29 Structural & Civil Engineers Cite Evidence for Controlled Explosive Demolition

[TruthersLie]

The north west corner did not move downward during that 1.75s. Read the post again. Look at the video I posted. The point NIST selected moves down but the north west corner does not during the 1.75s. The last wall to start moving was the west wall.

http://www.internationalskeptics.com/forums/showthread.php?postid=4853335#post4853335

Wait... let me get this right.

so even though OTHER PARTS OF THE BUILDING are collapsing (which you can see and measure) it is not part of the global collapse?

if any part of the "building as a whole" is buckling and moving, then the whole structure is moving.

you seem to want it both ways.. you want to ignore parts of the whole which are moving, but then you want to point to the whole 1.75 seconds later and say see the Whole thing fell down.

that is intellectual dishonesty at its best. Thank you.

Welcome to ignore.

 

[newton3376]

Yoke him in harness with an engineer who believes that weight = mass, and there's no telling what they won't be able to build!

Please tell me that he isnt really an engineer....

 

[Christopher7]

Here's my assessment of Chander's analysis.

One can see IMMEDIATELY that Chandler's claim that, over the interval of 1.75 to 4.00 seconds, the acceleration is a constant that is equal to G, as well as NIST's statement that it is "a constant approximately equal to G" is nonsense. The acceleration isn't close to being constant.

tom

This is so ironic.

You appeal to the authority of the 'experts' at NIST and believe their conclusions even though you have not read the final report, but you think this part of the NIST report is nonsense and you know better.

You use verbiage and sophistry to support this view. You are so transparent.

 

[FineWine]

This is so ironic.

You appeal to the authority of the 'experts' at NIST and believe their conclusions even though you have not read the final report, but you think this part of the NIST report is nonsense and you know better.

You use verbiage and sophistry to support this view. You are so transparent.

You know nothing. Stop advertising your abysmal ignorance by pretending to argue with a real engineer. His science is sophistry to you because you are incapable of understanding it and you refuse to make an effort.

 

[H'ethetheth]

...even though you have not read the final report...

I'm afraid you're confusing people. I have not read much of the report, but I'm under the impression that tfk has.

 

[Christopher7]

You know nothing. Stop advertising your abysmal ignorance by pretending to argue with a real engineer. His science is sophistry to you because you are incapable of understanding it and you refuse to make an effort.

A real engineer? In a pigs eye.

Edited by Gaspode: 

Edited for Rule 12

this is a question of physics, not engineering.

 

[funk de fino]

A real engineer? In a pigs eye. He is an anonymous arrogant adolescent and this is a question of physics, not engineering.

Are you a real carpenter?

 

[FineWine]

A real engineer? In a pigs eye.

Edited by Gaspode: 

Edited for Rule 12

this is a question of physics, not engineering.

You know nothing. Stop pretending to argue with people whose understanding of physics and engineering is on a vastly higher plane than yours. You can't understand a word he writes. You couldn't pass a high school physics exam.

 

[Christopher7]

You know nothing. Stop pretending to argue with people whose understanding of physics and engineering is on a vastly higher plane than yours. You can't understand a word he writes. You couldn't pass a high school physics exam.

Your superior attitude is just that, attitude, and tfk is full of it. He/she claims that the NIST free fall acceleration graph is nonsense and he/she knows better. Give me a break.

tfk's analysis has WTC 7 falling at more than free fall acceleration.

 

[Newtons Bit]

tfk's analysis has WTC 7 falling at more than free fall acceleration.

That's Chandler's data graphed. Can you figure ANYTHING out? That's why it's considered reasonably inaccurate!

 

[funk de fino]

Still unable to understand a graph eh?

ETA - This is getting funnier by the moment.

 

[tfk]

tfk, I have a question.

Your table contains raw video data, did I understand that correctly? If so, how did you differentiate it? Or are the derivatives from the NIST curve fit?

**** NERD ALERT **** NERD ALERT **** NERD ALERT ****
.
H,

I don't have raw data. I started with the empirical curve that NIST presented.

And then simply differentiated this formula. Twice.

The most important questions to ask are not, "are they pretty?" Or "are they mathematically easy to manipulate?" (although this helps...)

The important question is "how well do these curves reflect reality?"

And the only data points that we have are the position vs. time data points in Fig 12-76. And these look damn good.

Now the interpolating function forcibly smooths this raw data, and you would therefore EXPECT the first & second derivatives to be well-behaved and essentially "noise reduced". That is a good thing.

Chandler did the opposite. He took good data and forced it (with his "central difference" velocity approximations) to be artificially GRANULAR.

