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carlitos · 21st July 2012, 10:32 AM

Originally Posted by MileHighMadness

Anthony Hilder...you have to be kidding, the guy is an idiot, firebrand and lying con artist. He so far down the rabbit hole, even the mad hatter thinks he's nuts. I watched an interview between him and Jim Fetzer, it was like something out of SNL, everything they said kept getting more and more strange. Anthony Hilder...that's the best you got! Man...fold your tent and go home...the battle is lost.

TTFG* = first frame of video. You don't even have to press 'play' to see it.

*Time to first Godwin

Christopher7 · 21st July 2012, 09:29 PM

Originally Posted by femr2

My acceleration graph shows:

a) Rapid increase in acceleration from release to somewhat over-g in approximately 1s.

At the end of this period, the NW corner had descended ~9ft

b) Slow reduction in acceleration to approximately g over approximately 1.5s.

At the end of this period, the NW corner had descended ~83ft

c) More rapid reduction in acceleration to roughly constant velocity over approximately 2s.

At the end of this period, the NW corner had descended ~270ft

If you use the velocity graph you'll obviously miss some profile shape detail, but you could say...

~1.75s at ~FFA (and I'd not complain too much)

How do you explain the discrepancies in your graphs?
The acceleration graph has 0.0s at FFA
But the velocity graph has ~1.75s at ~FFA [sic].

dc1971 · 21st July 2012, 09:39 PM

Originally Posted by Christopher7

How do you explain the discrepancies in your graphs?
The acceleration graph has 0.0s at FFA
But the velocity graph has ~1.75s at ~FFA [sic].

Because acceleration and velocity are two different things.

Christopher7 · 21st July 2012, 10:45 PM

Originally Posted by dc1971

Because acceleration and velocity are two different things.

Sophistry.
In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g.

The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph.

But during that same time period, the acceleration graph has the acceleration at >g and then <g.

dc1971 · 22nd July 2012, 12:14 AM

Originally Posted by Christopher7

Sophistry.
In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g.

The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph.

But during that same time period, the acceleration graph has the acceleration at >g and then <g.

And you were shown two different things. You were shown (or explained) an acceleration graph, then you were shown (or explained) a velocity graph.

Once again, two different things.

Did you not tell me you studied physics or engineering at one point?

pgimeno · 22nd July 2012, 02:23 AM

Originally Posted by Christopher7

Sophistry.
In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g.

The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph.

You seem to like average accelerations. Can you show us what the average acceleration is during these 0.7 seconds, Christopher7?

Just so you don't make that false statement again, you know...

But notice how I didn't accuse you of lying, unlike what you've done with NIST so many times about what turned out to be a typographical error.

Care to retract your accusations that NIST lied about the width of the seat now, Christopher7? It's been two weeks since you were informed, and I haven't yet seen any statement from you taking back your accusations, much less issuing an apology. Is that how The Truth works for you? Or does 9/11 Truth follow different ethics rules where false accusations are just fine because they are evildoers anyway, so the more accusations the better, no matter if they are true or false?

Christopher7 · 22nd July 2012, 03:46 AM

Originally Posted by pgimeno

You seem to like average accelerations. Can you show us what the average acceleration is during these 0.7 seconds, Christopher7?

There cannot be negative velocity or negative downward acceleration [the building moving upward] so everything above the zero line is noise.
The velocity goes to ~1 foot per second at ~11.9s and the acceleration increases. The velocity stays at ~1's for ~0.3s [no acceleration] while the acceleration line says acceleration is increasing.
These two things are mutually exclusive. They cannot exist at the same time.

The velocity is = or > g between 12.6s and 13.2s but the acceleration says it hasn't reached g yet.
These two things are mutually exclusive. They cannot exist at the same time.

Christopher7 · 22nd July 2012, 03:58 AM

Originally Posted by pgimeno

Care to retract your accusations that NIST lied about the width of the seat now, Christopher7?

NIST lied again.

"The 5.5 in. dimension was the length of the girder bearing on the seat connection that had to slide off the seat axially to the girder. The 6.25 in. dimension accounted for the length from the flange tip to the far side of the web, so that the web was no longer supported on the bearing plate. This change corrects a typographical error which showed a lateral displacement of 5.5 in. instead of the correct value of 6.25 in., which was used in the analyses."

The bearing length was 6.25 (4.25+2) inches along the axis. Flange tip to far side of web was 6.05 = (11.51+0.58)/2 inches. Edge of bearing plate to far side of web was (12+0.58)/2 = 6.29 inches. Typographical error? What was 5.5 inches other than half the length of the fictitious 11-inch bearing plate length?

They made no attempt to explain the omission of the stiffeners that would have prevented walk-off failure.

Oystein · 22nd July 2012, 06:33 AM

Originally Posted by Christopher7

The velocity is = or > g between 12.6s and 13.2s ...

[ETA: In C7's graph, the interval from 12.6 to 13.3, not 13.2, is marked. I edit my post to reflect that change in Purple]

Which is it, Christopher7? = g? Or > g? (On average, of course). Can you do the math for us?
Here, I give you the numbers from the velocity graph:
12.6 s: -5 ft/s
13.3 s: -35 ft/s
Do you see those values, too?

So what's the average acceleration then in that interval?

My calculation is (-35 ft/s - (-5 ft/s)) / (13.3 s - 12.8 s) = -30/0.7 ft/s² = 42.857 ft/s²
Do you get the same result, C7?

Alright, since we are gauging this from a graph, we should add an important little wiggle there: ~ 42.857 ft/s²

Are we in agreement on this?

What is g? I look it up and find...

g ≈32.174 ft/s²

Are we in agreement on this value of g?

Now, if we compare
~ 42.857 ft/s² and g ≈32.174 ft/s²
Are they about equal, C7, or is one larger than the other?

So would you still say that

"The velocity is = or > g between 12.6s and 13.3s"?

Or would you not rather agree that

"The ~~velocity~~ average acceleration is ~~= or~~ > g between 12.6s and 13.3s"?

(I predict a total dodge of all these questions by C7)

(P.S. I agree with you that femr2's "derivation" of the acceleration graph from the velocity graph is not what people well-versed in math terminology actually call "derivation", this being a rechnical term with a specific meaning in math. What he has done is a complicated type of moving average which includes data points from several tens ofseconds before and after each instance. This results in the "derived" value of a to lag behind the actual derivative of the (smoothed) velocity curve. Since you and I agree on this point, there is no need to reply to this P.S. beyond nodding your head. Please reply instead to the easy calculation above!)

Christopher7 · 22nd July 2012, 06:37 PM

Originally Posted by Oystein

[ETA: In C7's graph, the interval from 12.6 to 13.3, not 13.2, is marked. I edit my post to reflect that change in Purple]
Which is it, Christopher7? = g? Or > g? (On average, of course). Can you do the math for us?

You ask for the average to hide the fact that the velocity and acceleration lines show two different things.
Correction:
The velocity line is = or > g between 12.6s and 13.2s but the acceleration line says it hasn't reached g ~~yet~~ until 12.75s.

Quote:

Here, I give you the numbers from the velocity graph:
12.6 s: -5 ft/s
13.3 s: -35 ft/s
Do you see those values, too?

So what's the average acceleration then in that interval?

