[psikeyhackr (OP)]

Ohhh!
Sorry, excuse me. A bit of misunderstanding from my part. [:I]
But now I see. Now isn't that wierd? []
What kind of a plane was it? How many passengers were on it and how many people were in the building? Are we given this information?

.
The NIST report goes into considerable detail about the planes, pitch, yaw, angle of impact.  One plane had 5 ton of cargo and the other had 9.  I never focused on the number of people.  The total mass of the planes was less than 150 tons.  That included 10,000 gallons of fuel which was 34 tons.

But my point in this thread is the collapse.  I am taking for granted that the plane and fires could cause the collapse.  But could the top of the north tower destroy the rest?  I say it could not but accurate information on the distribution of steel and concrete is the minimum information needed to begin analyzing this so why weren't the EXPERTS demanding this SEVEN YEARS ago?

psik

[Chemistry4me]

I say it could not but accurate information on the distribution of steel and concrete is the minimum information needed to begin analyzing this so why weren't the EXPERTS demanding this SEVEN YEARS ago?

Well I'm afraid I cannot answer you on that one...
I do agree that this information should be given.

[wolfekeeper]

The problem with this theory is that skyscrapers are not stronger at the bottom than the top- they're *thicker* at the bottom, but then again they've got more weight on them, so they have to be.

So if the top collapses, and it falls and overloads the next bit down by 50%. That in turn falls and overloads the next bit down by 50% (because it picked up the next stories weight as well) and so on. At each and every point the overload percentage is the same, and so the whole thing fails together.

And that's because these buildings are designed to be equally stressed at every point, because that minimises the construction cost.

The kind of failure you saw at 9/11 is exactly what you would expect.

[psikeyhackr (OP)]

The problem with this theory is that skyscrapers are not stronger at the bottom than the top- they're *thicker* at the bottom, but then again they've got more weight on them, so they have to be.

The kind of failure you saw at 9/11 is exactly what you would expect.

How structural steel gets thicker without getting stronger is beyond my comprehension.  Considering that any skyscraper most support more weight toward the bottom to say it doesn't get stronger makes absolutely no sense.

But my toothpicks were not getting stronger toward the bottom but adding mass obviously reduced the number broken.  So the effect of conservation of momentum slowed the falling mass down reducing its kinetic energy and the amount of destruction.  So why didn't that happen at the WTC?  And why don't we have distribution of mass data on the towers?  It looks like that Danish scientist is explaining why the towers came down so fast.

And then there is the matter of all that collateral damage.  Tons of material hurled 600 feet to the Winter Garden.

psik

PS - There seems to be a BIG jump in the number of views.

[Chemistry4me]

PS - There seems to be a BIG jump in the number of views.

You mean this thread or your Youtube video?
Is that good [] or bad []?

[wolfekeeper]

The reason it's not stronger is because metal has a maximum stress it can survive.

Stress is force per unit area. The area of girder is greater at the base because there's more weight on it, so it needs to be- the engineers optimised (minimised) the amount of girder so that the stress is the same at the bottom as at the top; and then added a 'safety factor' on top; usually a factor of 2 or so.

You could potentially simulate this by using more toothpicks to support the lower, heavier parts.

But unfortunately this means that when the building begins to pancake the proportion of the weight it's designed to withstand is exceeded all the way down, by the same proportion- basically each floor is trying to catch all the floors above it moving downwards, but there's more and more weight moving downwards as the failure propagates.

It's possible to make a building that doesn't fail like this, but it would make the building several times more expensive to build, because each floor would have to survive several times the force than the WTC girders were designed for.

[psikeyhackr (OP)]

PS - There seems to be a BIG jump in the number of views.

You mean this thread or your Youtube video?
Is that good [] or bad []?

This thread.  It was in the low 200s then the next time I checked it was 330.

[Chemistry4me]

Hmmm...shows how popular wolfekeeper is. []

[psikeyhackr (OP)]

But unfortunately this means that when the building begins to pancake the proportion of the weight it's designed to withstand is exceeded all the way down, by the same proportion- basically each floor is trying to catch all the floors above it moving downwards, but there's more and more weight moving downwards as the failure propagates.

The sections of columns were 36 feet long.  So there were 38 sections from the top to the bottom of the towers.  Lighter columns that the top would be bending and joints getting out of alignment long before failure would occur at the bottom.

But in order for that to be happening MASS would have to be accelerated from the top.  As my demonstration shows, stationary mass would slow down the falling mass.  It could not come down in less than 18 seconds.  Something had to be taking out the columns.

psik

[Chemistry4me]

Is it official that the collapse took less than 18 seconds?

[psikeyhackr (OP)]

Is it official that the collapse took less than 18 seconds?

Mostly.

http://www.pbs.org/wgbh/nova/wtc/cons-flash.html

psik

[paul.fr]

Is it official that the collapse took less than 18 seconds?

Mostly.

So is that a Yes or a No?

[psikeyhackr (OP)]

Is it official that the collapse took less than 18 seconds?

Mostly.

So is that a Yes or a No?

It's a MOSTLY!

I provided a link with a spokesman from the NIST who talks about the times.

Of ourse people on JREF said he misspoke when I brought this up.

psik

[Chemistry4me]

Okay, if you say so.

[psikeyhackr (OP)]

Okay, if you say so.

Fun with JREFers.

http://forums.randi.org/showpost.php?p=4223153&postcount=91

psik

[psikeyhackr (OP)]

Of course the distribution of mass is also related to analyzing the impacts.

The NIST says the south tower moved 12 inches at the 70th floor even though that was 130 feet below the impact point.  How much energy the building absorbed without doing structural damage would be necessary to know in order to figure out how much energy DID do damage.  Distribution of mass would be necessary for that analysis.

psik

[L_D]

Is it official that the collapse took less than 18 seconds?

Yes, according to the 9/11 commission report they fell in 10 seconds. 10 seconds is unrealistically fast looking at the video footage and the true collapse times would more likely be 14 to 16 seconds.

WRT Conservation of Momentum and the collapse of the Towers, if you could remove all the columns and just have the floors magically hovering until they were impacted then the mass alone of the hovering floors would still slow the collapsing mass more than what happened on 9/11. I guess a similar point is being made in the opening post of this thread.

That's even without considering any losses from the system, like the very significant energy needed to pulverise all the concrete which must slow the descent, and the huge amounts of mass that is billowing outwards and therefore cannot assist in collapsing the lower portion because it is falling outside of the collapse.

I think the Towers were brought down by explosives as was the third highrise to fall that day, WTC 7. Please have a look at this short video of WTC 7 collapsing if you are not familiar with it:

If you want to have a look at what is happening under the dust clouds when the Towers collapse then this clip has a very good angle, and it also explains how the Towers fell so quick (because they were blown to smitherines)...

psikeyhackr, I hope to have a good look at your video when I get back from a short holiday.

[Chemistry4me]

So are you and psikeyhackr on the same page here about this WTC business? Except you seem to have a theory that they were blown up! Or is that just my misunderstanding? []

[dentstudent]

What we have are either trollers or conspiracy theorists, neither of which stand up to scrutiny nor have a place on a scientific thread (IMHO).

[L_D]

So are you and psikeyhackr on the same page here about this WTC business? Except you seem to have a theory that they were blown up! Or is that just my misunderstanding? []

That's correct, there are millions around the world who, based on the evidence, think the same.

Here are also over 600 architects and engineers who are publicly saying the same thing (if you look on the right hand side of the page you will see the main reasons)..

http://www.ae911truth.org/