Offer to the Truth Movement: Let's Settle It

aggle-rithm said:
Your clever use of a 17-year-old pop-culture reference has convinced me completely. INSIDE JOB, EVERYONE!!!
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And where did I ever use the IJ term?

I can't even say the steel was inside since so much of it was in the perimeter columns. LOL

People should not be convinced. They should understand. But that can't be done without correct data.

The nation that put men on the moon can't tell everyone in the world the TONS of STEEL and TONS of CONCRETE on every level of a building designed before the moon landing. NO, they all have to buy a $2000 computer program.

ROFLMAO

psik
 
psikeyhackr said:
And where did I ever use the IJ term?

I can't even say the steel was inside since so much of it was in the perimeter columns. LOL

People should not be convinced. They should understand. But that can't be done without correct data.

The nation that put men on the moon can't tell everyone in the world the TONS of STEEL and TONS of CONCRETE on every level of a building designed before the moon landing. NO, they all have to buy a $2000 computer program.

ROFLMAO

psik
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There's a lot of information in the metadata file, which is in text format. Have you looked at that?
 
psikeyhackr:
Would you please stop posting off topic in this thread and post your concerns in the thread you started.
 
R.Mackey said:
There's not much to tell. Ms. McElwaine has extremely little knowledge of aircraft, as evinced by her use of nonstandard terminology, such as "spoilers" and "fins." She also describes what is nearly impossible, i.e. a jet aircraft passing within 100 feet of the ground, yet being almost silent. Her value as a witness is quite limited. (ETA: "Spoilers" are present on modern aircraft, but they aren't what she thinks they are. They are control surfaces on the upper wing that "spoil" aircraft lift, allowing descent without a great increase in speed.)

The most plausible explanation, from my perspective, is that the aircraft she described was the well-known white Falcon 20 business jet that was in the area, and was asked by Air Traffic Control to survey the area looking for the crash site. I believe they were flying at an altitude of only a few thousand feet, which would plausibly match the apparent size and speed of the object Ms. McElwaine described.

If the aircraft was not the Falcon 20, whatever it was went unnoticed by them and by Air Traffic Control. A stealth aircraft? Or flying at extremely low altitude? Ms. McElwaine seems to imply the latter.

However, this is not possible. If the aircraft was truly as low as she says, then it had to be very small as well, so small that it cannot have carried a pilot. Regarding UAVs, there are no UAVs that can operate so close to the ground. I've commented before on why UAV technology is inadequate to create "drone planes" that hit the World Trade Center, and the mission called for in this case -- flying nap-of-the-earth in rural Pennsylvania -- would be far more challenging.

The reason why this can't be done remotely is quite simple. At an altitude of, say, 100 feet, and speed of 250 knots, the time required to close the control loop without hitting ground obstacles is on the order of 200 milliseconds to execute the full cycle. This is at about the limit of human performance. If you add radio control and comm latency, this is totally impossible.

Similarly, there are no on-board autonomy systems with that level of performance. All current UAVs that are not remotely piloted will not let you fly that low. Global Hawk, for instance, only passes through those altitudes during takeoff and landing, and only after it has taken a radar image of the ground so that it knows there are no obstacles along its intended flightpath. Otherwise, it would not even sense the obstacles.

The only UAVs that can possibly operate at such low altitude are those which are both small and slow. There are some autonomous helicopter efforts at NASA Ames, for instance, but they are far from mature, and Ms. McElwaine wasn't describing a whirlybird. There are also several lightweight, hand-thrown and similar surveillance platforms, but these rarely exceed 100 knots, and many are slower still. I fail to see what possible threat such a small and impotent UAV could have presented to a jetliner. Such a UAV would not have a hope of intercepting or even tracking a 500+ knot capable large transport. It couldn't even get out of the way.

The fantasy UAV story strikes me as yet another unfounded UFO story, and nothing more.
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Thank you very much for the information on the control theory! Been hitting dead walls on this subject with some LC Forum posters!
 
Swing Dangler said:
R.Mackey said:
Since I do not have the resources at my disposal to build a structure and crash an aircraft into it, I humbly submit that neither I, nor indeed anyone in the world, are likely to satisfy you. You may wish to relax your constraints accordingly.
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Would a computer model suffice?

