• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

911 physics for dummies

Apollo20 said:
Britain's largest peace time explosion was on June 1st, 1974, at Flixborough, when 40 tons of cyclohexane ignited. The pressure at the center of the explosion was estimated to be about 360 psi or 2.5 x 10^6 Pa.
Click to expand...

Even for somebody who has no idea what cyclohexane is, this sounds like a pretty impressive explosion...
 
While the air inside the building had to go somewhere, to simplify the collapse as, essentially, a piston driving each ceiling down on each floor is going too far IMHO.

In places air certainly could have been trapped in this fashion and produced the breaking windows and outflows seen and attributed to 'squibs' by CT's. However for the most part I would think that broken concrete slabs would not be falling horizontally for any apprecaible distance. If air pressure under any such slab did build there would be many mechanisms that would cause the slab to tilt one way or the other. To my mind, much of the internal air had debris falling through it rather than pistoning that air and that the further into collapse the more the air mixed with the debris.

Its a limited analogy but , a load of gravel being dumped into a truck box does not create a great rush of air. It generates enough movement to cause dust to rise at the sides of the box but the tailgate is never in danger of being blown off.
 
I have seen gravel knock a tailgate off a truck. All that material in those towers had to go somewhere.

Excuse me if my mind seems to be wandering here. Are we treating the dust and sand-sized material as a solid?

I ask this because at some points, the dust appears to behave as a gas, and at others like a liquid. It seems to me to act mostly like a liguid as it piles up and flows up the sides of the perimeter columns until it escapes. It seems to me that it would thus put a great deal of pressure on the tops of the columns it was over-flowing, and would thus gain some mechanical advantage through leverage, thus somewhat speeding the collapse of the floors below by unpeeling the building like a banana.

If this model is accurate, does it actually alter the energy budget, as compared to a model in which it is merely the vertical force that snaps the floors loose from the columns?
 
I would say that a realistic MAXIMUM value for the compression ratio of the air sandwiched between two WTC floors would be ~ 1.5. If the compression of the air occurred adiabatically, (as opposed to a slow isothermal change), the gas temperature would increase by about 53 deg C. However, even such a modest temperature increase would require an energy input of about 0.5 GJ!
 
I promise not to prolong this thread forever. If I forgot to acknowledge anyone above , thanks for all of your replies.

Below are excerpts from a poster on another forum. Any comments appreciated, as analyzing molten metal isn't my specialty.

On the substance dripping down the South Tower:

I think the generally agreed temps [in the twin towers before collapse] were in the neighborhood of 800ish F. . . .Others ( http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html , for one) dispute the temperatures given. [chris lz is aware this conflicts with the NIST report] I know that paper burns at 451 F (Ray Bradbury could tell you that), so the heat of contents burning in an oxygen-starved environment (as indicated by the dark, sooty smoke) could not have gotten the temps a whole lot higher. . . . the aluminum was on the outside and could not have had a sustained heat application, the heat actually encountered by the aluminum had plenty of opportunity to wick away, there was no evidence of paneling slagging and melting, and people are turning cartwheels to suggest that it all was a natural event. . . with weird drippy metal exactly like thermite reactions on steel on film. . . .And the aluminum was at the very exterior and easily bled heat into the atmosphere. If you want to do logical gymnastics over the facts, you can conclude that the metal was most likely aluminum. But man, that's a stretch!
Click to expand...


Chris lz: Point me to a demonstration that the WTC aluminum construction was such that it could not have generated molten aluminum on 9/11.

Poster:
. . . the details of construction are available on the web, and a basic knowledge of what metal does with locally applied heat given huge sheets of it (distributing the heat throughout), as well as an understanding of its ability to dissipate heat into the atmosphere, the fact that melted aluminum becomes silvery and not glowy (unless it's heated to near boiling, and the temps weren't remotely THAT high), combined with all I gave above, and I must conclude that very little in the way of melted aluminum would be found, and that 9/11 was engineered by people with something to gain.
Click to expand...

Chris lz: I started a thread over at JREF a week ago. . . There are several physicists at JREF. . .I'd like to subject your ideas to them and see what they have to say.


I would love to hear from such a forum. I base my analysis of the data on logical thinking alone, pretty much.
. . .and let people know that what aluminum looks like in pools cooling has little to do with how it looks coming directly from a heat source... I have seen footage of aluminum in daylight, melted and cooling. It is silvery, not glowy.
Click to expand...
 
The "oxygen-stareved" argument does not hold water. I have fought a lot of jet fuel fires in the open air just for drill. They all smoke hideously, and they often melt aluminum and copper and glass.
 
chris lz said:
I promise not to prolong this thread forever. If I forgot to acknowledge anyone above , thanks for all of your replies.

Below are excerpts from a poster on another forum. Any comments appreciated, as analyzing molten metal isn't my specialty.
Click to expand...

Random Truther said:
I know that paper burns at 451 F (Ray Bradbury could tell you that), so the heat of contents burning in an oxygen-starved environment (as indicated by the dark, sooty smoke) could not have gotten the temps a whole lot higher. . .
Click to expand...

You might want to point out that this is a bunch of crap... 451 F is the auto-ignition temperature of paper, not the maximum temperature it can create. Office fires reach over 1200oC routinely. This is proven over and over again in full-scale fire tests.

Whoever this guy is, he's not impressing me with his knowledge.
 
You must log in or register to reply here.

Back
Top Bottom