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The towers did not fall at or below free fall speeds…

In every photo and every video, you can see columns far outpacing the collapse of the building. Not only are the columns falling faster than the building but they are also falling faster than the debris cloud which is ALSO falling faster than the building. This proves the buildings fell well below free fall speed. That is, unless the beams had a rocket pointed to the ground.

Just look at any video you like and watch the perimeter columns.

Deceptive videos stop the timer of the fall at 10:09 when only the perimeter column hits the ground and not the building itself. If you notice, the building just finishes disappearing behind the debris cloud which is still about 40 stories high.

Below is a more accurate graphic using a paper written by Dr. Frank Greening which can be found at: http://www.911myths.com/WTCREPORT.pdf

The paper takes the transfer of momentum into account. Like a billiard ball being hit by another on a pool table, each floor transferred its momentum to the next as represented below. The more weight, the less resistance each floor gave.

The time required to strip off a floor, according to Frank Greening, is a maximum of about 110 milliseconds = 0.110 seconds. It is rather the conservation of momentum that slowed the collapse together with a small additional time for the destruction of each floor.

Below are calculations from a physics blogger...

When I did the calculations, what I got for a thousand feet was about nine seconds- let's see,
d = 1/2at^2
t = (2d/a)^1/2
a is 9.8m/s^2 (acceleration of gravity at Earth's surface, according to Wikipedia), [He gives this reference so you can double check him.]
d is 417m (height of the World Trade Center towers, same source)
t = (834m/9.8m/s^2)^1/2 = 9.23s
OK, so how fast was it going? Easy enough,
v = at
v = (9.8m/s^2 x 9.23s) = 90.4m/s
So in the following second, it would have fallen about another hundred meters. That's almost a quarter of the height it already fell. And we haven't even made it to eleven seconds yet; it could have fallen more than twice its height in that additional four seconds.
If the top fell freely, in 13.23 seconds it would have fallen about two and one-half times as far as it actually did fall in that time. So the collapse was at much less than free-fall rates.

Let's see:
KE = 1/2mv^2
The mass of the towers was about 450 million kg, according to  this. Four sources, he has. I think that's pretty definitive. So now we can take the KE of the top floor, and divide by two- that will be the average of the top and bottom floors. Then we'll compare that to the KE of a floor in the middle, and if they're comparable, then we're good to go- take the KE of the top floor and divide by two and multiply by 110 stories. We'll also assume that the mass is evenly divided among the floors, and that they were loaded to perhaps half of their load rating of 100lbs/sqft. That would be
208ft x 208ft = 43,264sqft
50lbs/sqft * 43264sqft = 2,163,200lbs = 981,211kg
additional weight per floor. So the top floor would be
450,000,000 kg / 110 floors = 4,090,909 kg/floor
so the total mass would be
4,090,909 kg + 981,211 kg = 5,072,120 kg/floor
Now, the velocity at impact we figured above was
so our
KE = (5,072,120kg x (90.4m/s)^2)/2 = 20,725,088,521J
So, divide by 2 and we get
OK, now let's try a floor halfway up:
t = (2d/a)^1/2 = (417/9.8)^1/2 = 6.52s
v = at = 9.8*6.52 = 63.93m/s
KE = (mv^2)/2 = (5,072,120kg x (63.93m/s)^2)/2 = 10,363,863,011J
Hey, look at that! They're almost equal! That means we can just multiply that 10 billion Joules of energy by 110 floors and get the total, to a very good approximation. Let's see now, that's
110 floors * 10,362,544,260J (see, I'm being conservative, took the lower value)
= 1,139,879,868,600J
OK, now how much is 1.1 trillion joules in tons of TNT-equivalent? Let's see, now, a ton of TNT is 4,184,000,000J. So how many tons of TNT is 1,139,879,868,600J?
1,139,879,868,600J / 4,184,000,000J/t = 272t

Now, that's 272 tons of TNT, more or less; five hundred forty one-thousand-pound blockbuster bombs, more or less. That's over a quarter kiloton. We're talking about as much energy as a small nuclear weapon- and we've only calculated the kinetic energy of the falling building. We haven't added in the burning fuel, or the burning paper and cloth and wood and plastic, or the kinetic energy of impact of the plane (which, by the way, would have substantially turned to heat, and been put into the tower by the plane debris, that's another small nuclear weapon-equivalent) and we've got enough heat to melt the entire whole thing.

