• 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.

Fyziks 101

Last edited:
Im sure most of you have heard this question before, but ive never seen it answered. Why dont cd crews just go to the 11th floor of a 15 story building and blow the supports and let gravity take over? By debunkers explanations of why WTCs fell , gravity should be used in all demolitions.
I`m thinking they dont because stuff like this would happen.
 
Last edited:
Tweeter said:
Im sure most of you have heard this question before, but ive never seen it answered. Why dont cd crews just go to the 11th floor of a 15 story building and blow the supports and let gravity take over? By your explanation of why they fell , gravity should be used in all demolitions.
Click to expand...


Yes, you've seen the question asked many times. The answer will be the same: blowing supports close to the base allows the demolition team to control the collapse of the structure. No, you still don't get it.
 
Tweeter said:
Im sure most of you have heard this question before, but ive never seen it answered. Why dont cd crews just go to the 11th floor of a 15 story building and blow the supports and let gravity take over? By your explanation of why they fell , gravity should be used in all demolitions.
Click to expand...

Indeed. And if collateral damage or safety in general wasn't an issue, perhaps you'd have a point.

So. Let's just blow those babies, let gravity take its course and let the chips fall where they may. Sounds like a good idea for standard CDs huh?
 
Tweeter said:
Im sure most of you have heard this question before, but ive never seen it answered. Why dont cd crews just go to the 11th floor of a 15 story building and blow the supports and let gravity take over? By your explanation of why they fell , gravity should be used in all demolitions.
I`m thinking they dont because stuff like this would happen.
Click to expand...


what? a white out?
:dl:
 
Tweeter, not all buildings are the same. Something that would result in the collapse of a building built like the Twin Towers would not necessarily achieve the same result in a tower constructed differently, like the Chrysler Building, or the Empire State. I'll leave the details of the differences to someone like Architect, who could expound on that topic with authority, but the point is that the event that resulted in the WTC collapse wouldn't necessarily result in collapse in other buildings.
 
tweedle dumb,

You fixed your link and inserted a straw man

that's a reinforced concrete grain elevator. There are no sixty foot clear spans within that structure.
 
Porkpie Hat said:
Tweeter said:
<...snip> gravity should be used in all demolitions.
Click to expand...

It just keeps getting dumber...
Click to expand...

I just realized what was written there. Tweeter, I think that point could stand a rewrite. All explosives demolitions rely on gravity.

I think what you're trying to say (or rather ask) is: Why do companies not just rig a single upper floor and let that upper segment crash through the lower floors? If it is, then the answer goes back to several previous posts, including mine about differently built buildings behaving differently, as well as previous threads where people have noted that demolitions companies want to control where the debris lands. As seen by the damage to neighboring buildings, most notably WTC 7, the World Financial Center, the Verizon building, etc., collapse like what happened at the Twin Towers does not lend itself to controlling where the debris lands.
 
pomeroo said:
I'd be cautious about concluding that no one can be that stupid. My experience here has taught me that any sentence beginning with, "Nobody is dumb enough to...," is wrong. Somebody is just that dumb. The adjective "kirkmanic" was coined as a tribute to a poster who called himself "Malcolm Kirkman." You would think that any human making hundreds of comments over a hundred-page thread would accidentally get a few things right. You'd be mistaken. The fabulous idiot Heiwa was a truly kirkmanic dunce. Turbofan falls short of that twoofer ideal, as none of his spectacularly stupid pronouncements are his own inventions.

He merely stands on the shoulders of cretins.
Click to expand...

You're right and I stand corrected!
 
ElMondoHummus said:
I just realized what was written there. Tweeter, I think that point could stand a rewrite. All explosives demolitions rely on gravity.

I think what you're trying to say (or rather ask) is: Why do companies not just rig a single upper floor and let that upper segment crash through the lower floors? If it is, then the answer goes back to several previous posts, including mine about differently built buildings behaving differently, as well as previous threads where people have noted that demolitions companies want to control where the debris lands. As seen by the damage to neighboring buildings, most notably WTC 7, the World Financial Center, the Verizon building, etc., collapse like what happened at the Twin Towers does not lend itself to controlling where the debris lands.
Click to expand...

We could say that even the ability to walk depends on gravity. But some troofer would just post and say.. "Lul whut? space walks too?"
 
ElMondoHummus said:
I just realized what was written there. Tweeter, I think that point could stand a rewrite. All explosives demolitions rely on gravity.

I think what you're trying to say (or rather ask) is: Why do companies not just rig a single upper floor and let that upper segment crash through the lower floors? If it is, then the answer goes back to several previous posts, including mine about differently built buildings behaving differently, as well as previous threads where people have noted that demolitions companies want to control where the debris lands. As seen by the damage to neighboring buildings, most notably WTC 7, the World Financial Center, the Verizon building, etc., collapse like what happened at the Twin Towers does not lend itself to controlling where the debris lands.
Click to expand...

