BLM says:

After prolongued observation of the debate surrounding 9/11, I am mainly struck by how many, on both sides, invoke science to bolster their world view, but appear to have little understanding of the fundamental tenet of scientific investigation – that one should be asking an open question and performing experiments that could conceivably provide evidence for the truth or falsehood of the hypothesis under investigation. Very few seem really ready to admit that their preconceived notion of the impossibility, or inevitability, of government conspiracy has no bearing what so ever on the validity of a given body of scientific data. For whatever reasons, truly scientific data about that day is rare. What is not rare is speculation, coincidences, contradictions and self serving over-intepreatations of limited information. That is why when completely verifiable data exists it must be recognized as such. The roofline of WTC 7 fell at full free fall acceleration for at least 2.25 seconds. This observation is measurable and repeatable by anyone with good understanding of high school physics and access to motion tracking software. This particular piece of data, unlike many others under debate, has an absolutely unavoidable conclusion according to basic newtonian physics. The roofline had essentially zero resistance from underlying structure for approximately the first 100 feet of its fall. Thus, approximately 10 stories of the supporting steel structure failed, symmetrically and simultaneously, in a fraction of a second. I have seen no one, including the official NIST report, dispute this conclusion. Now, one can debate as to whether a conventional fire could lead to that type of event – complete structural collapse of approximately 10 floors in under half a second – but one cannot reasonably debate this particular aspect of physics in a supposedly scientific discussion.