That's not how I remember it. The forum's memory is pretty good. I read over everything you had said about Chandler and this was my response to your criticisms of his paper (ones you apparently borrowed from that skeptics forum):

I don't think you responded to this, or if you did it was very downstream of this post. And I believe we talked about Chandler's paper after that as well. So criticize my ideas about it if you can, but why keep asserting I didn't respond? I don't see how that makes any sense to keep saying that when it isn't true and you are more than willing to just start making things (as in the fire debate) up when you get backed into a corner. Is your memory just that bad?

That is either utter nonsense or, depending on how you define global collapse, just a tautology. Natural or gravitational collapse, of which collapse by fire would be a variant, doesn't look anything like a demolition. Natural collapses are uneven, incomplete, don't initiate suddenly, can progress in stages, and doesn't lead to massive pulverization or many other demolition-associated phenomena observed on 9/11.

You seem to have the idiotic notion that steel framed buildings respond like a game of Jinga to having some key component (from any number of possible candidates) removed which will set off something like what we saw on 9/11. That's not remotely how the world works. Just google building collapse if you don't believe me. There is no "expected speed" of collapse from random assaults. Just google images of building collapse ffs. Even look at wrecking ball demolition, which isn't random. You don't see whole buildings going down at once. They go down in sections, unevenly, incompletely, etc.

That is another perspective from which to evaluate the attacks, and it's a valid one. You're right, 3 global collapses, all from office fires, all within a few hours is an extremely, EXTREMELY rare event. Do you also understand that the collapses happening pursuant to a terrorist attack make them much more unlikely, on top of the already impossible odds, to be "natural" collapses? Never in history has a collapse which looked like a demolition not been a demolition. But how often have buildings been targeted and blown up in terrorist attacks? Quite often. In fact those very towers had been targeted (would like to talk to you people about the 93 bombing btw) for bombing not too long before the 9/11 attacks. Destroying buildings targets concentrations of people for killing and makes for a spectacle- the key ingredients in terror. There has never been such a spectacle of terrorism as 9/11, and you think it was due to a insanely impossible luck of young misfit terrorists.

Extremely rare events don't happen on cue. Any other philosophy is just pure childish fantasy.

Why doesn't the lack of audio on the plane impacts into the building prove my point?

People lie for money and career all the time. And there aren't that many scientists out there peddling that NIST crap anyway. Mainly, there is silence on the issue and that's a predictable response to the risk of career suicide.

But why no chorus of scientists willing to go the other way? Still waiting for one respected physicist to explain the top of a building accelerating through other building phenomenon. Is there one? All the myth busters go silent on 9/11?

lol Deuces.

do you ever think about the productive things you could have done with the time you spent misinforming yourself about 9/11?

What do you mean by that? Explain it a bit more maybe? Why when looking at the top of the building it looks like free fall accelerating when we know the bottom is crashing other surfaces? The crashing surface is also accelerating until it hits the ground floors that cannot be compressed any more. Dont forget most volume of a building is empty space so the entire thing can be compacted under gravity to a fraction of its initial volume and until this happens the top will appear accelerating down.

I offered you the eggs/balloons example. Put eggs on top of each other and then press with your hand and nothing breaks, they hold you, in fact quite a lot of force still is supported. Then try to put all your weight on top and see how you fall through to the bottom finding no resistance basically as if moving through paper/cards stacked like /\/\/\/\. There will be some force threshold that the crash starts and the temperature in the real building case is basically taking your slowly to that threshold assisted by the damage already in place (see the stress strain temperature curves to see why well before of even melting or even recrystallization that i think its called http://en.wikipedia.org/wiki/Recryst...8metallurgy%29).


Mythbusters had a piano fall from a big elevation to a roof of a building to see if it will puncture the roof and go throw to the inside of the house to hit the ground floor. After enough mass was added to it and enough elevation it was able to do it. But the piano is tiny compared to the weight of an entire building. Basically imagine 30 floors mass accelerated once a floor support breaks to hit the ground level of that floor.

The mass of 30 floors is close to say 1/2*30/110*250000tons ~34000 tons.

Can you imagine 34000 tons having accelerated for 417/110=3.8 meters/floor, when the support first gives in, what momentum it has?

If the piano was released from say 20 meters and had 1000 kgr mass (they added sand in it) and hit on the side even say some 2mx0.4 m area of 0.8m^2 then the roof felt a momentum push of mv/s=m*(2*g*h)^(1/2)/s of order 25000 kgr/(m*sec).

