No Planes Theories on 9/11

polishpaddy

Fact of the matter is, none of these claims are yours, are they?
Someone else made them up for you.

6th

polishpaddy, if you are addressing me then you can Pm me to keep this on topic. In the Pm could you include links to the claims I made.

polishpaddy

I'm addressing anyone thats reading this.

6th

Ok well then if you want to discuss the topic of this thread then fine but any off topic posts will be deleted etc. Read the chater and start a new topic if you like.

feoil

King Mob wrote: »

]


Actually that's not quite true.
Can you show one example of a similar size building in comparable circumstances that didn't collapse?

http://www.debunking911.com/firsttime.htm

Maybe you look it the discussions here before shooting off the same tired debunked arguments.

Empire State Building, July28, 1945

Of course Skyscrapers never catch fire, or rather they don't collapse when they do, in spite of combustible materials.

http://www.iklimnet.com/hotelfires/interstatebank.html

http://web.archive.org/web/20040216014121/http://www.sgh.com/expertise/hazardsconsulting/meridian/meridian.html

http://www.cbsnews.com/stories/2004/10/18/world/main649824.html

http://news.bbc.co.uk/2/hi/europe/4263667.stm
http://news.bbc.co.uk/2/hi/in_pictures/4262509.stm

The simple fact is that in over a century of steel frame building, only three buildings have ever collapsed due to fire damage, so what are the odds that these three fell in the same location within hours of each other?, astronomical.

polishpaddy

Thats cool.

What evidence do you have that planes hit the towers?
What evidence do you have that planes did not hit the towers?
Do i need to define evidence? The burden of proof is yours.

King Mob

feoil wrote: »

Empire State Building, July28, 1945

Of course Skyscrapers never catch fire, or rather they don't collapse when they do, in spite of combustible materials.

http://www.iklimnet.com/hotelfires/interstatebank.html

http://web.archive.org/web/20040216014121/http://www.sgh.com/expertise/hazardsconsulting/meridian/meridian.html

http://www.cbsnews.com/stories/2004/10/18/world/main649824.html

http://news.bbc.co.uk/2/hi/europe/4263667.stm
http://news.bbc.co.uk/2/hi/in_pictures/4262509.stm

The simple fact is that in over a century of steel frame building, only three buildings have ever collapsed due to fire damage, so what are the odds that these three fell in the same location within hours of each other?, astronomical.

And how many of these examples had similar construction and were in similar circumstances?

Answer: 0

And how many times this century have jetliners been flown into buildings at high speed?

I'd say the odds of buildings heavily damaged by this collapsing are a lot less than "astronomical".

Penn

feoil wrote: »

Empire State Building, July28, 1945

Of course Skyscrapers never catch fire, or rather they don't collapse when they do, in spite of combustible materials.

http://www.iklimnet.com/hotelfires/interstatebank.html

http://web.archive.org/web/20040216014121/http://www.sgh.com/expertise/hazardsconsulting/meridian/meridian.html

http://www.cbsnews.com/stories/2004/10/18/world/main649824.html

http://news.bbc.co.uk/2/hi/europe/4263667.stm
http://news.bbc.co.uk/2/hi/in_pictures/4262509.stm

The simple fact is that in over a century of steel frame building, only three buildings have ever collapsed due to fire damage, so what are the odds that these three fell in the same location within hours of each other?, astronomical.

The steel in steel frame buildings is coated in fireproofing materials in order to prevent the fire from weakening the steel for a few hours (depending on size of building, occupancy loading, structural importance etc). This gives the people in the building time to escape and for the fire departments to try and extinguish the fires. But this only works if the fireproofing remains intact. The impact of the planes would have not only damaged the fireproofing on the steel, but would also have significantly damaged some of the structural steel members. If a few of the steel beams and columns were knocked out of place, this places additional weight and forces on the other beams and columns, which were not designed to carry such loads.

