Ryan Mackey - NASA contractor debunks David Ray Griffin

Whilst browsing Peter Tatchell's opinion piece and its subsequent comments in the London Guardian I came across this link to a "debunking of David Ray Griffin's debunking of NIST".

LINK

It's a PDF doc by a NASA contractor called Ryan Mackey. He has his own thread about it on the James Randi boards.

LINK

I haven't had time to read it but in the interests of denying ignorance I imagined some of my fellow members here at ATS would be interested in its contents.

[edit on 14-9-2007 by uknumpty]

I'll start off by using the typical "debunker" course of action. What specialty is Ryan Mackey in?

Ryan Mackey is a research scientist at the NASA Jet Propulsion Laboratory, specializing in vehicle autonomy and Integrated Systems Health Management for aircraft and spacecraft.

911myths.com...

So, what does an integrated systems health manager know about demolitions or structural engineering?



[edit on 9/14/2007 by Griff]

It won't let me open the pdf. Just thought I'd let you know.

Edit: Never mind. I got it to work.

[edit on 9/14/2007 by Griff]

hmmm, sounds like garbage in = garbage out to me.

this report assumes that every core beam and every supporting beam gave way simultaniously. somehow there is no explanation for this (in the report).

this report also assumes that the top levels of the building were even when they fell.

this report also pulls numbers out of thin air, not citing sources.

Originally posted by Griff
So, what does an integrated systems health manager know about demolitions or structural engineering?
[edit on 9/14/2007 by Griff]

That's what I thought but on the Randi forums he seems quite bullish about his credentials and his ability to correctly interpret the cause of the collapses. Amongst the Randi forum members he seems to be attaining a god like status because of this report.

Originally posted by uknumpty

That's what I thought but on the Randi forums he seems quite bullish about his credentials and his ability to correctly interpret the cause of the collapses. Amongst the Randi forum members he seems to be attaining a god like status because of this report.

Randi has been proven a fraud and a closed minded skeptic. He has absolutely no objectivity in anything he tries to debunk. Read the numerous threads here on ATS about his hippocricy. It only goes to reason that most the people on his blog would be of the same mindset.

Originally posted by uknumpty
Amongst the Randi forum members he seems to be attaining a god like status because of this report.

Why? All his paper is is a rehash of what we discuss here daily. At least that's what I got from skimming through it. If there's anything definative I've missed, please advise me.

[edit on 9/14/2007 by Griff]

reply to post by Griff



Hi Griff ~

Is there anything in his paper that appears to be incorrect? I read it myself a couple weeks ago and with my VERY limited knowledge....I was too confused. I read the thread on the JREF website where he posted it. Many of the others there tend to agree with his findings.

I'd be intersted to see what you may find that is wrong.

Thanks dude,
CO

Originally posted by CaptainObvious
I'd be intersted to see what you may find that is wrong.

So far I've only skimmed through it. It was very interesting the part about wind loads and his analysis of them being the controlling load over dead and live load. I'm not saying he's wrong, but he sites NIST who sites the ACI 318-67. Now, ACI is the American Concrete Institute. Why would they use ACI's factored loading when AISC (the American Institute of Steel Construction) would have been the controlling code I would think? Now, I'm not sure on this so don't quote me just yet. The excepted code today would be the ASCE-7 but I haven't been able to find if that code was available back then.

Conclusion, so far, I haven't seen anything wrong with what he says. But, I do have to say that most of his assumptions are just as invalid as others. No one really knows for sure. A true investigation could stop all this but why the stall? Why did it take our government almost a year to even begin an investigation? When most of the evidence had already been "scooped and dumped"?

reply to post by Griff



Thanks Griff ~

His paper i believe from reading his thread over at the JREF site was to refute Dr. Griffins paper.

2 questions Griff...
1. have you read Dr. Griffins white paper?
2. Does Mackeys paper debunk Dr. Griffins?

I realize this would take alot of reading, but i would appriciate your input.

Perhaps Bsbray could assist?

That's what I thought but on the Randi forums he seems quite bullish about his credentials and his ability to correctly interpret the cause of the collapses. Amongst the Randi forum members he seems to be attaining a god like status because of this report.

he doesent show his math, or rather he only shows what he wants and doesent cite sources. if this was high school physiscs he would receive an F.

perhaps in a college level writing class he would receive credit.

either way it debunks nothing and proves nothing, simply fodder for the masses.

reply to post by jprophet420


JP ~

What are you credentials to claim that he would receive an F ? And, can you please point out to where his is in error with his paper?

