Physics Prof Says Bombs not Planes brought down wtc

Originally posted by MacMerdin

Originally posted by bsbray11
Much thanks for that clarification. So, if I just replace the term 'angular momentum' with 'angular momentum', my usage is golden, right?

You spelled them both the same.

Oops... bad habit.

So, now I'm realizing, especially from this remark of yours,

Simple mistake in English is all.

that I've just used the term "angular momentum" in a place where it sounds more like I'm talking about the energy behind the movement (which I was) rather than its speed (angular momentum), right? So whoever coined these terms made "momentum," as in linear momentum proper, and "momentum" as in "angular momentum" represent two completely different aspects of a problem: momentum proper, and speed. Do I have it now? lol.

Sorry if it's been any trouble. If that is the basis of my misunderstanding, then it sounds like whoever's been making these words needs to be slapped.

I think you have it. Plus, I hope I'm even using the correct terminology. English is not my strong point. If I am incorrect could someone please correct myself so I am not giving misinfo.

Well, I looked up some Wikipedia articles, and on angular momentum, Wikipedia says this:

In physics the angular momentum of an object with respect to a reference point is a measure for the extent to which, and the direction in which, the object rotates about the reference point.

In particular, if the body rotates about an axis, then the angular momentum with respect to a point on the axis is related to the mass of the object, the angular velocity and the distance of the mass to the axis.

Without applying torque to the object, with respect to the reference point, the angular momentum is constant. The angular momentum is a measure for the amount of torque that has been applied over time to the object. The object has rotational inertia that resists changes in rotational motion, quantified by the moment of inertia.

en.wikipedia.org...

I think the point in bold is what I was originally getting at anyway. The WTC caps stopped tilting for no good reason, when they should have kept tilting in the same direction regardless of additional torque. And then, of course, gravity was doing its job.

From Wikipedia's page on torque, en.wikipedia.org... :

In physics, torque can be thought of informally as "rotational force". Torque is measured in units of newton metres. The concept of Torque, also called moment or couple, originated with the work of Archimedes on levers. The rotational analogues of force, mass and acceleration are torque, moment of inertia and angular acceleration respectively.

And Wikipedia defines angular acceleration as:

Angular acceleration is the rate of change of angular velocity over time.

Is this maybe what you mean by angular momentum?

At any rate, the angular momentum, torque, and angular acceleration disappeared. Pretty much everything, I would imagine, relating to a body moving angularly, vanished without good reason (save a destroyed pivot).

And since we're already on the subject, I hope no one would mind to look into what the 9/11 Research Site says about the loss of angular momentum:

The deceleration of the top's rotation is even more discrediting to the idea of a gravity-driven collapse, which cannot explain the documented changes in angular momentum. Conservation of angular momentum is the tendency of a rotating solid object to continue rotating at the same rate in the absence of torque. Initially the block consisting of the top 30 stories of the tower acted as a solid object, and rotated about a fulcrum near the impact zone. Although the fulcrum was the axis of rotation, the block had two types of momentum: the angular momentum of the block around its center of gravity, and the linear momentum of its center of gravity tilting away from the tower's vertical axis. When the portion of the building below the collapse zone disintegrated, the block would preserve its angular momentum by continuing to rotate at the same rate (but the acceleration of the rotation would cease due to the removal of the torque that was being applied by intact columns at the fulcrum). But in reality, the rotation of the block rapidly decelerated as the downward plunge began. Once the fall started, any resistance it encountered from parts of the building would have imparted torque on the block in the same direction as the original fulcrum, and would have accelerated its rotation.

Given the apparent absence of any torque to counter the rotation of the block, the slowing of its rotation can only be explained by the breakup of most of the block, which would have destroyed its moment of inertia.

But two parts of this confuse me. The underlined section states that torque was being applied by intact columns around the fulcrum. Would that be a negative amount of torque applied from those intact columns? I don't see how they would contribute to the acceleration, but maybe someone here can shed some light on that.