IIRC, steel melts at 2000 degrees. Jet fuel burns at 800 degrees. But steel begins to lose its strength at 600 degrees. Even if just a small section of a beam was exposed to those temperatures, the whole beam loses it structural intergrity, thereby forcing other beams to take the load.

Added to this the fact that he maximum takeoff weight for a Boeing 767 is 395,000 pounds. Again, the building would not have been designed to carry such a load, escpecially as it would have been located on weakened steel members.


And the twin towers were not the only steel frame buildings to collapse because of fire. There have been other, smaller buildings which have, although they weren't hit by planes like the Twin Towers or have 2 skyscrapers collapse next to them, nor the structural design flaw like WTC7.

bonkey

feoil wrote: »

The simple fact is that in over a century of steel frame building, only three buildings have ever collapsed due to fire damage, so what are the odds that these three fell in the same location within hours of each other?, astronomical.

Were that accurate, it would indeed be an astronomical assertion.

Lets look at it though.

Firstly - the attributed causes of collapse for the three buildings you mention:

WTC1: Collapsed due to a combination of structural damage from an airliner crashing into it at speed and the resulting fire.
WTC2: Collapsed due to a combination of structural damage from an airliner crashing into it at speed and the resulting fire.
WTC7: Collapsed due to fire and a previously-unidentified design-weakness which made it susceptible to fire.

So of the three buildings, only one is actually even claimed to have collapsed "due to fire", and even then its due to an identified design flaw which would explain why its not something we see in buildings which don't share this flaw.

The other part of your claim - that these are the only steel-frame buildings to collapse due to fire - is also incorrect.

The Kader Toy Factory, The McCormick Center in Chicago and the Sight and Sound Theater in Pennsylvania are all examples of steel-frame buildings which collapsed due to fire.

There are "hybrid" designs - such as the Windsor Tower in Madrid - where the steel-support part of the structure has failed due to fire, but the reinforced concrete part has stood.

There are literally no end of examples of partial collapse to show that steel can fail in fire - something which should be evidence in the first place from teh simple fact that it is required to be protected with fireproofing.

So lets be accurate here...

There are twpo examples of steel-supported high-rise buildings being severely damaged in the upper third of the structure from impact by high-=speed, mid-size commercial aircraft. In both cases, the buildings behaved similiarly.

There is one example in all of history of a steel-supported high-rise building with the design flaw which WTC7 had suffering from a significant fire capable of exposing said flaw. As there are no other examples, there is nothing to compare to.

There are plenty of examples of steel failing from fire, so the basic physics which led to the collapse in all three cases is not something new.

So...what, exactly, is astronomical here?

murphaph

Bonkey,
I haven't heard about the inherent flaw in WTC7. Could you elaborate a little on that?

Does anyone think the investigation into 9/11 itself was of an acceptable standard? This was one of the world's largest crime scenes yet the evidence (the steel) was hurriedly melted down and not analysed thoroughly IMO.

Weren't buildings 3 and 4 also much more heavily showered with raining debris from WTC1 and 2 than building 7, yet 3 and 4 stood, albeit just their steel frames, pretty much everything else in them was destroyed.

Can anyone clarify this for me: I know the architects and engineers did in fact envisage an attack with at least a single laden Boeing 707 (a smaller jetliner) but did they design it to with stand multiple strikes with such an aircraft?

I actually find it hard to believe an aircraft travelling at app. 200~250mph would entirely penetrate the steel walls of the WTC (I was in and on top of tower 2, I remember how thick the outer columns were). Boeing aircraft engines have a safety bolt arrangement which shears off if the engines are pulled with enough force from the wings. The recent downed Airbus in the Hudson had similar bolts and in that crash the engines were ripped from the wings (as they are designed to do) by water. In the WTC incident they remained affixed to the wings which are made (like the rest of the plane) from lightweight aluminium yet even the skinny wingtips sliced through steel. This for me is simply unbelievable.

