9/11 Physics from Non-Experts

[GregoryUrich]

Who do you trust?

I stand corrected. I remember reading an interview, possibly with Robertson, that made the point that an aircraft hitting the Towers would have been presumed to have just taken off. Somehow I missed that reference on page 6 of NIST-NCSTAR 1 to 600 mph speeds.

“The Boeing 707 was the largest in use when the towers were designed. [Leslie] Robertson conducted a study in late 1964, to calculate the effect of a 707 weighing 263,000 pounds and traveling at 180 mph crashing into one of the towers. [Robertson] concluded that the tower would remain standing. However, no official report of his study has ever surfaced publicly.”[9]

Do you agree, speaking generally, that questions concerning the science of 9/11 have definitive answers? In other words, if you and R. Mackey argue to exhaustion, one of you will be proved right?

Here is a quote from Skilling in the Seattle times:

Business: Saturday, February 27, 1993
Twin Towers Engineered To Withstand Jet Collision
Eric Nalder

...Concerned because of a case where an airplane hit the Empire State Building, Skilling's people did an analysis that showed the towers would withstand the impact of a Boeing 707.

"Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed," he said. "The building structure would still be there."

This contradicts Robertsons claims of no consideration of jet fuel. Sometimes we have to decide who we are going to trust. Its' interesting to note that Robertson is nervously defending his work while Skilling had nothing to hide.

 

[tsig]

If Mr. Mackey and I argue to exhaustion we will be exhausted.

Instead, I hope we will both become aware of the errors in our thinking and limitations of certain arguments so that we both come away with a better understanding of the issue at hand. Who knows, twoofers have become OCSs and vice versa. I'm willing to change my conclusions based on solid evidence and cogent arguments.

What is it about gravity that seems to elude you?

Energy was built into the towers

Planes and fire released it.

 

[Furcifer]

All right, i have been sufficiently placated.

 

[GregoryUrich]

There are many kinds of thruthseekers, some with an agenda or an preconceived idea about the truth and some without...

Your results raise questions, as do your associations, hence the suspicion. But to jump to controlled demolitions from a lower weight estimate, that's very typically biased, not much to do with evidence...

Yes, I'll keep my suspicions...

I haven't claimed controlled demolition.

I simply stated that IF THERE WAS FREEFALL (which there wasn't), the only valid conclusion is controlled demolition. Otherwise you end up lost in the (Judy) Woods.

I make no bones about that I believe CD is a possibility. But, I don't make numbers to support a hypothesis. I do research to prove or disprove a hypothesis.

 

[pomeroo]

If Mr. Mackey and I argue to exhaustion we will be exhausted.

Perhaps, but will anyone give ground?

Instead, I hope we will both become aware of the errors in our thinking and limitations of certain arguments so that we both come away with a better understanding of the issue at hand.

Please point out an error made by Mackey.

Who knows, twoofers have become OCSs and vice versa. I'm willing to change my conclusions based on solid evidence and cogent arguments.

It is true that there are people who, through hatred of America, devotion to anti-intellectual theories, or simple cussedness, were once fantasists but now accept reality and realize that their imaginary conspiracy is impossible. The traffic is all one-way. Nobody has ever examined the evidence and abandoned rationalism for the joys of being a tinfoil-hatter.

 

[pomeroo]

Here is a quote from Skilling in the Seattle times:



This contradicts Robertsons claims of no consideration of jet fuel. Sometimes we have to decide who we are going to trust. Its' interesting to note that Robertson is nervously defending his work while Skilling had nothing to hide.

It should be, but apparently isn't, interesting to you that simulating plane crashes into the Twin Towers wasn't really feasible in the sixties. Everything said on the subject thirty to forty years ago should be taken with a grain of salt, right?

 

[Furcifer]

If you throw in a math term here and there maybe nobody will notice the lack of content.


To the appropriate tune
I got numbers

lots and lots of numbers.

But don't ask me what they mean

I never liked the structural steel mass calculation by NIST. It always seemed low in relation to the overall mass. 1/5 of a steel structure was steel? Does this number make sense to you? It doesn't to me. So yes, there are lots and lots of numbers, don't ask me what they mean because they don't make sense.