The bold section, if I interpret it correctly, suggests the caps themselves were destroyed to halt the momentum. The author states, "Initially the block consisting of the top 30 stories of the tower acted as a solid object," and this designates the "block" as what we refer to as the cap. So when he says "the breakup of most of the block," he seems to be referring to the block itself rather than the fulcrum. I wouldn't be surprised if explosives began going off indepedently within the caps, but how much damage would need to be dealt to totally compromise the momentum? No real damage was visible from the outside, as far as I know, when the momentum first disappeared. It was when the vertical collapse began that the momentum disappeared. Someone has even posted a link in another thread with an animation showing a close-up of a corner in the early stages of collapse. You could see when the building was tilting via that corner, and then you see an explosion erupt from the area from within the building, and everything beyond that is smoke and dust. My bet is that the momentum was lost then, from the fulcrum being destroyed.

Any "debunkers" still around to chip in on the discussion?

Originally posted by Bsbray11:You could see when the building was tilting via that corner, and then you see an explosion erupt from the area from within the building, and everything beyond that is smoke and dust. My bet is that the momentum was lost then, from the fulcrum being destroyed.

And there you have it. The fulcrum was destroyed by the collapse of the building. No bombs were needed. I'm glad you could clear up this issue on your own.

Since I still haven't seen any numbers I had to find my own.

Take note, you can at least get approximations from these figures, which many of you assume are only available from the blueprints.

www.tms.org...

Each floor was designed to withstand 1300 tons beyond it's own weight. When one floor collapsed the upper floors brought roughly 45,000 tons onto the level beneath the collapsed floor. Over 34 times the weight they were designed to hold. It is no wonder that the fulcrum was completely destroyed.

This led to the total collapse of the building. 80% of the debris does not equal 80% of the mass, so the weight of the caps at 45k tons combined with the structural steel from the collapsing floors was more than enough to bring down the entire building. Most of the weight was in steel and most of the steel ended up in or close to the footprint of the buildings.

No bombs, thermite or mini-nukes required.

Keep in mind the collapse did encounter resistance as it fell. They fell in less than 10 seconds at close to 200kph. If they had encountered no resistance, they would have fallen in 8 seconds at around 300kph.

Originally said by Lord Kelvin:I often say . . . that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be

Why do you need the blueprints to calculate how much force would be required to blow smoke out the windows?

You have the floor plan, and I just gave you the weight of the upper floors. Please show me with numbers how it is insufficient force. What do you need from the blueprints to calculate that?

Originally posted by MacMerdin: It's not the act of terrorism that's so horrible...it's the amount of deaths.

That is ridiculous. If, as some would have us believe, the Bush Administration needed a "new pearl harbor", the act of terror is absolutely necessary. If 9-11 had been caused by accident then there is no reason to go to afghanistan and there is no justification for a war on terror. If we are to believe that it was masterminded by the government then a collapse by demolition would be tottally unecessary. The terror attack would have been enough.

If most of the people on the upper floors would've survived the fire, why were people jumping out of windows?


I couldn't find who posted it, but someone asked why if engineers believe in progressive collapse, why aren't they doing anything about it.

Well, here are some links for you to look at, to see what they are doing about it.

PDF on Progressive collapse prevention in new buildings.

www.absconsulting.com...

training.bossintl.com...

And of course the source for said links.

Google

And what about the pre-collapse explosions ?? The facts show that WTC1, 2 & 7 were demolished with the assistance of explosives.

WTC7 and Silverstein the jew traitor murderer's admittance of WTC7 being 'pulled' plus the very obvious videos are more than enough evidence.

Indictments for murder should have been issued, but the media complicity and the activity of idiotic shills like leftbehind are only suppressing the truth of this crime.

Originally posted by LeftBehind

Originally posted by Bsbray11:You could see when the building was tilting via that corner, and then you see an explosion erupt from the area from within the building, and everything beyond that is smoke and dust. My bet is that the momentum was lost then, from the fulcrum being destroyed.

And there you have it. The fulcrum was destroyed by the collapse of the building. No bombs were needed. I'm glad you could clear up this issue on your own.

"...and then you see an explosion erupt from the area from within the building..."

Maybe you're a tad too dimwitted to read the posts, but as long as there is contact between the upper floors and lower floors, there will be a pivot for the momentum. So your explanation makes 0 sense.

If you don't believe me, educate yourself with the links provided. You should've done this before posting, anyway.

Each floor was designed to withstand 1300 tons beyond it's own weight. When one floor collapsed the upper floors brought roughly 45,000 tons onto the level beneath the collapsed floor. Over 34 times the weight they were designed to hold.