The use of the "central difference approximation" to calculate instantaneous velocity amplifies slight data errors.

To see this, switch back & forth between the position vs time (Fig 12-76) and velocity vs. time (Fig 12-77) curves in the NIST report. (vol 2, pg 602 & 603). If you look carefully, you can see this "error amplification" effect.

If the successive points on the position curve are both on (@ t=2.6 & 2.9 sec), both below (@ t = 2.2 & 2.4 sec) or both above (@ t = 3.2 & 3.4 sec) the position interpolation curve, then the derived velocity point will be right on the velocity curve. Which is true for the velocity points at 2.7, 2.3 & 3.3 sec, respectively.

But if the first data point is below the interpolated position curve and the next one is above the curve , then the calculated velocity will be too high. (e.g., poisition points @ t = 5.0 & 5.2 sec => velocity point @ 5.1 sec.)

If the first position point is above the curve & the second is below, then the calculated velocity point will be too low. (e.g., position point at 1.6 & 1.8 sec => velocity point at 1.7 sec).

You can see that the operation of piecemeal slope calculation is AMPLIFYING small errors into medium errors. And taking the second derivative to calculate acceleration amplifies medium errors into large errors. (small, medium & large being relative terms, of course.) This is the opposite of what you want to do. You want to eliminate these errors as early as possible. NOT amplify them.
___

There are two further checks that one can do (with the data available in the published reports) to see which method is better.

1. Integrate Chandler's velocity curves
Take Chandler's velocity graphs, numerically integrate them, and see how well they fit the raw position data. I haven't done this yet, but I'd predict that the answer is "not well".

2. Apply the central difference approximation to the velocity data points to see how they fit his "constant acceleration" conclusion.
This 2nd step will be MOST enlightening. On the velocity vs. time curve, estimate the slope of the straight line between successive velocity data points, and plot those values at the "timing midpoint" on a new acceleration graph.

Look at Chandler's velocity vs. time graph & compare the slope of the line connecting each successive data point. The successive slopes of his data shows a distinct "oscillation" above & below the average slope. Between 1.75 & 2 seconds, the slope is much higher than his interpolated (red line), the next slope below, the next above, the next below, etc. This oscillation is a classic "regression to the mean" that happens when your raw data is too lumpy.

So the answer to this question is that, when you apply Chandler's OWN technique to his velocity data, the conclusion is that "the acceleration ain't CLOSE to staying constant". Of course, these massive changes in acceleration are NOT real. They are simply artifacts of poor math technique.

The test of of how well the methodology described here fits WHAT REALLY HAPPENED lies buried in the raw data files. The answer would be found by using some of the "enhancement techniques" I mentioned in the last post. And by taking more data points. Perhaps I'll drop a note to NIST & see if they can provide raw video... Anyone know anyone over there?

But I am certain this techniques is far superior to Chandler's. You want to TAME data noise. Not AMPLIFY it.

Tom

 

[Newtons Bit]

But I am certain this techniques is far superior to Chandler's. You want to TAME data noise. Not AMPLIFY it.

Tom

Only if you want accurate results.

 

[FineWine]

Your superior attitude is just that, attitude, and tfk is full of it. He/she claims that the NIST free fall acceleration graph is nonsense and he/she knows better. Give me a break.

tfk's analysis has WTC 7 falling at more than free fall acceleration.

You are attempting to pit your ignorance against an engineer's knowledge. He has shown you why g is not the same as almost-g. You can't or won't (it amounts to the same thing) understand him. Your absurd myths depend on falsifying the actual evidence, and after eight years, everyone is bored. Your insane movement has produced nothing. Hatred and stupidity are no match for reason.

 

[ElMondoHummus]

That's Chandler's data graphed. Can you figure ANYTHING out? That's why it's considered reasonably inaccurate!

Oh.
My.
GOD!


This is proof positive that C7 only posts to attempt to negate other's arguments. TFK graph's Chandler's data, but because Tom did it, Chris feels obligated to find something wrong with it.

Figures. This is why I have him on ignore. Although I do take it I'm missing out on some sublime comedy.

 

[tfk]

Your superior attitude is just that, attitude, and tfk is full of it. He/she claims that the NIST free fall acceleration graph is nonsense and he/she knows better. Give me a break.

tfk's analysis has WTC 7 falling at more than free fall acceleration.

That is exactly right. This analysis concludes that, for a brief period of time, the wall is descending faster than free fall.

Now someone who'd never gone to engineering school might view this as a serious problem.

And engineering student who has only ever done the beautifully laid out & controlled experiments that they use in school to illustrate certain principles might find this to be a problem.