 

[tsig]

Your statement says more about your own bias than mine. You can continue being suspicious. I'll continue following the evidence.

Your evidence smells funny.

 

[Furcifer]

Your evidence smells funny.

Talk about lack of content

 

[Mr.D]

Here is a quote from Skilling in the Seattle times:

Business: Saturday, February 27, 1993
Twin Towers Engineered To Withstand Jet Collision
Eric Nalder

...Concerned because of a case where an airplane hit the Empire State Building, Skilling's people did an analysis that showed the towers would withstand the impact of a Boeing 707.

"Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed," he said. "The building structure would still be there."

This contradicts Robertsons claims of no consideration of jet fuel. Sometimes we have to decide who we are going to trust. Its' interesting to note that Robertson is nervously defending his work while Skilling had nothing to hide.

Without more information, you can't make that claim.

He makes two basic statements in the quote. First, the analysis shows the structure would survive the crash. Secondly, that the biggest problem (after the crash) would be the fire from the fuel. There is no indication that the analysis they did included what would happen to the structure AFTER the crash or what the fire might do to the structure.

 

[GregoryUrich]

Giving ground

It is true that there are people who, through hatred of America, devotion to anti-intellectual theories, or simple cussedness, were once fantasists but now accept reality and realize that their imaginary conspiracy is impossible. The traffic is all one-way. Nobody has ever examined the evidence and abandoned rationalism for the joys of being a tinfoil-hatter.

I have demonstrated repeatedly that I can accept corrections and new or better evidence. Or have you not read the entire thread?

Rather than speaking for Mr. Mackey, I think it would be better to ask him he has changed his mind about anything.

Your other comments just sound like fundamentalist blather.

 

[GregoryUrich]

Salt

It should be, but apparently isn't, interesting to you that simulating plane crashes into the Twin Towers wasn't really feasible in the sixties. Everything said on the subject thirty to forty years ago should be taken with a grain of salt, right?

You are just showing your ignorance of physics. Everything needed to do the damage estimate has been known since the early 1900's. Have you seen:

http://web.mit.edu/civenv/wtc/PDFfiles/Chapter%20IV%20Aircraft%20Impact.pdf

You wouldn't get the great computer generated images but the calculations are basic physics covered in undergraduate mechanical engineering courses.

Of course Wierzbicki, et.al. made a few mistakes which resulted in higher estimated damage.

The fires I can't really say anything about, but the fact is the towers withstood the impacts which proves Skilling must have been correct.

 

[GregoryUrich]

Good point

I never liked the structural steel mass calculation by NIST. It always seemed low in relation to the overall mass. 1/5 of a steel structure was steel? Does this number make sense to you? It doesn't to me. So yes, there are lots and lots of numbers, don't ask me what they mean because they don't make sense.

Good point. The steel mass has been confirmed by a number a methods. Maybe it means the overall mass is wrong. Hence, my investigation...

 

[pomeroo]

I have demonstrated repeatedly that I can accept corrections and new or better evidence. Or have you not read the entire thread?

Your problem is that I have read the entire thread.

Rather than speaking for Mr. Mackey, I think it would be better to ask him he has changed his mind about anything.

He's not too shy. I hereby ask him to summarize the current state of this debate.

Your other comments just sound like fundamentalist blather.

Actually, my comments sound like nothing of the sort. Fantasists cannot solve the intractable problem posed by the sheer magnitude of their imaginary conspiracy. What they have raved about for over five years is preposterous nonsense. They continue to tap dance around the core absurdity of their position by all sorts of bogus, pseudo-scientific carping.

 

[GregoryUrich]

Without more information, you can't make that claim.

He makes two basic statements in the quote. First, the analysis shows the structure would survive the crash. Secondly, that the biggest problem (after the crash) would be the fire from the fuel. There is no indication that the analysis they did included what would happen to the structure AFTER the crash or what the fire might do to the structure.

Skillings conclusion was that the structure would withstand the ensuing fire. This would be supported by the fact that no other steel structure had previously collapsed due to fire.

 

[Furcifer]

The biggest consequence of this reduced mass is going back over previous posts and replacing "...280 tons of TNT" with "...about 150 tons of TNT"

I'd suggest doubling your live-load outside the core and i'm not convinced you accounted for the truss hat entirely.