Compare with the wtc towers of say 30 floors of area 70*70m^2 and 34000000kgr for 3.8 meters fall it gives;

mv/s=m*(2*g*h)^(1/2)/S=34*10^6*(2*3.8*9.81)^(1/2)/4900~60000 or over double (2.4x) the mythbusters puncture threshold of the piano hitting the roof and penetrating to the living room say (plus i gave you the ultimate ideal piano cross section to hit on the side not the big face).

Basically it goes through losing little momentum and then that floor now crashes added up to the next floor only now we fall for another 3.8 meters starting with nonzero initial velocity of the aggregate mass so the next floor will experience an even more severe puncture and feel even less significant as resistance and so on, until the speed is so big now that practically every floor feels like nothing leaving the entire thing to appear indeed as free falling after the first 2-3 floors crashing.

Now notice if the WTC tower is 250k tons mass in 417*70*70m^3 volume the density is 122 kgr/m^3 or 8 times less than water. So if you compact it 8 times it gets to water density. A bit over that even and you arrive at a height of less than 10% the original or 10 floors really. This why it pancaked to the bottom like that.

Is that what you meant?

http://www.barnesandnoble.com/w/debu...wNw-_-10:1&r=1

FYP

9/11 is a natural choice of study given my academic interests. And I tend to think that pursuing justice is a very productive thing.

That said, yesterday I basically laid around like mud encrusted reptile, eating leftovers, posting here, and surfing the web. I admit that's not a very productive way to spend time but hey, it was Monday.

Text in bold doesn't lower the insane vibe. Jus sayin. Keep fighting the good fight tho.

Jetliners hitting skyscrapers has never happened any other time, so I guess 9/11 didn't even happen and the towers are still there

That is a book written by magazine editors, not scientists. One of the authors, David Dunbar, describes himself as a "brand manager". A brand manager is what the giant media conglomerate who published the book, the Hearst corporation, would want to write it's popular propaganda.

The article which the book is based on has been thoroughly discredited as a string of straw men murders or, where serious challenges are taken on, outright lies and hand waving are used.

I couldn't find the bibliography online, so I have no indication of what actual scientists have signed on to the cause or to what extent. You think they have, so show me. Show me where a physicist backs up the Bazant pile driver thesis. Or discuss any debunking claim made in the article or this book.

"like ikes...If I could be like ikes..."

Make your deliberate misunderstanding more obscure.

That's not how you remember it, because you are awful at reading and comprehending. I didn't borrow anything from a skeptics forum, but I'm not surprised more people are saying the same thing about it, because it's so obvious what is wrong with it. You are again conflating so many issues in a single post, that responding to all of would render this thread to white noise, so I'm sticking to the first claim of the Chandler paper for now, and see if you can actually follow along.

Your response above was to a post of mine in which I summarize Chandler's position as follows: when you simplify the collapse to a straightforward equation using Newton's third law, we see that averaged over the time of the collapse, the lower part exerted an upward force onto the upper part of approximately 0,36 mg.

I don't think anybody disputes this as such (save for inaccuracies of his measurements), but where Chandler fails miserably and/or is misleading all of you, is in thinking that this approach has any use when trying to understand the interaction of forces at play in a collapse.

Look at what he claims in his paper:

If I summarize his position in one sentence, it is: "assuming all dynamic forces were static during the time of the collapse, the lower part of the building only had to support 1/3rd of the weight of the upper part of the building".

To anybody with any understanding of physics, it's immediately clear how useless this observation is. But not for Chandler: he uses it as proof that the lower building could not have been damaged by the falling upper part and for you it is even the smoking gun!!

So really, it is on you to explain why Chandler's approach is useful at all, and if you do, you need to explain what mechanism would be able to apply a constant upward force of 0.36 mg on the upper part of the building, causing it not to accelerate at free fall acceleration, but at 0.64G instead.

You know... for when you guys are done debating free fall physics.

During the collision between the coming down floors and the next standing one, the weights of the objects involved are almost irrelevant for all practical reasons (in the first few floors crashing, when speed is still not very big, its not trivially unimportant, but the next ones make it really tiny to irrelevant). Momentum is the important thing.

