Merged David Chandler (ae911) sez "WTC7 was in free fall part of the time"

[Panoply_Prefect]

Hi!

I recently come across some youtube videos posted by "David Chandler". In it he uses footage of WTC7 and a software called "Physics Toolkit" to make the point that during a short intervall of the collapse, WTC7 was in fact in free fall, that NIST ignored this and that it is a sign of CD.

Contrary to the August 2008 NIST report on WTC7, the acceleration of Building 7 has been measured and is found to be indistinguishable from the acceleration of gravity over a period of about 2.5 seconds during the fall. Freefall indicates zero resistance. It also indicates that the energy of the falling mass is not available to do work on the lower structure (i.e. such things as breaking, bending, crushing, etc.) A video detailing the measurement process and commenting on the results is posted on the AE911Truth YouTube channel, accessible through http://www.ae911truth.org/freefall. The video responds to the recently released NIST WTC7 document.

http://www.911blogger.com/node/17685


First video from may this year:



Second one from september:



I'm not experienced enough in the art of collapsing buildings or usage of Physics Toolkit, but could someone help me out here? What does he mean, and what merits does his argument have, if any?

 

[boloboffin]

I responded to this in the other thread, so I'll just repeat my post here.

Chandler actually proves to my satisfaction that for about 2.5 seconds, the top northwest corner accelerated at the same rate as gravity would accelerate it.

The problem is how Chandler then interprets this. He believes this can only be due to controlled demolition. He thinks that NIST covered up this period of freefall with deceptive language.

Nothing of the sort. NIST measured from the very beginning of the descent of the top northwest corner to where they both stop, at the height of the 29th floor. The time it took the building to fall is 40% slower than it would be if the building had accelerated at the rate of gravity for the entire time. There's no deception here. Math is math.

The building encountered significant resistance during this time, so much so that it could offset a period of 2.5 seconds where the corner was essentially in freefall.

And NIST's explanation does allow for this period of freefall. The western core (remaining after the eastern interior has collapsed) is yanking the perimeter down behind it, and since it begins to pull apart at the seventh floor, the core has to fall about that far before it encounters significant resistance from below. As soon as it does, the building slows again and begins to crush up.

At least, that's how this layman understands it.

 

[Heiwa]

The building encountered significant resistance during this time, so much so that it could offset a period of 2.5 seconds where the corner was essentially in freefall.

At least, that's how this layman understands it.

The analysis covers 5 seconds:

The first second the acceleration of the top is small = plenty of resistance/support by the structure below (and above) the 29th floor.

The following 2.5 seconds the acceleration is 9.81 m/s² = no resistance at all by the structure below the 29th floor - the whole top part above floor 29 is in the air!! Only gravity (g = 9.81 m/s²) acts on it.

The last 1.5 seconds the acceleration ot the top is again small = plenty of resistance again by the structure below the 29th floor (or what remains of it).

The average acceleration during the 5 seconds is about 0.5 g, but that does not mean anything.

So the question is what happens below floor 29 during those 2.5 seconds when the top part was accelerating at g = 9.81 m/s²? Why doesn't the crumbling structure below floor 29 provide any resistance to the top part as it does before and after those 2.5 seconds?

The columns between ground and floor 29 are supposed to crumble due to the weight/load of the structure above floor 29 applied to them in combination with local failures caused by thermal expansion of supporting members of these columns.

But during 2.5 seconds the 49 columns below floor 29 do not offer any resistance at all. They are not there! Blown away?

 

[GStan]

The analysis covers 5 seconds:

The first second the acceleration of the top is small = plenty of resistance/support by the structure below (and above) the 29th floor.

The following 2.5 seconds the acceleration is 9.81 m/s² = no resistance at all by the structure below the 29th floor - the whole top part above floor 29 is in the air!! Only gravity (g = 9.81 m/s²) acts on it.

The last 1.5 seconds the acceleration ot the top is again small = plenty of resistance again by the structure below the 29th floor (or what remains of it).

The average acceleration during the 5 seconds is about 0.5 g, but that does not mean anything.

