This is page two of the September 11th: What Do We Know? article. If you were linked here by mistake, please refer to page one in this section.
We now have enough evidence to form a hypothesis regarding what happened to the World Trade Centers. We know for sure the planes struck the towers. We know for sure which planes struck the towers. We know for sure why they struck the towers (because they were hijacked). We can now surmise that it is likely that a cause-and-effect relationship exists between hijacking, plane strikes, and tower collapses, especially since it happened twice, not just once. However, this is a hypothesis; we now need to determine if (A) if we can determine that this cause-and-effect relationship exists, and (B) if there is any other evidence out there that explains the result better than the cause-and-effect relationship we are supposing.
Obviously, whether the plane strikes caused the towers to collapse depends on the sort of damage the strikes did to the WTC towers. Let's look at some evidence regarding this.
This paper collects and collates statements of people who got out of the World Trade Center towers, both WTC1 and WTC2, about the damage done to the towers. This paper is very extensive. Just a few of the reports collected here include:
The second page of the paper includes numerous direct quotes from survivors.
Purpose: direct eyewitness evidence of severe damage to the WTC towers, not just at the impact zones, but all up and down the buildings. Also, corroborates Carol Paukner that the plane strikes caused severe damage throughout the buildings.
I am unaware of any evidence that disputes the statements made by these witnesses, and they corroborate each other--as well as corroborating Carol Paukner.
"Approximately 40 minutes after I arrived in the lobby, I made a decision that the building was no longer safe. And that was based on the conditions in the lobby, large pieces of plaster falling, all the 20 foot high glass panels on the exterior of the lobby were breaking. There was obvious movement of the building, and that was the reason on the handy talky I gave the order for all Fire Department units to leave the north tower."
Purpose: evidence that the damage to WTC1 was so severe as to threaten the structural integrity of the building, and that collapse was thought to be likely before it happened.
I am unaware of any evidence that disputes Chief Callan's statement.
"I was in a discussion with Mr. Rotanz and I believe it was a representative from the Department of Buildings, but I'm not sure. Some engineer type person, and several of us were huddled talking in the lobby and it was brought to my attention, it was believed that the structural damage that was suffered to the towers was quite significant and they were very confident that the building's stability was compromised and they felt that the north tower was in danger of a near imminent collapse."
Purpose: corroborates Joseph Callan that damage to WTC1 was so severe as to threaten structural integrity, and that collapse was predicted before it happened.
I am unaware of any evidence that disputes Chief Peruggia's statement.
McMillan was in WTC2. She stated:
"As I was gathering it, I was saying to Mala, that I'm looking up at the building and I said to her, this is going to fall. She says I know. I think we are in the wrong place. I tried to tell Chief Grant and Chief McCracken I think it's going to fall, but they were so busy talking among themselves, I didn't have a chance to tell them what I was feeling."
Purpose: evidence that damage to WTC2 was so severe as to threaten the structural integrity of the building, and that collapse was predicted before it happened.
I am unaware of any evidence that disputes McMillan's statement.
Constantine was in WTC2. He stated:
"We were helping any way we could. A lot of people wanted to help. At that time, I don't know what time it was, we heard across the radio the tower's gonna fall, the tower's gonna fall."
Purpose: corroborates McMillan that the damage to WTC2 was so extensive that it threatened the structural integrity of the building, and that collapse was predicted before it happened.
I am unaware of any evidence that disputes Constantine's statement.
Our hypothesis is getting stronger. Let's hear from some experts.
Loizeaux explains precisely why the towers collapsed as a result of the plane strikes:
"First of all, you've got the obvious damage to the exterior frame from the airplane--if you count the number of external columns missing from the sides the planes hit, there are about two-thirds of the total. And the buildings are still standing, which is amazing--even with all those columns missing, the gravity loads have found alternate pathways. O.K., but you've got fires--jet-fuel fires, which the building is not designed for, and you've also got lots of paper in there. Now, paper cooks. A paper fire is like a coal-mine fire: it keeps burning as long as oxygen gets to it. And you're high in the building, up in the wind, plenty of oxygen.
