]minor [/b]damage and office fires.

Not sure it would be minor damage, the other towers were circa 1400ft tall!

and if you told them that the two biggest buildings in the world had just fallen down and smashed into the ground right next door causing a massive shock and raining debris on the building that also caught fire?

 

There's a big contradiction here: on one hand you have an argument that collapsing a building into its own footprint by controlled demolition is an incredibly tricky, lengthy, precise job, but on the other hand the results can be replicated exactly by smacking it on one side with a big heavy thing and setting it on fire.

There is no contradiction, and the only person who has made that ^ comparison is you.

[b] controlled [/b]demolition

I've emboldenated the important word for you.

Either it's easy to do this, or it's hard. Which is it?

It's hard, nobody has said otherwise. The fact that the Towers collapsed in the way they did doesn't mean it would be easy to replicate, and it certainly wasn't 'controlled' in terms of outcome compared to an actual controlled demolition.

Controlled demolition attempts to control the factors that it's possible to control, and leave as little to chance as possible, but chance still plays a part. That doesn't mean that chance can't also produce a similar outcome in certain circumstances. The two are not mutually exclusive.

Crash testing cars for example...

They attempt to replicate real world collisions but with a degree of control, but those same collisions happen in real life by chance, mostly the outcome is the same, sometimes 'weird stuff' happens but that doesn't change the fact that the controlled collisions and chance ones of the same type have broadly similar outcomes.

It's not a perfect analogy by any means but the same principle applies, buildings collapse downwards, there are some bits of the process you can influence, and other bits you can't.