Got this from NIST response to Dr. Steven Jones letter on SCL site:

"NIST carried its analysis to the point where the buildings reached global instability. At this point, because of the magnitude of the deflections and the number of failures occuring, the computer models are not able to converge on a solution."

There goes that option.....
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DaN K. StAnLeY said:
Got this from NIST response to Dr. Steven Jones letter on SCL site:

"NIST carried its analysis to the point where the buildings reached global instability. At this point, because of the magnitude of the deflections and the number of failures occuring, the computer models are not able to converge on a solution."

There goes that option.....
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Well, it's not that simple. The models that NIST used are totally unsuitable for simulating collapse progression, but that's by design. NIST's global model is a SAP2000 model, as we've been discussing here. SAP2000 is designed to solve static problems.

What the passage you've quoted means is that, as the structure gets more and more unstable, the SAP2000 model also grows more unstable. As a result, the SAP2000 model will fail to converge before the structure would actually collapse. Think of it this way: Suppose you're calculating 1 / x for various values of x. You can't calculate 1 / 0 by definition. If you don't know precisely what x is and it keeps changing slightly, but it's nowhere near zero, the changes don't make that much difference to your result. But when x starts to get close to zero, the changes have a larger and larger effect, until your calculation is no longer useful at all. In the SAP2000 model, instead of calculating 1 / x, you're inverting a matrix describing the material properties of the structure. As the structure gets closer to collapse, your matrix becomes ill-posed, and the results start jumping around wildly.

There are, however, other ways to model the problem. The other model, used in NIST's aircraft impact simulation, is LS-DYNA. This model doesn't work the same way and can handle loose pieces, unlike the SAP2000 model, but it comes at a great cost in complexity. This is why SAP2000 could model the whole structure to some degee, but LS-DYNA only treated a block of a dozen floors, greatly simplified.

If you really wanted to, you could probably simulate the early stages of collapse with LS-DYNA. But you would still have to make some gross simplifications. For instance, you could model only three contact floors above and below the interface, treating the rest as a big block to simulate inertia and boundary conditions. That should be sufficient to demonstrate progression of collapse past the first floor or two.

However, as I said, there are lots of simplifying assumptions. In particular, LS-DYNA will have trouble modeling the rotation of the upper blocks early in the collapses, and the resulting effect of plastic hinges in surviving connections. That's just plain a difficult thing to model, and I know of no good way to handle this.

Also, keep in mind that your model will only provide one possible outcome. The results will be extremely dependent on initial conditions, much more so than the models NIST carried out. As I've remarked before, not even the best model or computer in the world can predict what number will come up on a thrown six-sided die (and if they could, Las Vegas would fold their tents). If you're willing to run numerous trials and accept large uncertainties in the results, you can still give it a try, but not even the best computer in the universe will handle all of the details. Not even if we knew the pre-collapse condition of the structure perfectly, which of course we don't.

The mandate for NIST was to determine why the collapse happened, and this they did. Our interest in the fine details of how the collapse progressed is much less, although there are a few, Dr. Bazant at the forefront, who've taken this question a bit further. So far there appears to be no compelling reason to approach this problem through simulation, largely due to the enormous dependence on initial conditions this problem suffers. I also don't see any value in doing so, beyond the simple question of whether the progressive collapse was expected or not, and that question has been answered many times over and through multiple, non-overlapping approaches.
 
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Mackey,
Yeah.....thats what I meant:confused: LOL!

My point was that its pretty impossible to simulate a collapse of one of a kind buildings, with the exact same circumstances, on any computer. It would prolly be easier to build 2 more towers.
 
it is possible, simplified. but its possible , with LS Dyna.

but it has indeed some troubles to handle the toppling upper part like Bazant wants it to be handled.
 
I would hate to be a "truther" debating you Mack-a-roni. Did you go to "Debunker University" or what? Jeez! Everyone on this site has a PHD in "Truther Smack-down" I don't even think I'm smart enough to post on this site...hahaha. Im smart enough to know 9/11 was NOT and inside job though, that's a start.
 
DaN K. StAnLeY said:
I would hate to be a "truther" debating you Mack-a-roni. Did you go to "Debunker University" or what? Jeez! Everyone on this site has a PHD in "Truther Smack-down" I don't even think I'm smart enough to post on this site...hahaha. Im smart enough to know 9/11 was NOT and inside job though, that's a start.
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Mr Mackey is indeed a force to be reckoned with, but I think you'll find that there are others here like myself who are not exactly intellectual titans.