My calculation is (-35 ft/s - (-5 ft/s)) / (13.3 s - 12.8 s) = -30/0.7 ft/s² = 42.857 ft/s²
Do you get the same result, C7?

Interesting how you get an average acceleration of 42.857 ft/s² when the acceleration never exceeds 35 ft/s² on the velocity line or 39 ft/s² on the acceleration line.

Quote:

(P.S. I agree with you that femr2's "derivation" ...

FEMR's acceleration derivative distorts the data to the point that it is entirely different than the velocity graph which shows the acceleration as a descending line.

You ignored the part you cannot refute:

The velocity line goes to ~1 foot per second at ~11.9s and the acceleration line increases. [This is consistent]
But then the velocity line stays at ~1's for ~0.3s [no acceleration] while the acceleration line says acceleration is increasing.
These two things are mutually exclusive. They cannot exist at the same time.

Oystein · 23rd July 2012, 01:53 AM

Originally Posted by Christopher7

You ask for the average to hide the fact that the velocity and acceleration lines show two different things.
Correction:
The velocity line is = or > g between 12.6s and 13.2s but the acceleration line says it hasn't reached g ~~yet~~ until 12.75s.

Forget about the acceleration line. I already agreed with you that femr2's acceleration line is not the derivation of the velocity line. Just forget about it for a moment, ok?

Originally Posted by Christopher7

Interesting how you get an average acceleration of 42.857 ft/s² when the acceleration never exceeds 35 ft/s² on the velocity line or 39 ft/s² on the acceleration line.

What the... are you serious??
You do realize, do you, that the velocity line does NOT plot values expressed in ft/s², right? It's ft/s, without the ². You don't seem to understand the difference, or do you? Average acceleration between two points on the velocity graph is the slope of a straight line that connects these two points, right?

Here, I drew that line for you -it's thin and brownish and goes through the red line at 12.6 s|-5 ft/s and 13.3 S| -35 ft/s

See how that brownish line hugs the red curve nicely for most of that interval?

C7, do you understand that the slope of this brown curve is the average acceleration in that 0.7 seconds interval, given the red velocity curve?

Abd do you undertstand that this slope is calculated by dividing delta-v by delta-t, or (v₂-v₁)(t₂-t₁), which in this case is ((-35+5) ft/s)/((13.3-12.6) s) = -30/0.7 ft/s² = -42.857 ft/s²?

Do you understand that the black line represents g? Do you understand that the brown line represents > g?

Do you agree that femr2's acceleration line SHOULD, by and large, be below 1g from about 12.6 s to 13.3 s?

Originally Posted by Christopher7

FEMR's acceleration derivative distorts the data to the point that it is entirely different than the velocity graph which shows the acceleration as a descending line.

Wait a second, do you really think that "the velocity graph ... shows the acceleration as a descending line"???

Do you think the blue line should be identical to the red line??

Originally Posted by Christopher7

You ignored the part you cannot refute:
...

Again, I didn't ignore this, I fully conceded that femr2's acceleration line is not the derivation of the velocity line. I fully agree, without further argument, that his acceleration line is inconsistent with the velocity line.

So let's forget about the acceleration line.

Let's concentrate on the velocity line.

Let's concentrate on the interval from 12.6 s to 13.3 s.
In that interval of 0.7 s, velocity changes by -30ft/s.
Do you see that?
Do you understand that?

Do you agree that the average velocity in that interval is then ~ -42.857 ft/s²

Is that = g, or is that > g?

Christopher7 · 23rd July 2012, 04:11 AM

Originally Posted by Oystein

You do realize, do you, that the velocity line does NOT plot values expressed in ft/s², right? It's ft/s, without the ².

The black line is free fall acceleration.
FEMR "~1.75s at ~FFA" [~13.1 to 14.85s]
http://forums.randi.org/showpost.php...postcount=5636

Quote:

Here, I drew that line for you -it's thin and brownish and goes through the red line at 12.6 s|-5 ft/s and 13.3 S| -35 ft/s

I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g.

A line steeper than the black g or FFA line is >g

Quote:

Do you agree that femr2's acceleration line SHOULD, by and large, be below 1g from about 12.6 s to 13.3 s?

No, it should show the same rate of descent as the acceleration on the velocity graph.

NIST has the FFA line acceding [in red]. FEMR added his line in black

Oystein · 23rd July 2012, 05:02 AM

Again, C7, forget femr7 and his acceleration line. It's weird, too much processed in unintuitive ways, and isn't very helpful.

Forget about NIST, too, for the moment, let's not talk aboit two different sets of data at the same time.

Originally Posted by Christopher7

The black line is free fall acceleration.
...
I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g.

A line steeper than the black g or FFA line is >g

Ahhh wonderful - is that orange line of yours new, or did I miss that earlier? If I missed it, apologies.

So you would agree that the roofline, according to femr2's velocity data, was (on average) accelerating at MORE than g for about 0.7 seconds?

I want you to contrast your reply to your earlier post, where you said that for 0.6 s the roofline was accelerating at "= g or > g", and ask you straight: Should you not have dropped the "= g or" part, because clearly my brown line indicates an average of about 42.9 ft/s², which is ~ 33% more than the about 32.2 ft/s² = g? One-third higher than g for 0.7 s surely is significant, not?

(By the way - your orange line ends at ca. 13.1 s, even though the red curve continues to drop more steeply than the black line - why? Had you continued to the 13.3 s mark, as pgimeno did, then your orange line would have been even steeper, indicating an ever higher acceleration)

pgimeno · 23rd July 2012, 06:59 AM

Originally Posted by Christopher7

The velocity is = or > g between 12.6s and 13.2s but the acceleration says it hasn't reached g yet.

Thanks, So, I take it you will openly admit that this graphic of yours is misleading with respect to the first line you've painted.

On a different subject, I agree that if X is clearly greater than Y, then it's logically true that X is "equal or greater" than Y, but that's highly misleading too - it's too obvious to anyone how you are doubletalking here, something you often accuse others of doing, meaning you seem to have twice as many standards as others.

Originally Posted by Christopher7

These two things are mutually exclusive. They cannot exist at the same time.

It's the result of smoothing. But don't worry, I don't expect you to understand that simple concept. As they say, I can explain to you, but I can't understand it for you, much less if you're unwilling to understand, as you've shown is the case. So I won't bother explaining either.

pgimeno · 23rd July 2012, 07:03 AM

Originally Posted by Christopher7

I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g.

http://img826.imageshack.us/img826/9316/femr8e.jpg

Nice. But it spans a shorter period of time (until about 13.1s), out of which (in the period from 13.1 to 13.3s) the acceleration is even greater than that. So it's not a bad idea to average over the whole 0.7s period, after all.

You seem to be going through great effort to deny > g.

pgimeno · 23rd July 2012, 07:05 AM

Originally Posted by Christopher7

NIST lied again.

You can accumulate unproven accusations as much as you want, but we're talking about your specific accusation (that you've repeated multiple times as I noted) that they used in their analysis the wrong width of the seat in order to obtain the desired results.

I've shown you how the width of the seat in the diagrams showing the model they used is wider than the 11.5" flange of the girder, therefore they could not have used an 11" seat (figures 11-15 and 12-24) therefore it must be a typo.

So, will you retract that accusation?

fitzgibbon · 23rd July 2012, 07:45 AM

Originally Posted by Miragememories

Please explain what is significant about being told something by a professor of theology?