Ex boeing engineers have said that this is very difficult to believe. Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

Penn

murphaph wrote: »

Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

No it isnt. Thats not the same thing at all. Compare it to a bullet and a piece of wood. You fire a bullet at a piece of wood, it will penetrate the wood. Fire a piece of wood at a stationary bullet and the bullet will go flying through the air.

And I'm not sure but I think the plane was travelling faster than that, around 420mph. I'm not sure about that though.

Diogenes

murphaph wrote: »

Bonkey,
I haven't heard about the inherent flaw in WTC7. Could you elaborate a little on that?

The building was built with much of the load bearing weight carried about a single massive column. In addition it was built over a Con-Ed power station and NY underground station.

murphmphah wrote:

Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

Apparently someone was asleep during junior cert physics.

Momentum = mass • velocity

How about those road safety ads? "Hit me at 20mph and I'll live, at 30mph I'll die"

Mass is effected by velocity.

6th

Diogenes wrote: »

Apparently someone was asleep during junior cert physics.

Think about it for a second Diogenes.


Thats right, attack the post not the poster.

Diogenes

murphaph wrote: »

Bonkey,
I haven't heard about the inherent flaw in WTC7. Could you elaborate a little on that?

Does anyone think the investigation into 9/11 itself was of an acceptable standard? This was one of the world's largest crime scenes yet the evidence (the steel) was hurriedly melted down and not analysed thoroughly IMO.

The NIST investigation into the collapse of building 7 only concluded last year, thats hardly rushed.

Weren't buildings 3 and 4 also much more heavily showered with raining debris from WTC1 and 2 than building 7, yet 3 and 4 stood, albeit just their steel frames, pretty much everything else in them was destroyed.

None of those buildings would exactly be described as standing.

Can anyone clarify this for me: I know the architects and engineers did in fact envisage an attack with at least a single laden Boeing 707 (a smaller jetliner) but did they design it to with stand multiple strikes with such an aircraft?

No. They didn't.

They worked out whether a slow moving fog bound 707 low on fuel would do if it impacted the towers. But they worked off the assumption no one would aim to destroy them.

I actually find it hard to believe an aircraft travelling at app. 200~250mph would entirely penetrate the steel walls of the WTC (I was in and on top of tower 2, I remember how thick the outer columns were). Boeing aircraft engines have a safety bolt arrangement which shears off if the engines are pulled with enough force from the wings. The recent downed Airbus in the Hudson had similar bolts and in that crash the engines were ripped from the wings (as they are designed to do) by water. In the WTC incident they remained affixed to the wings which are made (like the rest of the plane) from lightweight aluminium yet even the skinny wingtips sliced through steel. This for me is simply unbelievable.

Ex boeing engineers have said that this is very difficult to believe. Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

Again to reiterate paddys point, if someone threw a bullet at you, you'd hardly credit it with the ability to pierce skin, beyond perhaps a minor abrasion.

meglome

murphaph wrote: »

Does anyone think the investigation into 9/11 itself was of an acceptable standard? This was one of the world's largest crime scenes yet the evidence (the steel) was hurriedly melted down and not analysed thoroughly IMO.

This is constantly raised as an issue. Firstly we need to establish what the standard or normal amount of material that would be kept in a situation like is. So in how many building collapses was all the material kept? In how many of these cases was the cause obvious, i.e. a big plane slammed into the building? There's only an issue here is we assume conspiracy otherwise it's about what you can expect. And remember this isn't a plane crash where you put the plane into a hanger, this was two 100 story buildings and a 40 story building.

They sold the steel as scrap to the Chinese so if it was hurriedly melted down it had nothing to do with the US.

murphaph wrote: »

Weren't buildings 3 and 4 also much more heavily showered with raining debris from WTC1 and 2 than building 7, yet 3 and 4 stood, albeit just their steel frames, pretty much everything else in them was destroyed.

