This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
Look at the numbers. I saw a video the other day showing "free fall". They used video from the event to find out how long free fall was.
Let's see, free fall from 1400 ft would mean a free fall time of < 10 second. Both "Free falls" lasted longer that 15 seconds.
They didn't fall into their "foot print", they just didn't topple, debris was blowing out the sides. The collapse was anything but controlled.
Grist is right. There are a lot of numbers involved. The conspiracists though fail to ever look at any that don't support their cause. They suffer from the same failure that many scientists (epidemiologists in specific) like to demonstrate. Focussing on that which is interesting and ignoring all the data that defies it.
To often science is presented as proving the hypothesis. The reality is that science is the failure to disprove the hypothesis.
Forgive me for restating the obvious. I have found, though, that the obvious is rarely as obvious as it seems and we should all be ready to restate it regulary, no matter how silly.
wow, someones actually discussing the numbers.
Where did you get 15sec from?
In the past, I often found non-collapse theorys use the bottom of the explosion cloud as their start, and the top of the cloud as their end point for collapse.
The cloud cannot be used this way for timing the collapse because it is significantly suspended in the air.
The destruction height, the height where the clouds shoot out from the building, moves down WTC1,2 at free fall speed.
>They didn't fall into their "foot print", they just didn't topple, debris was blowing out the sides. The collapse was anything but controlled
For WTC1,2 Your right. But if they didn't topple and they didn't go into their foot print, what did they do? Blow out? What was blowing them out?
I assume you think the building below the destruction height acted to convert the vertical motion of the top of the building into horizontal motion. This is as well as shattering all the steel structure and pulverizing the concrete, and creating a pyroclastic flow. All this when it was falling itself at free fall speed. How can any mass falling at gravity act so greatly on a surface which is itself falling at gravity? And all of this in a stucture which was designed to resist all of these so-blamed gravity effects with a redundancy of 20:1
Can you point to any real models, i.e. not computer simulated, that do the same?
What about WTC7?
>Focussing on that which is interesting and ignoring all the data that defies it.
Don't be so forward with your judgement. I'll try to focus on anything involving numbers or physics.
>For one thing, I notice that you have opted to use the heaviest model of the 707,
a.) Of course. There was no 'opt' about it. Engineers have to design for the worst case scenario. In fact they always design for much more than worst case scenario. For example they were designed 20:1 the maximum gravity load. You don't know this?
b.) Largest 707 was the Intercontinental 320B began flying in 1958. WTCs design in the early '60s.
>rubble falling faster than the vast dust plume.
Your the 2nd person here to go for the rubble falling faster than the destruction level is evidence against WTC free fall. So this response is for Andrew aswell.
The said rubble didn't start it's trajectory at zero velocity. A more obvious co-example is the debris which gained high horizontal velocity at their moment of separation. It is no leap of fantasy to say it's not just possible, but very likely that other debris at the destruction level recieved an impulse which set them off with downward velocity before they were in free fall. Therefore it's erroneous to use these debris as a reference for free fall. Using simple measurements such as frame by frame time and position is correct.
Now, you all seem to be resisting me on the freefall assertion.
Drop an object from the top of the WTC. How long does it take?
Height of WTC = 417m, grav = 9.81, free fall equation s = 0.5at^2
t = 9.2sec
Look at Jim Masterson's link to the official NIST report, the response to question 6, they say the collapse of WTC2 was approximately 9sec. i.e 9.5sec max.
Near enough free fall for you? Or are you saying, with the assumption of 9.5sec, the tiny fraction of gravitational potential that didn't go into the downward KE collapse, was able to totally destroy the structure at the destruction level, was great enough that the underlining structure could barely resist free fall motion through itself, and also throw debris out?
>You have not yet made any clear point regarding 7WTC. You seem to regard it as compelling proof of your pet theory, but how so?
A few key reasons...
a) Because the building isn't obscured by dust, it's very easy to do a frame by frame analysis of the motion.
b.) It looks precisely like a conventional demolition in every way.
c.) It wasn't hit by an aircraft. The fires were smaller.
It's not _my_ pet theory by the way.
Here's a frame by frame analysis
Here's a spectacular failed demolition jobs. Total symmetrical demolition at the base. But the result is little damage to rest of building structure. Why's there such a contrast between this and the WTCs?
>> Then why did the core columns, and the outer columns fail effectively simultaniously all the way around the building? <<
>I'm not sure which building you're talking about.
All 3 of them. And I don't think you see why symmetrical total collapse is significant. This behaviour is never observered except in controled demolitions.
Can you give 1 other case where a structure has undergone total symmetrical collapse at >95% free fall speed, and high degree destruction of all in components by only it's gravitational potential?
I agree with Steve Jones. Paraphrase:
Most people's analysis the controled demolition assertion of 911 goes...
Controled demolition would mean the Bush admin planned it, therefore can't be true.
For them, physics is just a irrelevent side show to be hammered or ignored into place to fit this belief.