So the question is what happens below floor 29 during those 2.5 seconds when the top part was accelerating at g = 9.81 m/s²? Why doesn't the crumbling structure below floor 29 provide any resistance to the top part as it does before and after those 2.5 seconds?

The columns between ground and floor 29 are supposed to crumble due to the weight/load of the structure above floor 29 applied to them in combination with local failures caused by thermal expansion of supporting members of these columns.

But during 2.5 seconds the 49 columns below floor 29 do not offer any resistance at all. They are not there! Blown away?

Are you saying that the support was blown up 1 second after it had already failed? Boy, I hope this conspiracy is fully revealed someday, just so I can see how friggin awesome and complex it really was.

 

[boloboffin]

The average acceleration during the 5 seconds is about 0.5 g, but that does not mean anything.

Pay no attention to that average acceleration behind that curtain.

So the question is what happens below floor 29 during those 2.5 seconds when the top part was accelerating at g = 9.81 m/s²? Why doesn't the crumbling structure below floor 29 provide any resistance to the top part as it does before and after those 2.5 seconds?

The columns between ground and floor 29 are supposed to crumble due to the weight/load of the structure above floor 29 applied to them in combination with local failures caused by thermal expansion of supporting members of these columns.

But during 2.5 seconds the 49 columns below floor 29 do not offer any resistance at all. They are not there! Blown away?

When you quoted my post, you deceptively snipped away the part where I explained this. Here it is again, bolded for your edification:

...The building encountered significant resistance during this time, so much so that it could offset a period of 2.5 seconds where the corner was essentially in freefall.

And NIST's explanation does allow for this period of freefall. The western core (remaining after the eastern interior has collapsed) is yanking the perimeter down behind it, and since it begins to pull apart at the seventh floor, the core has to fall about that far before it encounters significant resistance from below. As soon as it does, the building slows again and begins to crush up.

At least, that's how this layman understands it.

Now feel free to knock holes in that. I am a layman in this and welcome actual criticism from anyone. But don't play sophistic fallacy games and expect to get away with it here, Heiwa.

 

[boloboffin]

I did some math. According to the measurements by Chandler, the building is moving about 1.5 m/s when it begins freefall, and then hits 26.5 m/s 2.5 seconds later.

Using this site:

http://www.ajdesigner.com/constantacceleration/cadisplacement.php

I first calculated the average velocity (14 m/s), and then the actual distance traveled during this 2.5 seconds. It's 35 meters.

Now according to the figures provided by Chandler from NIST, the elevation of the top of Floor 29's windows was 683' 6" and the elevation of the top of the parapet wall was 925' 4". The difference is 241.83 feet for the 18 floors, an average height of 13.4 feet, or 4 m.

So, since the building falls 35 m in 2.5 seconds, it falls about 9 floors distance in that time.

The buckling of the building model (Figure 3-14 in NCSTAR_1A (page 38, pdf 76)) is between floors 7 and 14, 7 floors distance (or 28 m). The entire building would have been in virtual freefall during this time. If during the buckling, two more floors were destroyed (one on top and one on bottom), then the distance the top of the roof drops in freefall is fully explained.

Again, I'm a layman. Any structural engineers that want to jump in and correct me, please do so.

 

[double_o]

The average acceleration during the 5 seconds is about 0.5 g, but that does not mean anything.

But a free fall would require a 1g average acceleration.

Is that mean that after seven years of screaming "free fall speed" a truther actually took the time to measure WTC7 collapse time and found out that it wasn't free fall. Can we consider the the "WTC7 free fall" claim debunked now?

 

[Galileo]

Hi!

I recently come across some youtube videos posted by "David Chandler". In it he uses footage of WTC7 and a software called "Physics Toolkit" to make the point that during a short intervall of the collapse, WTC7 was in fact in free fall, that NIST ignored this and that it is a sign of CD.



http://www.911blogger.com/node/17685


First video from may this year:



Second one from september:



I'm not experienced enough in the art of collapsing buildings or usage of Physics Toolkit, but could someone help me out here? What does he mean, and what merits does his argument have, if any?

