Cannonfire is leaving

[Iroquois]

In any event, the question stands to that particular CD camp. What about CD allows the building to approach freefall speeds? Why don't the arguments about Conservation of Momentum apply regarding a controlled demolition? It is clear that floor hits floor hits floor. The C of M argument would then apply.

I apologize for my clumsy attempt to answer this part of your question above. I'll try to do a little better.

The only way for the collapses to have durations anywhere approaching the near freefall durations observed in the video evidence or the actual freefall durations interpreted from the seismic data is to have the lower floors start falling before each floor above makes contact with it.

In the controlled demolition hypotheses, this could be accomplished by having the charges that remove the final structural links holding up each floor fire at the point of impacts of the planes then progress down the building at near the rate of freefall or faster.

The gravity collapse hypotheses on the other hand have no analogous theory that allows for collapse durations that do not take into account the mass of each impacted floor reducing the rate of the collapse due to the afore mentioned Law of the Conservation of Momentum.

Edited to correct typos and to improve the clarity in a couple of key sentences.

[Infernal Optimist]

Nomo:

where's Gravity in your equation? Where's Potential Energy? Kinetic Energy? Think they got magically suspended when the towers collapsed?

No, but apparently conservation of momentum did.

Where's gravity? How would they fall without gravity?

Where's potential energy? Explain to me how that would effect the speed of the fall. Is this your "the bigger they are the faster they fall" theory?

And kinetic energy would be absorbed when the floors collided. How much kinetic energy would be absorbed? Gee, if they did a real investigation we might have an idea. And it would be nice to have blueprints. And for your edification this is kinetic energy:

1/2m1v1 squared = 1/2m2v2 squared

So you're still left with the problem that as mass goes up velocity goes down. So we're waiting for your explanation. Oh, yeah: they were really, really big.

And, still, everyone here knows you got nothin'

[Occult Means Hidden]

In this case, in case you weren't paying attention, we're talking about multiple floors falling onto eachother. 110 floors, in fact. Do you really believe that, say, the 30th floor is capable of slowing down the 80 floors above it?

If so, you must be on crack.

Are you serious? Wasn't the 30th floor holding up those 80 floors for the thirty some years before the "collapse?"

[OnoI812]

I'm not going to read through this whole thread but I did read the first few replies...I'm just wondering if NO MO is aware that Hopsicker appeared on Rense radio last week?
If I'm not mistaken, Rense is on GCN. I wonder how long it will take for Dan to write about how Kashuggi radio controls all the debate and won't let him have his say? Or tie Rense into UFOlogy, even though Rense bent over backwards to be cordial to Dan, and offered no disagreement. In fact he was cheerleading for Dan's (send me MO money) pleas, because we (talkshow hosts, writers, and other peddlers) need to be able to fight back when people sue us.

[orz]

In the controlled demolition hypotheses, this could be accomplished by having the charges that remove the final structural links holding up each floor fire at the point of impacts of the planes then progress down the building at near the rate of freefall or faster.

.....WHY would anyone ever want to accomplish this?

What possible benefit would the supposed CD plotters gain from having the building collapse at speeds which seem to be 'wrong'?

If for the sake of argument an accidental collapse should have happened at significantly less than freefall speeds as some here claim, then WHY ON EARTH would those trying to fake such a collapse go to extremely complex (and unprecidented in demolition as far as i know) lengths to make the building fall much faster than anyone would expect?

Would the american public have turned around and said "no, we shouldn't invade afganistan!" if the buildings had taken a couple more seconds to fall?



Just thought: has anyone compared the WTC fall speed with the fall speed of conventional demolition? Does a conventionally demolished building fall at 'free fall' speed or near?

[Seamus OBlimey]

good bye chesterfield chimneys

[orz]

Cool video but do I really have to break it to you that the WTC was not, by any stretch of the imagination, a chimney!

[Iroquois]

.....WHY would anyone ever want to accomplish this?

What possible benefit would the supposed CD plotters gain from having the building collapse at speeds which seem to be 'wrong'?

There were several major deviations between the destruction of the main towers of the World Trade Center and any preceeding demolition that I know of:

1) These buildings were far larger than any ever attempted to be brought down in a controlled demolition. A smaller miscalculation would have much greater repercussions. (This would not have been a problem, of course, if the planners were willing to allow the buildings to topple.)

2) The charges had to be set to fire from the point of impacts of the planes rather than from the bottom, as is typical in controlled demolition. This would have been an even more serious complication if the general area of impact was not known in advance to a sufficient degree of certainty, as was likely the case

3) The building could not be properly prepared by wrecking crews in advance.

4) The charges had to remain hidden, possibly for days, while the buildings were occupied.

5) The charges had to be hardened against fire.

6) The damage due to the impact of the planes could not be entirely predertermined and would certainly be asymmetric.

There were likely other complications, but these should be sufficient to understand why a more conventional demolition method would have to be abandoned.

Why then did they fall quite so fast? Again with all of the above complications, the planners likely felt they could not achieve their goals in the demolition (such as a vertical collapse rather than toppling and/or the apparent degree of disintigration of the buildings and their contents) while letting the floors just slap into each other and the falling mass following whatever happened to be the path of least resistance. And, unless they could suppress discussion of the collapses after, some would still be scratching their heads and asking what happened to the core anyway.