Buildings around were badly damaged but they also didn't have the same design as WTC 1,2 and 7. Nor were they hit by a plane and/or left burning.

murphaph wrote: »

Can anyone clarify this for me: I know the architects and engineers did in fact envisage an attack with at least a single laden Boeing 707 (a smaller jetliner) but did they design it to with stand multiple strikes with such an aircraft?

Nope no evidence of that. It was all about an accidental crash. So the plane was smaller, there's no evidence they accounted for fuel and they didn't think the plane would be doing around 500mph.

murphaph wrote: »

I actually find it hard to believe an aircraft travelling at app. 200~250mph would entirely penetrate the steel walls of the WTC (I was in and on top of tower 2, I remember how thick the outer columns were). Boeing aircraft engines have a safety bolt arrangement which shears off if the engines are pulled with enough force from the wings. The recent downed Airbus in the Hudson had similar bolts and in that crash the engines were ripped from the wings (as they are designed to do) by water. In the WTC incident they remained affixed to the wings which are made (like the rest of the plane) from lightweight aluminium yet even the skinny wingtips sliced through steel. This for me is simply unbelievable.

Well it think it was near 500mph. If we could compare the WTC collapses to another event then we'd all be able to see what could/should happen. However there is no comparable event so the idea that this shouldn't happen is not based on any fact. We also know that steel framed buildings have collapsed in the past so this would lend credibility to the official account being true.

Not really sure why you're comparing an Airbus landing at under 100mph on the water to a Boeing ploughing into a building at 500mph. I agree that apples are not like oranges.

murphaph wrote: »

Ex boeing engineers have said that this is very difficult to believe. Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

And yet the people that engineered the buildings have no problem believing it.

King Mob

murphaph wrote: »

I actually find it hard to believe an aircraft travelling at app. 200~250mph would entirely penetrate the steel walls of the WTC (I was in and on top of tower 2, I remember how thick the outer columns were). Boeing aircraft engines have a safety bolt arrangement which shears off if the engines are pulled with enough force from the wings. The recent downed Airbus in the Hudson had similar bolts and in that crash the engines were ripped from the wings (as they are designed to do) by water. In the WTC incident they remained affixed to the wings which are made (like the rest of the plane) from lightweight aluminium yet even the skinny wingtips sliced through steel. This for me is simply unbelievable.

That's not quite true. The walls ot WTC weren't just thick slabs of steel.
And Beoing and Airbus are completely different manufacturing companies.
And there's a huge difference in an emergency landing in water and using a plane as a missile.
So if a plane's wing couldn't have "sliced through the walls" how exactly did they make holes in the side of the building consistent with the plane that hit it? All while millions of people were looking at the hole?

murphaph wrote: »

Ex boeing engineers have said that this is very difficult to believe. Slamming a 100 tonne aircraft into a 500,000 tonne building at app. 250 mph is physically identical to slamming a 500,000 tonne building into a stationary plane at the same speed. Do you think the steel would completely give way or the aluminium plane would be flattened in the latter action?

It's not the identical at all.
The planes momentum played a huge part in the damage.

bonkey

murphaph wrote: »

Bonkey,
I haven't heard about the inherent flaw in WTC7. Could you elaborate a little on that?

To quote briefly from NIST:

while the partial or total collapse of a tall building due to fires is a rare event, we strongly urge building owners, operators and designers to evaluate buildings to ensure the adequate fire performance of the structural system. Of particular concern are the effects of thermal expansion in buildings with one or more of the following features: long-span floor systems, connections not designed for thermal effects, asymmetric floor framing and/or composite floor systems.” Engineers, the team said, should be able to design cost-effective fixes to address any areas of concern identified by such evaluations

WTC7 "suffered" from a combination of all of these features.

In laymans terms, the fire caused expansion of horizontal steel supports. These were long enough that the thermal expansion essentially broke the connections by which these supports were anchored. This caused failure of a critical, load-bearing horizontal support...which in turn led to the collapse.

