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June 21, 2007 4:31 PM PDT

Scientists reconstruct still-horrifying 9-11 images

by Greg Sandoval

A computer simulation of the attack on the World Trade Center is now showing at YouTube. While the images are designed to help engineers and scientists study how a large structure behaves when smashed into by an airliner, they are still horrifying.

Flight 11 crashed into the WTC's North Tower on Sept. 11, 2001. A team of researchers from Purdue University used scientific principles, state-of-the-art simulation code and animation computer system to recreate the three-quarters of a second following impact.

Click for gallery

Over and over again, wreckage from the Boeing 767 careens towards the viewer. Sometimes the simulation includes only the body of the aircraft. Other times, the plane is removed from the image so fuel or debris can be tracked.

At one point, the crash is played back and the focus is exclusively on the damage done to the tower's core beams, which are left sliced and twisted in the plane's wake.

The recreation culminates when all the elements: fire, fuel, debris and plane metal are added and the tragedy is depicted with bloodcurdling accuracy.

The simulation is no doubt a scientific marvel. But can anyone watch the scenes without their imaginations adding people to the pictures?

Greg Sandoval covers media and digital entertainment for CNET News. He is a former reporter for The Washington Post and the Los Angeles Times. E-mail Greg, or follow him on Twitter at http://twitter.com/sandoCNET.
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Well...
by o2mcgovem-20822100750713932708 June 21, 2007 7:10 PM PDT
Try and see the good in the situation, at least the horrid attacks are helping us to advance our engineering.

I know, it's actually quite hard to see the good in the situation. :(
Reply to this comment
Also see the hidden bad...
by DraconumPB June 22, 2007 5:40 AM PDT
...as a result, our foreign policy has gone horribly awry, and even domestic policy (every day there's a new story posted to BoingBoing about ridiculous TSA procedures or innocent people getting detained and ridiculued or treated like criminals or terrorists).

But I definately see your point.
Horrifying? Not so much.
by Axemaster June 21, 2007 7:43 PM PDT
From a purely engineering point of view, this is great. However, I
fail to see why this was posted online. The computer
programmers probably had plenty of fun doing this, but they
should have anticipated that the images would be viewed as
"horrifying".

Personally, I just cannot see what is so "horrifying". I certainly
didn't start imagining people in the simulation.

The press has such a bizarre take on things...



-Axemaster
Reply to this comment
WTC was evidence and it was melted down.
by inachu June 22, 2007 5:51 AM PDT
Scientists were not allowed to take samples but a few unknown scholars did take samples without informing that they were and they did find chemical residue that matches thermate.

How about that glowing picture of red hot steel 3 weeks later? nothing stays red hot that long unless thermate was being used.
Reply to this comment
It's a terrible thing when cousins marry.
by jjnitzh July 18, 2007 9:01 AM PDT
Please take chemistry, and maybe a physics course before you start spewing out something you saw in a video.

Thermate is a military variant of Thermite which is used mostly for on site welding of ironwork. It is essentially powdered aluminum and or magnesium mixed with powdered iron oxide (rust). Thermate adds barium nitrate (small boom to go with the burn) and sulfur (easier to light). You are going to find the same "residue" from that as burning an aluminum and magnesium airframe in a Kerosene (contains sulfur) fire in a steel box.

Now take a piece of coat hanger and bend it back and forth a few times. WOW you've put a couple thousandths of a Joule of work into the metal and it got hot. No realize that the TONS of weight some of which fell 1000 feet put MILLIONS!! of joules into that steel on top of the heat introduced by the impact of the plane plus the fire, which was still smoldering in the wreckage after the collapse. That is why it stayed hot for weeks. not to mention the stuff that was hot was underneath (insulated by) other debris that was being removed as pictures were being taken. How long something stays hot has NOTHING to do with HOW it was heated, only how much energy was put in and the rate at which it can give it off (Insulation, airflow).

How many imploded buildings do you see smoldering hot for weeks?? NONE. The ENERGY supplied by explosives is actually fairly small. The thing is that they supply it all at once, the the POWER (energy / time)is huge. That is why they use explosives for the job. It cuts the metal without heating the whole building up. The fact that the debris was hot is an indication that it was the massive amounts of burning fuel, not explosives that brought the towers down. Enough explosives to generate that amount of ENERGY would have had workers picking up rivets in New Jersey.

The towers came straight down because the central supports buckled. Think of a straw with a toothpick up the center. Most other skyscrapers are built like a stack of blocks. The WTC was different to give more floor plan flexibility and lighter weight. It's a stronger design, but more susceptible to damage.

The center of the building supported the weight and the curtain walls with the floor struts kept it from buckling. The outside walls didn't fail because they had cooling air on the outside. The center colums were sitting in essentially a 1300 deg furnace for half an hour. Not enough to melt them, but more than enough to destroy their load carrying ability.
The curtain wall that still had strength kept every thing lined up so that it fell nice and straight.

This is exactly the type of scenario that the people who implode buildings put a lot of work into creating. The architecture of the WTC is to blame NOT some nefarious government plot!

If you insist on being PO'd at someone how about the psycho-religious murdering wack jobs that crashed the planes!
A few unknown scholars...
by rivsys July 24, 2007 9:03 AM PDT
I had now idea it was possible for someone to actually survive the effects of such profound brain impairment...
Reconstruct all they want
by hyperborean11 June 22, 2007 9:27 AM PDT
Does it really matter if the fireproofing was stripped? The building collapsed at free fall speed into it's own footprint. Let's see perdue study the molten steel and thermate found at the collapse site. Scientists have to spend less time supporting anti-science (NIST) and start doing some real research.
Reply to this comment
I would like to know somethings
by aka_tripleB June 23, 2007 12:46 AM PDT
What is the most logical thing to happen if you fly a plane into a building? And after I find that out, I would then like an explanation of why it didn't?

I know what happened could be the most logical thing a plane would do, but we need to know why other things DIDN'T happen. Why didn't the plane stop mid-way through the building like a car does or a bullet through that gelitin stuff they use on "Mythbusters?" Why wouldn't the towers fall over instead of colapsing down on itself? Obviously, on side of the towers was weaker than the other, a whole plane went through one side while only some parts came out another.

What caused the fuel to ignite? I'm almost certain I know the answer to that one, but I'm want to make sure my reason is the most logical. Why would several people need to take box cutters on a plane? I'm sure before this happened, virtually no one tried bringing box cutters on a plane, so why wouldn't a person see this a something strange and ask a person what its doing with box cutters?

These are real questions I DO have, why shouldn't I or anyone else ask them? If we ever want to know what happened they will have to be answered. Before you start calling me insensitive, science is trying to destroy people's live every day by trying to prove: this is how Moses parted the Red Sea, these are the remains of Jesus, or "that" won't cure "this", but if we extract a perticular part of "that," we CAN cure "this." And we do need to answer everyone's questions so this doesn't become another: there had to be a second person on the grassy knoll, O.J. had to have done it, or Elvis isn't dead. (Ok the last one is a bad example but it's something people don't seem to have gotten closure for.)

Oh, and by the way, police still "haven't" found who killed Nicole or Ron.
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