Why WTC7 was allowed to look so much like a conventional demolition is a better question. The best speculation I have heard is that the intent was to demolish it while it was under the cover of the dust cloud produced by the collapse of one or both of the other towers and something went wrong.

[orz]

There were likely other complications, but these should be sufficient to understand why a more conventional demolition method would have to be abandoned.

They're also sufficiant to make CD seem pretty unlikely.

I see where you're coming from, but step back and read thru your list and I'm sure you can appreciate that it pretty much doubles as a list of arguments against CD.

As for "toppling" i'm not at all sure about that... I mean, I can't see skyscrapers of this height falling any way but down really? And there was a fair bit of debris in all directions as it was, despite the old "neatly in their own footprints" meme.

I mean, you're not talking totally falling sideways like a felled tree, or a chimney demolition.... ...right?

[Seamus OBlimey]

do I really have to break it to you that the WTC was not, by any stretch of the imagination, a chimney!

No, thanks.

[Wombaticus Rex]

Just thought: has anyone compared the WTC fall speed with the fall speed of conventional demolition? Does a conventionally demolished building fall at 'free fall' speed or near?

Aye, and that's the #1 reason I remain unconvinced.

[orz]

It seems to me that there are a lot of demolition videos out there, and a lot of info on the subject... surely someone could calculate the speed of a representative selection of buildings (ie steel skyscrapers if possible, not brick chimneyS!) and do some maths.

The thing is that most normal controlled demolitions DO rely on the weight of the building bringing itself down... they don't blow up every floor so it all free falls; it's usually a matter of breaking the beams at the bottom and other key points and letting gravity and, yes, good old conservation of momentum do the rest! And clearly in most demolitions the mass of the building above crushes the lower levels quite nicely and quite quickly, accellerating rather than decellerating as it falls...

So I'm hoping someone else will do the math, as i'm not much good at it!

[Iroquois]

They're also sufficiant to make CD seem pretty unlikely.

I see where you're coming from, but step back and read thru your list and I'm sure you can appreciate that it pretty much doubles as a list of arguments against CD.

The likelihood that controlled demolition was the method used to bring down the three main buildings of the World Trade Center Complex comes from the physical evidence, one aspect of which has already been well covered in this thread.

The complications I mentioned, certainly an incomplete and partly erroneous list, merely make controlled demolition more difficult. If bringing those towers down was a key objective of the operation (for the psychological effect, the insurance money, they required costly renovation, they were no longer making money, to destroy the evidence of illegal transactions, to steal gold or other valuables stored inside, etc), like all complications to an important operation, they would have been overcome.

As for "toppling" i'm not at all sure about that... I mean, I can't see skyscrapers of this height falling any way but down really? And there was a fair bit of debris in all directions as it was, despite the old "neatly in their own footprints" meme.

I mean, you're not talking totally falling sideways like a felled tree, or a chimney demolition.... ...right?

Think of the moving mass of the upper stories relieved of the structural supports that previously held them in place as energy. Energy tends to prefer the path of least resistance, which in that case would have been the open air all around the towers, not the remaining tens of thousands of tons of intact structure within them.

I have posted this excerpt from HowStuffWorks.com a few times already, please read it carefully:

The main challenge in bringing a building down is controlling which way it falls. Ideally, a blasting crew will be able to tumble the building over on one side, into a parking lot or other open area. This sort of blast is the easiest to execute, and it is generally the safest way to go. Tipping a building over is something like felling a tree. To topple the building to the north, the blasters detonate explosives on the north side of the building first, in the same way you would chop into a tree from the north side if you wanted it to fall in that direction. Blasters may also secure steel cables to support columns in the building, so that they are pulled a certain way as they crumble.

Sometimes, though, a building is surrounded by structures that must be preserved. In this case, the blasters proceed with a true implosion, demolishing the building so that it collapses straight down into its own footprint (the total area at the base of the building). This feat requires such skill that only a handful of demolition companies in the world will attempt it.

Source: http://science.howstuffworks.com/building-implosion.htm

[orz]

Energy tends to prefer the path of least resistance, which in that case would have been the open air all around the towers, not the remaining tens of thousands of tons of intact structure within them.

I'd say a bit of both... certainly lots of stuff actually DID fall in the open air around!... but path of least resistance can also partly include the tower, ...in fact how can it not?... stuff IS falling on it and must damage it... it's not water falling on a solid, it's a solid falling on a solid, both pretty breakable and with lots of mass. You're not saying the falling floors would simply slide off the sides of the building leaving the floors they fell on intact?

As for that stuff about demolition, fair enough, but as it points out they have to go out of their way to make a building fall sideways, by setting charges at one side at the bottom and even pulling it with a cable! It's not something that happens naturally. And with such a tall building as the wtc i can't imagine the possible sideways motion to be too great... even if it had been blown up at the bottom 1993 style and tilted, surely after a certain amount of tilt it would tend to break up and collapse downwards... it's never gonna literally fall sideways like a tree.

ike all complications to an important operation, they would have been overcome.

Well, not ALL complications can be overcome surely, there are limits such as time, laws of physics, etc.

[sunny]

but as it points out they have to go out of their way to make a building fall sideways, by setting charges at one side at the bottom and even pulling it with a cable! It's not something that happens naturally.

No, they simply don't want it falling in the wrong direction.