The collision takes a fraction of the second (to break the floor) and the forces generated are many times that of the weight that floor used to support all these years. This is why you can jump on a board and break it on the way down but if you just carefully stand on it, it will hold you just fine. You can stand on top of a car and it wont bend but if you jump up and down you can create a bad dent. So its not your weight that does it, its the momentum you have on impact, the contact interactions create that force, during deceleration, that crashes the surface of contact. Read about eg impulse here; http://en.wikipedia.org/wiki/Impulse_%28physics%29. Then recall what it feels to get hit by a baseball ball from a pitcher etc (the weight of the ball is almost irrelevant).

The floor below upon contact with the upper floors ,that were dropping, starts reacting and decelerating the upper floors by exerting forces on them and at the same time it feels the same forces opposite stressing it until it crashes when the maximum level it can withstand is exceeded. These forces in fact exceed the strength of the material by many times and they crash it easily, without even more than a tiny fraction of the second managing to produce a deceleration (resistance to crashing). Have no doubt that during that fraction of the second the floors falling do indeed also feel a force many times their weight but it is very briefly so their overall drop is not significantly inhibited. Obviously all these collision surfaces are locally destroyed/broken in pieces as it all falls but the majority of the building above that area is still intact, not broken as it falls.

Try it. Is the collision less than 0.01sec? Then for momentum m*v of falling floors to even change by 5% you would need impulse (the integral of F over time) to be 0.05*m*v so the avg F (Impulse~F*Dt) is like order 0.05*m*v/0.01= 5*34*10^6*(2*9.81*3.8)^(1/2)~1.5 *10^9 Nt which is like;

0.05/0.01(2*9.81*3.8)^(1/2)/9.81~4.4 times the weight of the building at the first crashing floor level!

See what i did here? I basically told you that if the force acts 0.01s and takes off only 5% of the momentum the system has, it will feel as if 4.4x the weight. Massive. Reduce the momentum by 10-20% and you get 10-20 times the weight etc. And you still havent done a lot to stop it from falling (20% is still little). This is why i said the weights are irrelevant during the collision. The forces created on impact are many times larger. This is why it crashes so easily. Its like a car collision accident.

Can it be more than 0.01-0.02sec during collision per floor? Not really. Because 100*0.02=2sec and the free fall from say 325-375m avg height of the destroyed floors is like 9 seconds and the entire fall is like 10-11 sec or so, so its cant be more than 0.02sec as you have to do it for nearly 80-90 floors one by one and it has to remain below 10sec or so total.


When each building floor is designed to hold say a bit over the weight of the floors above, say eg 1.5x that weight (to leave some room for safety), the collision forces it to experience many times that. It is impossible for it not to break and join the collapse. I am not sure what tolerance they have given it but it cant be much more than 1+ something little, because its not needed for anything big ever ( ie more than earthquakes and other fluctuations or an occasional building accident/local failure etc) other than now and even now it wont matter how big the tolerance is, if the collapse happens at lower than 100-105th floor or something like that, its game over anyway, it cant stop it.


Now obviously i am simplifying things to make them easier to understand at a practical working level. The real effect is much more complicated and its chaotic in certain sense as breaks are taking place all over the structure and a floor is never uniformly falling to another floor, its always a bit asymmetric, some part feels the forces first etc. But the main idea is not going to change. Once the drop has started and the mass of the floors falling is significant, the forces generated upon contact of each new floor with the falling floors are easily exceeding the strength of the materials of that floor and the break happens one floor after another with even easier manner and this is why it looks like free fall. It delays only slightly with each collision and the speed continues to increase as the forces experienced last only a tiny fraction of the second each floor, never really reducing the speed gained all that much, until another 3.8m of floor height gives in to lead to more acceleration again and a new collision with even greater momentum to follow, repeating the cycle with advanced ferocity.

Yeah, great stuff. Really.

Anyhoo... Did Saudi fund the attacks? Did the Bush administration conceal that truth? Should anything be done about it? ... Does your math help?

They haven't released the documents yet, jiggs, how can he know that?

I didn't expect an answer. It's just funny watching you guys focus 100% of your attention on teh thermites... And zero % on the very unflattering money trail. Tells quite a story re: the mind of the average coincitard.

fwiw This was just a slam on the core belief that bush and his cronies did it.
I must have forgotten to hit the quote box. oops.

It was fun reading Deuces posts for a while but at this point I can literally feel my brain cells dying so I'm forced to conserve what little I have left. Unsubbed.

You seem upset and not amused though.

Not too many people think Bush had anything to do with it. The sheeple like you think he's a good guy, just religious. The truthers think he was just a clueless figurehead. He certainly did what he was told to do (read the Paul O'Neil book about his time in the administration and that will be clear) and followed cues, but he almost certainly was taken by complete surprise when the **** went down. Cheney is another matter.

