“Hand Waving” the Physics of 9/11

This guy(David L Griscom) is a physicist and wrote this article earlier this year about the physics behind 9/11. I did a search on ATS and didn't see it discussed so I'm posting it now.

I'm not an engineer or a physicist so I really don't know if what he is saying is correct. I would like to start up a conversation about this article to see what yall think. The only thing I don't like about this article is that he interjects some humor and sarcasm at times which I think it could do without.

Americans have a right to know exactly what happened on 9/11, and this right justifies a major effort to simulate every millisecond of the collapses by means of supercomputers and perhaps mechanical scale models. For $20 million taxpayer dollars, NIST should already have delivered such. That they did not is inexcusable.

impactglassman.blogspot.com...

reply to post by Conundrum04


Thanks for posting this, it's a very easy read and does some nice work putting actual numbers to work against the assumptions--he calls it "hand-waving physics"--used to justify the collapse of the WTC.

He focuses on a narrow point, though critical one: the nature and timing of the initial collapse, and neatly rebuts the official version of events with a few simple equations, thereby explaining in mathematical terms plain common sense.

Too bad the post was not more far-reaching; you want to see more of this.

wow. he completely debunks the official story 100%. he debunks the NIST report and Garcia all in one page.

on a persoanal not, its nice to see a Ph.D saying the same thing i have been saying, except showing the math to support it.

dude, im getting in john titors time machine and going back to 2006 when i can vote for you for way above top secret.

if any thread deserves the smoking gun tag, this is it.

TheDman said...
"publishing the 108 papers that I wrote fully myself. I know this because I’ve caught virtually all of them myself by double-, triple-, and quadruple-checking my data, logic, and mathematics before allowing my manuscripts to go to press. My published works are highly respected by my peers according to my score (h=39) on the recently devised Hirsch index [J.E. Hirsch, Proc. Nat. Acad. Sci. 0507655102 (2005)]. This means that 39 of the 185 total papers of which I am the principal author or a coauthor have each been cited at least 39 times in other refereed publications."


Looks like you're doing a lot of hand waving yourself in this paragraph!

Certainly a man who's written 108 articles himself can write one more refuting the NIST report and publish it in a scientific journal, right?

August 24, 2007 3:12 PM
TheDman said...
"Even a rough calculation for the concrete alone indicates that the energy needed it to pulverize it is several times the total gravitational potential."


Really? Can we see those rough calculations?

I wonder if that is the same thedman as on here?

Nice thread. It's nice to see that some of our academics are waking up.

Originally posted by Griff
Nice thread. It's nice to see that some of our academics are waking up.

I just read a book that makes a good case that science is stubborn and won't change after a major breakthrough is made, for about 10 years. For example, Galileo's work, Einstein's, Ohm's, etc., all took some time to gain acceptance. When Georg Ohm first published "Ohm's Law" relating voltage, amperage, and resistance, it was dismissed out-of-hand by the experts of the day as being too simple of a relationship to actually work. No one even gave it a chance. It was years/decades before Ohm got credit for his work. A new generation of scientists had to come in and objectively review it, because the old ones were stuck permanently in their ways. And that's NOTHING compared to the psychological battery you make against most people when you say 9/11 was an inside job. Experts also wrote lengthy treatises on why Galileo's model of our world must have been wrong, too.

The same book (Prometheus Rising -- good book!) makes a point of how "what the thinker thinks, the prover proves." It makes more difference, for most people, what they already think, not how things "really are". This is why people with fresh perspectives, unattached to the old views, are required before any real progress can be made.



Edit to add: Anyone seen the latest federal studies into the USS Maine disaster? Experts went through the evidence again some time around the 1970's, and found completely different ways of looking at the same key pieces of evidence, and suggested that it was a completely internal explosion and nothing to do with the Spanish. I saw it on the History Channel, and when the two cases were compared, you could see how authorities were painting up the event to go to war at the time, even in their investigations of what really happened. They didn't care what really happened. A lot of people just had their minds made up and were ready to go kill people for it.