So how exactly did the buildings stand before 9/11, if these floors weren't designed to carry the weight they'd been carrying for about 30 years? Knock out one floor and suddenly the weight held for so long is now unbearable for the lower floors, despite massive redundancy?

Your problem, and the problem with everyone looking at it by a floor-by-floor basis, is that the columns were not set up floor by floor. The core columns were welded together across lengths of floors, if not the whole buildings in cases of some columns. The perimeter columns were interlocked in a staggered fashion. That, and the fact that you totally ignore the support being provided by all the floors beneath, just to focus on the destruction of one floor, lasting somewhere around 0.15 seconds, and then the next floor, in its 0.15 seconds, and so on and so on, ignorant of the fact that columns were not set up in 12-foot increments as the floors were, and forcing any viewpoint out of your head out that would suggest that those small caps couldn't crush all the floors below. You must have to actually force reasoning out of your head for that one. And I'm assuming that's where this "floor by floor" bullcrap comes from, taking the massive weight and saying "welp this floor alone wouldn't be able to hold all that" and moving along to the next floor to say the exact same thing, as if starting over with a new problem completely rather than being forced to accept that massive amounts of energy would be required to crush so many multitudes of very strong materials. An amount of energy that the caps no doubt did not possess.

Keep in mind the collapse did encounter resistance as it fell. They fell in less than 10 seconds at close to 200kph. If they had encountered no resistance, they would have fallen in 8 seconds at around 300kph.

So, in other words, steel is about 25% more resistant to a much smaller mass of other steel falling upon it than absolutely nothing. Interesting. But I have ask, where does the figure of 10 seconds come from? Such a quick time is support for the demo case, but is also inaccurate. But you try to back it up and show us your sources for your figures that you calculated, and then I'll show you some calculations from CNN clocks and seismic records and we'll see which is a more accurate means. Mr. Eager seems to be talking out of his ass on that one. I'm shocked.

Why do you need the blueprints to calculate how much force would be required to blow smoke out the windows?

You have yet to establish that it would be possible for air to have caused the squibs. See my last post on that and follow the links to the Wikipedia articles, if you want to learn about pressure gradients.

You have the floor plan, and I just gave you the weight of the upper floors. Please show me with numbers how it is insufficient force. What do you need from the blueprints to calculate that?

Because what you're suggesting is physically impossible in the first place. It doesn't make any sense. Again, establish that air could have possibly caused the squibs as they were seen, so far below the collapses and so forcefully in such a single spot.


Here's a paper using plenty of calculations for you to consider, LB: WTC 1 Collapse - The First Moments. It's based mostly on figures NIST has provided, and is much more in-depth and scientific than Mr. Eager's. Enjoy.

Originally posted by bsbray11

But two parts of this confuse me. The underlined section states that torque was being applied by intact columns around the fulcrum. Would that be a negative amount of torque applied from those intact columns? I don't see how they would contribute to the acceleration, but maybe someone here can shed some light on that.

I agree...kinda confusing. I think your right in saying that the intact columns would have given a resisting torque. Thanks for clearing up the problem with the terminology. I guess I wasn't being perfectly correct in what I was saying either. Again...thanks for clearing that up.

Originally posted by LeftBehind

Originally posted by MacMerdin: It's not the act of terrorism that's so horrible...it's the amount of deaths.

That is ridiculous. If, as some would have us believe, the Bush Administration needed a "new pearl harbor", the act of terror is absolutely necessary. If 9-11 had been caused by accident then there is no reason to go to afghanistan and there is no justification for a war on terror. If we are to believe that it was masterminded by the government then a collapse by demolition would be tottally unecessary. The terror attack would have been enough.

Oh really? So, I guess the act of terrorizm in 1993 was enough to lead us into Afghanistan? Hmm....I guess I missed the war on terrorism back then? Obviously a terror attack was not enough in 1993.....we needed the death bags and the ever present "scar" in the NYC skyline.

As far as your numbers...who's to say they are correct? Eager? How does he know they were designed to withstand 1300 tons beyond their own weight without knowing how or with what they were constructed? You can't say with certanty how much resistance they contained without knowing their construction. See my point now?

SOrry to change the subject slightly, but a recent event has highlighted something to me.

