"As it turns out, it fell at FFA [free fall acceleration] for ~100 feet. As a physicist you should understand the significance. For a building to fall at FFA, all the supporting structure must be removed. Bending columns provide resistance and prohibit FFA."
Do you understand that in order for a building to fall at FFA, all the supporting structure must be removed?
Do you understand that 150+ columns
bending provide resistance and prevent FFA?
Do you understand what Dr. Sunder is saying here:
[FONT="][SIZE=3]"a free fall time would be an object that has no structural components below it . . . there was structural resistance that was provided in this particular case. And you had a sequence of structural failures that had to take place. Everything was not instantaneous."[/SIZE][/FONT][/quote].
[QUOTE="DaveThomasNMSR, post: 6274113, member: 39130"]I
have responded to this.
For the record, I've already said
The collapse did take several seconds - at least 16 seconds. As Dr. Sunder said, "Everything was not instantaneous."
The collapse proceeded not only vertically, but horizontally as well. The supporting columns you cite were most likely pulled down collaterally, in time to pull the rug from under the visible facade for a couple of seconds, out of 16 at least. For a brief moment, a part of WTC7 wasn't supported as it collapsed. This in no way proves controlled demolition, sorry.