Gravity Can't Do This!

reply to post by psikeyhackr


The core was a box of steel sheetrock lift shafts and stairwells. Have a look at my next post more details!

Originally posted by psikeyhackr

Originally posted by samkent
Did you see the pictures of how the core was constructed?

It was mostly a large hollow concrete box containing elevators and hallways and other equipment. It wasn't a solid filled concrete monolith. I don't know how thick the walls were but if you had the floor truss bolts being ripped out, that would likely have an large impact on the integrity of the structure as a whole.
Plus it was likely that the plane punched one or more holes through it. Yes it had rebar inside it but that stuff would bend like a coat hanger. They bust up these kind of things with a swinging steel ball all the time.

There is dispute over how much concrete was in the core and how high. I presume there was lots of concrete in the base. Sources from before 9/11 say there were 425,000 cubic yards in both towers which comes to more than 300,000 tons per building. The floors outside the cores only account for about 70,000 tons. So where was the rest? How much was in the 6 basement levels that had to anchor the buildings against the wind?

psik

Well there are lots of disputes re the quantity of steel and concrete etc. The figs I have seen for the mix used on the floor slab would be around 700 tons that includes the floor in the core area outside the lifts etc, there was no concrete in the walls of the core area it was encased in sheetrock for fire protection.

Another survivor, window cleaner Jan Demczur, found the drywall so soft that he was able to dig through it with a squeegee to break out of a lift he was trapped in.

Taken from here www.bbc.co.uk...

The tonnage of steel is hard to get I have seen quotes of 78-96,000 tons and looking at construction of older buildings and modern ones the 96,000 looks a better bet. The foundations were large blocks of concrete with a steel grid laid on top the the baseplates for the columns were on that. So again I dont know were this huge amount of quoted concrete comes from but it may be an error and may include the concrete used in the bathtub/basement and service areas below the towers, so would not actually be in the towers.

reply to post by ANOK


Look at your picture




Notice the cross bracing is for the cranes and was only on the crane towers and was removed also notice how they built the floor system quickly so there was not a great deal of steel work above floor height for stabilty due to wind.

The very base steel of the core did survive BUT if you bother to look at the loads generated by the falling mass the core wasn't going to help and trying to ignore sites which provide info which p*&^% on your parade doesn't help anybody if you think the science is wrong show us why, If you think the loads are wong show us why!

Originally posted by ANOK
No wonder you're confused when you get your info from sites that like that.

It looks like the typical truther site to me, including images with random lines in it.

Originally posted by wmd_2008
reply to post by ANOK

 

Well as you cant answer DYNAMIC loading has everything to do with it, when the falling mass hits a floor what has to take that increased load the FLOOR CONNECTIONS.

The floors are hung between the wall and core colums ONLY the connections of the floor the mass is falling on take the load.Now since the area is one acre only a tiny fraction of the falling mass was will hit wall columns a bit more core columns the bulk will hit the 40,000+ sq ft of concrete floor.

You have no doubt looked at the video of the rice bag as an example when an object falls it generates MANY TIMES its static load.

You have an angle bracket welded on the walls at either side of a truss they are bolted through by the 2no 5/8" bolts if the mass falling generates enough load to either snap the angles or shear the bolts NOTHING is holding the floor up that then joins the falling mass.

If you stand on a set of scales and you weigh 150 lbs stand on something one foot high and drop on the scales you will go way past 150lb, the floors that fell would be doing 19mph when they dropped that one floor at the start of the collapse.

ITS impossible for them to generate less than their static load as some have claimed think about it as soon as the mass touched a lower floor the MINIMUM LOAD it could generate WAS ITS STATIC LOAD and that doesn't take into consideration its velocity.

You keep quoting "equal and opposite" but once its maximun restance is reached the connections give they can only resist to their maximum load then they give way if the force applied is greater than that.

edit on 22-7-2011 by wmd_2008 because: (no reason given)

edit on 22-7-2011 by wmd_2008 because: missing word

If a boulder is placed on the roof of my car, it will buckle from the weight...same boulder dropped even 2 stories high will cause much more damage. Now suppose that boulder were dropped 10 stories. I would think my car could not bear any weight under it. Now think of this, we all know bathtubs are on 2nd floors. But now suppose the bathtub is full of water and propelled from 3rd floor, it would crash through the 2nd floor, and then the 1st floor. But suppose that bathtub were full of fire and hurled into the house going 200 miles per hour. Would the house not catch on fire?