MM

Or a television editor for that matter? If it isn't about split edits, the merits of FCP vs Avid vs Premiere, etc. I'd venture such an editor would be into the realm of opinion as concerns structural engineering and such.

What do you think, MM?

Fitz

fitzgibbon · 23rd July 2012, 08:09 AM

Originally Posted by Miragememories

Your statement puts the credibility of this thread to the test.

MM

Fitz

tfk · 23rd July 2012, 09:19 AM

Here are a couple of curves that are at least self-consistent.

Velocity:

Acceleration:

Notice the inflection points (i.e., minimum & maximum) in the velocity curve at 3.8 sec (minimum) and 4.2 sec (maximum). At all inflection points, the acceleration has to be zero. Note that, as expected, the acceleration curve crosses the zero axis at 3.8 & 4.2 sec.

Note the near horizontal "shelf" at ~7.4 sec in the velocity curve. Note that the acceleration trends upward at this same time, approaching (but not reaching) the zero axis.

Note that there is another minimum in the velocity curve at about 8.9 seconds. Note that the acceleration curve also has a zero crossing at this same time.

So these two curves are self-consistent and demonstrably show "near instantaneous" velocity & acceleration.

They show 4 points of instantaneously passing thru g, and they show no time at all "at g".

Note 1: the red fill on the acceleration chart is, obviously, the time intervals over which the acceleration is >G.

Note 2: the time indices do not align between my graphs & femr's because I truncated his data set.

Christopher7 · 23rd July 2012, 10:19 PM

Originally Posted by Oystein

Again, C7, forget femr7 and his acceleration line. It's weird, too much processed in unintuitive ways, and isn't very helpful.

The point is:
FEMR's acceleration line has entirely different results than the acceleration as shown on the velocity graph. It is not valid.

Spanx · 23rd July 2012, 10:29 PM

Originally Posted by Christopher7

The point is:
FEMR's acceleration line has entirely different results than the acceleration as shown on the velocity graph. It is not valid.

A bit like MS paint on pictures then

Christopher7 · 23rd July 2012, 11:01 PM

Originally Posted by pgimeno

Thanks, So, I take it you will openly admit that this graphic of yours is misleading with respect to the first line you've painted.

http://img543.imageshack.us/img543/3540/femr5ec.jpg

This just demonstrates that the data for this time period can be interpreted in different ways. The input data is imperfect because it was taken from a video and there is a margin of error in the derivative of that information.
It's reasonable to say that there was a moment of >g but beyond that is conjecture.

Quote:

These two things are mutually exclusive. They cannot exist at the same time.

Quote:

It's the result of smoothing.

No, the results are entirely different.
FEMR's acceleration line shows 0.8s from release to >g but the acceleration as shown on the velocity graph shows release to >g as ~0.1 to 0.2s

From 12s to 12.3s the velocity line shows no acceleration but the acceleration line shows increasing acceleration.

Even with the smoothing there is variation in the data points from the actual acceleration. There cannot be negative velocity or negative downward acceleration [the building moving upward] so all the points above the zero line are erroneous. This demonstrates that FEMR's more accurate method, even when smoothed to minimize the error, is still imperfect.

Christopher7 · 23rd July 2012, 11:10 PM

Originally Posted by Spanx

A bit like MS paint on pictures then

MS paint is adequate to show the discrepancies between FEMR's velocity and acceleration graphs. The poo-pooing of MS paint is a lame excuse to hand wave the fact that FEMR's acceleration graph is not valid.

Spanx · 23rd July 2012, 11:36 PM

Originally Posted by Christopher7

MS paint is adequate to show the discrepancies between FEMR's velocity and acceleration graphs. The poo-pooing of MS paint is a lame excuse to hand wave the fact that FEMR's acceleration graph is not valid.

Ok, when have enough posts and I am able to upload an image, would you be prepared to use your MS magic on it ?

tfk · 24th July 2012, 12:39 AM

You know, even a blind pig finds a truffle now & again.

Chris7 is absolutely right about this: femr's graph is totally hosed.

Originally Posted by Christopher7

MS paint is adequate to show the discrepancies between FEMR's velocity and acceleration graphs. The poo-pooing of MS paint is a lame excuse to hand wave the fact that FEMR's acceleration graph is not valid.

Of course, Chris7 is totally unable to explain the why's & wherefore's.

Here it is.

We can only check for self-consistency at the moment. It'd be interesting to see how good or bad his height to velocity calculation is. I suspect that it is just as bad as his velocity to acceleration. Only because I believe that he used the same algorithm going from height to velocity as he did going from velocity to acceleration.

And that algorithm is screwed.

Here is a summary of what ferm's acceleration graph should look like.

The chart shows 12 zones separated by 11 arrows.

Each of those arrows represent an inflection point in the velocity curve. As such, the acceleration (blue line) at each arrow point should be crossing the X (acceleration = 0) axis.

It is easy to see that femr's acceleration graph has only 2 zero crossings (@11.7 & 12.1 sec), and neither of them have any temporal relationship to their proper locations.

So right off the bat, something is drastically wrong.

When we look at the sign that the magnitude of the acceleration should have, the picture gets even worse.

Here is what sign of the acceleration should be over the interval of each zone, and what is shown on femr's acceleration (blue) line:

Zone	Should be	is	Result
1	+	- then +	wrong
2	-	+	wrong
3	0	+	wrong
4	-	+	wrong
5	+	+ then -	wrong
6	slightly -, constant	-, changing	wrong
7	+	-	wrong
8	slightly -	highly -	wrong
9	+	highly -	wrong
10	start @ 0, moderately -	start @ highly -, -	wrong
11	0	highly -	wrong
12	-, approx constant	-, changing	wrong

In short, femr's acceleration graph is completely incompatible with his velocity graph.

"Sounds like truffles for dinner, boys!!"

tom

PS. BTW, is "derivation" a British equivalent to the US's "take a derivative"?

Over here, "derivative" is the noun. "Take the derivative" is the verb.

"Derivation" is something completely different.

Oystein · 24th July 2012, 02:48 AM

Originally Posted by Christopher7

...
It's reasonable to say that there was a moment of >g but beyond that is conjecture.
...

Let me get this clear:

You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA?

tfk · 24th July 2012, 07:00 AM

Originally Posted by Oystein

Let me get this clear:

You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA?

Just as important, he's back-peddling from his previous "there is only one interpretation of the data"...

Originally Posted by Christopher7

The black line is free fall acceleration.
FEMR "~1.75s at ~FFA" [~13.1 to 14.85s]
http://forums.randi.org/showpost.php...postcount=5636

I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g.

http://img826.imageshack.us/img826/9316/femr8e.jpg

Christopher7 · 24th July 2012, 10:08 AM

Originally Posted by Oystein

Let me get this clear:

You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA?

FEMR's velocity graph shows the acceleration to be indistinguishable from FFA for ~1.75s. I rounded off to 1.8s. The descent just before that was >g. The duration of >g is a matter of interpretation of the data.

Christopher7 · 24th July 2012, 10:16 AM

Originally Posted by tfk

Just as important, he's back-peddling from his previous "there is only one interpretation of the data"...

Please show where I said that.

ETA: Thank you for acknowledging that FEMR's acceleration graph is incorrect.

tfk · 24th July 2012, 11:15 AM

Originally Posted by Christopher7

Please show where I said that.