One of the arguments is that the fires in the WTC were oxygen starved and this is why they were producing thick black smoke. Hence they were not able to reach and sustain temperatures over wide enough areas to cause any structural failure.

However, todays explosion and fire in Hemel Hempsted (in a fuel depot mainly storing aviation fuel) is in the wide open and yet the smoke is still thick and black, I don't think anyone can say this fire is 'oxygen starved' as it has just about the best ventilation a fire could hope for...

www.abovetopsecret.com...

However....







When I last checked they were still not tackling the fire, and they definately were not when those pictures were taken, so what you are seeing is an open fire fuelled by aviation fuel, petrol, etc.

The smoke is very black and dense, it is very hot, in fact the smoke is covering a substantial area. All this from a fire with all the oxygen it could wish for, now seeing as they predict this continuing for at least 24 hours or more (on top of the day so far) and it looks pretty hot, does that throw into question any assumptions that the WTC fires were small, cool and insignificant just because of the dark smoke?
I know the fireman only reported 'two small pockets of fire' but was that not at the bottom of the damaged area?



[edit on 11-12-2005 by AgentSmith]

Originally posted by bsbray11

Maybe you're a tad too dimwitted to read the posts, but as long as there is contact between the upper floors and lower floors, there will be a pivot for the momentum. So your explanation makes 0 sense.

It is possible that I'm dimwitted, but I'm not dimwitted enough to believe this new bit of craziness.

So basically your saying that it doesnt matter that the collapse already started? Once the cap fell ten feet and hit the rest of the building the fulcrum was somehow reestablished?

What was that you said about zero sense?

So how exactly did the buildings stand before 9/11, if these floors weren't designed to carry the weight they'd been carrying for about 30 years? Knock out one floor and suddenly the weight held for so long is now unbearable for the lower floors, despite massive redundancy?

Massive redundancy? Do you even know what that means? Tell you what, use that SAP2000 program to drop a 10 storey building on top of a skyscraper, and then tell me it's the same load as building 10 more stories.

Remember that momentum you keep talking about? 45000 tons falling ten feet is a dynamic load. I'm sure someone here can explain to you the difference a static load and a dynamic force.

Your problem, and the problem with everyone looking at it by a floor-by-floor basis, is that the columns were not set up floor by floor. The core columns were welded together across lengths of floors, if not the whole buildings in cases of some columns.

No.

I think your problem is that you are ignoreing that the building was put together in floors. They had to make some of the load bearing horizontal as well.

Remember these?



But I guess those are superfluous, and really the floors could have been planks of wood, as they had no part in the strength of the building.

. And I'm assuming that's where this "floor by floor" bullcrap comes from, taking the massive weight and saying "welp this floor alone wouldn't be able to hold all that" and moving along to the next floor to say the exact same thing, as if starting over with a new problem completely rather than being forced to accept that massive amounts of energy would be required to crush so many multitudes of very strong materials. An amount of energy that the caps no doubt did not possess.

Really? Well then I gave you weight for the caps. We all appreciate your learned opinion on this, but it would be nice for you to prove your outrageous claims. Why is 45000 tons not enough? How much would be required?

But I have ask, where does the figure of 10 seconds come from? Such a quick time is support for the demo case, but is also inaccurate. But you try to back it up and show us your sources for your figures that you calculated, and then I'll show you some calculations from CNN clocks and seismic records and we'll see which is a more accurate means.

You got me I was wrong about the ten seconds. Not that hard to admit your wrong now is it?

However a longer time means even more resistance encountered, destroying your hardly-any-resistance mumbo jumbo.

You have yet to establish that it would be possible for air to have caused the squibs. See my last post on that and follow the links to the Wikipedia articles, if you want to learn about pressure gradients.

Sorry pal, the burden of proof is on the one making outrageous claims. NIST, ASCE, MIT, all see no problem with air causing the squibs. It is up to you to prove otherwise.


I'll post later about that ridiculous paper you posted. He actually believes that the metal could be twisted and completely warped by by heat, and then magically go back to normal. Wow.

Macmerdin, did you even look at that link? The sources were clearly posted at the end. You might not have recognized them, as most conspiracy sites don't believe in sources.

