A science question

[Foi4895]

I just watched the '9/11 conspiracy video' and I have to agree, there isn't much truly 'hard' scientifically empirical evidence, save for one fact.

 

The documentary says kerosene burns at 1120 C and that isn't enough to melt either steel or titanium, and you have to keep the heat on it for several hours. But they say that the kerosene the jets used as fuel weakened the reinforced steel they used in the WTC.

 

They have a quote from an engineer at the company who certified the steel in the 70's and said it should take over 3000 degrees for several hours to cause them to be that weakened enough to cause the NEAR freefall collapse of the WTC.

 

Isn't that something you can check. I mean, just those facts should be enough... I would think...

 

Are they lying, just making up the science?

[DV8 2XL]

Well it wasn't just the Jet A burning. Also temperatures in a fire depend on any number of things, not just the open-cup burning temperature of the excelerant.

[YT2095]

actualy even if it WAS just the jet burning, Blue fire and the metals employed in a jet (magnesium, titanium, duralumin, magnalium etc...) wuold react and have a Thermit effect on oxidsed iron and steel.

 

but even if we ignore this fact, the Impact and softening of the steel (it doesn`t have to be molten to be structuraly useless) would have done it too eventualy.

 

oh yeah, and the Mega Slack work on the fire retardant foam/insulation played a major role in this too

[Phi for All]

They have a quote from an engineer at the company who certified the steel in the 70's and said it should take over 3000 degrees for several hours to cause them to be that weakened enough to cause the NEAR freefall collapse of the WTC.

... unless the steel was somehow pre-damaged from a shock of some kind, and impact or something, a titanic jolt that might have happened just before the flames started....

 

And the temp of burning kerosene bit has already been debunked. The conspiracy assumes there was nothing else flammable in the building.

[encipher]

... unless the steel was somehow pre-damaged from a shock of some kind' date=' and impact or something, a titanic jolt that might have happened just before the flames started....

 

And the temp of burning kerosene bit has already been debunked. The conspiracy assumes there was nothing else flammable in the building.[/quote']

 

Excluding all the factors that might have affected the temperature and fire, and taking into consideration only the fact that the towers collapsed, the video provides examples of other buildings that have had planes crash into them. Some continued to burn for over 24 hours. None of the other buildings collapsed except the World Trade Center towers. Now I personally don't think the buildings were rigged with explosives.. but there must have been something that we dont know about that caused the towers to collapse like they did within a few hours of the planes' collision.

[DV8 2XL]

Thing is that once you get even a bit of off-center plastic deformation at one area on a structure like those towers past a critical point catastrophic failure (in the engineering sense) soon follows.

[Foi4895]

But what about the building below? It was not exposed to the trauma of having a plane hit it, it experienced it's secondary effects, but surely they built it stronger than that. Like encipher said it gave examples of buildings made of similar materials exposed to similar trauma, not collapsing.

 

I am guessing you aren't talking about chairs and carpeting when you say there was something else flammable. They said it would take hours to weaken that much steel, or very high temps. What kinds of materials would be in a building like that? Maybe propane in the various resturaunts, I've heard those mentioned.... I can't think of anything else, anything glaringly significant.

 

DV8, when there are catastrophic engineering failures it doesn't not hold to logic to have so little collateral damage. Think about the teams of people who train for so long to 'pull' a building with so little damage.

[insane_alien]

there are no buildings similar to the twin towers. they're structural architecture was pretty unique. super tall buildings tend to have a specialised load bearing structure rather than a generic one. we have no idea how much load bearing capacity was destroyed on impact and then that would be further reduced by the heat. structural steel begins to lose load bearing capacity at only 500*C so in an already compromised structure this becomes significant.

[DV8 2XL]

Also you must understand that the thermal profile of a fire like this cannot be simplified to the flash-points and open air combustion temps of the fuel. Heat can be focused by air-shafts and other features raising the temperature in some zones far above the source temp. As for fuel - you would be surprised how much there is, particularly at elevated temps. Synergy's abound in these situations

[YT2095]

it`s important also to factor in the weight involved in the "untouched" floors above, a drop of even 6 inches (arbitrary figure) would still have enough inertial force to continue down the rest of the way to ground.

if it were hit at the Top it`s very unlikely that it would have fell at all.

sadly, they got it more or less "Just right"

[insane_alien]

it probably only took 1 or 2 load bearing struts to fail(after the initial damaage of a great big plane slamming into it) or even partially fail to let the top floors drop slightly to bring the hole thing down. "the straw that broke the camels back" is a good analogy for this.

[abskebabs]

Why did building 7 near the twin towers also collapse? Wasn't it at least 200 metres from them?

[YT2095]

impossible to determine without schematics of the place.

but don`t forget that the Footings of the towers went many stories Down and a quite a distance outwards also.

it Could be like resting a plank of wood across a fulcrum, putting an egg on one end and then droping an engine block on the other!

[insane_alien]

still, if two of the tallest buildings in the world fell down 200 meters from your house, i'm pretty sure it wouldn't be in such good shape structurally.

[Foi4895]

But what about ALL the buildings around it? From what I understand there was no structual damage to the buildings surrounding 7.

 

That is an interesting thought YT, about the egg engine analogy, but do you really believe a few guys reportedly trained to fly small private aircraft could aim 'just right'? I'm not saying they couldn't just asking if you think they could.

[insane_alien]

Just because one building collapsed from structural damage(besides the towers) doesn't mean the other buildings took as much of a beating on the support structure. the debris can hit the superficial(sp?) structure and not reduce the structural integrity of the skeleton. infact, if the superficial structure is knocked off, the skeleton has less to support so is more likely to stay standing.