Ummm … you're kidding, right??

I want you to think very hard about 2 concepts.

1) the "quote" function.
2) the "bold" function.

Now, with these two concepts firmly in mind, I want you to go back & re-read this very short post in which I drew that conclusion. See if there is anything, any thing at all, that you can find in that post, something that might be related to the "quote" function and/or the "bold" function, that might give you an idea where I drew that conclusion.

___

Originally Posted by Christopher7

ETA: Thank you for acknowledging that FEMR's acceleration graph is incorrect.

Oh, trust me on this one ...

... my pleasure.

tfk · 24th July 2012, 11:25 AM

Christopher7,

BTW, I said that "at least" his acceleration graph is hosed. I also said that I believed that his velocity one was too, because I believe that he used the same algorithm to generate it from his position vs. time data.

To be complete, I believe that his position vs. time data is very good. That is why I used it as the source data to generate my own velocity & acceleration curves.

Note: I also believe that there are likely significant uncorrected perspective errors even in his position data.

My graphs are not hosed. They are completely consistent with each other.

Now, using my acceleration vs. time graph, please show me where you think "free fall acceleration" occurred for any length of time.

2nd question: do you understand the difference between instantaneous acceleration & average acceleration?

Do you understand that, if you change the length of time over which you average something, then the reported average value can (and generally will) change?

Do you understand the inexorable conclusion that results from attempting to calculate acceleration by applying a "linear fit to the velocity data"?? If so, please state that conclusion as concisely as you can.

Do you understand that, if one were to apply a linear fit to the height versus age of humans, then - no matter how accurate the measurements, no matter how frequent the measurements - the inexorable - and WRONG - conclusion would be that "humans do not experience growth spurts"?

Do you understand that the error in this conclusion is NOT the result of "measurement errors"?

Do you understand how this last example applies to the collapse of the outer walls of WTC7?

Let's see if you can step up & answer a couple of simple questions.

carlitos · 24th July 2012, 12:07 PM

Add me to the list of people that were confused by the unorthodox use of the word "derived."

Oystein · 24th July 2012, 02:14 PM

Originally Posted by Christopher7

FEMR's velocity graph shows the acceleration to be indistinguishable from FFA for ~1.75s. I rounded off to 1.8s. The descent just before that was >g. The duration of >g is a matter of interpretation of the data.

http://img543.imageshack.us/img543/3540/femr5ec.jpg

Ok, those ~ 1.8 seconds of what you interprete as "indistinguishable from FFA" are preceded by ~0.8 seconds of >0 acceleration, i.e. collapse, that you divide into...
0.1 s of <g
0.3s of very roughly around g
0.4 s clearly >g

How much did the north wall descend during that time?
What happened to the vertical supports further below during that time?
How do you explain >g?
Did the WTC7 north wall go into ~FFA immediately, suddenly, as AE911Truth claims?

Christopher7 · 24th July 2012, 02:43 PM

Originally Posted by tfk

I believe that his position vs. time data is very good.
... using my acceleration vs. time graph ...

Post the graphs you are referring to please.

Insulting and irrelevant subject shifting questions deleted.

tfk · 24th July 2012, 04:52 PM

Originally Posted by Christopher7

Post the graphs you are referring to please.

Insulting and irrelevant subject shifting questions deleted.

Look upward on this page. Post #6059.

I asked you several directly relevant questions.
You find my asking you questions "insulting & irrelevant"?

FYI, I happen to find your continuing predilection to ignore questions asked of you to be rude, bordering on insulting.

Christopher7 · 24th July 2012, 06:35 PM

Originally Posted by Oystein

Ok, those ~ 1.8 seconds of what you interprete as "indistinguishable from FFA" are preceded by ~0.8 seconds of >0 acceleration, i.e. collapse, that you divide into...
0.1 s of <g
0.3s of very roughly around g
0.4 s clearly >g

How much did the north wall descend during that time
What happened to the vertical supports further below during that time?
How do you explain >g?
Did the WTC7 north wall go into ~FFA immediately, suddenly, as AE911Truth claims?

Point taken. That interpretation of the data does not work with my original hypothesis: The core columns started down a split second before the exterior walls and pulled them down a little before the lower floors of the exterior walls were removed allowing the exterior walls to fall at FFA. The interior columns, which were already moving downward, pulled the exterior columns down at slightly faster than FFA for a split second until they equalized. This was confirmed by Major Tom in post 5782.
http://forums.randi.org/showpost.php...postcount=5782

Tom never responded to my request to show his data and how it relates to the video like I did in post 5786.
http://forums.randi.org/showpost.php...postcount=5786

This interpretation fits the above scenario:
The building did not grow several inches so the red velocity line above the zero line between 11.6s and 11.8s is noise. It follows that the 0.3s of 1'/s descent may also be noise.
If not, between ~12s to 12.3s, the core columns pull the exterior columns down ~4 inches.
There is a slight pause (?)
For 0.25s the core columns pull exterior columns down at an average of 2.5'/s [~8 inches].
Then a miracle happens.

Or
All the supporting structure is removed in a synchronistic manner.

Oystein · 24th July 2012, 10:03 PM

Originally Posted by Christopher7

Point taken. That interpretation of the data does not work with my original hypothesis:

Good.

Originally Posted by Christopher7

The core columns started down a split second before the exterior walls and pulled them down a little before the lower floors of the exterior walls were removed allowing the exterior walls to fall at FFA. The interior columns, which were already moving downward, pulled the exterior columns down at slightly faster than FFA for a split second until they equalized.

I am slightly confused - that is not your original hypothesis, ir is it?

Originally Posted by Christopher7

This was confirmed by Major Tom in post 5782.
http://forums.randi.org/showpost.php...postcount=5782

Tom never responded to my request to show his data and how it relates to the video like I did in post 5786.
http://forums.randi.org/showpost.php...postcount=5786

Never mind Major_Tom

Originally Posted by Christopher7

This interpretation fits the above scenario:
The building did not grow several inches so the red velocity line above the zero line between 11.6s and 11.8s is noise. It follows that the 0.3s of 1'/s descent may also be noise.

Yes, but a) it may also be not noise an b) it may be due to noise that we miss some earlier slow downward motion.
Such is the nature of noise, and it's pure guesswork at least until someone has quantified noise.

Originally Posted by Christopher7

If not, between ~12s to 12.3s, the core columns pull the exterior columns down ~4 inches.

How could this be, if the exterior columns aren't slowly giving way already?

Originally Posted by Christopher7

There is a slight pause (?)
For 0.25s the core columns pull exterior columns down at an average of 2.5'/s [~8 inches].
Then a miracle happens.

The miracle must have already happened then: In order for this displacement of ~8 inches to take place (at less than g), the exterior columns must already be slowly giving way somewhere.

Originally Posted by Christopher7

Or
All the supporting structure is removed in a synchronistic manner.

http://img10.imageshack.us/img10/2165/femr8e3.jpg

All the supporting exterior structure has already been in the process of failing for some non-zero interval at this point, AND the core, and with it the floors, have been in the process of failing even a split-second longer.

PLUS:
The >FFA episode, which you time to have lasted ~0.3 s, shows that real and significant down forces beyond and above mere gravity were acting on the north wall - obviously a "pull" from neighboring structure. How do you know this pull did't start earlier, end later, or wasn't of greater magnitude than what's needed to account for the difference between actual acceleration (above g) and g?
In other words: Once you know that another, not quantified force was acting on the north wall, how dou know it had no support for some of the time that the descent was very near (indistinguishable from) g?