From the Eager Link:References

1. Presentation on WTC Collapse, Civil Engineering Department, MIT, Cambridge, MA (October 3, 2001).
2. D. Drysdale, An Introduction to Fire Dynamics (New York: Wiley Interscience, 1985), pp. 134–140.
3. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 10–67.
4. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 6-62 to 6-70.
5. Steven Ashley, “When the Twin Towers Fell,” Scientific American Online (October 9, 2001); www.sciam.com/explorations/2001/100901wtc/
6. Zdenek P. Bazant and Yong Zhou, “Why Did the World Trade Center Collapse?—Simple Analysis,” J. Engineering Mechanics ASCE, (September 28, 2001), also www.tam.uiuc.edu/news/200109wtc/
7. Timothy Wilkinson, “World Trade Centre–New York—Some Engineering Aspects” (October 25, 2001), Univ. Sydney, Department of Civil Engineering; www.civil.usyd.edu.au/wtc.htm.
8. G. Charles Clifton, “Collapse of the World Trade Centers,” CAD Headlines, tenlinks.com (October 8, 2001); www.tenlinks.com/NEWS/special/wtc/clifton/p1.htm.

Thomas W. Eagar, the Thomas Lord Professor of Materials Engineering and Engineering Systems, and Christopher Musso, graduate research student, are at the Massachusetts Institute of Technology.

Smoke can turn black under different conditions. One is being fuel-rich (see initiatory explosions in either tower). Another is soot from a poor burn. Considering jet fuel burned out in a few minutes in either tower, as even NIST or FEMA can tell you, I wouldn't assume being fuel-rich was the problem.

Hope that clears it up a bit.

[edit on 11-12-2005 by bsbray11]

Originally posted by LeftBehind
It is possible that I'm dimwitted, but I'm not dimwitted enough to believe this new bit of craziness.

So basically your saying that it doesnt matter that the collapse already started?

Clarify what you mean here. The tilting and vertical collapses, in the South Tower, can be viewed as separate events.

Once the cap fell ten feet and hit the rest of the building the fulcrum was somehow reestablished?

I don't know where you get this ten feet figure but apparently not. The cap did move around more later in the collapse, as it was being destroyed and ejected with all the other debris. But as far as the initial tilt, that thing was gone after the first 2.5 seconds or so.

What was that you said about zero sense?

That your claim that the building crushed its own fulcrum makes zero sense.

Massive redundancy? Do you even know what that means?

It means the columns could carry much more weight than they were designed to. It's in NYC building codes that they are able to do this. The WTC could hold about 75% more weight than they were designed to. So your goal is to get the weight of the caps and prove that a maximum of 12 feet of momentum applied to the caps provides enough force to destroy a 110-story building in whole, down to nothing but dust and shards of steel.

Tell you what, use that SAP2000 program to drop a 10 storey building on top of a skyscraper, and then tell me it's the same load as building 10 more stories.

But see, was Eager referencing the force from momentum, or the static weight of that material? It sounded to me as if he meant static weight, and yet here you come in, apparently assuming he meant momentum, arguing something completely different. Get what you're saying straight. If you want to do the figures to calculate how much momentum was behind the fall, you'll need the weight of the caps. And then you should take that weight, figure up the momentum, not by the maximum speed, but by how fast it would be going after accelerating in only about 12 feet at most according to the gravity-driven b.s., and then compare that weight to the amount of weight the buildings were designed to hold.

And remember that crushing one floor does not compromise the rest of the building's ability (meaning the ability of every additional floor crushed beneath, if you must continue to look at it floor-by-floor despite column set ups) to withstand a similar amount of weight.

I think your problem is that you are ignoreing that the building was put together in floors. They had to make some of the load bearing horizontal as well.

Remember these?

That's a truss, genius. Not a column.

Unless they were going to put trusses down through the middle of halls, sticking out of the walls everywhere, it would make sense to put them between floors. The core columns were still spanning multiple floors, and the perimeter columns were still staggered.

On top of that, the core structure had a floor system that was independent of the floor systems between the core and perimeter. Just another problem with the pancake theory.

Really? Well then I gave you weight for the caps.

Which are based on..... ? Eager? Who also says the buildings fell in 10 seconds?

We all appreciate your learned opinion on this, but it would be nice for you to prove your outrageous claims. Why is 45000 tons not enough? How much would be required?

