9/11 Pentagon Physics question

[grumby]

I received this link about the pentagon 9/11 tragedy. It takes a minute to D/L the flash file so be patient.
http://pixla.px.cz/pentagon.swf
Assuming that it is not complete spin and nonsense and the scenes depicted are true, is it possible for a 757 to do what is shown?
I am not a physicist and would like to hear some educated discussion about this. It seemed that a physics forum would be a good place to get some answers.
Does a 757 have enough mass, density/structural integrity and velocity to punch a clean hole like this?
Is it possible that the ensuing fire was hot enough to disintegrate the plane?

[Fernanda]

well, I guess we didn\'t land on the moon either then...

I don\'t think conspiracy theories are worth discussing in this forum, so if this thread heads that way then we\'ll close it.

regardign your question, it\'s easy for me...one plane, at high velocity (maybe even max vel.), two solid engines (the most solid part of a plane), and a hugely hollow body...

Remember the Blue Jet crash in the Everglades? there was nothing left! All that said there was a plane there might have been there was the swamp grass was gone.

The body is aluminum, that thoughvery strong, it\'s very thin. Withstanding flight is one thing, withistanding an impact with a building while exploding is another. You don\'t need something big to make an even bigger hole on the wall if there is enough momentum.

[Xerxes314]

The music and pretty pictures are cute and all, but these kinds of conspiracy theories should be reserved for alien encounters and moon landing hoaxes.

Xerxes

[Fernanda]

haha...

I gotta admit that the flash animation was good....:P

[grumby]

The author’s interpretation (spin) of the situation is what I assume you are regarding as \"conspiracy theories\". I am not asking if anyone believes if we were lied to, that\'s philosophy not physics. I guess I was hoping to see some basic math to support the pictures. Personally I think it was a plane, my curiosity wants to know how. The author’s interpretation in this instance is almost irrelevant. Except that\'s what sparked the question for me.... how?

[Xerxes314]

How what? It\'s sort of a limited case study. How many planes have ever crashed into buildings? You want to know what happens? That.

Xerxes

[partyk1d24]

As with the original poster of this topic I am not a career physisit and am just looking for insight. I too have been researching this subject and have tried to steer clear of propoganda sights and look at University reports. There was a report that was put out by Purdue that does a good job of explaining how there was little to no damage, the velocity of the plane disentigrated it on impact, however, the gas in the plane rushed forward and took out the building like a wave hitting a wall. This explanation has left me with a few questions,

1. Aren\'t the main fuel tanks in an airliner stored in the wings, so wouldn\'t that have mean that the damage should be the size of the wingspan if caused by fuel?

2. If this was the case wouldn\'t the windows in the building have been blown out due to the displacement of the aircraft?

Thanks again

[Edited on 11-19-2004 by partyk1d24]

[Fernanda]

depends on the angle of the airplane...

if it hit head on, horizontally, then maybe. But I would expect that the weakest part of the wing would be the joint to the body and the wings would snap back and fuel would begin to leak next to the body.

I\'m not an aerospace engineer though...so my plane knowledge.

[partyk1d24]

It hit horizontally to the ground and in the 3rd ring it left a nearly perfect hole. If the fuselage had disintegrated and the reliance was totally on the heavier items why wouldn\'t they have scattered like a shotgun? And another question, if the wing joints had given out wouldn\'t it have cause the plane to spin the plane and send the other wing into the ground?

Also does anyone know aren\'t there problems with flying that low? I mean the plane would have had to fly about 2ft off the ground for at least 50ft or so, wouldn\'t the ground have hindered air flow and slowed the speed of airl flowing underneath the wing?

Thanks guys and sorry if I sound like a moron conspiracy theorist this is the first one I have ever thought to have some warrent.

[lysdexia]

Structural material strengths are anisotropic. Look at the egg, arch, or copper bullet jacket. It can be hard enough to cause damage to other materials, yet be softened or scattered by heat. Have you heard of tornados that punch posts or splinters through trees, seen the airgun that shoots toothpicks through wood, or seen the 50s BIC pen commercial that used a high-powered rifle to shoot a ballpoint pen through wood? The missile survived in each. I think, due to nonlinear effects that the brief time for the missile to go through the material there wasn\'t enough time for the missile to deform but plenty of time for the material to deform, and by the time that the missile had made it through the material the open structure braced the missile so that it couldn\'t deform as it came to rest. Of course heat and entropy are glad to erase the evidence...

Stuff flies better when it\'s low to the ground, due to the ground effect providing a cushion. By fly better, I mean heightwise and not lengthwise, as there might be more turbulence and drag.