I think, with all the noise, you can't rule out that the north wall came down a significant drop distance with some structural resistance (some of it offset for some time by a downward pull from the core structure), which means failure wasn't sudden, it was gradual.

(By the way: Drop distance shouldn't be calculated from average velocity eyeballed in a graph; we have drop distance in the raw data.)

tfk · 24th July 2012, 10:25 PM

Bump for Chris7.

Any reply to any of the following?

http://forums.randi.org/showpost.php...postcount=6071
http://forums.randi.org/showpost.php...postcount=6075
(which references http://forums.randi.org/showpost.php...postcount=6059)

pgimeno · 25th July 2012, 06:24 AM

Originally Posted by Christopher7

For 0.25s the core columns pull exterior columns down at an average of 2.5'/s [~8 inches].
Then a miracle happens.

Or
All the supporting structure is removed in a synchronistic manner.

... or...

... the joints give way as bolts break, thus losing all structural integrity and going to zero strength in a snap (excuse the pun),

... or...

... the pull-down force continues, roughly equating the resistance force.

The "all the supporting structure is removed in a synchronistic manner" hypothesis being the least likely of all four. Yes, even less than the miracle one, for a relaxed definition of 'miracle'. And the bolts breaking at the joints being the most likely one.

DGM · 25th July 2012, 09:24 AM

Originally Posted by Christopher7

The core columns started down a split second before the exterior walls

By "split second" you mean 5 or 6, to coincide with the fall of the penthouses.

21st July 2012, 09:39 PM	#6043
dc1971 Banned Join Date: Oct 2009 Posts: 3,033	Originally Posted by Christopher7 How do you explain the discrepancies in your graphs? The acceleration graph has 0.0s at FFA But the velocity graph has ~1.75s at ~FFA [sic]. Because acceleration and velocity are two different things.
dc1971 Banned Join Date: Oct 2009 Posts: 3,033

22nd July 2012, 12:14 AM	#6045
dc1971 Banned Join Date: Oct 2009 Posts: 3,033	Originally Posted by Christopher7 Sophistry. In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g. The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph. But during that same time period, the acceleration graph has the acceleration at >g and then <g. And you were shown two different things. You were shown (or explained) an acceleration graph, then you were shown (or explained) a velocity graph. Once again, two different things. Did you not tell me you studied physics or engineering at one point?
dc1971 Banned Join Date: Oct 2009 Posts: 3,033

22nd July 2012, 02:23 AM	#6046
pgimeno Graduate Poster Join Date: Feb 2009 Location: Spain Posts: 1,320	Originally Posted by Christopher7 Sophistry. In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g. The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph. You seem to like average accelerations. Can you show us what the average acceleration is during these 0.7 seconds, Christopher7? Just so you don't make that false statement again, you know... But notice how I didn't accuse you of lying, unlike what you've done with NIST so many times about what turned out to be a typographical error. Care to retract your accusations that NIST lied about the width of the seat now, Christopher7? It's been two weeks since you were informed, and I haven't yet seen any statement from you taking back your accusations, much less issuing an apology. Is that how The Truth works for you? Or does 9/11 Truth follow different ethics rules where false accusations are just fine because they are evildoers anyway, so the more accusations the better, no matter if they are true or false?
	__________________ Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.

22nd July 2012, 03:58 AM	#6048
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by pgimeno Care to retract your accusations that NIST lied about the width of the seat now, Christopher7? NIST lied again. "The 5.5 in. dimension was the length of the girder bearing on the seat connection that had to slide off the seat axially to the girder. The 6.25 in. dimension accounted for the length from the flange tip to the far side of the web, so that the web was no longer supported on the bearing plate. This change corrects a typographical error which showed a lateral displacement of 5.5 in. instead of the correct value of 6.25 in., which was used in the analyses." The bearing length was 6.25 (4.25+2) inches along the axis. Flange tip to far side of web was 6.05 = (11.51+0.58)/2 inches. Edge of bearing plate to far side of web was (12+0.58)/2 = 6.29 inches. Typographical error? What was 5.5 inches other than half the length of the fictitious 11-inch bearing plate length? They made no attempt to explain the omission of the stiffeners that would have prevented walk-off failure.
	Last edited by Christopher7; 22nd July 2012 at 04:00 AM.

22nd July 2012, 06:33 AM	#6049
Oystein Philosopher Join Date: Dec 2009 Location: Germany Posts: 9,929	Originally Posted by Christopher7 The velocity is = or > g between 12.6s and 13.2s ... [ETA: In C7's graph, the interval from 12.6 to 13.3, not 13.2, is marked. I edit my post to reflect that change in Purple] Which is it, Christopher7? = g? Or > g? (On average, of course). Can you do the math for us? Here, I give you the numbers from the velocity graph: 12.6 s: -5 ft/s 13.3 s: -35 ft/s Do you see those values, too? So what's the average acceleration then in that interval? My calculation is (-35 ft/s - (-5 ft/s)) / (13.3 s - 12.8 s) = -30/0.7 ft/s² = 42.857 ft/s² Do you get the same result, C7? Alright, since we are gauging this from a graph, we should add an important little wiggle there: ~ 42.857 ft/s² Are we in agreement on this? What is g? I look it up and find... g ≈32.174 ft/s² Are we in agreement on this value of g? Now, if we compare ~ 42.857 ft/s² and g ≈32.174 ft/s² Are they about equal, C7, or is one larger than the other? So would you still say that "The velocity is = or > g between 12.6s and 13.3s"? Or would you not rather agree that "The ~~velocity~~ average acceleration is ~~= or~~ > g between 12.6s and 13.3s"? (I predict a total dodge of all these questions by C7) (P.S. I agree with you that femr2's "derivation" of the acceleration graph from the velocity graph is not what people well-versed in math terminology actually call "derivation", this being a rechnical term with a specific meaning in math. What he has done is a complicated type of moving average which includes data points from several tens ofseconds before and after each instance. This results in the "derived" value of a to lag behind the actual derivative of the (smoothed) velocity curve. Since you and I agree on this point, there is no need to reply to this P.S. beyond nodding your head. Please reply instead to the easy calculation above!)
	Last edited by Oystein; 22nd July 2012 at 06:41 AM.

21st July 2012, 10:32 AM	#6041
carlitos "más divertido" Join Date: Jul 2009 Posts: 11,635	Originally Posted by MileHighMadness Anthony Hilder...you have to be kidding, the guy is an idiot, firebrand and lying con artist. He so far down the rabbit hole, even the mad hatter thinks he's nuts. I watched an interview between him and Jim Fetzer, it was like something out of SNL, everything they said kept getting more and more strange. Anthony Hilder...that's the best you got! Man...fold your tent and go home...the battle is lost. TTFG* = first frame of video. You don't even have to press 'play' to see it. *Time to first Godwin

21st July 2012, 09:29 PM	#6042
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by femr2 My acceleration graph shows: a) Rapid increase in acceleration from release to somewhat over-g in approximately 1s. At the end of this period, the NW corner had descended ~9ft b) Slow reduction in acceleration to approximately g over approximately 1.5s. At the end of this period, the NW corner had descended ~83ft c) More rapid reduction in acceleration to roughly constant velocity over approximately 2s. At the end of this period, the NW corner had descended ~270ft If you use the velocity graph you'll obviously miss some profile shape detail, but you could say... ~1.75s at ~FFA (and I'd not complain too much) How do you explain the discrepancies in your graphs? The acceleration graph has 0.0s at FFA But the velocity graph has ~1.75s at ~FFA [sic].