NIST went so far as to say that they believe that none of the damage suffered from falling debris was critical in the collapse, other than that it is what started the fires.

Does anyone think the investigation into 9/11 itself was of an acceptable standard? This was one of the world's largest crime scenes yet the evidence (the steel) was hurriedly melted down and not analysed thoroughly IMO.

It depends what you mean by "hurredly". The materials were removed both as part of the rescue operation which lasted for something like the first 17 days (going from memory), and then as part of the cleanup operation. At all times, the material being removed was guarded, and the vehicles transporting it offsite were tracked using GPS to ensure nothing untoward happened. It was then stored until such times as the investigators said that they had what samples they wanted and needed.

The NIST investigation of WTC7 is a bit of an exception, because it was only requested after the original investigation (led by FEMA) concluded that it couldn't satisfactorily explain things. It is possible that NIST would have wanted more samples then they had, but the same is true of any investigation. Rescue operations generally (always?) take precedence. Then the crime-scene is analysed, until such times as the investigators say they are satisfied. If further investigations are required, they are limited to what evidence was collected originaly.

Weren't buildings 3 and 4 also much more heavily showered with raining debris from WTC1 and 2 than building 7, yet 3 and 4 stood, albeit just their steel frames, pretty much everything else in them was destroyed.

Yes, it isn't claimed that WTC7 collapsed from the damage of falling debris, but rather from the effects of the fires that were started as a result.

Can anyone clarify this for me: I know the architects and engineers did in fact envisage an attack with at least a single laden Boeing 707 (a smaller jetliner) but did they design it to with stand multiple strikes with such an aircraft?

Not entirely true. The architects and engineers envisaged a plane crashing into the building in a manner similar to what happened to the ESB - a slow-travelling plane, lost in fog, impacing the building. As it happens, WTC1 and 2 did withstand a plane crashing into them. What they didn't withstand was the cumulative effect of the ensuing fire on top of the damage.

Given that the modelling techniques for the effects of fire on buildings didn't exist when WTC1 and 2 were designed, nor was the computing power available to run such models, its a reasonably safe bet to say that the towers were not explicitly designed for this.

AFAIK, the people you refer to have confirmed this, and even gone on to say that the behaviour of the towers was better than they expected (in terms of how long they stood, and thus how many people could be safely evacuated).

I actually find it hard to believe an aircraft travelling at app. 200~250mph would entirely penetrate the steel walls of the WTC (I was in and on top of tower 2, I remember how thick the outer columns were).

I find it hard to believe someone would do it in the first place...but its not about what you or I believe. Its about whether or not its possible.

Have a look here for details of how the perimiter columns were constructed. At the top of the tower, the columns were effectively hollow "boxes" with 1/4" steel on each face.

Personally, I don't find it hard to believe that an aircraft travelling at upwards of 500mph could penetrate 2 1/4" steel faces. I'd rather say the opposite...that I'd be amazed if that amount of mass could be stopped by so little.

murphaph

paddyirishman85 wrote: »

No it isnt. Thats not the same thing at all. Compare it to a bullet and a piece of wood. You fire a bullet at a piece of wood, it will penetrate the wood. Fire a piece of wood at a stationary bullet and the bullet will go flying through the air..

Your wrong Paddy. Newton's Third Law of Motion says so. In physics, there is no difference between the force exerted on the bulding by the plane and the force exerted by plane on the building so the same result would occur if you just propelled the 500,000 tonne builng into the 100 odd tonne plane. You seem surprised by that? Do you not think the same outcome would occur if you propelled the building into the plane as the plane into the building? Do you think if the building were propelled at 250mph into the plane that the aluminium bodied plane would entirely penerate the outer skin of structural steel?

(in your example if it were possible to propel your piece of wood at the speed of a bullet and hit a stationary bullet the same damage to bullet and timber would occur. It's jut hard to picture it because it's practically impossible to do it, but it would.)

paddyirishman85 wrote: »

And I'm not sure but I think the plane was travelling faster than that, around 420mph. I'm not sure about that though.

