New video of David Chandler: rockets at the World Trade Center

[DGM]

You know, I think they may have used a giant tarp, printed to mimic the exterior of the trade towers, put that over the green netting, and put the green netting over the exterior walls.

I'm still trying to figure out how the office workers didn't notice the construction port-a-potties in the middle of the aisle. I'll get back to you on that.

They could have "hid" it like they did the Citicorp repairs.
http://www.damninteresting.com/a-potentially-disastrous-design-error/

Oh wait.............we did find out.

 

[Oystein]

(deleted - no food for trolls!)

 

[femr2]

The panel section...

...cannot be traced by automated methods for rather boring technical reasons, but can be manually traced per frame (insert pointless discussion about field/frame separation).

Accuracy of manual tracing in this instance cannot be sub-pixel accurate, and so applying similar techniques as those I've used on WTC7 yields inconsistent and demostrably inaccurate derived acceleration profile data.

However, it's still possible to track the displacement fairly reasonably, and perform simple curve fitting techniques...


Low order poly fit with R² ~= 0.999898

Ramping that up to a 3rd order poly fit and deriving to acceleration obviously gives a linear result, but interesting range...


...24.8ft/s^2 increasing to 27.5ft/s^2.

With an original displacement fit R² of ~0.999899


Clearly such low order fitting is removing some real variation in object velocity and acceleration change, and there may well be small periods of "faster" motion.

I'll post another plot series when I have the manual trace errors sorted out.

 

[ozeco41]

The panel section.......

.....Clearly such low order fitting is removing some real variation in object velocity and acceleration change, and there may well be small periods of "faster" motion.

I'll post another plot series when I have the manual trace errors sorted out.

Noted with interest - including your comments on difficulties faced and possible effects on accuracy.

 

[MIKILLINI]

Watch the plane go in at 590 mph. Then watch the artifact strreak out the other side. Which looks faster ?

No calculations Bill? No physics? This is your type of evidence? I suppose in your case, youtube video judgement on a world scale is good enough. Unless your computer sets on the kitchen table.

 

[Oystein]

Thanks, femr2, much appreciated!

I have a few questions:

1. Once you have sorted out whatever you need to sort out, can you post your "raw data" in a table? I reckon I am thinking of drop distance (in m or ft) vs. time.
2. Do you believe that your t=0 is the same as in Chandler's video, or close?
3. What assumptions did you use when you converted pixels into real world distances? In other words...,
3.1 ...how did you scale your measurements
3.2 ...how did you treat the (unknown, I think) 3D-trajectory of the object? This probably breaks down into...
3.2.1 ...What's the distance between object and tower wall relative to camera distance?
3.2.2 ...What's the horizontal speed of the object towards the camera, or the angle between trajectory and vertical in each frame?
4. What are the approximate dimensions of the object?
5. Do you see if and how the object rotates? If so, does orientation (more vertical, more horizontal) somehow correlate to acceleration?



Not expecting you to answer all questions just like I asked them. A discussion which touches on these issues would be fine.

 

[Oystein]

@ Mikillini, NoahFence, TsuDhoNimh, Animal, Dash80, GlennB, ElMondoHummus:

Could you please pause for a moment and think if you are discussing the topic of this thread ("rockets at the WTC", i.o. the allegation that a particular piece of free-falling debris was propelled by whatever), or if you are not rather feeding a troll by replying to his derail? Thanks!

 

[femr2]

1. Once you have sorted out whatever you need to sort out, can you post your "raw data" in a table? I reckon I am thinking of drop distance (in m or ft) vs. time.

The dataset for the current displacement curve is here. I'll link to additional sets as and when.

2. Do you believe that your t=0 is the same as in Chandler's video, or close?

I imagine I'm a bit earlier. I could synchronise. Will post a reference probably tomorrow.

3. What assumptions did you use when you converted pixels into real world distances? In other words...,
3.1 ...how did you scale your measurements

Vertical scalar determined via distance between upper and lower mechanical floor regions (on WTC1). Largest vertical distance available to minimise error. ft/pixel determined.