21st July 2012, 10:45 PM	#6044
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by dc1971 Because acceleration and velocity are two different things. Sophistry. In physics, acceleration is the rate at which the velocity of a body changes with time. The velocity graph shows the velocity increasing [accelerating] at g. The acceleration is indistinguishable from g for ~1.75s [13.1 to 14.9s] in the velocity graph. But during that same time period, the acceleration graph has the acceleration at >g and then <g.

22nd July 2012, 03:46 AM	#6047
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by pgimeno You seem to like average accelerations. Can you show us what the average acceleration is during these 0.7 seconds, Christopher7? There cannot be negative velocity or negative downward acceleration [the building moving upward] so everything above the zero line is noise. The velocity goes to ~1 foot per second at ~11.9s and the acceleration increases. The velocity stays at ~1's for ~0.3s [no acceleration] while the acceleration line says acceleration is increasing. These two things are mutually exclusive. They cannot exist at the same time. The velocity is = or > g between 12.6s and 13.2s but the acceleration says it hasn't reached g yet. These two things are mutually exclusive. They cannot exist at the same time.

22nd July 2012, 06:37 PM	#6050
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Oystein [ETA: In C7's graph, the interval from 12.6 to 13.3, not 13.2, is marked. I edit my post to reflect that change in Purple] Which is it, Christopher7? = g? Or > g? (On average, of course). Can you do the math for us? You ask for the average to hide the fact that the velocity and acceleration lines show two different things. Correction: The velocity line is = or > g between 12.6s and 13.2s but the acceleration line says it hasn't reached g ~~yet~~ until 12.75s. Quote: Here, I give you the numbers from the velocity graph: 12.6 s: -5 ft/s 13.3 s: -35 ft/s Do you see those values, too? So what's the average acceleration then in that interval? My calculation is (-35 ft/s - (-5 ft/s)) / (13.3 s - 12.8 s) = -30/0.7 ft/s² = 42.857 ft/s² Do you get the same result, C7? Interesting how you get an average acceleration of 42.857 ft/s² when the acceleration never exceeds 35 ft/s² on the velocity line or 39 ft/s² on the acceleration line. Quote: (P.S. I agree with you that femr2's "derivation" ... FEMR's acceleration derivative distorts the data to the point that it is entirely different than the velocity graph which shows the acceleration as a descending line. You ignored the part you cannot refute: The velocity line goes to ~1 foot per second at ~11.9s and the acceleration line increases. [This is consistent] But then the velocity line stays at ~1's for ~0.3s [no acceleration] while the acceleration line says acceleration is increasing. These two things are mutually exclusive. They cannot exist at the same time.

23rd July 2012, 01:53 AM	#6051
Oystein Philosopher Join Date: Dec 2009 Location: Germany Posts: 9,929	Originally Posted by Christopher7 You ask for the average to hide the fact that the velocity and acceleration lines show two different things. Correction: The velocity line is = or > g between 12.6s and 13.2s but the acceleration line says it hasn't reached g ~~yet~~ until 12.75s. Forget about the acceleration line. I already agreed with you that femr2's acceleration line is not the derivation of the velocity line. Just forget about it for a moment, ok? Originally Posted by Christopher7 Interesting how you get an average acceleration of 42.857 ft/s² when the acceleration never exceeds 35 ft/s² on the velocity line or 39 ft/s² on the acceleration line. What the... are you serious?? You do realize, do you, that the velocity line does NOT plot values expressed in ft/s², right? It's ft/s, without the ². You don't seem to understand the difference, or do you? Average acceleration between two points on the velocity graph is the slope of a straight line that connects these two points, right? Here, I drew that line for you -it's thin and brownish and goes through the red line at 12.6 s\|-5 ft/s and 13.3 S\| -35 ft/s See how that brownish line hugs the red curve nicely for most of that interval? C7, do you understand that the slope of this brown curve is the average acceleration in that 0.7 seconds interval, given the red velocity curve? Abd do you undertstand that this slope is calculated by dividing delta-v by delta-t, or (v₂-v₁)(t₂-t₁), which in this case is ((-35+5) ft/s)/((13.3-12.6) s) = -30/0.7 ft/s² = -42.857 ft/s²? Do you understand that the black line represents g? Do you understand that the brown line represents > g? Do you agree that femr2's acceleration line SHOULD, by and large, be below 1g from about 12.6 s to 13.3 s? Originally Posted by Christopher7 FEMR's acceleration derivative distorts the data to the point that it is entirely different than the velocity graph which shows the acceleration as a descending line. Wait a second, do you really think that "the velocity graph ... shows the acceleration as a descending line"??? Do you think the blue line should be identical to the red line?? Originally Posted by Christopher7 You ignored the part you cannot refute: ... Again, I didn't ignore this, I fully conceded that femr2's acceleration line is not the derivation of the velocity line. I fully agree, without further argument, that his acceleration line is inconsistent with the velocity line. So let's forget about the acceleration line. Let's concentrate on the velocity line. Let's concentrate on the interval from 12.6 s to 13.3 s. In that interval of 0.7 s, velocity changes by -30ft/s. Do you see that? Do you understand that? Do you agree that the average velocity in that interval is then ~ -42.857 ft/s² Is that = g, or is that > g?
	Last edited by Oystein; 23rd July 2012 at 01:56 AM.

23rd July 2012, 04:11 AM	#6052
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Oystein You do realize, do you, that the velocity line does NOT plot values expressed in ft/s², right? It's ft/s, without the ². The black line is free fall acceleration. FEMR "~1.75s at ~FFA" [~13.1 to 14.85s] http://forums.randi.org/showpost.php...postcount=5636 Quote: Here, I drew that line for you -it's thin and brownish and goes through the red line at 12.6 s\|-5 ft/s and 13.3 S\| -35 ft/s I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g. A line steeper than the black g or FFA line is >g Quote: Do you agree that femr2's acceleration line SHOULD, by and large, be below 1g from about 12.6 s to 13.3 s? No, it should show the same rate of descent as the acceleration on the velocity graph. NIST has the FFA line acceding [in red]. FEMR added his line in black

23rd July 2012, 05:02 AM	#6053
Oystein Philosopher Join Date: Dec 2009 Location: Germany Posts: 9,929	Again, C7, forget femr7 and his acceleration line. It's weird, too much processed in unintuitive ways, and isn't very helpful. Forget about NIST, too, for the moment, let's not talk aboit two different sets of data at the same time. Originally Posted by Christopher7 The black line is free fall acceleration. ... I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g. A line steeper than the black g or FFA line is >g Ahhh wonderful - is that orange line of yours new, or did I miss that earlier? If I missed it, apologies. So you would agree that the roofline, according to femr2's velocity data, was (on average) accelerating at MORE than g for about 0.7 seconds? I want you to contrast your reply to your earlier post, where you said that for 0.6 s the roofline was accelerating at "= g or > g", and ask you straight: Should you not have dropped the "= g or" part, because clearly my brown line indicates an average of about 42.9 ft/s², which is ~ 33% more than the about 32.2 ft/s² = g? One-third higher than g for 0.7 s surely is significant, not? (By the way - your orange line ends at ca. 13.1 s, even though the red curve continues to drop more steeply than the black line - why? Had you continued to the 13.3 s mark, as pgimeno did, then your orange line would have been even steeper, indicating an ever higher acceleration)