Airliners cruise at those sorts of speeds where the air is thin and consequently drag is low. They are unable to fly at such speeds near to the ground. The wings would be torn off at 420mph.

King Mob

murphaph wrote: »

Your wrong Paddy. Newton's Third Law of Motion says so. In physics, there is no difference between the force exerted on the bulding by the plane and the force exerted by plane on the building so the same result would occur if you just propelled the 500,000 tonne builng into the 100 odd tonne plane.

No, that's not how it works.
You're completely ignoring momentum and inertia. Basically you're ignoring Newton's First and Second Laws.

murphaph wrote: »

You seem surprised by that? Do you not think the same outcome would occur if you propelled the building into the plane as the plane into the building? Do you think if the building were propelled at 250mph into the plane that the aluminium bodied plane would entirely penerate the outer skin of structural steel?

Yes it would (at the speed it actually went not the speed you're claiming here). The sides of the WTC weren't solid steel.

murphaph wrote: »

(in your example if it were possible to propel your piece of wood at the speed of a bullet and hit a stationary bullet the same damage to bullet and timber would occur. It's jut hard to picture it because it's practically impossible to do it, but it would.)

Yes it would if the bullet was held in place by a force equal to the momentum it would have if it was traveling.

murphaph wrote: »

Airliners cruise at those sorts of speeds where the air is thin and consequently drag is low. They are unable to fly at such speeds near to the ground. The wings would be torn off at 420mph.

You gonna back that up with something?
Or back up the speed you keep quoting?

Penn

murphaph wrote: »

Your wrong Paddy. Newton's Third Law of Motion says so. In physics, there is no difference between the force exerted on the bulding by the plane and the force exerted by plane on the building so the same result would occur if you just propelled the 500,000 tonne builng into the 100 odd tonne plane. You seem surprised by that? Do you not think the same outcome would occur if you propelled the building into the plane as the plane into the building? Do you think if the building were propelled at 250mph into the plane that the aluminium bodied plane would entirely penerate the outer skin of structural steel?

(in your example if it were possible to propel your piece of wood at the speed of a bullet and hit a stationary bullet the same damage to bullet and timber would occur. It's jut hard to picture it because it's practically impossible to do it, but it would.)

There is a difference. You are not taking into account resistance and momentum. A man tries to push a wall, the force he applies to it is not enough to move it, so his feet start to slide out and he is essentially pushing himself backwards. A wall moves with the same force at a man, he does not have the strength or resistance to stop it, so he is pushed back.

Fire a bullet at a tree, and it penetrates the tree. Fire a tree at a bullet which is standing still, even hypothetically floating in the air, and the tree will move the bullet. Unless the bullet is fixed somehow so it will under no circumstances move, only then will penetrate the tree.

Again, baseball and bat. Baseball travelling at 40mph hits a bat being held by a player who is standing still, bat goes backwards a little bit and the ball falls to the ground. Bat hits stationary baseball with the same force, home run.

Airliners cruise at those sorts of speeds where the air is thin and consequently drag is low. They are unable to fly at such speeds near to the ground. The wings would be torn off at 420mph.

As I said, I wasn't sure. Although you have to remember that the plane wasn't cruising. It was being flown towards the building as fast as it could in order to inflict the most damage possible. But I'm no expert in this field so I rest my case.

Diogenes

murphaph wrote: »

Your wrong Paddy. Newton's Third Law of Motion says so. In physics, there is no difference between the force exerted on the bulding by the plane and the force exerted by plane on the building so the same result would occur if you just propelled the 500,000 tonne builng into the 100 odd tonne plane. You seem surprised by that? Do you not think the same outcome would occur if you propelled the building into the plane as the plane into the building? Do you think if the building were propelled at 250mph into the plane that the aluminium bodied plane would entirely penerate the outer skin of structural steel?

