Yes, I too enjoyed the Nova explanation... I think I've seen it twice. Very explicitly denotes the pancaking and falling of one floor onto the next...

I seem to recall that some more recent tests have been critical... claims are being made that the buildings could not possibly have fallen as quickly as they did... very close to freefall speed... and not a little ruckus is being made about the 'nice and neat' conclusion... apparently a building that falls onto itself without much 'help' would have created a taller less tidy heap...

I guess I just want everyone to get resonable answers to what seem like resonable questions... so people dont feel like some kind of 'close encounters' ufo nut... or worse... tearing the basis for our democracy to shreads by eroding the much needed faiths in both God and Humanity... or at least making them appear to be a odds with one another...
ttr