 

[Mr.D]

Skillings conclusion was that the structure would withstand the ensuing fire.

Source?

 

[Pookster]

Skillings conclusion was that the structure would withstand the ensuing fire. This would be supported by the fact that no other steel structure had previously collapsed due to fire.

Can you describe the analysis that Skilling perform? And, can you show that it was sound enough for Skillings conclusion to be considered correct today (realizing this is hindsight), or even at the time the buildings were designed? If you can show it was sound, then you may have something. Otherwise, it's not useful in any real way for making a case that the buildings could withstand what they did on 9/11.

Even if it is sound, using a comparison to other steel structures is inherently flawed and pointless when looking for supporting evidence. The twin towers had no peers.

 

[GregoryUrich]

Source?

Already gave it to you. See above.

 

[GregoryUrich]

Can you describe the analysis that Skilling perform? And, can you show that it was sound enough for Skillings conclusion to be considered correct today (realizing this is hindsight), or even at the time the buildings were designed? If you can show it was sound, then you may have something. Otherwise, it's not useful in any real way for making a case that the buildings could withstand what they did on 9/11.

Even if it is sound, using a comparison to other steel structures is inherently flawed and pointless when looking for supporting evidence. The twin towers had no peers.

Actually, I was just just pointing out that there is evidence that contradicts Mr. Mackey's claim:

As NIST points out, there is no evidence of this at all. There is only a letter, backed by a calculation even sparser than your paper, suggesting they might survive a hit from a 707 at cruising speed. This was before they were even built, and a proper consideration of impact mechanics and especially fire dynamics was utterly impossible.

The Towers also were not "designed" to do this, because it was never a requirement. Only a scenario that the designers considered potentially viable, and they considered a low-speed impact far more plausible.

The evidence being:

Regarding the impacts I quote Gregg Roberts:

"GR: NIST’s estimates of the impact speeds are 443 mph ± 30 mph for the North Tower and 542 mph ± 24 mph for the North Tower. (ref 9) These speeds are far below the cruise speed stated on Boeing’s website, although of course cruise speed is not normally reached below 10,000 feet. Regardless, the question here is not whether the planes were flying above their rated speed or maximum safe speed, but whether the planes’ mass and speed exceeded what the buildings were designed for. Skilling says, and the Port Authority and NIST agreed,(ref 10) that they were designed to survive a 600 mph impact by a 707. Such a plane if fully loaded (as Skilling claimed the design assumed) would have 336,000 / 395,000 = 85% (ref 11) of the mass of a fully loaded 767 (which the impact planes were not, since they were not carrying full loads of fuel). (ref 12) Thus, the North Tower impact would have had less than 87% of the momentum and 64% of the kinetic energy designed for, while the South Tower impact would have had less than 106% of the momentum and 96% of the kinetic energy designed for. Correcting for the estimated fuel load of 10,000 gallons, I get 300,000 pounds for the 767s (close to FEMA’s 274,000 figure) and accordingly far lower momentum and kinetic energies than designed for. Thus, the impacts were either close to, or well within, the Towers’ capacity to absorb them without collapse."

The important reference is ref 10 = NISTNCSTAR1 pg. 6. This reference alone is a clear refutation of your claims above. Regarding this point, I respectfully request that if you don't agree, you take it up with NIST, not with me.

And:

Here is a quote from Skilling in the Seattle times:

Business: Saturday, February 27, 1993
Twin Towers Engineered To Withstand Jet Collision
Eric Nalder

...Concerned because of a case where an airplane hit the Empire State Building, Skilling's people did an analysis that showed the towers would withstand the impact of a Boeing 707.

"Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed," he said. "The building structure would still be there."

(my comments)
This contradicts Robertsons claims of no consideration of jet fuel. Sometimes we have to decide who we are going to trust. Its' interesting to note that Robertson is nervously defending his work while Skilling had nothing to hide.

I have no way of showing that Skilling was correct. But, I haven't asserted that he was. I am doing research to find out.

By the way, you are correct regarding the comparison to other buildings. Not because there weren't similarly designed buildings, there were. Even if a similar building had a fire it would still be circumstantial evidence.