Theres a difference between motion and velocity, Newton explained that.

Airliners cruise at those sorts of speeds where the air is thin and consequently drag is low. They are unable to fly at such speeds near to the ground. The wings would be torn off at 420mph.

Do I need to drag out the youtube video of low flying high speed passes by passenger jets at airshows again?

bonkey

Lads - neither Newton's second nor third laws will give you all the information you need here.

Newton's second law explains why a building travelling at 500mph has a completely different momentum to a plane travelling at 500mph.

Newton's third law explains why the impact will transfer energy "equally" - that one object will lose the same amount of energy that the other gains.

Neither of these tell us what the effect of that energy-transfer will be. Personally, I would absolutely expect the building to suffer the same damage if it was the one travelling and the plane was stationary.

Airliners cruise at those sorts of speeds where the air is thin and consequently drag is low. They are unable to fly at such speeds near to the ground. The wings would be torn off at 420mph.

NIST put the impact speed at 443mph for WTC1 and 546mph for WTC2.

Are you suggesting that you (or someone else) can show or has shown that these speeds are impossible?

bonkey

Incidentally, I got those speeds from this pdf on NIST's site

Its worth a look, because it also shows the damage to the walls in clear detail...including that the wings did not cut through the outer columns all the way to the wingtips, as was suggested in an earlier post.

King Mob

bonkey wrote: »

Lads - neither Newton's second nor third laws will give you all the information you need here.

Newton's second law explains why a building travelling at 500mph has a completely different momentum to a plane travelling at 500mph.

Newton's third law explains why the impact will transfer energy "equally" - that one object will lose the same amount of energy that the other gains.

Neither of these tell us what the effect of that energy-transfer will be. Personally, I would absolutely expect the building to suffer the same damage if it was the one travelling and the plane was stationary.

Not exactly bonkey. A completely stationary plane would just bounce off a building traveling at 500 mph.
It would need a force operating on it equal to the momentum it would have if the plane was traveling.
And the building would need to be traveling at a constant speed so it's acceleration would equal zero.

bonkey

Duh me...you're right. The forces (momentums) involved are completely different.

Penn

King Mob wrote: »

Not exactly bonkey. A completely stationary plane would just bounce off a building traveling at 500 mph.
It would need a force operating on it equal to the momentum it would have if the plane was traveling.
And the building would need to be traveling at a constant speed so it's acceleration would equal zero.

I was thinking the same thing, just had trouble trying to word it.

King Mob

And my mother said my degree would never be useful.

bonkey

Actually...I've been thinking more about this, and I'm not sure I agree.

Momentum is calculated based on velocity. Velocity, however, is relative.

Take two situations:

A stationary spacecraft hit by a meteorite travelling at 10 km/sec

and

A spacecraft travelling at 10km/sec hitting a stationary meteorite.

From a relativistic point of view, both of these are the same event. What is stationary and what is in motion is relative to the observer, but doesn't effect the event. Fom the perspective of someone sitting in the spacecraft, there is - in both cases - a meteorite approaching at 10km/sec. From the perspective of someone sitting on said meteorite, there is - in both cases - a spaceship approaching at 10km/sec. In both cases, the meteorite and spaceship should behave identically. How they behave relative to the rest of the universe may be different, but their effect on each other should be the same.

Similarly, if throwing a stone at a window will break the window at 5m/sec, but not at 4.999m/sec, then hitting the stone by swinging the window at it should break the window at 5m/sec, but not at 4.999m/sec (ignoring effects such as wind resistance etc.)

So, I go back to my previous position. Hitting an stationary aircraft with a building moving at 500mph will do exactly the same damage to the building as hitting a stationary building with an aircraft moving at 500mph will do. After all, from the perspective of the (doomed) passengers on that flight, this is exactly what happened.

feoil

Bonkey,
First let me thank you for your excellent posts.