That gets me to thinking what if you would of used a conventional controlled demolition. Wonder what the debris field would of been.
If it were truly in its own footprint they would of had a 30 story pile or more, no? Lucky it fell the way it did.
 
Last edited:
Tweeter said:
That gets me to thinking what if you would of used a conventional controlled demolition. Wonder what the debris field would of been.
If it were truly in its own footprint they would of had a 30 story pile or more, no? Lucky it fell the way it did.
Click to expand...

I'm not sure if the authorities would have allowed the towers to be demolished with explosives. It's an interesting question, what the result would have been. Remember that a lot of the dust-causing elements would be removed prior to demolition, so the spread of that would be considerably smaller than when the towers collapsed on September 11th.
 
Big bricks and little bricks,, trucks and trains....... Forgive me if I do not read this entire thread.

When the building was in pristine working condition the floor spans carried the mass of only one floor. They transmitted the force of the mass of ONE floor to the core and perimeter columns and thus the column systems bore the mass of the entire structure.

now note that at initial collapse the columns supporting the mass above the level of initial collapse must bend. They can do so only so far before being broken. Obviously as they bend the upper portion of those columns do not line up with the lower portion in a straight line, the upper portion is offset from the lower portion. Thus when the mass of the upper block of floors reaches the next intact floor where is its mass going to be borne? Certainly not directly by the vertical columns.

Instead we now have the vast bulk of the mass of the upper block coming down upon the floorspace of the next intact floor and this is a large multiple of the mass that any single floor could ever be expected to carry let alone absorb the kinetic energy of that mass as it fell. Thus the connections of the floor spans to the columns fail all but immediatly. The ability of those connections to resist being severed would tiny compared to the energy of the impact.

The visible effect would be the very quick loss of lateral support to the perimeter columns. So now you have perimeter column 'trees' that are unsupported but they also have a vast amount of debris to one side of them. Therefore the most common direction for these column trees to fall will be to the outside of the building.

The not readily visible effect will be all that is occuring beyond the perimeter. Only those few poor souls that happened to still be in the structures would be in a position to breifly glimpse what occured within the building before they were crushed and torn apart. However we know that the floor spans also would be separated from their connection to the core columns and that the intercore connections would also have debris tearing at them. This leaves the core with no lateral support either. No lateral support and debris buffeting them as well. . The core columns then also would fail to be able to stand. This is illustrated quite well by the so called 'spire' a remanant of a few core columns that stood for a few seconds after the rest of one tower had collapsed to the ground.

This is in some fashion the well known 'pancaking' of floors in that the upper block causes the next floor to pancake down onto the floor below. However this is only relatively accurate for a few floors. Note that the upper block is also being broken up by the fall. Thus after a few floors we have a looser collection of debris impacting the next floors with the still intact portion of the upper block of floors above it and that in short order all that remains is an enormous collection of loose falling debris. However that looser collection is also moving faster. Physics 101 tells us that if an object accellerates then as time passes its velocity is increasing and that as velocity increases so too does momentum. Thus even if the amount of debris ejected as each floor became involved with the collapse was equal to the mass of one floor the momentum transfer would remain the same. It matters not that the columns at lower levels were larger since it is the floor span to collumn connections that will be called upon to bear the falling mass and they vary little from floor to floor as each one is only designed to bear the mass of ONE floor.

The least dense materials in that collection of falling debris will be more prone to being ejected to the outside of the building. It simply takes less force to change its direction of travel than it does for say a core column section of steel. Thus the most dense material becomes more prevalent in the debris falling through the building. Few, if any, core columns were found outside the footprint of the original structure.

TF, I had some respect for you in the FDR thread. In this one, not so much.
 
SezMe said:
"...would have..." Tweeter, I know you'll never get Physics 001 right so maybe you could work on English 002?
Click to expand...

In a tangentially related way I have to admit that I like being told by a CT that they "could care less" about things I have to say. After all it is a statement that they actually do care about what I have to state on the given subject. The English phrase they are torturing being "I could not care less".
 
AZCat said:
I'm not sure if the authorities would have allowed the towers to be demolished with explosives. It's an interesting question, what the result would have been. Remember that a lot of the dust-causing elements would be removed prior to demolition, so the spread of that would be considerably smaller than when the towers collapsed on September 11th.
Click to expand...

Hmm..Imagine the cost to take those buildings down manually.Heh, i think i might be on to something. lol.
 
Tweeter said:
Hmm..Imagine the cost to take those buildings down manually.Heh, i think i might be on to something. lol.
Click to expand...

Are you neglecting the cost of cleaning up the surrounding area and repairing the damage to nearby structures. After all, you break it, you fix it.

Let's see when the towers came down they caused the complete destruction of how many neighbouring structures?
(both immediatly and in the months following)
 
You must log in or register to reply here.

Back
Top Bottom