Originally posted by -PLB-

Originally posted by ANOK
No wonder you're confused when you get your info from sites that like that.

It looks like the typical truther site to me, including images with random lines in it.

So what? Do you ever see me using links to 'truther' sites?

No, I link to sites that are not involved in the 911 debate, in other words non-bias sites that simply state the facts about the physics I'm talking about.

Regardless, it's obvious that site is wrong, as I proved with a pic of the real core, not some made up nonsense about tubes of concrete.

Originally posted by wmd_2008
reply to post by ANOK

 

Look at your picture




Notice the cross bracing is for the cranes and was only on the crane towers and was removed also notice how they built the floor system quickly so there was not a great deal of steel work above floor height for stabilty due to wind.

So what? It is not a concrete tube like the poster claimed. Why are you even replying to that FACT. The core was 47 columns cross braced. This is not something that should be argued, it's fact.

You are just making assumptions as to why the floors were built so quickly behind the core. There is no reason why they would build up the core way ahead of the floors, why would they? Time is a huge factor in cost, so they would build everything as quickly as possible, that is why the floors are built right behind the core going up, because there is no reason to wait. Your reasoning is illogical as usual.

Even if what you claim is true, the core would not collapse down through it's own increasing mass, no matter how unstable it was, objects simply do not act that way.

This site that I source often is not a 'truther' site it is NISTs own core date site....

wtcmodel.wikidot.com...

Pay attention to how the core columns were constructed.

Maybe you should pay more attention instead of just dismissing everything because it's in a 'truther' post.

The very base steel of the core did survive BUT if you bother to look at the loads generated by the falling mass the core wasn't going to help and trying to ignore sites which provide info which p*&^% on your parade doesn't help anybody if you think the science is wrong show us why, If you think the loads are wong show us why!

Again, I know the load of the falling mass, it has been addressed, you are ignoring the FACT that the loading makes NO difference to the equal opposite reaction laws. Once again, no matter how much loading you claim there was it was still a smaller mass impacting a larger mass, and according to the KNOWN and scientifically accepted laws of motion there is an equal and opposite reaction. No matter how much load the top puts on the bottom the bottom is going to push back with the SAME FORCE. The object with the least mass will be the loser, every time. 15 floors can not have more mass than 95 floors, falling a few feet does NOT increase mass AT ALL. Mass is not increased until speed is near light speed.

You might think what you're saying is correct, but it's not. You are making the very fundamental and common mistakes of someone who has never taken a physics class or worked in mechanics. Everything you say can be traced to biased 911 web sites, that are not physics sites, and should not be trusted for any kind of education.

This is not a 'truther' site, it teaches the laws of motion...

www.can-do.com...

Originally posted by WarminIndy
If a boulder is placed on the roof of my car, it will buckle from the weight...same boulder dropped even 2 stories high will cause much more damage. Now suppose that boulder were dropped 10 stories. I would think my car could not bear any weight under it. Now think of this, we all know bathtubs are on 2nd floors. But now suppose the bathtub is full of water and propelled from 3rd floor, it would crash through the 2nd floor, and then the 1st floor. But suppose that bathtub were full of fire and hurled into the house going 200 miles per hour. Would the house not catch on fire?

Again the higher you drop the rock the more force the rock will put on the car but ALSO more force will be put on the rock from the car. That is the equal opposite reaction law.

If your rock has more mass than the car roof then the roof will dent. If the rock has less mass than the roof then rock will break. How much the roof dents, or the rock breaks, depends on the difference in mass between the two objects. Velocity increases the force on BOTH objects, not just the car roof. You can never make a small mass go through a larger mass no matter how fast it is moving. For example a bug will not go through a windshield no matter how fast either is moving, the bug will always be splattered.

This is the question I've asked before and was not replied to, what experiences more force the bug or the windshield? If you answer that correctly you contradict your claims. I guess that's why none of you answer it.

Don't they teach this in high school anymore?

Originally posted by ANOK

So what? It is not a concrete tube like the poster claimed. Why are you even replying to that FACT. The core was 47 columns cross braced. This is not something that should be argued, it's fact.