3.2 ...how did you treat the (unknown, I think) 3D-trajectory of the object? This probably breaks down into...

Didn't. There will be perspective error, including change in perspective due to camera motion. Static point extraction was performed however. No attempt to determine object-to-camera distance changes applied either.

3.2.1 ...What's the distance between object and tower wall relative to camera distance?

No idea, and varies during the descent an'all.

3.2.2 ...What's the horizontal speed of the object towards the camera, or the angle between trajectory and vertical in each frame?

Again, no idea. Not sure it's worth drilling into too much detail for this one though. Probably impossible to determine accurately due to lack of footage to cross reference to.

4. What are the approximate dimensions of the object?

Can be determined. Haven't worked it out.

5. Do you see if and how the object rotates?

Sure. The GIFs above are useful if you zoom them full screen. Watch over and over...

If so, does orientation (more vertical, more horizontal) somehow correlate to acceleration?

Depends which end you trace, but as it is rotating, each end does of course exhibit varying acceleration (omission of perspective correction will compound such)

Not expecting you to answer all questions just like I asked them. A discussion which touches on these issues would be fine.

Some can be sorted, though unless I end up with verifiable over-g then looking for additional sources of error won't be a high priority, for me at least.

 

[MIKILLINI]

@ Mikillini, NoahFence, TsuDhoNimh, Animal, Dash80, GlennB, ElMondoHummus:

Could you please pause for a moment and think if you are discussing the topic of this thread ("rockets at the WTC", i.o. the allegation that a particular piece of free-falling debris was propelled by whatever), or if you are not rather feeding a troll by replying to his derail? Thanks!

Duly noted Oystein(Sometimes feeding the trolls gets the best of me): I'm more interested in these calculations of femr2 to determine whether or not there is any acceleration of the falling object. Carry on.

 

[Oystein]

The dataset for the current displacement curve is here. I'll link to additional sets as and when.


I imagine I'm a bit earlier. I could synchronise. Will post a reference probably tomorrow.


Vertical scalar determined via distance between upper and lower mechanical floor regions (on WTC1). Largest vertical distance available to minimise error. ft/pixel determined.


Didn't. There will be perspective error, including change in perspective due to camera motion. Static point extraction was performed however. No attempt to determine object-to-camera distance changes applied either.


No idea, and varies during the descent an'all.


Again, no idea. Not sure it's worth drilling into too much detail for this one though. Probably impossible to determine accurately due to lack of footage to cross reference to.


Can be determined. Haven't worked it out.


Sure. The GIFs above are useful if you zoom them full screen. Watch over and over...

Great, thanks.

Depends which end you trace, but as it is rotating, each end does of course exhibit varying acceleration (omission of perspective correction will compound such)

I was more thinking of the acceleration of the center of gravity is noticeably affected by the orientation of the object; one might expect that there is more drag when the object is horizontal, and less when it's vertical, but the magnitude of that effect would depend on its density, surface-to-mass ratio, and what not. I am aiming at establishing with more confidence the identity of the object - is it really a wall panel? Or Al-cladding?
Then again, the effect may well be overwhelmed by noise.

Some can be sorted, though unless I end up with verifiable over-g then looking for additional sources of error won't be a high priority, for me at least.

Understandable.

However, a 3rd order poly approximation is not likely to give you that over-g, even if it were real. As you hinted yourself, the plot a vs. t necessarily gives a straight line, with the maximum either at the very beginning of the dataset, or at its very end. Any real maximum of a somewhere in between would be masked by the (arbitrary?) choice of poly order. I'd do at least a 4th order fit, or, for the heck of it, try to do the 3rd-order poly with a dataset that ends at approximately Chandler's t=2.2s. I think you will find that it ends at larger than g.

 

[tmd2_1]

The dataset for the current displacement curve is here. I'll link to additional sets as and when.


I imagine I'm a bit earlier. I could synchronise. Will post a reference probably tomorrow.


Vertical scalar determined via distance between upper and lower mechanical floor regions (on WTC1). Largest vertical distance available to minimise error. ft/pixel determined.