And a baby engineer, 1 - 5 years out of school, who'd never taken data in the lab or in the field, might find this to be a problem.

But what do you think that an experienced engineer might conclude from your "astonishing" observation that "for a brief interval, the acceleration was calculated to be about 8% over the theoretical maximum"??

That this value was the result of:
a) data error
b) math approximation error
c) both a) and b)
d) silent explosives
e) super-duper nanothermite
f) invisible rocket packs on the walls
g) NWO mo-jo
h) magic

C'mon, Chris. It's a multiple choice...

tk

PS. There are only two of us in this tete-a-tete. You ARE insulting one of us with your "he's not an engineer. He's a teenager" crap. You might think that it is me that you are insulting.

You'd be wrong about that, too.

 

[H'ethetheth]

**** NERD ALERT **** NERD ALERT **** NERD ALERT ****
.
H,

I don't have raw data. I started with the empirical curve that NIST presented.

[snip]

Tom

Thanks a lot for taking the time for this detailed reply, but despite having disclaimed my authority as an engineer for argument's sake in this thread, I am an (aerospace) engineer. I have in fact told Christopher a lot of the things you just told me (in much less detail though).
The first line was basically the answer I was looking for. I just wasn't sure from your post.
That said, I'd actually also like to see both NIST's and Chandler's raw data, but I'm pretty sure I won't ever think this is important enough to badger either of them with an e-mail.

 

[tfk]

Thanks a lot for taking the time for this detailed reply, but despite having disclaimed my authority as an engineer for argument's sake in this thread, I am an (aerospace) engineer. I have in fact told Christopher a lot of the things you just told me (in much less detail though).
The first line was basically the answer I was looking for. I just wasn't sure from your post.
That said, I'd actually also like to see both NIST's and Chandler's raw data, but I'm pretty sure I won't ever think this is important enough to badger either of them with an e-mail.

Greetings, H, from the Department of Pedantic Overstatement of the Obvious.

I could tell that you were well versed in all of this. Most of that was for someone who wanted to try to follow along in some of the details.

BTW, what kind of aerospace? Worked on anything cool?

I graduated in '74, and at the time, the aerospace industry was collapsing faster than the Hindenberg. So, as much fun as that would have been, I ended up in underwater cameras & TV systems, (I had some cameras on the Trieste, Sea Cliff & DSRV), electronic connectors & switches (worked on the main power transfer switch for the Shuttle and all IUSs) and medical devices.

But aerospace always looked SOOOOooooo cool...

Tom

 

[rwguinn]

Greetings, H, from the Department of Pedantic Overstatement of the Obvious.

I could tell that you were well versed in all of this. Most of that was for someone who wanted to try to follow along in some of the details.

BTW, what kind of aerospace? Worked on anything cool?

I graduated in '74, and at the time, the aerospace industry was collapsing faster than the Hindenberg. So, as much fun as that would have been, I ended up in underwater cameras & TV systems, (I had some cameras on the Trieste, Sea Cliff & DSRV), electronic connectors & switches (worked on the main power transfer switch for the Shuttle and all IUSs) and medical devices.


But aerospace always looked SOOOOooooo cool...

Tom

Sure- It's cool 'till you get to work MRB (rejection tags).
That's where the company decides it is cheaper to get an engineer to explain why the shop ****-up is good anyway than it is to hire people who can actually put stuff together right.
H'ethetheth--the only people you actually fooled were troofers. Welcome out of the closet.

 

[H'ethetheth]

Greetings, H, from the Department of Pedantic Overstatement of the Obvious.

I could tell that you were well versed in all of this. Most of that was for someone who wanted to try to follow along in some of the details.

BTW, what kind of aerospace? Worked on anything cool?

I graduated in '74, and at the time, the aerospace industry was collapsing faster than the Hindenberg. So, as much fun as that would have been, I ended up in underwater cameras & TV systems, (I had some cameras on the Trieste, Sea Cliff & DSRV), electronic connectors & switches (worked on the main power transfer switch for the Shuttle and all IUSs) and medical devices.

But aerospace always looked SOOOOooooo cool...

Tom

I don't want to derail the thread too much, but I'm basically a fresh engineer (since last december). You can see part of my thesis project in my avatar. It's a render of plastic head of the robotic zebra fish larva I developed for Wageningen University to do performance measurements with. Unfortunately, there was only money to hire me for a couple of months to get the build started after I graduated, so I'm looking for a job at the moment.

ETA: Oh, and I see I forgot to mention what kind of aerospace. Well, all kinds, basically. My major (not sure if that's the right term) was design and integration, so you could say I'm a generalist. Among specialists you could also say that I know next to nothing about just about anything.