Gretavo debates Richard Dawkins fans...

1) Econ has not answered the question of whether he accepts that there was molten iron (or steel, but for simplicity henceforth I will refer only to molten iron since it is common to both pure molten iron and molten steel) present at the wtc on 9/11. Instead he says, essentially, "so what if there was". The significance of molten iron is twofold. First, the official account does not include a credible explanation of what caused the presence of the molten iron, seen before and after the collapses. Second, molten iron is a byproduct of incendiary materials such as thermite and as such the presence of molten iron indicates the possible presence of incendiaries.

2)

Not a bad start. OK do you recognise that the "global collapse" of the towers occured after some weakening of the "impact and fire zone" caused it to stop supporting the upper block of stories in each of the towers? Therefore that "top block" fell. So how did explosives achieve that? What members were cut? How many members were affected by Aircraft impact? By fire? how did these combine? How dod the explosives assist that action?

I would suggest, Econ, that since you claim to support the official explanation and therefore already have answers to these questions that the best way to frame this discussion would be to start with the answers that *you* have. Since I am familiar enough with the NIST report I will attempt to do that and you may correct me if I'm wrong by citing the primary source (i.e. the NIST report) on which your side's claims that:

the established-narrative thesis has already survived major tests in thousands of hours of examining the evidence

are based. Fair enough?

I should say at this point that the NIST rather unhelpfully makes all its reports available in a pdf format from which it is not possible to copy text so that if it is to be quoted it must be done by typing out the relevant passages. So tu sum up the NIST case on which various appeals to authority are commonly made:

1) A plane hit each tower with three distinct consequences: a number of structural columns in the exterior (observed) and interior (inferred) of the building were severed, fireproofing material was dislodged from the trusses and columns (inferred), and fires were ignited in several areas across a number of floors (observed.)

Immediately we should note that there is a big difference between evidence cite by NIST based on observation and on inference. The former is based on directly observed and non-controversial facts, the latter is based on speculation. I take for granted that in addition to the observed exterior column damage a certain number of core columns were severed by the planes' impacts. At issue is how many did, and how the NIST arrived at their estimate for that number which was one of the variables in the computer model they used to validate their hypothesis of the cause of collapse initiation.

At issue as well is the inference that a significant (i.e. extensive enough to contribute to collapse initiation) amount of fireproofing was dislodged as a result of the planes' impacts. It should be noted at the outset that NIST's model of collapse initiation hinges on the dislodging of a large amount of fireproofing since said fireproofing was rated for 2 hours (i.e. there would be no performance degradation of the steel until after 2 hours of exposure to fire) and neither of the twin towers burned that long before collapsing. NIST supports its contention that a large enough amount of fireproofing was dislodged in a portion of their report, an OCR processed copy (to enable easier citation) is available at: http://wtcdemolition.com/nist%20shotgun ... oofing.pdf . At issue is whether NIST adequately showed that the planes' impacts would have dislodged (in the absence of direct evidence that they *did*) enough fireproofing so as to render the towers' steel susceptible enough to the fire to validate their hypothesis of collapse initiation.

We see therefore that NIST's computer model used inferred values and not observed values, and it is a fact admitted by NIST that they found that their model only predicted collapse initiation within the higher ranges of their values for the number of columns severed and the effects of the fire on the remaining steel structure. Once the variables inputted caused the model to predict collapse initiation NIST concluded that the correct value of the variables had been approximated since the result matched what was observed--the tops sections of the towers were observed to begin falling. This is an example of circular reasoning however since the process operates under the a priori assumption that only impact and fire effects were involved. Once the value for those was set high enough, based not on observation but on inference, their computer model predicted collapse initiation. This does not mean that NIST proved that the twin towers collapsed without the help of explosives and/or incendiaries, it simply postulates the extent of the damage that would have been required for the collapse to initiate without the help of explosives and/or incendiaries. It leaves open the possibility that the actual values for impact and fire damage were on the lower end of their inferred estimates and that collapse would *not* have initiated without the help of explosives and/or incendiaries, based on their own computer model. At issue is whether NIST credibly ruled out any role played by explosives and/or incendiaries in the destruction of the towers, i.e. not simply whether they showed the possibility of the destruction without explosives and/or incendiaries.

Now, this is just a starting point focusing on NIST's hypothesis for collapse initiation--it leaves untouched the question of whether once collapse initiated the collapse, in the absence of explosives and or incendiaries, would have conformed to what was observed, i.e. would have been global.