"So you've got a hot fire. And you've got these floor trusses, made of fairly thin metal, and fire protection has been knocked off most of them by the impact. And you have all this open space--clear span from perimeter to core--with no columns or partition walls, so the airplane is going to skid right through that space to the core, which doesn't have any reinforced concrete in it, just sheetrock covering steel, and the fire is going to spread everywhere immediately, and no fire-protection systems are working--the sprinkler heads shorn off by the airplanes, the water pipes in the core are likely cut. So what's going to happen? Floor A is going to fall onto floor B, which falls onto floor C; the unsupported columns will buckle; and the weight of everything above the crash site falls onto what remains below--bringing loads of two thousand pounds per square foot, plus the force of the impact, onto floors designed to bear one hundred pounds per square foot. It has to fall."
Purpose: engineering/scientific explanation of how and why the plane strikes resulted in the collapse of both towers.
These engineering experts state:
"The combination of six effects: a) overload of some columns due to initial stress redistribution, b) lowering of yield limit and creep, c) lateral deflections of many columns due to sagging floor trusses, d) weakened lateral support due to reduced in-plane stiffness of sagging floors, e) multi-story buckling of some columns (for which the critical load is an order of magnitude less than it is for one-story buckling), and f) local plastic buckling of heated column webs finally led to buckling of columns (Fig. 1b). As a result, the upper part of tower fell, with little resistance, through at least one floor height, impacting the lower part of tower. This triggered progressive collapse because the kinetic energy of the falling upper part far exceeded the energy that could be absorbed by limited plastic deformations and fracturing in the lower part of tower."
Purpose: scientific explanation for how and why the plane strikes resulted in the collapse of both towers; corroborates Mark Loizeaux.
In this paper, Dr. Jones questions the hypothesis that plane strikes caused the collapses. He states:
"In this paper, I call for a serious investigation of the hypothesis that WTC 7 and the Twin Towers were brought down, not just by impact damage and fires, but through the use of pre-positioned cutter-charges. I consider the official FEMA, NIST, and 9-11 Commission reports that fires plus impact damage alone caused complete collapses of all three buildings. And I present evidence for the controlled-demolition hypothesis, which is suggested by the available data, and can be tested scientifically, and yet has not been analyzed in any of the reports funded by the US government."
Okay, now we have conflicting views on the science regarding the hypothesis.
Dr. Rogers states:
"Speaking as a person with a PhD in Physics who has peer reviewed papers, I would have advised rejection of this paper for publication in any serious scientific journal, quite possibly without the option of a re-write...Suffice it to say, this is not a scientific paper, follows nothing remotely similar to scientific methodology, contains numerous obvious errors, unsupported assertions and misceptions about many subjects including the nature of controlled demolitions, contradicts its own findings in places, and appears at times to be deliberately attempting to mislead the reader. It has been extensively criticised elsewhere, and I have little to add except one point I haven't seen emphasised:
Jones claims that the liquid running from one of the corners of one of the WTC towers cannot be aluminium and must therefore be molten steel. From the emission colour he estimates its temperature at 1000 C. Elsewhere in the paper he quotes the melting point of structural steel as 1510 C. His own analysis therefore contradicts his own conclusions. For him to have published such a thing suggests a serious loss of ability for self-criticism that is unacceptable in a serious scientist.
Overall this paper is an appallingly bad piece of scientific analysis."
We now have two competing hypotheses:
We know these cannot both be true. Therefore, we must decide which of them is more likely to be true.
Dr. Steven Jones, and those who agree with him (Richard Gage, Kevin Ryan etc.), attack Hypothesis A on scientific grounds. However, let's view Hypothesis A versus Hypothesis B on logical grounds, and then return to the scientific question.
Which is more likely?
In order for Hypothesis B to be true, by definition someone must have planted cutting charges in both WTC1 and WTC2 sometime before the morning of September 11, 2001. Hypothesis B cannot be true without this having happened.
