Well...the theory goes that if an intentional demolotion can only cause a building to fall close-ish to the 9.8m/s, then a 'non-intentional' collapse surely must be slower.
There's a lot of stuff that has to break. Theory being that (at least until there's a certain amount of momentum) the structure of the undamaged building will slow the collapse. Remember, the damage was three quarters of the way up the building, not at the foundation.
I'm no demolitions expert nor am I a physics major, so I can't speak as to how structures of that size behave under those conditions - though I'm sure the conspiracies have been thoroughly debunked by now. But that's the thinking.
Personally I'm more inclined to disbelieve a conspiracy theory simply because there's no way our government is competent enough to keep a secret that big for eleven years - across multiple administrations. But who knows - maybe there're better at their jobs than I'm willing to give them credit for.
> there's no way our government is competent enough to keep a secret that big
Counterexamples to refute the assertion that the US government cannot keep "big" secrets:
(1) A US bomber accidentally dropped a hydrogen bomb out of an airplane into the dessert near Albuquerque, New Mexico, triggering a conventional but non-nuclear detonation. This happened in 1957 but was kept secret until 1986 -- a span of 29 years. "It was only in 1986 when an Albuquerque newspaper published an account based on military documents recovered through the Freedom of Information Act." (ref: http://www.hkhinc.com/newmexico/albuquerque/doomsday/ )
(2) The British were regularly reading encrypted German messages by around 1940. The codebreaking of the German Enigma machine was one of the greatest secrets of World War 2, and the British shared the knowledge with the Americans. This secret was revealed in 1974--after 34 years--because of two books by key intelligence figures. (ref: http://en.wikipedia.org/wiki/Ultra#Post-war_disclosures )
In both cases, at least dozens of people--but more likely hundreds of people--would have been privy to the secrets. But these two secrets did not leak for 3 decades.
Note: I am not endorsing any 911 conspiracy theories. I am simply showing that the stubborn meme that the US government cannot keep big secrets is incorrect.
Those are a military secrets that actually righteous person would be inclined to keep secret, feeling he/she serves his country well.
Murdering innocent people is not this kind of secret (it's dangerous lunacy) and would need to involve murders to silence witesses.
I think a more accurate statement is, the bigger the secret - the more incentives there are for it to be leaked, thereby the more likely it will be leaked.
a) Monica Lewinsky
b) Watergate
c) CIA Renditions
d) Waterboarding
e) More recently, intimate details of Seal Team Six & the Bin Laden raid.
f) Warrantless Wiretapping
Suffice it to say, the larger the likely public interest - is the more likely that leaks will appear.
The government? The one that we "elected" (election between two preselected candidates/puppets? Really?). Or maybe the real one, who's behind the scene, the puppet-masters?
If this was an inside job, there are not so many people (especially public people) who were behind it. They just needed to hire some Arabs (through several proxies) and train them to intercept the airplanes. And I'm sure those Arabs didn't know who was really behind it (they were sure it was Osama who could be an agent or a legend). Then make sure the secret services somehow fail to do their job at time X. Then eliminate/threat/silence those people at lower levels who couldn't understand some actions/lack of actions and were suspicious about that.
It isn't so hard for people with sufficient power and money, don't you think?
Wow....I couldn't have articulated my position better myself. Hence my bringing up this topic.
It's not that I doubt that people would want to (and perhaps have motive) to pull off a stunt like this.
It is the subsequent burying of the evidence and keeping it a secret for so long - something that has attracted more scrutiny than any other terrorist attack in recent history.
Either the gov't is far more sophisticated than we imagine, which I doubt - or the theories are just that. Theories.
The time taken for an uncollapsed floor to become a collapsed floor in the face of even a fraction of a tower falling onto it is unimaginably brief.
In short, the reason that the towers' collapses looked like controlled demolitions is because controlled demolitions don't rely on the explosives to destroy the building, they rely on destabilising it enough that it falls in on itself. The "controlled" part is just making sure it collapses inwards.
in case of intentional demolition there are explosive at all levels they blow up and speed up the demolition. So when the airplane hit the building, it should had taken more time than when using explosives, or airplane + explosives.
The energy contained in that much mass falling down is far FAR more than any explosive (more than what would be using to bring down a building anyway).
For the North tower that's 120 floor equivalents as the 15 floors fell, about 12 tons of TNT.
For the entire tower that's 700 tons of TNT (assuming the mass of the tower is distributed evenly, which it isn't, but it's still a huge amount of energy).
Just out of curiosity, the 'result' from that Wolfram computation: 4.807 * 10^8 kgm^2/s^2.
What is that in relation to the speed of free fall of that floor? Is that roughly half? - i.e. in total free fall, you would expect that the floor would fall at 9.8 * 10^8 kgm^2/s^2?
Gravity is 9.8 m/s^2. Not 9.8 * 10^8!!! And the result is kg m^2/s^2 not m/s^2.
The result assumes a free fall at 1 g. I multiply it by g in order to accomplish that. (It's on earth, it can't really fall slower. If you want it to fall slower, the only thing it can do is fall, hit something and stop, then fall again - but that has 0 impact on the energy released! The energy released does not care if the building hit something and stopped momentarily in the processes.)
I know the result looks superficially like the units for gravitational acceleration but it's not, it's also multiplied by kg * m. i.e. I multiply gravity by mass and by how far it fell. The end result is the units for energy.
There is a reason they push so hard to make sure you do the units correctly in Physics - you can gain a lot of insight into what you are calculating if you manipulate them properly.
So, in concluding...what would you say - based on your analysis here - about the assertion that this may have been caused by a 'controlled demolition'.
If you can just summarize your findings here, into a succinct statement that would be greatly appreciated :)
E.g. "The theories don't make sense, because as we saw here....X, Y & Z." or "The theories DO make sense, because Z, Y & X".
The numbers don't quite tell the whole story here. 100kg of TNT would direct its energy in a roughly spherical shockwave, like a point light source. The 480MJ per storey is directed straight down, like a laser.
That the effect of the building's mass is much greater than the TNT-equivalent would apply, in the same way that while a 10 Watt bulb is barely bright enough to read by, a 10 Watt laser will set your book on fire.
I'm saying that there is more energy in simply the tower falling than there would be in any explosive. So it would not fall any faster with an explosive - there already is much more energy there than needed.
How are you sure that they wouldn't be able to use "more than enough" explosives though? 1/10 of a ton of TNT on each floor, sounds like a lot...but doesn't sound like an enormous amount.
Can you put that in terms that a layman may understand?
Thanks.
P.S. I would love more details, so that I can properly refute these claims based on physics and facts - than just based on philosophy and intuition.
1/10 of a ton (200 pounds) of explosives is a staggering amount in comparison. The energy involved in the building falling down swamps the explosives by such a large degree that you couldn't even tell the difference.
Remember that the fire did the same thing that a controlled explosion would do: Weaken the central support. The fire by softening the metal, an explosion by cutting it.
A controlled demolition does not actually explode the building, all it does is weaken the support, and gravity does the rest.