I do, however feel your examples of structural failure of steel frame buildings due to fire aren't particularly helpful in trying to understand the failure of the WT buildings. You cited the Kader Industrial toy factory in Bangkok, two points about this building. Firstly, this building was a mere four stories tall, secondly, it was hardly built to US construction standards. In fact one report by Peter Symonds claims that it wasn't even built to Thai standards. A fact convieneintly omitted by Mark Roberts in his attempt to debunk 9/11 conspiracies. The other two buildings you cite, The McCormick Center in Chicago and the Sight and Sound Theater in Pennsylvania, were both one story buildings, barns compared to the WT buildings.
Further investigation into these three events also show inadequate fire suppression systems. The Kader factory had none, while the Sight and Sound theater has it's turned off while those of the McCormick centre were reduced. Also both the Kader factory and the McCormick building were aparently packed with flammable material at the time of the fires.
Some links for your perusal.
http://www.wsws.org/articles/2003/may2003/kade-m16.html
http://en.wikipedia.org/wiki/McCormick_Place
http://www.interfire.org/res_file/pdf/Tr-097.pdf

I quote you, "There are literally no end of examples of partial collapse to show that steel can fail in fire - something which should be evidence in the first place from teh simple fact that it is required to be protected with fireproofing." The key word here is partial, not the complete collapse witnessed on 9/11.
When one considers the points of impact of the two planes, would it not be reasonable to expect that the portion of building above the impact site would topple to the side rather than force the collapse of the levels underneath?.

King Mob

bonkey wrote: »

Actually...I've been thinking more about this, and I'm not sure I agree.

Momentum is calculated based on velocity. Velocity, however, is relative.

Take two situations:

A stationary spacecraft hit by a meteorite travelling at 10 km/sec

and

A spacecraft travelling at 10km/sec hitting a stationary meteorite.

From a relativistic point of view, both of these are the same event. What is stationary and what is in motion is relative to the observer, but doesn't effect the event. Fom the perspective of someone sitting in the spacecraft, there is - in both cases - a meteorite approaching at 10km/sec. From the perspective of someone sitting on said meteorite, there is - in both cases - a spaceship approaching at 10km/sec. In both cases, the meteorite and spaceship should behave identically. How they behave relative to the rest of the universe may be different, but their effect on each other should be the same.

Similarly, if throwing a stone at a window will break the window at 5m/sec, but not at 4.999m/sec, then hitting the stone by swinging the window at it should break the window at 5m/sec, but not at 4.999m/sec (ignoring effects such as wind resistance etc.)

So, I go back to my previous position. Hitting an stationary aircraft with a building moving at 500mph will do exactly the same damage to the building as hitting a stationary building with an aircraft moving at 500mph will do. After all, from the perspective of the (doomed) passengers on that flight, this is exactly what happened.

I hate to disagree with you Bonkey.
We can assume the the reference frame is Earth and that the building is a zero velocity and zero acceleration.

The plane is traveling at 540mph (or whatever) and is being accelerated by it's engines at whatever value in the direction of the building.

When it hits the building it experiences an acceleration in the opposite direction due to resistance form the structure.

Now we can see that the force of the plane was enough to overcome the structural integrity of certain parts of the building. This slows the plane down but it continues on. So eventually the plane isn't going fast enough and doesn't have the force to overcome the strength of the structure and stops.

Now it the case of the building slamming into the plane. The plane is zero velocity and acceleration. We will also assume that building has zero acceleration (as it has no jet engines) thus in traveling at a constant velocity.

When the building strikes the plane, the strength of it's structure imparts an acceleration in the direction the building is traveling in. Thus the plane (or pieces of) are now traveling in the same direction as the building.

There would be a little damage from the mass of the plane. But it would be much less than it would be if the plane was accelerating.

Also consider that a building traveling at the same speed as a jet plane would have a much much larger force due to the fact it is so much bigger.
Not sure if that makes it any clearer.