Cross braced? Where? Oh you mean the crane during construction. No, the core was not cross braced. About all the core had was vertical columns, both large box and smaller I-beams, and the the horizontal beams were for the "floors" inside the core to allow for the staircases and areas to walk on. But the columns themselves did not have diagonal bracing. If they did, then people would have had a hell of a time trying to get from the elevators to the floor, or to the bathrooms.

Again, I know the load of the falling mass, it has been addressed, you are ignoring the FACT that the loading makes NO difference to the equal opposite reaction laws. Once again, no matter how much loading you claim there was it was still a smaller mass impacting a larger mass, and according to the KNOWN and scientifically accepted laws of motion there is an equal and opposite reaction. No matter how much load the top puts on the bottom the bottom is going to push back with the SAME FORCE. The object with the least mass will be the loser, every time. 15 floors can not have more mass than 95 floors, falling a few feet does NOT increase mass AT ALL. Mass is not increased until speed is near light speed.

Boy so many errors in such a little quote. So when the mass of 30 floors impacts one floor at 19mph, that one floor will magically stand up to the 30 floors? ANOK, did those 10-30 floors impact the 80-90 floors at the same time? Riddle me that. Or did those 30 floors impact one floor, then another, then another, etc etc etc? What vertical resistance of one floor would have been able to withstand 30 floors coming down under gravity? It didnt hit any vertical columns. It just the floor and the floor truss connections were all that were holding up each floor. Equal and opposite, yeah yeah, we all know how that works, however, you have no idea how it works in reality. That one floor reacted on the mass of the 30 floors with the same amount of force as the mass of the 30 floors impacting it. If you looked at the forces, both "hit" each other and exerted the same amount of force on each other (ie equal and opposite). However, just like a truck hitting a bug, even though the bug puts the same amount of force on the truck as the truck on the bug, the bug loses. And no ANOK, the 15-30 floors was not hitting the mass of 95 or 75 floors at the same time. I thought that was at least obvious.

The object with the least mass will be the loser, every time. 15 floors can not have more mass than 95 floors, falling a few feet does NOT increase mass AT ALL. Mass is not increased until speed is near light speed.

No, you forgot what happens to the mass of the floor that got impacted. It does not disappear. It is now joined with the falling mass, which no was more mass and is now gaining momentum, again. That extra mass is now going to give a much bigger slam on the floor below it. And that poor floor does not stand a chance.

You might think what you're saying is correct, but it's not. You are making the very fundamental and common mistakes of someone who has never taken a physics class or worked in mechanics. Everything you say can be traced to biased 911 web sites, that are not physics sites, and should not be trusted for any kind of education.

This is not a 'truther' site, it teaches the laws of motion...

www.can-do.com...

edit on 7/25/2011 by ANOK because: typo

Yes ANOK, and by your warped version of physics, a person would not be able to push a car. How can one person get a car to roll, by just pushing on it? The car is in neutral, and has a lot more mass than say, me. So how is it that I can push the car and get it rolling, faster and faster, until I dont have to push as hard to keep the car rolling? What would happen if someone tried to get in front of it and stop it? According to you, the car should be stopping me everytime.

Originally posted by GenRadek
Yes ANOK, and by your warped version of physics, a person would not be able to push a car.

GenRadek, why do you want to push cars, when most others in the thread are discussing the tower collapses?

Please explain how you think that pushing cars is relevant to a collapsing building.

Originally posted by ANOK
You can never make a small mass go through a larger mass no matter how fast it is moving.

Here we see again how little physics truthers actually know, as according to Anok a bullet cannot go through a human, as the bullet weighs say a SS109 bullet weighs 62gr, whilst a person weighs say 80kg, the person outweighs the bullet by about 80,000 times, so truther physics claims the bullet would bounce off....

Just how silly can they get?

Originally posted by spoor

Originally posted by ANOK
You can never make a small mass go through a larger mass no matter how fast it is moving.

Here we see again how little physics truthers actually know, as according to Anok a bullet cannot go through a human, as the bullet weighs say a SS109 bullet weighs 62gr, whilst a person weighs say 80kg, the person outweighs the bullet by about 80,000 times, so truther physics claims the bullet would bounce off....

Just how silly can they get?

Yes how silly it gets. You obvioulsy do not understand the difference between mass and weight?