Figure it out yourself, if it's that easy without the figures from NIST, and I'm such an idiot.

You got me I was wrong about the ten seconds.

Nah, actually, Eager was wrong and you trusted him enough to cite him. Point: Don't trust Eager. He doesn't know wtf he's talking about.

However a longer time means even more resistance encountered, destroying your hardly-any-resistance mumbo jumbo.

How? The additional time is only a few seconds. As someone else referenced a sidewalk, imagine a brick falling and destroying a sidewalk into dust. Suppose someone claimed the destruction lasted 1 second. In reality, it lasted 2. Does that prove a brick can destroy a sidewalk without additional sources of energy in 2 seconds? No, it doesn't

The example may have little relevance, as I know you'll try to call that out, but I'm trying to make a point with it. You just provided an "essay" (more like a sentence) instead of numbers. Prove that it makes that big of a difference.

Sorry pal, the burden of proof is on the one making outrageous claims.

So in other words you can't find anything to suggest it's even possible, so you're just going to dodge it.

I can post sites showing how it would be possible for explosives to do something like that, but I would assume that's common sense, seeing as how it's in the nature of explosives to cause explosions. So really, the outrageous claim is air. So take your own advice on that one. I'm still waiting for sources explaining the specifics.

I'll post later about that ridiculous paper you posted. He actually believes that the metal could be twisted and completely warped by by heat, and then magically go back to normal. Wow.

I must've missed that part, but I'll be waiting for your response to that paper.

Macmerdin, did you even look at that link? The sources were clearly posted at the end. You might not have recognized them, as most conspiracy sites don't believe in sources.

Do you know what footnotes are, LeftBehind? He used them in that paper. No references at all were given for most of the figures he gave, including all of the important ones. Just thought I'd let you know. You'll be seeing a lot more of footnotes when you get into college education.

[edit on 11-12-2005 by bsbray11]

Originally posted by AgentSmith

The smoke is very black and dense, it is very hot, in fact the smoke is covering a substantial area. All this from a fire with all the oxygen it could wish for, now seeing as they predict this continuing for at least 24 hours or more (on top of the day so far) and it looks pretty hot, does that throw into question any assumptions that the WTC fires were small, cool and insignificant just because of the dark smoke?
I know the fireman only reported 'two small pockets of fire' but was that not at the bottom of the damaged area?

that's all well and good, but:

a. you are making it seem like there are similarities. the 'official word' is that the jet fuel burned up within the first ten minutes(and that could be a lie).

b. see a.

c. the official reoprt has most of the steel exposed to only 250 degrees celcius. and only one incidence of 750 or 800 degrees.

a 10, 000 gallon tank is about the size of an office, i've heard. that's really not that much in terms of the enourmous surface area of the world trade center towers one and two.

most of the heat energy from fire goes into the AIR and steel only picks up an ambient amount of that energy.
steel is a great heat conductor, and the tower were giant heat sinks. ever seen a tiny transistor attached to a huge heat sink? like say, a two hundred watt solid state amplifier?

that chip would melt in less than a second if it wasn't touching that metal. the towers not only distributed loads dynamically, but would also have distributed heat dynamically. the lie requires ALL the heat energy from the fuel to be applied to the beams. the lie requires ALL the mass to descend at once for one floor, .....because the floor truss clips gave out on one floor(all at once, all the way around the tower).

so, because a four inch sheet of concrete fell 3 metres(with all clips giving out simultaneously), the whole tower instantly disintegrated.

okay. i get it, now.

[edit on 12-12-2005 by billybob]

Wow BSBray I don't even know where to start.

You show such misunderstanding of basic concepts that I can't believe that you even talk about your knowledge of basic physics.

There is a huge difference between the static load a building was designed to hold and a dynamic load which isn't even taken into account. Eager was plainly talking about the weight of the caps and I gaurantee you that the building was not designed to withstand a dynamic load of 45000 tons. No building is even designed with dynamic loads like that even considered.

I have no idea how you got confused about momentum and static weight and I have no idea what you are talking about.

Horizontal loads mean a truss, not a column. Way to not know the difference between vertical and horizontal, genius.

Since you plainly don't have the first clue about sourcing material, here is where Eager got his numbers.

www.tms.org...