I can help you. The free fall proves that WTC 7 was a controlled demolition. Science has proved that.

What science can't prove is who set the explosives. Some believe that Osama bin Laden set them. Others believe Saddam Hussein set them. And some think Dick Cheney or Larry Silverstein did it.

 

[dudalb]

I can help you. The free fall proves that WTC 7 was a controlled demolition. Science has proved that.

 

[beachnut]

I can help you. The free fall proves that WTC 7 was a controlled demolition. Science has proved that.

What science can't prove is who set the explosives. Some believe that Osama bin Laden set them. Others believe Saddam Hussein set them. And some think Dick Cheney or Larry Silverstein did it.

That is a dumb statement. Good job offering no proof. BTW, the WTC7 fell slower than free fall. You failed to do your own work.

 

[technoextreme]

Chandler actually proves to my satisfaction that for about 2.5 seconds, the top northwest corner accelerated at the same rate as gravity would accelerate it.

In order to do the type of analysis that he is talking about we first have to know where he got the video and the camera. The weird thing is that they could be doing analysis on video that is missing information. You have optical distortions that you need to correct for which you can't do with that software package (Technically, don't need the camera).
EDIT:
After re-watching five seconds of the movie he validated my opinion. He's a )*(Y&(*&ing moron that isn't an engineer because an engineer wouldn't be caught dead doing the moronic, half brained, idiotic things he is trying. YOU DON'T CALIBRATE THE FREAKING IMAGE USING LINES DRAWN ACROSS IT. IT'S A BLOODY DAM COMPLICATED PROCESS. WARNING. WARNING. DO NOT FALL FOR STUPIDITY. THEIR ANALYSIS IS STILLBORN.
EDIT EDIT:
I was right. He's a mathematician/physicist. You would think the electrical (Yes this is electrical engineering's domain.) engineers would help out.

 

[Panoply_Prefect]

I still don't fully understand the fault... Does anyone know the software he uses (Linked above)? Does it in fact do what he claim it does? What is it typically used for?

Physics ToolKit, previously named World-in-Motion, is a useful educational tool for lecture, lab, and student assignments.

Video analysis software with videos covering common topics in mechanics, sound and electromagnetic fields and waves.

What error margin does it have? (eg, he claims it shows freefall, in the first video he calibrates on different markers and still get values close to what he claims shows free fall). Eg how exact must the measurement be to draw the certain conclusion that it is indeed "freefall" and not just due to pixelerrors or speed of the shutter of the camera or what have you (just making examples here). How exact a measurement do you get by doing what Chandler does with this particular toolkit?

 

[Panoply_Prefect]

I can help you. The free fall proves that WTC 7 was a controlled demolition. Science has proved that.

Well if that is true, Im equally interested in learning that. Im just trying to understand what Chandler actually does. Feel free to help out explaining this.

 

[technoextreme]

I still don't fully understand the fault... Does anyone know the software he uses (Linked above)? Does it in fact do what he claim it does? What is it typically used for?

Judging from the website high school physics labs. True video analysis software would be Matlab, or even OpenCV.

 

[Panoply_Prefect]

Again, I'm a layman. Any structural engineers that want to jump in and correct me, please do so.

Any structural engineers inhouse that can help me understand Chandlers little demo? Technoextreme says that optical distortions could umm... distort the results, however Chandler does two or three different measures which all, so he claims, shows freefall. This would indicate that there would have to be helluva distortion to make his claim invalid. Is he correct in this assertion?

Apparently his claim made it into the San Luis Obispo County Tribune in a piece written by "Mark Phillips a retired mechanical engineer" (and yes, it contains a lot of standard trutherism, including Jowenko):

http://www.sanluisobispo.com/182/v-print/story/466920.html

Because the collapse of WTC 7 is not obscured by smoke or debris it is possible to measure its rate of descent with considerable accuracy.
David Chandler, who believes it was an inside job, has done a very precise measurement (see “WTC7 in Freefall” on YouTube) and found that for approximately 2.5 seconds, WTC 7 fell at a rate that is indistinguishable from freefall. This means that for those 2.5 seconds, thousands of tons of structural steel and concrete offered essentially zero resistance. This is impossible given the official theory but is consistent with a controlled demolition.
NIST avoids this problem by using a longer time span and calculating an average acceleration. In this way it hides the evidence that disproves its theory.