Remember, we haven't added the energy of four floors of burning wood, plastic, cloth and paper, at- let's be conservative, say half the weight is stuff like that and half is metal, so 25lbs/sqft? And then how about as much energy as the total collapse again, from the plane impact? And what about the energy from the burning fuel? You know, I'm betting we have a kiloton to play with here. I bet we have a twentieth of the energy that turned the entire city of Nagasaki into a flat burning plain with a hundred-foot hole surrounded by a mile of firestorm to work with.  -
Schneibster edited by Debunking 911

Let me make this clear, I don't assume to know what the ACTUAL fall time was. Anyone telling you they know is lying. The above calculation doesn't say that's the fall time. That was not its purpose. It's only a quick calculation which serves its purpose. To show that the buildings could have fallen within the time it did. It's absurd to suggest one can make simple calculations and know the exact fall time. You need a super computer with weeks of calculation to take into account the office debris, plumbing, ceiling tile etc.. etc... Was it 14 or was it 16? It doesn't matter to the point I'm making, which is the fall times are well within the possibility for normal collapse. Also, the collapse wasn't at free fall as conspiracy theorists suggest.

For more analysis of the building fall times, go to 911myths free fall page.

Please refer to Dr Frank Greening's paper for detailed calculations.


Italian debunker shows us more than 16 seconds to collapse. That's almost twice free fall speed from the 110th floor.


One of the more absurd arguments is the idea that there was a "Pyroclastic flow" during the collapse. This is easily debunked. You will note not one person was poached at ground zero. Pyroclastic flows are a minimum of 100C, or 212F.

The gas is usually at a temperature of 100-800 degrees Celsius. The flows normally hug the ground and travel downhill under gravity, their speed depending upon the gradient of the slope and the size of the flow.


Not ONE person, even the ones trapped INSIDE the towers, complained of dusty air burning their skin. Trees were left green next to the towers. Paper floated around ground zero without being burned.

When I brought this up to one conspiracy theorist, he produced some photos showing burning cars and such. Yet I easily found photos which show their photo was being taken out of context.

Are the cars, papers and trees in this photo made of asbestos except for the ones on fire? If you think there was a pyroclastic flow and photos of fires at ground zero is your proof then that's exactly what you must think.

It's obvious that the collapse rained paper on fire and even hot steel which could easily explain the spotty fires. Unless the pyroclastic flow hopped from one place to another.

Critical thinking skills will tell the average person there was NO pyroclastic flow but since this was brought up by a "scholar," thinking seems to be optional.

What really makes this argument absurd is the amount of explosives needed to turn that much concrete into dust. (We are only talking about 10% of the total concrete in the building anyway. There was a massive amount of gypsum as well, which conspiracy theorists would like you to forget.) The argument is the pyroclastic flow (which there is no evidence of) was created by explosives. (Some have suggested an absurd amount of thermite) If the incredible amount of POTENTIAL ENERGY (Energy the building had just standing there due to the stored energy of lifting the steel into place.) which converted to Kinetic energy (as it collapsed) is not enough to create the dust cloud, then the assumption is explosives must have created it. How much? And why would they overload the building with powerful explosives? Why put more than would be needed to cut the steel? Why put enough to cut the steel AND create a pyro show? As you can see above, the collapse released enough energy to equal 272 TONS of TNT. Why wouldn't this amount of energy be enough to cut the steel connections AND create some dust as the floors impacted each other 110 times per building?

More on the pulverization of concrete

Another absurd straw man is that they say Greening is saying the collapse weakened the steel. Nowhere in Greening's paper does it say the collapse "weakened" the steel. The massive potential energy converted to kinetic energy in the collapse and was MORE than enough to destroy the connections. No "weakening" of steel needed. The only weakening was on the fire floors which had its fireproofing blown off. This has NOTHING to do with Greening's paper.

Reader contribution:

Just a few numbers that make 9/11 conspiracies nearly impossible:

J.L. Hudson’s in Detroit, Michigan, the tallest building ever razed, was 439 ft. (26 stories)

WTC 7 was 570 ft. (47 stories) 1.3 times the height of the J.L. Hudson. http://en.wikipedia.org/wiki/7_World_Trade_Center

 WTC 1/2 was 1,368 ft. (110 stories) 3.12 times the height of J.L. Hudson.

So, on 9/11, three buildings were razed with perfect precision.  One was 131 ft. taller than the record tower and the other two (minus cell phone antennas) were 929 ft. taller than the record holder.

The Hudson Building “It took us 24 days with 12 people doing nothing but loading explosives…” James Santoro – Controlled Demolition Incorporated"

Even according to the Loose Change guys, the heightened security and bomb-sniffing dogs had only been lifted for 5 days.

Of course, the construction is different and the towers would need less explosives if they were the same height. However, the towers were much taller and had more columns to cut as a result. Even if they did have the same amount of columns it would still take over 72 days with 12 people doing nothing but loading explosives. That's just one building. Add the second tower and WTC7 and you see where this is going. It quickly becomes absurd. As if this absurdly complex plan was the ONLY way to scare Americans.

I'd like to thank Slugman from Political Myths blog for his contribution.


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