References

1. Presentation on WTC Collapse, Civil Engineering Department, MIT, Cambridge, MA (October 3, 2001).
2. D. Drysdale, An Introduction to Fire Dynamics (New York: Wiley Interscience, 1985), pp. 134–140.
3. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 10–67.
4. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 6-62 to 6-70.
5. Steven Ashley, “When the Twin Towers Fell,” Scientific American Online (October 9, 2001); www.sciam.com/explorations/2001/100901wtc/
6. Zdenek P. Bazant and Yong Zhou, “Why Did the World Trade Center Collapse?—Simple Analysis,” J. Engineering Mechanics ASCE, (September 28, 2001), also www.tam.uiuc.edu/news/200109wtc/
7. Timothy Wilkinson, “World Trade Centre–New York—Some Engineering Aspects” (October 25, 2001), Univ. Sydney, Department of Civil Engineering; www.civil.usyd.edu.au/wtc.htm.
8. G. Charles Clifton, “Collapse of the World Trade Centers,” CAD Headlines, tenlinks.com (October 8, 2001); www.tenlinks.com/NEWS/special/wtc/clifton/p1.htm.

And Eager doesn't know wtf he's talking about? I bet he knows the difference between vertical and horizontal, after all here is his title.

Thomas W. Eagar, the Thomas Lord Professor of Materials Engineering and Engineering Systems,

I don't think you make it to that position at one of the most prestigious Universities in the US by not knowing anything about engineering.


On the resistance of the building.

I did give the amount of time it would take to fall with no resistance, 8 seconds. Since it took longer than that to fall that proves that there was resistance contrary to what you say.

Your analogy about a brick shows that you also have problems understanding scale.

First you complained that you had no info for calulations. I give you something to go on, and now you expect me to do it for you. I am not making claims about demolition, I am defending the consensus of structural engineers who understand what happened that day.

If you make claims, it only makes sense that you back them up. It seems you have plenty of time to make pictures with pretty little missiles surely you can do back of the envolope equations on volume. But go ahead keep dodging it, it only proves how weak your case is.

If you can't be bothered to read the link you post, then I'm not going to bother debunking it. Read your link, post some relevant info out of it and then we can discuss it.

As to the references. You say

No references at all were given for most of the figures he gave, including all of the important ones.

Maybe intead of thinking up clever quips about college you should read the link.Here it is again.

References

1. Presentation on WTC Collapse, Civil Engineering Department, MIT, Cambridge, MA (October 3, 2001).
2. D. Drysdale, An Introduction to Fire Dynamics (New York: Wiley Interscience, 1985), pp. 134–140.
3. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 10–67.
4. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 6-62 to 6-70.
5. Steven Ashley, “When the Twin Towers Fell,” Scientific American Online (October 9, 2001); www.sciam.com/explorations/2001/100901wtc/
6. Zdenek P. Bazant and Yong Zhou, “Why Did the World Trade Center Collapse?—Simple Analysis,” J. Engineering Mechanics ASCE, (September 28, 2001), also www.tam.uiuc.edu/news/200109wtc/
7. Timothy Wilkinson, “World Trade Centre–New York—Some Engineering Aspects” (October 25, 2001), Univ. Sydney, Department of Civil Engineering; www.civil.usyd.edu.au/wtc.htm.
8. G. Charles Clifton, “Collapse of the World Trade Centers,” CAD Headlines, tenlinks.com (October 8, 2001); www.tenlinks.com/NEWS/special/wtc/clifton/p1.htm.

If you can't tell the difference between horizontal and vertical maybe you should lay off calling others stupid. And until you can back up your claims about basic physics, maybe you should make it clear that it is your opinion, not fact.

Mod edit: Fixed Link.

[edit on 13/12/2005 by Mirthful Me]

Originally posted by LeftBehind

I did give the amount of time it would take to fall with no resistance, 8 seconds. Since it took longer than that to fall that proves that there was resistance contrary to what you say.

9.6 sec., maybe?
the buildings showed no stutter as the y collapse.

8 sec. is faster than freefall.

Originally posted by LeftBehind
Keep in mind the collapse did encounter resistance as it fell. They fell in less than 10 seconds at close to 200kph. If they had encountered no resistance, they would have fallen in 8 seconds at around 300kph.