Didn't. There will be perspective error, including change in perspective due to camera motion. Static point extraction was performed however. No attempt to determine object-to-camera distance changes applied either.


No idea, and varies during the descent an'all.


Again, no idea. Not sure it's worth drilling into too much detail for this one though. Probably impossible to determine accurately due to lack of footage to cross reference to.


Can be determined. Haven't worked it out.


Sure. The GIFs above are useful if you zoom them full screen. Watch over and over...


Depends which end you trace, but as it is rotating, each end does of course exhibit varying acceleration (omission of perspective correction will compound such)


Some can be sorted, though unless I end up with verifiable over-g then looking for additional sources of error won't be a high priority, for me at least.

Thanks for your work. I have a few questions. I noticed you said that you believe that piece could have started falling before, but to get that kind of separation, I am estimating that it is about 300-400 feet ahead of the rest of the pile, it would have needed to start falling 4-5 seconds before the other debris. This assumes it is falling from the same height and pure free fall.

Also I why did you assume the 3rd order poly was the best fit? It would seem to me that you would get a below g result whether it was real or not? Perhaps I missed it in your comments. Thanks again for your work.

 

[Oystein]

The dataset for the current displacement curve is here. I'll link to additional sets as and when.
...

Whoa - noisy data.
I am playing around with the table rather clumsily in a spreadsheet, trying to get a feel for it.

The raw data contains a handful of instances where the object seems to move upwards from one frame to the next.
Even when I only look at what happens from one 0.2-second interval to the next, it sometimes appears as if downward velocity decreases (acceleration upwards). Depending on what t I start sampling 0.2-second intervals (well, 0.1998s intervals really), acceleration jumps up and sown between -51 and +41m/s².

I have severe doubts that any smoothing or fitting gives us reasonable curves. I do see above-g averages between 1.42s and 2.0s.
I have a hunch that this is due to one or two distinct events at 1.70s and possibly 1.88s - a collision with a faster object from above, or the object breaking up, or something like that.

 

[Dave Rogers]

While we're on the subject, Chandler's idiotic claim also requires this rocket propelled projectile has a thrust of... what, about 0.5 g? Or less?

What's the point of that?

Insofar as I can ascribe a rational line of argument to Chandler, I don't think he's suggesting that there was a point to attaching a rocket motor to a piece of falling debris. What I think he's claiming is that this piece of debris fell away from the structure with an unexploded nanothermite device attached to it, and that, at the point during its fall where his measured acceleration exceeds 1G, the nanothermite device inadvertantly went off; the resulting explosion propelled the piece of debris downwards because the device happened to be on the upper side, directing the blast upwards and hence transferring downward momentum to the piece of debris.

The obvious gaps in this line of argument are that there is no particular reason for the device to go off while the debris is falling, as there won't be a heat source available to set it off, and that the flash of the explosion would be very clearly visible, whereas in fact it isn't. But that, I think, is what Chandler is suggesting, rather than that the falling debris was deliberately fitted by the conspirators with rocket motors. At least, I hope that's not what he's suggesting.

Dave

 

[ozeco41]

Insofar as I can ascribe a rational line of argument to Chandler, I don't think he's suggesting that there was a point to attaching a rocket motor to a piece of falling debris. What I think he's claiming is that this piece of debris fell away from the structure with an unexploded nanothermite device attached to it, and that, at the point during its fall where his measured acceleration exceeds 1G, the nanothermite device inadvertantly went off; the resulting explosion propelled the piece of debris downwards because the device happened to be on the upper side, directing the blast upwards and hence transferring downward momentum to the piece of debris.

The obvious gaps in this line of argument are that there is no particular reason for the device to go off while the debris is falling, as there won't be a heat source available to set it off, and that the flash of the explosion would be very clearly visible, whereas in fact it isn't. But that, I think, is what Chandler is suggesting, rather than that the falling debris was deliberately fitted by the conspirators with rocket motors. At least, I hope that's not what he's suggesting.