[edit on 4-9-2007 by bsbray11]

reply to post by gottago



I remember reading this article several months ago and saved it to my favorites. I was actually very surprised not to find it here on ATS, I actually thought I got the article from here.

Anyway, sorry my OP wasn't introduced better, I sort of skimmed through it before I posted it. I don't understand the mathematics behind it so I thought it would be better for the people with the proper professional backgrounds to dissect it.

reply to post by Griff

lol griff, it would be hand waving if he didn't show the math, which he does.

David L Griscom... hmmmm...the same David Griscom that claims this?:

An underlying postulate, or working hypothesis, of my earlier Pentagon model was that the passengers on AA-77 volunteered to feign their deaths in return for cushy “witness protection” programs. This concept is not original to me. It was explored by the CIA in the early 60s as a component of a scheme to fake the shoot-down of an American airliner over international waters as a justification for invading Castro’s Cuba. “The plan [Project Northwoods] was to replace said aircraft with an identical drone, flown by remote control, and land the original plane at an [Air Force] base where passengers, boarded under prepared aliases, would be evacuated. The drone would then fly the route and when over Cuba, emit a distress signal before being destroyed by radio signal.”

I envision a similar 9/11 scheme, but one where the passengers boarded under their true names. Indeed, the seat occupancies on all four aircraft allegedly hijacked on 9/11 were very much lower that industry average (averaging 26% of capacity vis-à-vis 71% for all domestic flights in July 2001). So, here I extend my “all passengers survived” postulate to all four 9/11 “hijacked” flights on the notion that this small number of passengers might have been considered by conspirators as the minimum number for public credulity, while at the same time not exceeding the maximum number of “true believers in the cause” willing to accept long separations from their loved ones (sweetened by handsome Swiss bank accounts).

www.impactglassresearchinternational.com...

Not sure about how accurate his calculations are. Perhaps Griff can give us his .02 into them.

Not sure about how accurate his calculations are. Perhaps Griff can give us his .02 into them.

what part dont you understand, they were pretty basic to me?

reply to post by jprophet420


Jprophet ~

The reason I asked for Griff, is that his credentials support those of someone that may be able to explain the appropriate numbers in determining if the calculation that is being done is accurate. You response that you understood it was not what I was looking for.

Although David Griscom is a PH.d, his background was not in building construction / engineering it was more in the non-crystalline solids, flourine gases ... etc.... that being said I was willing to give him the benifit of the doubt by asking Griff or someone else to verify his calculations. Since you have not ever posted any of your own, I was a little suspect to see how quick you were to agree with his.

I would also like to add that his hypothisis as to all 4 planes that crashed were drones is a disgrace. It is an isult to the victims and their families. To suggest these people were all paid off via a "Swiss Bank account" sickens me.

This educated kook was obviously not at any of the memorial services for any of the victims from the airliners. He didn't see the wives, husbands,mothers, fathers, sisters, brothers, friends, etc.. crying... wishing for the "just on more day" to see their loved ones...to hold them...to tell them that they loved them. He dismissed their murders in his obscene hypothisis.

Were his calculations correct? I don't know. Was his hypothisis that all the passengers and crew on the 4 airliners are alive and paid off a disgrace? YES!

Originally posted by CaptainObvious
I would also like to add that his hypothisis as to all 4 planes that crashed were drones is a disgrace.

Really, perhaps you could post a link to that hypothesis.

An underlying postulate, or working hypothesis, of my earlier Pentagon model was that the passengers on AA-77 volunteered to feign their deaths in return for cushy “witness protection” programs.

Because this here only mentions one plane.


Hand waving indeed.

The reason I asked for Griff, is that his credentials support those of someone that may be able to explain the appropriate numbers in determining if the calculation that is being done is accurate. You response that you understood it was not what I was looking for.

there was no structural engineering needed to understand them, so i asked what part you didn't understand.

also, he shows that mr garcia used an arbitrary number, which means his story is just that, a story.

Originally posted by jprophet420
wow. he completely debunks the official story 100%. he debunks the NIST report and Garcia all in one page.

Could you point out some specific parts where he does this? Because I sure don't see it.