You don't need to be a rocket scientist to smack down most truthers, I find a sense of humour and an ability to read and comprehend is sufficient.
 
Dictator Cheney said:
even rocketscientists can be wrong.
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I just noticed the spelling mistake in your sig. Is it a mistake, or are you referring to an incompetent vampire hunter?



Sorry a bad joke at the expense of a non english speaker. Not very noble of me.

Carry on...
 
Brainache said:
I just noticed the spelling mistake in your sig. Is it a mistake, or are you referring to an incompetent vampire hunter?



Sorry a bad joke at the expense of a non english speaker. Not very noble of me.

Carry on...
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lol its not a bad joke :)

its pretty stupid to have spelling errors in a sig, even if its not the main language. i guess even google translator would know that better.

i can take it :D
 
psikeyhackr said:
It makes more sense to point out to people how idiotic the NIST is for not providing the TONS of STEEL and TONS of CONCRETE on every level in a comprehensible form after they took 3 years and $20,000,000. You want to twist this around from the lying incompetence of the NIST to an ego attack on me. ROFL Sorry, this is about solving a grammar school physics problem that should have been finished by 2003.

But the NIST can tell us the buildings were 70% air. :duck:

http://www.pbs.org/wgbh/nova/wtc/cons-flash.html

I computed that to be 15 tons of air per level. The steel "averaged" 862 tons per level but the dummies at NIST can't tell us the distribution. And can't tell us the total concrete at all. Of course they can also tell us that one plane had 5 tons of cargo and the other had 9. Those guys are really good at figuring out what the important information is. NOT! Of course anyone that takes them seriously can't be too swift.

psik
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Psik,

Let's keep this honest.

NIST gave detailed specifications for concrete (except for the foundation) in terms of floor thickness, type of concrete and density. Anyone can add up the details if they have a need for it.

My spreadsheet is not from the SAP data. Only the core column steel mass is. The rest of the data is from NIST. I have provided possible explanations for the insignificant anomaly (from the SAP data) you have identified but you continue to hack on my work. The article is published in the "truther" Journal of 9/11 Studies after being reviewed in detail both by skeptics here and "truthers" at the Scholars for 9/11 Truth and Justice forum and subsequently revised. No significant problems have been identified with the most recent version, which I have linked previously.

Have you read the entire article?

If you have a significant problem please describe it and its significance. I will be glad to correct my work.
 
GregoryUrich said:
Psik,

Let's keep this honest.

NIST gave detailed specifications for concrete (except for the foundation) in terms of floor thickness, type of concrete and density. Anyone can add up the details if they have a need for it.

My spreadsheet is not from the SAP data. Only the core column steel mass is. The rest of the data is from NIST. I have provided possible explanations for the insignificant anomaly (from the SAP data) you have identified but you continue to hack on my work. The article is published in the "truther" Journal of 9/11 Studies after being reviewed in detail both by skeptics here and "truthers" at the Scholars for 9/11 Truth and Justice forum and subsequently revised. No significant problems have been identified with the most recent version, which I have linked previously.

Have you read the entire article?

If you have a significant problem please describe it and its significance. I will be glad to correct my work.
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my problem with your paper is, that you say the tower weighed ca. 290k tons (metric oc) but actually thats only the weight of the steel and concrete. when i did understand your paper correctly.
 
Dictator Cheney said:
my problem with your paper is, that you say the tower weighed ca. 290k tons (metric oc) but actually thats only the weight of the steel and concrete. when i did understand your paper correctly.
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You might want to take another look at the article.

The weight of everything else is the "superimposed dead load" (SDL) and "superimposed live load" (SLL) which are included in my calculation. In fact this is where my estimate differs from the commonly used value of 500,000 tons. Most floors were built to safely hold 100 psf. If this design parameter is used to calculate the weight of building contents the result is close to the popular value. However, statistical surveys have shown that the in-service (actual) live load is usually less than 25% of the design live load. I use the same in-service live load as NIST (25% design live load based on live load reduction as per design specs) which is an over-estimate if anything.
 
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