Dave

Plus, let us not forget, that thermite - nano or not, is not a rocket fuel.

Actually, given the extreme idiocy of what he proposes, the concept of a deliberately manually fitted rocket starts to look more probable......

 

[Dave Rogers]

Plus, let us not forget, that thermite - nano or not, is not a rocket fuel.

Good point. Chandler is committing the nanothermite variation on the appeal to magic fallacy, in which nanothermite is assumed to have whatever properties are required to sustain a line of argument; in this case, it's assumed to eject a significant amount of mass at high velocity, something nanothermite, even with additives to provide some form of gas release, is particularly bad at.

Actually, given the extreme idiocy of what he proposes, the concept of a deliberately manually fitted rocket starts to look more probable......

I'm trying to give Chandler the benefit of what doubt is available by interpreting what he says as the least stupid claim possible, but there's not much to work with here.

Dave

 

[ozeco41]

.... but there's not much to work with here.

 

[little grey rabbit]

As they say at that link: This power down condition meant there was no electrical supply for approx 36hrs from floor 50 up.

So you are going to bring in generators and fuel and cutting torches and repair supplies and haul them up how many floors? In which stairwell?

And when did you get the crane up there, and how?

And what about the other tower?

Oh TDN, you are so naive....

The WTC was DESIGNED by the Bin Laden family to be demolished should such a contingency ever arise.

Its all here on youtube
http://www.youtube.com/watch?v=a_3ScRx9gvc

 

[little grey rabbit]

@ Mikillini, NoahFence, TsuDhoNimh, Animal, Dash80, GlennB, ElMondoHummus:

Could you please pause for a moment and think if you are discussing the topic of this thread ("rockets at the WTC", i.o. the allegation that a particular piece of free-falling debris was propelled by whatever), or if you are not rather feeding a troll by replying to his derail? Thanks!

Ouch Oystein, no need to yell like that.

Nothing says that Trutherism is dead more than videos claiming rockets were fired at the WTC. Ceased to be, 'e's a stiff etc etc.

Mr. Praline: Um...now look...now look, mate, I've definitely 'ad enough of this. That parrot is definitely deceased, and when I purchased it not 'alf an hour ago, you assured me that its total lack of movement was due to it bein' tired and shagged out following a prolonged squawk.

Owner: Well, he's...he's, ah...probably pining for the fjords.

Mr. Praline: PININ' for the FJORDS?!?!?!? What kind of talk is that?, look, why did he fall flat on his back the moment I got 'im home?

Owner: The Norwegian Blue prefers keepin' on it's back! Remarkable bird, id'nit, squire? Lovely plumage!

Mr. Praline: Look, I took the liberty of examining that parrot when I got it home, and I discovered the only reason that it had been sitting on its perch in the
first place was that it had been NAILED there.

(pause)

Owner: Well, o'course it was nailed there! If I hadn't nailed that bird down, it would have nuzzled up to those bars, bent 'em apart with its beak, and VOOM! Feeweeweewee!

Mr. Praline: "VOOM"?!? Mate, this bird wouldn't "voom" if you put four million volts through it!

Although, and it may be just me, I think that last line would be funnier if it read: "If you put four million volts through it, this bird wouldn't "voom."

 

[femr2]

I noticed you said that you believe that piece could have started falling before

Where ?

but to get that kind of separation, I am estimating that it is about 300-400 feet ahead of the rest of the pile, it would have needed to start falling 4-5 seconds before the other debris. This assumes it is falling from the same height and pure free fall.

Makes no difference where it originated.

Also I why did you assume the 3rd order poly was the best fit?

I didn't. It's "a" fit. Not a bad fit over the full trace duration.

It would seem to me that you would get a below g result whether it was real or not?

Low order poly fit could certainly mask moments of variation in acceleration, sure.

 

[Cl1mh4224rd]

Lol right, because youtube is god?

Do you even believe the **** you peddle or are you just trolling for attention? Maybe you're lonely?

Buy a cat, or join an internet dating site.

Don't feed the little grey troll...