Also consider, regarding Hypothesis B:
On logical grounds alone it is clear that Hypothesis A must be correct and Hypothesis B cannot be. However, let's examine the question...
Is there any evidence of these "cutting charges," which by definition must have been present if Hypothesis B is true?
This is the linchpin of Hypothesis B. Because there is no evidence of these explosive charges, there is no reason to believe that they existed. If they did not exist, Hypothesis B cannot be true.
Steven Jones states he believes he has found minute particles of explosives in WTC debris:
"We have discovered distinctive red/gray chips in all the samples we have studied of the dust produced by the destruction of the World Trade Center. Examination of four of these samples, collected from separate sites, is reported in this paper. These red/gray chips show marked similarities in all four samples. One sample was collected by a Manhattan resident about ten minutes after the collapse of the second WTC Tower, two the next day, and a fourth about a week later. The properties of these chips were analyzed using optical microscopy, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (XEDS), and differential scanning calorimetry (DSC). The red material contains grains approximately 100 nm across which are largely iron oxide, while aluminum is contained in tiny plate-like structures. Separation of components using methyl ethyl ketone demonstrated that elemental aluminum is present. The iron oxide and aluminum are intimately mixed in the red material. When ignited in a DSC device the chips exhibit large but narrow exotherms occurring at approximately 430 °C, far below the normal ignition temperature for conventional thermite. Numerous iron-rich spheres are clearly observed in the residue following the ignition of these peculiar red/gray chips. The red portion of these chips is found to be an unreacted thermitic material and highly energetic."
In this email exchange, Dr. Frank Greening indicates serious scientific problems with the "thermitic material" claims.
"And as for coal fired boilers, a little research will show you that iron-rich microspheres are a well documented component of coal fly ash even though pulverized coal combustion temperatures are less than 1400 deg C. So you must accept that iron-rich microspheres do not need temperatures of 1538 deg C or higher to form in a coal/wood/paper combustion environment. If you cannot accept this fact there is no point in continuing this "debate"...We can debate this in the New Year, if you wish, but until you can show me that iron-rich microspheres COULD NOT be present in the WTC dust without "added" thermite, I think we won't have much to talk about!"
This is anecdotal and not very authoritative. It cannot be regarded as conclusive. However, it does illustrate that Dr. Jones's scientific credibility is open to serious question.
Let's zoom out for a moment and set aside whether Dr. Jones is a credible expert. We already know that Hypothesis B is pretty unlikely. However, is there any scientific evidence we can bring to bear directly on whether Hypothesis B is possible, much less likely?
In this peer-reviewed paper written for the Department of Civil and Environmental Engineering of Northwest University, four prominent engineers conclude that Hypothesis B is scientifically impossible. These researchers state:
"Previous analysis of progressive collapse showed that gravity alone suffices to explain the overall collapse of the World Trade Center (WTC) towers. However, it remains to be checked whether the recent allegations of controlled demolition have any scientific merit. The present analysis proves that they do not. The video record available for the first few seconds of collapse is shown to agree with the motion history calculated from the differential equation of progressive collapse but, despite uncertain values of some parameters, it is totally out of range of the free fall hypothesis, on which these allegations rest...The calculated crush-down duration is found to match a logical interpretation of seismic record, while the free fall duration grossly disagrees with this record."
Purpose: direct evidence, from scientific experts, that Hypothesis B is scientifically impossible and that Hypothesis B has no scientific merit.
Therefore, to sum up:
Regarding Hypothesis A:
Regarding Hypothesis B:
We have thoroughly examined these competing hypotheses. It is very clear that Hypothesis A is correct and Hypothesis B is incorrect. We have proven Hypothesis A, which means it is no longer a hypothesis, but a conclusion.
Before we move on to the next section let's sum up the conclusions that we now know must be true:
We have already eliminated almost all of the leading conspiracy theories. This (intentionally limited) analysis is nearly concluded, but for the sake of completeness we'll look (briefly) at a few other subjects.