And his claims that the passengers of flight 77 all played along? wow...

I'd also like to point out that the lack of calculations for the collapse itself is not a valid argument. We know how collapses work and there is no need for the calculations since they are pretty standard and well known. What is unique to each event is the cause of the collapse, not the collapse itself. The goal of the report is to find the cause of the collapse because that is what is in question, not that collapses happen.

ok, so we know how collapses work. so tell me, why is there no need for calculations?

What is unique to each event is the cause of the collapse, not the collapse itself.

thats the point. in this case the cause for collapse does not fit the collapse. we know how they work as you pointed out and this one did not work as it should have, or could have according to the given cause.

the specific parts? sure...
the building would handle 20x load. according to garcias work based on the nist report the falling of the building produced 6.8x load. this is not enough force to overcome the floors underneath the building. the number he (garcia) used to calculate this was arbitrary. furthermore, all of the support beams would have had to give out 100% AND simultaniously. beyond that, if there was a variation in the angle on the plane that the floors dropped on of only 1 degree, it would change the 6.8x load to 1.8x. the building tilted over 20 degrees.

and of course...

Moreover, even neglecting the different strengths of steel at different temperatures, it is astronomically improbable that approximately 250 steel columns would fail due to “natural causes” within the same very short time interval. In more popular language, this hidden assumption underlying Dr. Garcia's calculation is "statistically impossible."

It would be very informative to know in history if there was ever a plane that toppled a steel structure.

reply to post by CaptainObvious


Cap'n,

You wouldn't be attempting thread derailment and character assassination here, now would you?

Henry Ford was an antisemite, Howard Hughes ended his life as a raving paranoid lunatic, and Nixon was a monster, but you wouldn't discount their insights regarding autos and mass production, aeronautics, or the art of politics, would you?

.....................................................

Conundrum,

I think you misunderstood my previous comment; the remark of wishing for a longer post was in regards to that you linked to, not your own. The collapses are the most obvious evidence, being impossible without other inputs, and this line of investigation that brings physical proofs to bear is extremely valuable.

Originally posted by CaptainObvious
Not sure about how accurate his calculations are. Perhaps Griff can give us his .02 into them.

I believe he's closer to it than Greening et al. with their out of no where freefall drop of a single floor (including columns). He also doesn't show how he gets .14 sec for delta-t. As far as his math, I think he's just trying to show how much Dr. Garcia's assumptions could be off and not really trying to prove anything with it.

Most part of engineering (including physics) is getting the assumptions correct in the first place. My opinion is that anyone (PHD or not) saying that an entire floor just fell with no resistance into the next one down is not being very realistic.

But then there are the ones who go to the other spectrum (like Dr. Woods et al).

My opinion is the answer is in-between. I don't have the manpower or the time to do the correct calculations. Neither does Dr. Garcia, Dr. Greening, Dr. Woods, Dr. Jones etc. NIST does though. I liked this quote in the blog.

simulate every millisecond of the collapses by means of supercomputers and perhaps mechanical scale models. For $20 million taxpayer dollars, NIST should already have delivered such. That they did not is inexcusable.

So in conclusion, no one is exactly correct. I believe Dr. Griscom is closer than Dr. Garcia though. But, as always, that's just my opinion.

Originally posted by snoopy
I'd also like to point out that the lack of calculations for the collapse itself is not a valid argument. We know how collapses work and there is no need for the calculations since they are pretty standard and well known. What is unique to each event is the cause of the collapse, not the collapse itself. The goal of the report is to find the cause of the collapse because that is what is in question, not that collapses happen.

With this type of logic, we'd still be in the middle ages. No need to find out what happened? What if it was just shoddy workmanship? Shouldn't we at least know? Thanks but no thanks, as an engineer, I am extremely curious as to what happened. You might want to bury your head in the sand but the rest of us don't.

reply to post by Griff


Griff,

bingo, great post.

Garbage in, garbage out. It's the assumptions you operate under that largely determine the outcome. This kind of obfuscation was used extremely effectively to give some sort of physical plausibility to accidental collapse.