I think a bullet has more mass than skin.

It gets extremely silly, and humorous, when people continuously show they fail to understand the terms, and concepts, we are talking about. If you want to talk physics you have to drop the common misconceptions, and learn what the terms really mean, and how to apply them in context. We used to learn this stuff in high school when I went there in the 1980's.

Whatever way you guys try to deny it, the laws of motion are well known, and accepted, as the basis of mechanics. And yes PLB, if you're reading, structures do fall under 'mechanics'. Another example of a common misconception, that mechanics only means engines and stuff of that nature.

Mechanics is a part of physics. It says what happens when forces act on things. There are two parts of mechanics. The two parts are classical mechanics and quantum mechanics. Classical mechanics is used most of the time. It is good to say what happens to most of the things we can see. Some of the time, for example when the things are too small, classical mechanics is not good. Then we need to use quantum mechanics.

simple.wikipedia.org...

The Three Laws of Motion

The basis of all solutions to mechanics problems are the Newton’s laws of motion in one form or the other. The laws are:...

engineering.myindialist.com...

How do you answer this question?...

1. While driving down the road, Anna Litical observed a bug striking the windshield of her car. Quite obviously, a case of Newton's third law of motion. The bug hit the windshield and the windshield hit the bug. Which of the two forces is greater: the force on the bug or the force on the windshield?

When you answer that, I will provide the link to the answer (you can look it up, but show your source pls) to show I didn't just make it up, as I keep getting accused of.
If you answer this correctly you will have to admit that you were wrong. If you don't answer it then you will lose all credibility, like all the other OS supporters who refuse to answer it. If you can't be honest in debate you shouldn't be here. I'm tired of being told I'm wrong, so c'mon a bit of honesty here! Quit being fools and educate yourselves.

Pls note; no 'truther' websites were used in the construction of this post, thank you, thank you very much, you've been a wonderful audience.

Originally posted by ANOK
I think a bullet has more mass than skin.

Yet another show of ignorance by a truther, a bullet has a mass of 62 gr, skin has a mass of about 8kg, yet you think the bullet has more mass......

Originally posted by spoor

Originally posted by ANOK
I think a bullet has more mass than skin.

Yet another show of ignorance by a truther, a bullet has a mass of 62 gr, skin has a mass of about 8kg, yet you think the bullet has more mass......

First off, where are your sources for those figures? A bullet hitting skin has other factors that are not present when concrete impacts concrete, or steel impacting steel. You have pressure in a very small area to consider, there is not much skin mass to stop the bullet.

Regardless, I have shown and proved my point. How can you keep ignoring the facts I present based on some silly misunderstanding? The laws of motion always apply, and if they seem to not be, there is an explanation and the law still applies.

Can you explain the laws of motion, in context of what we are actually talking about, solid objects colliding?

BTW I notice you didn't answer the question, why? Why are you OSers afraid to answer that question? Or did you not even read that far?

reply to post by ANOK


ANOK how structures react is also well known the floors of the towers were suspended between the outer an inner tube (wall,core).

What held the floors in postion was the welded angle section and the 2no 5/8" bolts that went through the slotted holes in the angle.

If each connection would break at for example 8 tons then if the load the falling mass imposed exceeded what all the connections that floor could hold it would fail, the mass below or the floors below cant repeat CANT change the load that a connection would break at.

That is the simple thing YOU and others on here can't grasp which I put down to NO construction experience.

You will have heard the expression a chain is only as strong as its weakest link well the weak link is the floor connections.

Compare the thickness of the angles to say a core or wall column do you honestly think it would take the same force to break a wall or core column as the angle! Is that what you think??

Also I will re state this if you look at the pictures of the construction of the towers you see that steel work is never high above the floor level because the floor system helps with the stability of the walls.
There is a limit to how high a column of steel or any other material can be built as a slim column go to high and it will start to bend and buckle under its own weight.

That's the problem with the tube in tube design and how the floors failing could cause serious problems for the structure its was great for floor space but led to their downfall.

reply to post by ANOK

If your rock has more mass than the car roof then the roof will dent. If the rock has less mass than the roof then rock will break. How much the roof dents, or the rock breaks, depends on the difference in mass between the two objects. Velocity increases the force on BOTH objects, not just the car roof. You can never make a small mass go through a larger mass no matter how fast it is moving. For example a bug will not go through a windshield no matter how fast either is moving, the bug will always be splattered.