Thanks
CO

lol.
i dont need any credentials to realize that if you dont show your math you dont have #.

and as i already mentioned he cites equations with no source for the numbers, which completely nullifies anything he got 'right'.

reply to post by jprophet420


JP,

Mr. Mackey is offering explinations as to WHY Dr. Griffins paper is not plausible. From what I have read, Mr. Mackey has indeed showed math where appropriate to explain that falacies described in Dr. Griffins paper.

For instance Mr. Mackey is discussing a section of Dr. Griffins paper in regards to the horizontal ejection of steel. Mr. Macky quotes a source with math,

For a worked example, Rememnikov [148] presents a typical charge of 100 kg TNT exploding at a distance of 15 meters. A series of objects placed at this distance would experience 272 kPa or just under 40 PSI, but would only experience the overpressure for 17.2 milliseconds, including the reflection of the blast, after which the pressure wave has passed the objects. Let’s assume we’re discussing a section of unattached, hollow square steel column 3 m high by 20 cm wide, with walls 4 cm thick. This object presents a maximum of 0.6 m2 to the blast front, so it experiences a maximum force of 272 kPa x 0.6 m2 = 163,200 N for 17.2 milliseconds, for a total impulse of 2807 Newton seconds

911guide.googlepages.com...


then continues further with his explination:

The actual expected impulse per facing area, seen in Table 1 of Rememnikov’s paper, is a mere 955 kPa-msec, or only 573 Newton seconds imparted to our column as above. We therefore are using a very generous estimate, almost five times higher than we actually expect. We will use our simplified estimate rather than the lower, more accurate number to silence any doubts that we have potentially underestimated the maximum imparted velocity.

The total impulse is equal to the mass of the object times the change in velocity. In this case, our column contains 256 cm2 x 3 m of steel or 76,800 cm3 of steel, for a mass of approximately 600 kg. The column would, therefore, be accelerated by 2807 N s / 600 kg = 4.7 meters per second, or about 10 miles per hour – hardly a remarkable value compared to the ricochet scenario described above. In order to propel this column at the speed required, say 30 meters per second, we would need charges of at least 700 kg TNT equivalent – very large and clearly audible explosives indeed, even accepting our generous assumptions above.

911guide.googlepages.com...

This paper carefully examines the claims by Dr. Griffin and refutes it.

JP should I listen to you be saying "he didn't show the math?"

Or do I take the words of a NASA scientist?

I am openminded for the most part, so please show me where his mistakes are so that I can e-mail him.

Thanks

cutting explosives were used to bring it down in exact pieces.that was their goal.
for the destrution from top to bottom (dont forget), a massive weapon like DEW could have been used. just read the facts.

reply to post by anti72


Did you read the flashing yellow statement? Thread derailment is not being tolerated. There is a thread ongoing about the sci-fi / Judy Woods garbage.

Originally posted by CaptainObvious

This paper carefully examines the claims by Dr. Griffin and refutes it.

JP should I listen to you be saying "he didn't show the math?"

Or do I take the words of a NASA scientist?

I am openminded for the most part, so please show me where his mistakes are so that I can e-mail him.

Thanks

Cap'n,

Very nice figures cited, and lots of them. But this whole question of computing the explosive forces necessary to eject the steel members, to somehow debunk the point that the steel members were not explosively ejected, is absurd on its face.

Fact is, those steel members wereexplosively ejected. Period. The math is a crude approximation of what we can all see occurring. It means next to nothing in the big scheme of things. This debunks nothing. Nada. Zilch. It happened. Huge steel members went flying hundreds of yards. That's the real point here.

This is a five fingered exercise of no real value. Especially coming from a US gov't bureaucrat with tenuous credentials at best in structures and statics.

reply to post by gottago


Hello Gottago ~

Can you please point out the calculations that are incorrect in his paper? I am not asking to be rude or pompus, I will respectfully e-mail him all errors that are found. I believe his calculations are backing those of another scientist. Mr. Mackey is in fact a scientist. He does work for NASA...so that makes him Sheeple? Does it take away that fact that his is incredibly smart?

Instead of judging his paper for his credentials and his place of employment, please, I ask again to point out the falacies so that I may bring them to his attention. If you don't want to point them out ot me, he does leave his e-mail on his paper.

Thanks again,

CO

Originally posted by gottago
This is a five fingered exercise of no real value. Especially coming from a US gov't bureaucrat with tenuous credentials at best in structures and statics.

Gottago, could you please forward me papers written by dr's or scientists with the credentials you have stated that explain the "FACT" as you put it that the debris being discussed were explosivley ejected.

Thanks again,

CO

Originally posted by Griff
The excepted code

Doh. Accepted. Not excepted.