9/11 Physics anyone ?

soretoe

The World Trade Centre 7 building over 550 feet tall, 47 story’s was not hit by any plane but fell down around 5pm after some fires in the building and after suffering some damage from falling debris from the towers.
This debris damage is agreed to have been on one particular side and affected a small number of support structures. The fires were in isolated pockets mainly on floors 5 and 7 and were not widespread or severe enough to have caused any kind of collapse.
But this steel structured sky scraper fell down at approximately what would equal freefall speed of an object falling from the same height. And it fell straight down into its own footprint - in other words symmetrically straight down.
Objects fall at the same speed and acceleration unless air resistance or wind affects them such as in the case of a feather versus a bowling ball. World Trade Centre 7 certainly wasn't affected by wind in its descent nor would a bowling ball be….and if you had dropped a bowling ball from the same height as WTC 7 - the ball would take approx the same time to get to the ground as WTC 7's roof did on 9/11.
There is a problem with this as I'm sure you can guess. There is nothing stopping our bowling balls descent through the air in its 550 foot fall and so it simply falls freely to the ground increasing in velocity at the universal rate of all falling bodies (which Galileo worked out..)which is approx 32 feet per second per second.
This means that after the first second the bowling ball falls 32 feet, but is speeding up now and covers twice that in the next second, and three times that in the next second, and so on, and when you add them up 32 + 64 + 96 + 128 + 160 + etc.. you will find that it takes the bowling ball around 5 to 6 seconds to hit the ground from 550 feet in an almighty thump traveling at least 175 feet per second!
Now there is ample video footage of the World Trade Centre building collapsing around 5 pm on 9/11 and the fall of the building has been measured and agreed at less than 7 seconds with the first 100 meters of the collapse having been accurately timed at 4.5 seconds by many people who have studied the footage. That means that a falling bowling ball would hit the ground from approx the height of WTC7 just a little quicker than did the actual building collapse on that day, and that is an amazing fact for many reasons and is what is known in the scientific community as ‘Counter Intuitive’ - or against reasoning and rational prediction.
Firstly WTC 7 was not a bowling ball and was in fact a very large concrete and steal structured building with nothing but very strong steel and concrete between its roof and the ground as opposed to our bowling ball which had just air between it and the ground. Secondly unless there was a mysterious pushing force being applied to the roof pushing WTC 7 down into the ground, OR, a mysterious pulling force yanking it downwards into the earth then the only source of energy being applied on WTC 7 during its collapse was gravity, and that acts in only a downward direction, and in the precise manner in which we have already explained using the bowling ball example (at approx 32 feet per second per second). Except that this acceleration toward the ground would have been hampered by all the steel and concrete between the roof and the ground which unless it all disappeared literally into thin air at the very start of the collapse then it would have slowed the falling roof as all the floors crashed down into the next floors all the way to the ground, breaking all the joints that hold the floors to the structural steel columns and smashing every bit of concrete and steel on its way down. But I said - the collapse time or 'Fall-time' of the building was just under 7 seconds which is just a little slower than free fall speed - in fact only a fraction of a second slower. So how can this have happened?
What allowed the roof to collapse symmetrically straight down at nearly free fall speed all the way to the ground leaving the whole building in a neat pile of rubble very mostly inside of its own site.
There's another law of physics called 'the law of conservation of momentum' and it is exactly what it says. If the bowling ball has nothing but air between it and ground then it will fall at free fall speed losing no momentum really except say taking some air resistance into account based on its shape which isn't as aerodynamically efficient as say a dart would be.
If the steel and concrete roof of WTC 7 had just air between it and ground then you'd factor in air resistance and just apply the law of falling bodies and you'd have an answer which would be in or around the same as the ball - especially over only 550 feet - we're not talking skydive height here so the air resistance difference especially with such heavy objects in question would be very minimal relative to the total time. Basically in plane English - because of simple proven and accepted laws of physics, World Trade Centre 7 should not have fallen down so fast because there was so much of itself in its way from the roof to the ground as it collapsed and this stuff should have really slowed if not stopped its collapse on the way down. It did not however and the fall time as I have repeated many times now was around FREE FALL SPEED - THE SAME AS OUR TRUSTY BOWLING BALL! ABOUT 7 SECONDS
AND THAT JUST AINT RIGHT!....which means that we are, all of us.....government, public, media and scientists, missing some crucial piece of the collapse puzzle when it comes to World Trade Centre 7, 47 story’s, over 550 feet tall which fell down at around 5pm on September 11th 2001 killing no one.
This building was not hit by a plane. It suffered fire mainly on the fifth and seventh floors and some damage from falling debris of the twin towers. FEMA said in its initial findings that structural weakening caused by fire was the main theory being put forward and NOT damage from the falling debris. It is important to note that WTC 7 was more than 300 feet away from the nearest twin tower and was not in the direct path of any serious debris falling from the towers. It is important to remember it was not hit by a plane. It is important to remember that the government experts initially blamed fire related structural weakness for its collapse. This potential cause has been studied extensively by both sides – government AND those who challenge the official story and it is looking very unlikely that it can be proven that these fires could have collapsed the entire building as symmetrically as it did, and in under 7 seconds.
BUT if we decide to simply accept this ‘Very criticized cause theory’ and try to imagine the collapse in our heads while rationally analyzing its manner and speed taking into account as we do, the law of falling bodies and the law of conservation of momentum as we now understand them, then we are back to the same problem…..even if fires…or anything for that matter is the reason WTC 7 did collapse on that day……it still collapsed….which means fell down….which means we time it….which we have….and it is too close to free fall speed to make any sense……the matter between the roof and the ground floor of this building acted very strangely….it moved out of the way too quickly to make any sense physically…………that is unless you stop in your tracks for a second and start to think in a different kind of way……the ‘What if ?’ kind of way….
And when you do this - you come up with different new causes and reasons from your imagination and you visualize and test them in your head taking into account their possibility, how ‘crazy’ they seem and would it have looked the same if ‘this’ were the reason or if ‘that’ were the reason….and eventually you are going to consider that the buildings were brought down using explosives - to move the matter out of the way of the falling building….. - to sever the supporting structures and allow the building to fall symmetrically at almost free fall speed as it did - into its own footprint, as it would - if it were demolished by controlled demolition …………AS……IT……PROBABLY……WAS!

