An interest in physics coupled to a horrible event: as the floors pancaked down, wouldn’t there have been a crushing spike in air pressure from the instant the ceiling was driven downwards before it traveled the few feet onto the heads of the office workers?
I wonder if many of the mortal effects of explosives actually occur that way, as if it really matters.
I doubt it. I don’t thing the air would travel from floor to floor so if just the air on that floor were compressed to half of its volume (10’ to 5’ height) it would still be a less than a 15 psi differential.
That’s also assuming each floor was air tight, which it wouldn’t be. Even if it was, the blown out windows would have relived any pressure.
High explosives detonate - that is, the reaction occurs with extreme rapidity, progressing across the mass of the explosive at supersonic velocities (typically a few thousand meters per second). The reaction products build up so quickly that they can’t get out of their own way, so to speak; they build up enormous localized pressures, resulting in a shock wave that propagates outwards. Behind the shock wave there is region of greatly increased pressure, and that pressure is what causes blast-related injuries and damage.
To generate a shock wave, the collapsing floors of the WTC would need to fall with a speed above that of sound, i.e. something greater than ~768 MPH. IIRC from the video footage, they did not fall with anywhere near that velocity - nor could they have, given the height from which they fell. Indeed, IIRC from the videos, each tower took something on the order of ten seconds to collapse; that’s 130 feet per second, or just 90 MPH. So there certainly would be no shock wave propagating downward from the ceiling of each collapsing floor, and the shattering windows wouldn’t provide any kind of containment to allow the buildup of air pressure that might have resulted from the collapse of each floor. There would have just been a great wind blowing out from every window as ceiling collapsed to floor and squished out the air, no devastating/fatal air pressure increase.
There was a handful of firefighters that survived the collapse.
No.
Luckily, there were only four other posts to review in an attempt to find out why this statement might have been made, but … couldn’t find one. Care to mention what inspired you to write it?
I’m guessing it proves they weren’t killed by a shock wave or high air pressure.
If you watch videos of the towers as they collapse, you can find some that show windows many floors below the “pancake” point blowing out, presumably from the increased air pressure. I don’t know how much pressure it takes to do this, but my WAG is that it is much less than needed to kill someone.
The conspiracy theorists point to these as proof of additional explosives.
I would guess that it’s just the weight of the floors above (and the vibration) popping the panes out.
I mean, if you drop a few thousand pounds right on the edge of my house (over a window), even if it doesn’t go all the way to a window, it’s still probably going to break it as it deforms the structure.
I could not understand why the tone changed beginning here, but after Fallen, I figure I figured it out, which
confirmed.
Now, I think it’s too early in the morning for this, but I couldn’t get to sleep thinking about it and want to get it off my mind.
Analog, not argumentum, ad Hitlerum: perhaps there are long time members who are Truthers, but I would think that spending so much time on GQ would have revealed themselves as such by now. The first posters know who I am, virtually; even had they not, the answers were SD quality (MachineElf hit it out of the park, even picking up on my suggestion of where my query was coming from).
But let us say some unknown poster, just as Leo Bloom is to most, posted this query: “Wouldn’t typhus have spread incredibly rapidly through Auschwitz?”–I too, perhaps, would have jumped down his throat, because this is a staple of Holocaust “likelihoods” that the Joos have covered up. So I get it. The question is a good one, but the “it did or it didn’t, but I’m interested in epidemiology” part is left unsaid. Back to WTC, I actually was aware of blown out windows messing up the idea, but the idea was expressable so well with the phenomenal pancaking, a measurable speed and an idealized, almost piston-cylinder setup.
So, since you asked, I’ll tell you why I posted, as a proximate cause (the ultimate one I stated right out, as a question of physics).
For years I would tell an awe-shucks-it-was-nothing anecdote–as I’m doing right now 
–about how a Scud landed so close that the previously taped windows in our barracks were blown out (it also took out some defense department muckety muck’s house, so for both reasons was not officially reported at first). The blast was so strong, I would tell my awed audience, that my vision unfocused and tunneled just for a moment, because the overpressure was so strong. I was told a few years later that had that been the case I would have been blown to smithereens, and it was a result of an overload of adrenalin coursing through my scared shitless mind.
(I now find that interesting, and have revised my anecdote; it now includes this bit about my misapprehension and that it was pointed out by a professor under contract to DARPA to induce such adrenalin overloads in enemy soldiers without going to the bother and uncertainty of causing it by plain old fear of death.)
More proximate causes, which is why I said “macabre.” I meant it; I am a New Yorker and watched it burn, opened my door to my wife’s sister a walking statue who walked three miles barefoot, and I still cover the screen as the fall becomes Zapruderized. (I’ve wondered since how much of the gray that covered her was human ash; an SDGQ post I have yet to ask.)
More proximate causes for this very post, and we return to Hitler: I’ve wondered about death-inducing pressure when considering, and hoping, about infants being shipped to and dealt with in Auschwitz: what the pressure was in the cattle cars that killed many (as well as older people) before the doors were opened at the camp, the pressure at the top of the gas chambers where they were stuffed in above the heads of those standing, and more recently when I read about it, my fervent backwards prayer that of all infants at the bottom of the heap in the dump trucks tipping them alive, into pyres, that some of them were already killed by the pressure of the others above them.
I have not posted these questions seeking discussion of mortal pressure on the chest, and I don’t think I will.
So that’s why I got interested in the effects of pressure in malevolent situations.
ETA to above: did I get “ultimate” and “proximate” backwards?
Leo Bloom, I can’t say I was able to follow all that but I was just replying to the physics. I didn’t think CT at all.
I was stuck on the initial question. I thought the floors below the crash zones were mostly empty of people, excepting the firefighters trying to reach the upper floors. It’s not like the “office workers” were just sitting at their desks working on spreadsheets as the buildings came down from above.
Probably not a spike, but there may have been a whoosh. The other kind.
(Well I just sucked the air right out of this room.)
(As it were.)
(So this wouldn’t be the time to ask about the pressure wave in front of a bullet, as long as we’re on the topic?)
(Didn’t think so.)
(So how 'bout those Yankees?)