 

[boloboffin]

Any structural engineers inhouse that can help me understand Chandlers little demo? Technoextreme says that optical distortions could umm... distort the results, however Chandler does two or three different measures which all, so he claims, shows freefall. This would indicate that there would have to be helluva distortion to make his claim invalid. Is he correct in this assertion?

Apparently his claim made it into the San Luis Obispo County Tribune in a piece written by "Mark Phillips a retired mechanical engineer" (and yes, it contains a lot of standard trutherism, including Jowenko):

http://www.sanluisobispo.com/182/v-print/story/466920.html

I like the way both you and Heiwa have made SURE to quote my admission of being a layman.

Tell you what. If you have problems understanding Chandler's presentation, that's not the fault of any structural engineer here. Take it up with Chandler.

I'm quite sure, also, that one or two of the structural engineers we have inhouse have been able to look at this thread. If they didn't see anything wrong with my answer, I would say the ball is in your court to find something wrong with it yourself.

So get cracking.

 

[technoextreme]

Any structural engineers inhouse that can help me understand Chandlers little demo? Technoextreme says that optical distortions could umm... distort the results, however Chandler does two or three different measures which all, so he claims, shows freefall. This would indicate that there would have to be helluva distortion to make his claim invalid. Is he correct in this assertion?

Why are you asking the wrong type of engineer? It's the equivalent of asking an electrical engineer why the mechanism involved in the collapse of the World Trade Center. The reason why I can't give you a straight answer is because of the complexity involved. You have the distortions caused by the camera which would make lining up any of the straight lines close to impossible because a straight line would not be straight even though you knew the line was straight to start with. You may or may not have lost informattion from the compression method.

 

[Panoply_Prefect]

I like the way both you and Heiwa have made SURE to quote my admission of being a layman.

Actually there was no malicious intent in doing so, I just quoted a smaller part of your post to hook onto your call for structural engineers to join in. I don't see Heiwas posts as he is on my ignore list.

Tell you what. If you have problems understanding Chandler's presentation, that's not the fault of any structural engineer here. Take it up with Chandler.

I've contemplated that, but I'm not sure if that would do any good - after all he has already presented his case (but if he reads this thread, feel free to join in). Instead I've written the makers of the Physics Toolkit to see what they have to say about Chandlers "experiment"

I'm quite sure, also, that one or two of the structural engineers we have inhouse have been able to look at this thread. If they didn't see anything wrong with my answer, I would say the ball is in your court to find something wrong with it yourself.

So get cracking.

I'm still not sure I understand it, thats why Im asking for more input, its not a criticism of your argument.

/PP

 

[Panoply_Prefect]

The reason why I can't give you a straight answer is because of the complexity involved. You have the distortions caused by the camera which would make lining up any of the straight lines close to impossible because a straight line would not be straight even though you knew the line was straight to start with. You may or may not have lost informattion from the compression method.

I think I get it: Chandler uses the known width of the building (at least in the may-video), to calibrate the software. The software uses a straight red line, which Chandler gives the value of the known width. However if the building is angled even the smallest, the calibration will be off. The more the angle, the longer/shorter the red line, the more error.

Is this correct or is it more to it?

 

[technoextreme]

I think I get it: Chandler uses the known width of the building (at least in the may-video), to calibrate the software. The software uses a straight red line, which Chandler gives the value of the known width. However if the building is angled even the smallest, the calibration will be off. The more the angle, the longer/shorter the red line, the more error.

Is this correct or is it more to it?

Yes. In most optical systems straight lines in a picture become curved. The pictures on wikipedia show the distortion but the effects are exaggerated for clarification purposes. http://en.wikipedia.org/wiki/Distortion_(optics)