23rd July 2012, 06:59 AM	#6054
pgimeno Graduate Poster Join Date: Feb 2009 Location: Spain Posts: 1,320	Originally Posted by Christopher7 The velocity is = or > g between 12.6s and 13.2s but the acceleration says it hasn't reached g yet. Thanks, So, I take it you will openly admit that this graphic of yours is misleading with respect to the first line you've painted. On a different subject, I agree that if X is clearly greater than Y, then it's logically true that X is "equal or greater" than Y, but that's highly misleading too - it's too obvious to anyone how you are doubletalking here, something you often accuse others of doing, meaning you seem to have twice as many standards as others. Originally Posted by Christopher7 These two things are mutually exclusive. They cannot exist at the same time. It's the result of smoothing. But don't worry, I don't expect you to understand that simple concept. As they say, I can explain to you, but I can't understand it for you, much less if you're unwilling to understand, as you've shown is the case. So I won't bother explaining either.
	__________________ Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.

23rd July 2012, 07:03 AM	#6055
pgimeno Graduate Poster Join Date: Feb 2009 Location: Spain Posts: 1,320	Originally Posted by Christopher7 I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g. http://img826.imageshack.us/img826/9316/femr8e.jpg Nice. But it spans a shorter period of time (until about 13.1s), out of which (in the period from 13.1 to 13.3s) the acceleration is even greater than that. So it's not a bad idea to average over the whole 0.7s period, after all. You seem to be going through great effort to deny > g.
	__________________ Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.

23rd July 2012, 07:05 AM	#6056
pgimeno Graduate Poster Join Date: Feb 2009 Location: Spain Posts: 1,320	Originally Posted by Christopher7 NIST lied again. You can accumulate unproven accusations as much as you want, but we're talking about your specific accusation (that you've repeated multiple times as I noted) that they used in their analysis the wrong width of the seat in order to obtain the desired results. I've shown you how the width of the seat in the diagrams showing the model they used is wider than the 11.5" flange of the girder, therefore they could not have used an 11" seat (figures 11-15 and 12-24) therefore it must be a typo. So, will you retract that accusation?
	__________________ Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.

23rd July 2012, 07:45 AM	#6057
fitzgibbon Master Poster Join Date: May 2007 Location: Just west of the centre of the universe Posts: 2,553	Originally Posted by Miragememories Please explain what is significant about being told something by a professor of theology? MM Or a television editor for that matter? If it isn't about split edits, the merits of FCP vs Avid vs Premiere, etc. I'd venture such an editor would be into the realm of opinion as concerns structural engineering and such. What do you think, MM? Fitz
	__________________ "Television is a circus, a carnival, a traveling troupe of acrobats, storytellers, dancers, singers, jugglers, side-show freaks, lion tamers, and football players. We're in the boredom-killing business! So if you want the truth... Go to God!" Howard Beale, "Network"

23rd July 2012, 08:09 AM	#6058
fitzgibbon Master Poster Join Date: May 2007 Location: Just west of the centre of the universe Posts: 2,553	Originally Posted by Miragememories Your statement puts the credibility of this thread to the test. MM Fitz
	__________________ "Television is a circus, a carnival, a traveling troupe of acrobats, storytellers, dancers, singers, jugglers, side-show freaks, lion tamers, and football players. We're in the boredom-killing business! So if you want the truth... Go to God!" Howard Beale, "Network"

23rd July 2012, 09:19 AM	#6059
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Here are a couple of curves that are at least self-consistent. Velocity: Acceleration: Notice the inflection points (i.e., minimum & maximum) in the velocity curve at 3.8 sec (minimum) and 4.2 sec (maximum). At all inflection points, the acceleration has to be zero. Note that, as expected, the acceleration curve crosses the zero axis at 3.8 & 4.2 sec. Note the near horizontal "shelf" at ~7.4 sec in the velocity curve. Note that the acceleration trends upward at this same time, approaching (but not reaching) the zero axis. Note that there is another minimum in the velocity curve at about 8.9 seconds. Note that the acceleration curve also has a zero crossing at this same time. So these two curves are self-consistent and demonstrably show "near instantaneous" velocity & acceleration. They show 4 points of instantaneously passing thru g, and they show no time at all "at g". Note 1: the red fill on the acceleration chart is, obviously, the time intervals over which the acceleration is >G. Note 2: the time indices do not align between my graphs & femr's because I truncated his data set.
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Last edited by tfk; 23rd July 2012 at 10:06 AM.

23rd July 2012, 10:19 PM	#6060
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Oystein Again, C7, forget femr7 and his acceleration line. It's weird, too much processed in unintuitive ways, and isn't very helpful. The point is: FEMR's acceleration line has entirely different results than the acceleration as shown on the velocity graph. It is not valid.

23rd July 2012, 10:29 PM	#6061
Spanx Muse Join Date: Jul 2012 Posts: 638	Originally Posted by Christopher7 The point is: FEMR's acceleration line has entirely different results than the acceleration as shown on the velocity graph. It is not valid. A bit like MS paint on pictures then
Spanx Muse Join Date: Jul 2012 Posts: 638

23rd July 2012, 11:01 PM	#6062
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by pgimeno Thanks, So, I take it you will openly admit that this graphic of yours is misleading with respect to the first line you've painted. http://img543.imageshack.us/img543/3540/femr5ec.jpg This just demonstrates that the data for this time period can be interpreted in different ways. The input data is imperfect because it was taken from a video and there is a margin of error in the derivative of that information. It's reasonable to say that there was a moment of >g but beyond that is conjecture. Quote: These two things are mutually exclusive. They cannot exist at the same time. Quote: It's the result of smoothing. No, the results are entirely different. FEMR's acceleration line shows 0.8s from release to >g but the acceleration as shown on the velocity graph shows release to >g as ~0.1 to 0.2s From 12s to 12.3s the velocity line shows no acceleration but the acceleration line shows increasing acceleration. Even with the smoothing there is variation in the data points from the actual acceleration. There cannot be negative velocity or negative downward acceleration [the building moving upward] so all the points above the zero line are erroneous. This demonstrates that FEMR's more accurate method, even when smoothed to minimize the error, is still imperfect.
	Last edited by Christopher7; 23rd July 2012 at 11:38 PM.

23rd July 2012, 11:10 PM	#6063
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Spanx A bit like MS paint on pictures then MS paint is adequate to show the discrepancies between FEMR's velocity and acceleration graphs. The poo-pooing of MS paint is a lame excuse to hand wave the fact that FEMR's acceleration graph is not valid.

23rd July 2012, 11:36 PM	#6064
Spanx Muse Join Date: Jul 2012 Posts: 638	Originally Posted by Christopher7 MS paint is adequate to show the discrepancies between FEMR's velocity and acceleration graphs. The poo-pooing of MS paint is a lame excuse to hand wave the fact that FEMR's acceleration graph is not valid. Ok, when have enough posts and I am able to upload an image, would you be prepared to use your MS magic on it ?
Spanx Muse Join Date: Jul 2012 Posts: 638

24th July 2012, 02:48 AM	#6066
Oystein Philosopher Join Date: Dec 2009 Location: Germany Posts: 9,929	Originally Posted by Christopher7 ... It's reasonable to say that there was a moment of >g but beyond that is conjecture. ... Let me get this clear: You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA?