I don't know what to tell you if the government creating and pushing a narrative of stateless foreign terrorist to the exclusion of any other theories and, in fact, any real investigation is "insane". This is the standard blueprint for post war militarism- half the damn budget. Exaggerating foreign threats has been the primary mechanism by which the excuses for defense money and aggressive interventions and wars are crafted. Depicting ideological battles of a existential scale is another (they hate our freedoms? Ok). 9/11 fits right into that history and context. Thinking that a few kids with box cutters and some flying lessons were the real reason behind the multi-trillion dollar, tectonic geopolitical response to 9/11 is would actually be insane if it wasn't accepted uncritically by the majority.

And that's not your brain cells dying. That's just your out of shape neurons getting a little much needed exercise.

It seems like you are ignoring my explanation of how you are misreading the paper and just repeating what you said before. Can I get you to acknowledge that Chandler doesn't think the "block" ever impacted anything in anything like the manner Bazant describes?

To be clear, that was a constant force, not a variable force that averaged .36 the weight (not absolutely constant, but approximately).


I think the bold is what you're not getting, and that's the key point. Think of it this way: if the roof line was measured to start accelerating at g and it kept going at that acceleration all the way down, what would you be able to conclude? Now just substitute in another constant acceleration.

Look at the top of the building as it starts to go down. As soon as it starts, look down at the impact zone, identified by the fire. You see the impact zone stay level as the roof goes down- the top is not crushing anything. If it was, the impact zone would start descending almost immediately.

Chandler's approach refutes Bazant's crushing thesis by showing that there is no impact of building on building of the kind Bazant describes.

As to .64g instead of g, I will just paste what I said before:

Please cite evidence that this is one of the most 'widely read scientific paper of the last decade'. Are you just assuming this to be the case because of it's controversial nature?

The fact of the matter is that while the Harrit paper did re-invigorate the 911 debate among those who were still interested in the topic, the vast majority of people have already moved on and no idea that such a study even exists. 99% of people have no idea who Neils Harrit is, and very little if any attention was paid by the media when the study came out. All of the youtube videos talking about it, including interviews with him, all have a paltry amount of views. Even an Alex Jones interview posted 6 years ago has garnered less than 15k views. I'm not saying that to dismiss him, but the reality is that his findings simply didn't get that much attention. I highly doubt any scientists felt compelled to challenge the study given it's lack of interest to the populace, especially when it's just going to result in people attacking your credibility no matter what you find.

Lol no, but you go right ahead believing that.

Controlled demolitions contain massive BOOM sounds, usually several of them in succession. Camera microphones did not have an 'ignore explosions' function, nor do you need people to be silent to catch them. As somebody else noted, the mental gymnastics here are astounding.

I just looked at several videos that capture the audio of the towers being hit and, what a surprise, IT'S EXTREMELY LOUD AND YOU CAN HEAR IT PERFECTLY.

https://www.youtube.com/watch?v=cVEmAWaKoYQ

https://www.youtube.com/watch?v=Ys41jnL2Elk

https://www.youtube.com/watch?v=SZH7KNkSqGk

https://www.youtube.com/watch?v=814rcm4KC5w (last half has a bunch of good footage from amateurs)

There is simply no comparison between the explosions heard when the towers were hit and the sounds that preceded their eventual collapse. Not acknowledging this fact in your next post will tell me that you are simply not looking to have an honest debate.

Ah, so we're just going to chalk it all up to feelings. then. Where have I seen this before?

Stop playing stupid. They did not evacuate the area out of mere precaution. WTC7 was reported by nearly every news agency as on the verge of imminent collapse, and countless firefighters used that specific language to describe it.

Here's a video showing tons of different angles of WTC7 collapsing. Notice all the news coverage beforehand talking about how it's considered likely to fall soon according to authorities? Also notice how when it does come down, there's no audible explosions like those heard when the towers were hit?

All firefighters should be considered experts in this, but when your testimony is in the minority among your fellow firefighters and the available video and audio evidence contradicts your claims, there's little reason at that point to believe their accounts are accurate.

Firefighters at the scene saying they're going to "pull it" or "control down" it are ridiculous unless you want us to believe that AFTER the fires had gone out of control the building was then wired with explosives and then demolished and then covered up. That doesn't seem to match your kook theories at all.

Excelent jpg usage