This is foolishness. You need a remedial course in physics.

The concept of equal and opposite reactions is well known and accepted. But it is not needed in the context of the collapse. In fact it is confusing you and making you look.. well foolish. You need to back off the physic catch phrases and use some common sense bases on real world events.

Here is a meteorite that goes through a car.

Here

Plus here is the damage a 30mm shell leaves behind.

Here

Plus a bullet hole in an engine.

Here

The object with the least mass will be the loser, every time.

You need to stop right there.
There are more than a few cases where little bullets take out big airplanes.

And yes a bug can go through a windshield, given enough velocity. Google NASA for paint chip damage to the shuttles.

Originally posted by GenRadek
Cross braced? Where? Oh you mean the crane during construction. No, the core was not cross braced. About all the core had was vertical columns, both large box and smaller I-beams, and the the horizontal beams were for the "floors" inside the core to allow for the staircases and areas to walk on. But the columns themselves did not have diagonal bracing. If they did, then people would have had a hell of a time trying to get from the elevators to the floor, or to the bathrooms.

What is meant by "cross-braced" here?

The diagonal cross bracing seen at the corners of the core during construction were for the cranes.
But 47 core columns didn't just go straight up 1360 feet without any other connections. There were horizontal beams on every level connecting the core columns. It had to be about 1500 feet of steel at every level. They can be see in the Purdue simulation.



psik

Originally posted by samkent
You need to stop right there.
There are more than a few cases where little bullets take out big airplanes.

And yes a bug can go through a windshield, given enough velocity. Google NASA for paint chip damage to the shuttles.

Bullets can take out big airplanes.

Once again you are confusing weight with mass. A bullet is not concerned with the mass of the whole aircraft just the tiny part the tip of the bullet impacts.

A bug can not go through a windshield.

Here is the answer to the question...

Trick Question! Each force is the same size

www.mwit.ac.th...

If each force is the same size, how can a smaller mass cause more damage to the larger mass it hits? A bug will never have more mass than a windshield, unless it's huge.
Mass not weight. The overall weight of an object has nothing to do with the mass of part of it that is being impacted (in the case of small objects like bullets hitting large objects). You can't for example use the mass, or weight, of the whole car ONLY the windshield.

Our scenario is large objects of more or less equal mass and size. 15 concrete floors falling on 95 floors, to make it simple, because the forces on the falling and impacting floors is the same, mass is the only factor that is different.

As far as paint chips, do you realise how fast space debris is moving?

Orbital debris generally moves at very high speeds relative to operational satellites. In low Earth orbit (altitudes lower than 2,000 km) the average relative velocity at impact is 10 km/sec (36,000 km/hr or 21,600 mph).

www.aero.org...

The laws of motion break down at high speed. The falling floors of the towers were not moving fast enough for their speed to be significant in increasing their mass, and overloading the larger mass.

Please stick to physics that actually relate to what we're talking about, and there will be less confusion. Buildings here on the Earth, that are not moving at high speeds and putting pressure force on small areas of a large object.

BTW as far as bullets striking skin...

When the bullet strikes, its high velocity and small frontal cross-section means that it will exert large stresses in any object it hits. This usually results in it penetrating any soft object, such as flesh.

en.wikipedia.org...

Originally posted by samkent
Here is a meteorite that goes through a car.

Here

Plus here is the damage a 30mm shell leaves behind.

Here

Plus a bullet hole in an engine.

Here

First you need to learn to read mate...

Boat number 12 is no longer in use, and sat inside Denver’s fire station on Farm Tree Lane Monday afternoon. Last week crews noticed a bullet hole in the boat’s engine cover.

The engine cover is not the engine.

Regardless none of that contradicts what I've said.

That meteorite obviously had more mass than the material it hit, it pushed in that part then stopped when it hit the cars frame that has more mass.

Some rounds can penetrate an engine if it is a high caliber round, but then a whole new set of physics comes into play that does not when it comes to what were actually disusing.

Again you seem to want to include the mass of the whole object, when the bullet is only hitting a tiny part of it.
You are the one who needs to take physics classes, I already did when I took engineering fundamentals years ago.

reply to post by ANOK


Then under your understanding this cant happen!!!