Bin Laden told followers not to 'waste [their] effort' attacking the UK

Don't worry.

He's living in a dream land with such bogus claims.

I'd be quite interested in seeing him go to the 9/11 memorial and spout these claims there!

Did I claim that? There is little evidence to support that but a lot of evidence to support 911 was an inside job.

Those towers were designed to withstand the impact of multiple planes, like all sky scrapers.

http://www.youtube.com/watch?v=ssuAMNas1us

The potential force of the impact from each plane can be approximately calculated and the figures are very large. The weight of each plane would have been approximately 150 tonnes, according to the media reports and Boeing data on this type of plane. The plane would have been traveling at around 800 kms/hour at impact. This gives a momentum of

Momentum = 150 x 800/3.6 = 33,333 tonnes.m/sec.

If the plane was arrested by the building in effectively 0.6 seconds, which is a reasonable estimate based on a linear deceleration over the 63.5 m width of the building, then the force exerted on the building is the momentum/effective time to arrest, i.e.,

Force = 33,333/0.6 = 55,555 kN.

To put that in perspective, the ultimate limit state design wind pressure over the entire height of the building is 220 kg/m2 (45 lb/ft2). This gives a ULS wind force on one face of the building of 58,400 kN.

Wind Force = 220 x 63.5 x 411 = 5,741,670 kg-force = 5,741,670 x 9.8 N = 56,268,400 N = 56,268 kN

Thus the potential force of impact from the plane is 95% of the design ultimate limit state wind load on the building!

The towers did not fail from the initial impact of the planes. The resulting fires were intensified by hydrogen combustion. The aluminium melted and leached through the debris. When the molten aluminium from the planes contacted the water it produced hydrogen gas, causing intermittent explosions whilst the aviation fuel was burning.*20 to 50 tons of molten aluminium can also be seen pouring from the 72nd floor of the south tower. This occurs 49 minutes after impact, after sufficient time has allowed the intense heat to sag the floor joists, leading to ultimate failure through buckling.

I would find your highly simplified momentum explanation entertaining (nobody is saying they failed from the force of impact), if you weren't so*callously insulting to the memories of the people who died that day.

I count this as fourth time correcting you.

Yes he makes a great point. The buildings DID withstand the impact of the planes. They collapsed hours later due to other factors. Therefore this is well and truly debunked.

i think the fact that a 747 impacting on the towers tends to leave a large flaming hole in its structure is kind of relevant to it eventually falling down....

Besides which, didnt bin laden and al quaeda admit to planning the attacks, as well as those captured that were involved and the hi-jackers all had links with al-quaeda etc etc. Are there really morons around today that refuse to believe this?

But they can't account for EVERY possible event. They can never be 100% perfect or account for every variable.

but they can account for a plane hitting into it.

I could probably take the "impact" of a punch from David Haye. Doesn't mean I wouldn't go down like a sack of spuds 2 minutes later.

I could probably take the "impact" of a punch from David Haye. Doesn't mean I wouldn't go down like a sack of spuds 2 minutes later.

ad........ hominem.....

I'm actually logging out until exams are over... see you in about 2 weeks!

but they can account for a plane hitting into it.

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And as I and others have said, the towers DID withstand the impact of the planes. It's not like the collapsed as soon as the plane hit, they stood for quite a while. Seems to me they did exactly what they were designed to do: not collapse on impact.

I'm actually logging out until exams are over... see you in about 2 weeks!

exam monday, i'll be back at a later date.

i wouldn't know how he died, but according the people in the government, he died 10 years ago, what do you have to say about that?

So...to summarise how this thread turned out: