I will answer your question and also try to answer the former.
I do not believe testing for chemical residue is even possible in the WTC case, for a variety of reasons:
- If I was running the testing, I would test steel pieces at the initiating event, i.e. the collapse zone. We have exactly zero steel pieces from the core within a floor of the point of failure, from either structure. All of them were so heavily damaged that they could not be identified.
Is this statement accurate?
According NIST:
Summary of metallographic analysis – Core Columns
• Two core columns in impact area with sufficient paint
• Columns 603 (floors 92-93) and 605 (floors 98-99)
Source: NIST
Not all of them were so heavily damaged that they could not be identified.
Besides if they were so heavily damaged, then through process of elimination by using the rest of the steel that was identifiable you can determine the location of the steel. I don't blame NIST for this however, it wasn't them who ordered the removal of the debris without testing and detailed examination.
[*]We would, therefore, have to test a much larger volume of steel. This introduces uncertainties. First, we know we're contaminating our sample, and so the likelihood of false-negative goes up substantially; we thus have to adjust our sensitivity, and this affects false-positive as well.
Most if not all scientific experiments have the potential for contamination. This does not mean experiments should not be conducted. This excuse can now be rejected. I would refer you to the chemical tests done in the case of TWA 800 as example.
Not only that, increasing the sample size will help to determine the presence or absence of explosives or to reduce measurement error (e.g., perhaps through increased sample size or longer observation time) so that the densities are more tightly defined around the mean measurement as detailed here.
Second, the damage suffered by the core columns that prevents identification also is expected to interfere with the chemical signatures.
This goes back to your erroneous first point.
The probability of observing a false positive is referred to as the “false positive probability” or “false positive rate” and is equivalent to the specificity of the detector not the condition of the steel. Source:Here.
Third, even if we believe we have a positive result, we cannot uniquely position them and thus cannot confirm it either way. Results are, therefore, almost guaranteed to be inconclusive.
The location of the piece tested has no bearing on whether explosive devices were used or not. I'm kind of surprised you listed this as a reason for the inconclusive result.
[*]As if that wasn't bad enough, the fires in particular are expected to destroy such chemical residue. Explosives, with no exceptions that I am aware of, are highly heat sensitive. That goes for their products as well. Even if the chemicals remained intact, most would have been baked off, melted, expressed as volatiles in the plume rather than found on the steel itself.
That of course depends on the temperature of the steel and the properties of steel and whether or not it the sample was even exposed to fire.
[*]The fires also create a confounding signal. Burning plastics create a diversity of aromatic compounds. There are several official reports confirming this.
The fires of course were not on all floors below the impact area. This of course can be rejected as well as the above point.
- As a result, I do not see any possiblity of these tests being conclusive.
The more rational approach is to focus on explosives signatures that are not susceptible to these effects, of which there are several. Perhaps the most acceptable signature, from your perspective, is the characteristic fracture pattern created by explosives. Again, this is not wholly conclusive because not all steel could be identified and much was heavily damaged, but this test was conducted. All of the recovered steel was examined by experts for signs of unusual failure modes. This failure mode was not seen in any piece of steel. That's about as close as we are likely to ever come to proving a negative.
I think we might all agree that it was unfortunate the amount of steel that was sampled represented a quarter to half a percent of the 200,000 tons of structural steel used in the construction of the two towers. The rational scientific approach is the one found in the process of forensic examination via chemical testing.
The bad logic that follows is if we don't see any evidence on this tiny percentage, then it didn't happen. So what we are left with is 99.95% of the steel unexamined visually and 100% of the steel that was not exposed to tests that could identify the chemical residue of explosives.
The reason I don't feel there is any hypocrisy here -- my stating a belief that there were no explosives, based on no testing, while rejecting a belief in molten steel, also based on no testing -- is that the two situations are not actually symmetric. As I've described above, there actually have been tests that should have revealed explosives. Chemical tests, no, but tests nonetheless.
Chemical tests are of course my entire point and match nicely with chemically testing molten metal to determine if the properties do indeed match AISA classifications of steel.
Regarding molten steel, on the other hand, if you actually go to the source of the "molten steel" statements, not a single one was made by an expert, and two of the five I know about have been traced to transcription errors and thus never occurred at all.
So a metallurgist would have to test the metal to determine if it were steel or not to corroborate what was witnessed? Or a metallurgist would have to be present to examine the metal before you accept it as molten steel?
Furthermore, the signature of molten steel, unlike the chemical residue, includes "pigs" of formerly molten steel. It is not nearly so fragile a signature, and it is expected to survive the collapses, fires, and cleanup process. It also would have been found through simple sorting and inspection, and does not require a specialized test. Nonetheless, it was not found. I am therefore more comfortable declaring this negative result. I don't find this to be hypocritical at all.
Again this goes back to the illogical statement: if it isn't seen, then it didn't happen.
What exactly
was found? Are there any descrpitions during the debris removal early on or later on fitting the items the descriptions below match?
If not, are all the accounts below lies? Even the first hand accounts?
The president of Tully Construction of Flushing, NY, said he saw pools of "literally molten steel" at Ground Zero. Bollyn also cites Mark Loizeaux, president of Controlled Demolition Inc. (CDI) of Phoenix, MD, as having seen molten steel in the bottoms of elevator shafts "three, four, and five weeks" after the attack.
A report by Waste Age describes New York Sanitation Department workers moving "everything from molten steel beams to human remains."
A report on the Government Computer News website quotes Greg Fuchek, vice president of sales for LinksPoint Inc. as stating:
In the first few weeks, sometimes when a worker would pull a steel beam from the wreckage, the end of the beam would be dripping molten steel 3
A Messenger-Inquirer report recounts the experiences of Bronx firefighter "Toolie" O'Toole, who stated that some of the beams lifted from deep within the catacombs of Ground Zero by cranes were "dripping from the molten steel."
So the following comment from R. Mackey regarding testing of explosives in the WTC attacks.
1. He chemically test in the impact area only. Thereby ignoring a vast percentage of the tower itself. Tsk, tsk. Not a proper forensic investigation in my opinion when compared to other investigations that used the chemical testing for explosive residue.
2. By doing this, he can claim the tests would be inconclusive because of the heat's effect on the chemical properties of steel despite the laboratory evidence not displaying high temperature exposures of the confiscated debris.
3. But just in case tests are positive, they are inconclusive because we aren't sure the part of the tower the steel came from. This is nonsense of course and the point has no bearing on the tests themselves nor the scenario itself.
4. Despite the sample size fallacy mentioned by Ryan, an increased sample size would reduce the false positive probability of the detector and serve to remove a very good criticism of the process, the extremely small percentage size of the steel samples that was investigate.
5. Ryan is satisfied that there were no explosive devices because there was no visual indication in any of the. 05% sample size from the recovered steel.
I would argue that a .05% of a sample is too little of a sample to conduct a proper investigation in the first place. But that is neither here nor there at this point.
I'm sorry Ryan, your answer has failed to answer the critical question it has also failed as an official excuse to not chemically test for explosives.
It is in a sense, the answer is one huge fallacy of omission to reach a desired conclusion, the official conclusion.
You can now understand why the answer is not a critical answer.
Finally, there is the avoidance to offer empirical proof for either the molten steel or the presence of explosives: the chemical tests that would prove one way or another.
) will agree, and you will subsequently agree, also.