Nonsense. WTC1 was 1368ft tall, which gives a free fall time in vacuum of 9.22 seconds, striking the ground at 325Km/h. Add in air resistance and whaddyaknow, Mr. Eagar's stated 10 seconds fall time is pretty darn close to free fall. You got your figures verbatim from Eagar, did you not? This is what happens when you automatically assume that individuals' hypotheses are correct or shills are telling the truth, simply because they have a degree, without actually checking to see for yourself. If that's your standard, what on Earth do you do when two people with the same credentials express contradictory views. Oh my God, brain aneurysm!!

Just for laffs, take a look at Eagar's now infamous "columnless pancake core":



I'd caution anyone against linking to Thomas "Pancake" Eagar as their infallible hero. Not just because he doesn't seem to be capable of performing a simple motion calculation (maybe he ran out of envelopes), but more importantly because he has been proven wrong on countless occasions, not only by 9-11 skeptics, but also by government institutions such as NIST which refute his ridiculous waffle/crepe/pancake theory. He changes his tune every time he is shown to be wrong, hoping that no one will notice. And it seems that some people indeed didn't.

Discussing stress and load in structural components and assemblies is certainly within Mr Eagar's field of expertise, ignoring for a moment the fact that he opens his mouth without bothering to actually do calculations or check facts regarding the structures and collapses. But once you get into the actual physics and mechanics of a gravity-driven collapse, Mr Eagar's credentials don't mean much. He should talk to a physicist for that one.


[edit on 2005-12-14 by wecomeinpeace]

Are you counting the time for the top of the building to hit the ground, or the top portion of the building to hit the ground? How can you tell with all of the dust when exactly that was?

Are you sure you aren’t looking at the portions of the building that were falling outside the building envelope?



Those exterior column trees are obviously in free fall, they are also, quite obviously falling faster than the building behind them.

Originally posted by HowardRoark
Are you counting the time for the top of the building to hit the ground, or the top portion of the building to hit the ground?

Eagar states:

This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour.

The collapse points on WTC1 and 2 differed by about 20 floors, however Mr Eagar's paper references both buildings without differentiating collapse times based on those two very different heights. He is clearly referring to the buildings as a whole.

How can you tell with all of the dust when exactly that was?

You should be asking Mr Eagar that. The 10 second figure was his, not mine.

Those exterior column trees are obviously in free fall, they are also, quite obviously falling faster than the building behind them.

I never stated the collapses occurred in free fall. I was pointing out that Mr Eagar's cited 10 second collapse times puts them within 0.78 seconds of free fall. Even most 9-11 researchers place the collapses at around 12 seconds or more, as does NIST. I have no idea where Eagar comes up with this stuff.

As I said, Mr Eagar must have run out of envelopes, or maybe he's just shooting from the hip. Why don't you email him and ask? While you're at it, be sure to ask him about his "outward bowing perimeter columns" and his columnless pancake core.


[edit on 2005-12-14 by wecomeinpeace]

Just for the record WTC took around 18 - 20 seconds for the top to hit the ground.

Just for the record WTC took around 18 - 20 seconds for the top to hit the ground.

Freefall in a vacuum for the WTC is 9.6468243 seconds (an exact calculation). Its some considerable resistance is if took around 20 seconds to fall.

The big question is was this evident resistance that made it a 20 sec fall due to all air resistance or both air resistance and structural resistance?

The conspiracy theorists are going to want to say its all air resistance. The conspiracy thoerists arent smart enough to verify that though. Theyll need to know the "air resistance parameter" (which they dont have) which is how "thick" the air is, and how the shape of the falling building parts effects its air resistance (shape is a factor too). And assuming they can get this information, theyll have to know how to calculate the fall speed using this information assuming air resistance is the ONLY resistance. Based on all conspiracy sites I have seen, and posts by conspiracy theorists, their is strong evidence that conspiracy theorists cant bring forth any quantitative evidence, all I see is qualitative speculation. Our conspiracy theorists are definitly not mathematics savy. And qualitative evidence just dont cut it.

Id love to see myself proven wrong though. Show me some quantitative evidence conspiracy theorists, you guys "know" you are right and are "So scientific", this shouldnt be a problem.


[edit on 14-12-2005 by bob2000]

[edit on 14-12-2005 by bob2000]