I hope that I’m missing something…and that the missing piece of this puzzle will slap me in the face soon but I have a bad feeling about this one.
• Too many gaps in the stories.
• Not enough rationality being employed.
• Not enough possibilities being considered.
• Not enough questions being raised
….or answered….

Intuition drives me….but doesn’t force me into tunnel vision which is dangerous, irrational and unproductive….I want to know for reasons of sanity why it fell down so fast and so straight…that is all…..everything else about that day seems a little too complicated for me……too cloudy…..too infinite.
I want the truth about WTC 7 and I want it in my life time. I feel if it isn’t understood within the next 3 years that it never will be and that would be very, very sad for us all.

Son Goku

soretoe wrote:

Intuition drives me….but doesn’t force me into tunnel vision which is dangerous, irrational and unproductive.

Very few people (read nobody) have intuition about multibody high mass constrained systems. You can't, with intuition, understand how a building falls to the ground. You have to have the building plans, structural constants, e.t.c.
And then run the whole thing on a matlab, e.t.c. simulation.

Unless you can start giving me Lagrangians, or other such data, I'm going to move this to the Conspiracy forum, it seems more suited there.

(This isn't a warning or anything, there just isn't much physical content to this, given that the actual dynamics would be almost impossible discuss without a few computers at hand.)

nesf

Son Goku wrote:

Very few people (read nobody) have intuition about multibody high mass constrained systems. You can't, with intuition, understand how a building falls to the ground.

Pfft, I make sure to solve at least one while eating my Raisin Wheats in the morning...


This is conspiracy based stuff, unless we've all turned into structural engineer/physicist hybrids. Damn, I remember trying model cardboard boxes collapsing for the MCM one year and that was horrendously complicated never mind something actually complex internally. You could approximate the Towers as 'empty boxes' but you wouldn't get very far tbh.

Any chance of copying this to Engineering as well if you're moving it? There are a few structural guys over there who might wish to contribute.

breadmonkey

1) For the love of God, use metric.
2) Move to conspiracy theories.

Smurfpiss

have this awful feeling he copied an pasted from some conspiracy website.
yeaaahhhh.
you're so close.
except the actual building is still there.
they just have massive tv screens to make you think its not.:rolleyes:
but seriously your are dealing with a hugely complex system there with so many factors to take into account, temperature, stress points, a very large number of masses, the structure of the building itself.
like Son Goku says there's no point speculating unless you are prepared to model it using matlab. and even then you'll have a crude approximation with little or no information to work from.

CathalMc

There's an hour and a half "documentary" asking the same questions, sceptical of the official story: http://video.google.com/videoplay?docid=-6708190071483512003&q=911+Mysteries+-+Demolitions
I'm not convinced of the arguments - alot of the conclusions reached are not self-evident.

mawk

breadmonkey wrote:

1) For the love of God, use metric.
2) Move to conspiracy theories.

oh metric.. god how i love you.

anyway.. maybe there was a huge boiler or refrigeration plant up high near the top which ruptured after the impact and bled out at high pressure vertically up pushing the building down with an exactly equal force resulting in a collective force greater than just gravity?

or aliens!! I bet they did it!

breadmonkey

mawk wrote:

or aliens!! I bet they did it!

Those fúcking aliens!

ZorbaTehZ

Larry Silverstein, the controller of the destroyed WTC complex, stated in a PBS documentary that he and the FDNY decided jointly to demolish WTC 7 late in the afternoon of September 11, 2001.

The above demonstrates that WTC 7 was indeed demolished, so why did FEMA spend many hours dreaming up a report which claims the building collapsed through fire?

From: http://www.whatreallyhappened.com/wtc7.html
bottom of the page^^

"I remember getting a call from the, er, fire department commander, telling me that they were not sure they were gonna be able to contain the fire, and I said, 'We've had such terrible loss of life, maybe the smartest thing to do is pull it.' And they made that decision to pull and we watched the building collapse."

What Silverstein said^^
From: http://www.whatreallyhappened.com/cutter.html

IMO this should be in the Conspiracies forum

mawk

ZorbaTehZ wrote:

From:
IMO this should be in the Conspiracies forum

buy that man a pint.

to the conspiracies forum!! nananananananaFORUM!!

Tails142

As a structural engineer I would love to reply to this post, but I can't pull any coherent point out of it to rebuke =P

Son Goku

to the conspiracies forum!! nananananananaFORUM!!

The people have spoken and thus I proclaim it so.

civdef

Whatever hope the OP has of getting the answers he/she desires on the conspiracy theory forum, copying it to science and engineering sections is likely to result in mockery mostly, I reckon.