24th July 2012, 07:00 AM	#6067
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Originally Posted by Oystein Let me get this clear: You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA? Just as important, he's back-peddling from his previous "there is only one interpretation of the data"... Originally Posted by Christopher7 The black line is free fall acceleration. FEMR "~1.75s at ~FFA" [~13.1 to 14.85s] http://forums.randi.org/showpost.php...postcount=5636 I drew a similar line in orange. Either is a reasonable interpretation of the data. Both are >g. http://img826.imageshack.us/img826/9316/femr8e.jpg
tfk Master Poster Join Date: Oct 2006 Posts: 2,978

24th July 2012, 10:08 AM	#6068
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Oystein Let me get this clear: You, Christopher7, have changed your long-held conviction that the north wall fell at g = FFA for uhhh 2 seconds or thereabouts, and now assert that for a non-zero span of time within those ~ 2 seconds, it accelerated above g, i.e. not at FFA? FEMR's velocity graph shows the acceleration to be indistinguishable from FFA for ~1.75s. I rounded off to 1.8s. The descent just before that was >g. The duration of >g is a matter of interpretation of the data.

24th July 2012, 10:16 AM	#6069
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by tfk Just as important, he's back-peddling from his previous "there is only one interpretation of the data"... Please show where I said that. ETA: Thank you for acknowledging that FEMR's acceleration graph is incorrect.
	Last edited by Christopher7; 24th July 2012 at 10:18 AM.

24th July 2012, 11:15 AM	#6070
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Originally Posted by Christopher7 Please show where I said that. Ummm … you're kidding, right?? I want you to think very hard about 2 concepts. 1) the "quote" function. 2) the "bold" function. Now, with these two concepts firmly in mind, I want you to go back & re-read this very short post in which I drew that conclusion. See if there is anything, any thing at all, that you can find in that post, something that might be related to the "quote" function and/or the "bold" function, that might give you an idea where I drew that conclusion. ___ Originally Posted by Christopher7 ETA: Thank you for acknowledging that FEMR's acceleration graph is incorrect. Oh, trust me on this one ... ... my pleasure.
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Last edited by tfk; 24th July 2012 at 11:33 AM.

24th July 2012, 11:25 AM	#6071
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Christopher7, BTW, I said that "at least" his acceleration graph is hosed. I also said that I believed that his velocity one was too, because I believe that he used the same algorithm to generate it from his position vs. time data. To be complete, I believe that his position vs. time data is very good. That is why I used it as the source data to generate my own velocity & acceleration curves. Note: I also believe that there are likely significant uncorrected perspective errors even in his position data. My graphs are not hosed. They are completely consistent with each other. Now, using my acceleration vs. time graph, please show me where you think "free fall acceleration" occurred for any length of time. 2nd question: do you understand the difference between instantaneous acceleration & average acceleration? Do you understand that, if you change the length of time over which you average something, then the reported average value can (and generally will) change? Do you understand the inexorable conclusion that results from attempting to calculate acceleration by applying a "linear fit to the velocity data"?? If so, please state that conclusion as concisely as you can. Do you understand that, if one were to apply a linear fit to the height versus age of humans, then - no matter how accurate the measurements, no matter how frequent the measurements - the inexorable - and WRONG - conclusion would be that "humans do not experience growth spurts"? Do you understand that the error in this conclusion is NOT the result of "measurement errors"? Do you understand how this last example applies to the collapse of the outer walls of WTC7? Let's see if you can step up & answer a couple of simple questions.
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Last edited by tfk; 24th July 2012 at 11:43 AM.

24th July 2012, 12:07 PM	#6072
carlitos "más divertido" Join Date: Jul 2009 Posts: 11,635	Add me to the list of people that were confused by the unorthodox use of the word "derived."

24th July 2012, 02:14 PM	#6073
Oystein Philosopher Join Date: Dec 2009 Location: Germany Posts: 9,929	Originally Posted by Christopher7 FEMR's velocity graph shows the acceleration to be indistinguishable from FFA for ~1.75s. I rounded off to 1.8s. The descent just before that was >g. The duration of >g is a matter of interpretation of the data. http://img543.imageshack.us/img543/3540/femr5ec.jpg Ok, those ~ 1.8 seconds of what you interprete as "indistinguishable from FFA" are preceded by ~0.8 seconds of >0 acceleration, i.e. collapse, that you divide into... 0.1 s of <g 0.3s of very roughly around g 0.4 s clearly >g How much did the north wall descend during that time? What happened to the vertical supports further below during that time? How do you explain >g? Did the WTC7 north wall go into ~FFA immediately, suddenly, as AE911Truth claims?

24th July 2012, 02:43 PM	#6074
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by tfk I believe that his position vs. time data is very good. ... using my acceleration vs. time graph ... Post the graphs you are referring to please. Insulting and irrelevant subject shifting questions deleted.

24th July 2012, 04:52 PM	#6075
tfk Master Poster Join Date: Oct 2006 Posts: 2,978	Originally Posted by Christopher7 Post the graphs you are referring to please. Insulting and irrelevant subject shifting questions deleted. Look upward on this page. Post #6059. I asked you several directly relevant questions. You find my asking you questions "insulting & irrelevant"? FYI, I happen to find your continuing predilection to ignore questions asked of you to be rude, bordering on insulting.
tfk Master Poster Join Date: Oct 2006 Posts: 2,978

24th July 2012, 06:35 PM	#6076
Christopher7 Philosopher Join Date: Aug 2006 Posts: 6,535	Originally Posted by Oystein Ok, those ~ 1.8 seconds of what you interprete as "indistinguishable from FFA" are preceded by ~0.8 seconds of >0 acceleration, i.e. collapse, that you divide into... 0.1 s of <g 0.3s of very roughly around g 0.4 s clearly >g How much did the north wall descend during that time What happened to the vertical supports further below during that time? How do you explain >g? Did the WTC7 north wall go into ~FFA immediately, suddenly, as AE911Truth claims? Point taken. That interpretation of the data does not work with my original hypothesis: The core columns started down a split second before the exterior walls and pulled them down a little before the lower floors of the exterior walls were removed allowing the exterior walls to fall at FFA. The interior columns, which were already moving downward, pulled the exterior columns down at slightly faster than FFA for a split second until they equalized. This was confirmed by Major Tom in post 5782. http://forums.randi.org/showpost.php...postcount=5782 Tom never responded to my request to show his data and how it relates to the video like I did in post 5786. http://forums.randi.org/showpost.php...postcount=5786 This interpretation fits the above scenario: The building did not grow several inches so the red velocity line above the zero line between 11.6s and 11.8s is noise. It follows that the 0.3s of 1'/s descent may also be noise. If not, between ~12s to 12.3s, the core columns pull the exterior columns down ~4 inches. There is a slight pause (?) For 0.25s the core columns pull exterior columns down at an average of 2.5'/s [~8 inches]. Then a miracle happens. Or All the supporting structure is removed in a synchronistic manner.