Hi (journalist’s name,)

I am asking journalists what entity in the United States has the power to muzzle and control the main stream media. This, in fact, is my primary accusation...that this happens and has happened in the instance of the events of 9/11. Someone or something has the ability to control the entirety of the main stream media in the US today.

wtc 1 911 e50c2What follows will be the facts about my analysis of the collapse of one of the two tall World Trade Center (WTC) towers, WTC1, the North Tower, the one which was struck by an aircraft nearest the top of the building. It’s the one easiest to analyze with my technique. In a way, I am trying to convince you that the physics doesn’t support the official explanation presented by NIST, the National Institute of Standards and Technology, the US government body tasked with researching and reporting the cause of the collapses of each of the WTC buildings that collapsed on 9/11/2001. I hope, of course, that I am successful, and as importantly, I hope you will give me feedback that will help me improve my presentation of this material to an audience that will likely not be very familiar with “the 9/11 physics” or physics in general. How to quickly and solidly teach this to a general audience has been the challenge for me from the beginning of my work on this. In my opinion, as I continue to follow the work of Architects and Engineers on this issue, I find that keeping it simple and short while maintaining understandability has always been a problem. This physics, after all, is not difficult.

My original question for you

I asked the question, “Why are journalists not digging into 9/11?” Because of what the basic physics shows us about what both must and what cannot happen in a collapse such as that of WTC1 and 2—as well as WTC7—I am astonished and troubled that journalists are not studying and reporting on this event aggressively.

No conspiracy theory

Although questions of the who and why of 9/11 jump to mind, I have no “conspiracy theory” about that aspect of the events of that day. I have my thoughts as we all might but I have nothing solid on which to base anything more than what the physics shows. The physics, however, shows a lot. What conspiracy-theory-like thoughts I have, I have put in “Appendix E, what I think of all this.” What I believe is not important. What I can prove, though, is important and is what I wish to present here to justify my question.

What I see as the crux of this affair

Before I get into the analysis itself, I want to mention a general truth I discovered as I did my research so I could “do the math.” It’s this: one must learn the difference between fact and belief, what one knows and what one doesn’t know but believes, and keep them separate. Keeping this in mind guided me to see what to doubt and throw out and what to keep. It won’t surprise you that I found I had to throw out almost everything I read or heard about the events and could keep very little.

England’s Royal Society's motto 'Nullius in verba' is taken to mean 'take nobody's word for it'. It is an expression of “the determination of Fellows to withstand the domination of authority and to verify all statements by an appeal to facts determined by experiment.” (https://royalsociety.org/about-us/history/.) My father, an engineer, one of the “fathers of radar,” told me when I was a child, “Believe nothing of what you hear and only half of what you see.” We would all do well to keep skepticism in highest regard as we make our way in the modern world. We should also note that where skepticism is shunned, it is likely done to mask mischief. It says, “Don’t look here.” 9/11 is important not only in itself as an unsolved public murder of some 2996 people (https://en.wikipedia.org/wiki/Casualties_of_the_September_11_attacks), the maligning of a major world religion and the justification for the killing of an estimated million Iraqis and other incursions around the world justified by “we were attacked,” but also for what it teaches about the importance of self-empowerment, personal responsibility and knowing well the difference between fact and belief.

WTC1 building statistics

1368 feet high; 110 floors; each floor an acre (43264 sq. ft.) of area, 12 foot floor intervals.

What I did and what that shows in a nutshell

I did three mathematical models of the collapse of WTC1, the North Tower, the first more general and simple than the second and the third done once by hand but which is complicated enough to be best and most powerfully presented by a computer program like Excel. I’ve not completed the third one yet to my satisfaction, a computer analysis that includes the effect of mass thrown wide of the building footprint during the collapse. That that happened during the WTC1’s collapse is documented and we can include it in our studies. WTC1 was damaged at the 98th floor by an aircraft impact. Fires ensued and WTC1 fell straight down 1 hour and 46 minutes later. It fell in “approximately 11 seconds” per NIST, 10 seconds timed by others and if you time it from the videos. The block of 12 upper floors fell undamaged while appearing to smash everything it struck below it.

My models of the WTC1 collapse begin with NIST’s statement of what happened and applies physics to determine whether or not that explanation is physically possible. Here is NIST’s statement of what happened to WTC1:

  1. 11. How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)? The below is taken from their answer.
  2. "The structure below the level of collapse initiation [Floor 98] offered minimal resistance to the falling building mass [the block of 12 floors] at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.
  3. Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass." https://www.nist.gov/el/faqs-nist-wtc-towers-investigation NIST FAQs ans.# 11.

I’d like to highlight three aspects of the NIST statement: 1.) NIST admits that WTC1 “came down essentially in free fall;” 2.) NIST tells us that the entire structure was intact when the building collapsed (in order for the “stories below” to “sequentially fail,” they had to be in place when they were hit;) 3.) NIST says that, “The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.” Potential energy is created by gravity and this potential energy, says NIST, was enough to cause the building to collapse as quickly as it did the “intact structure below,” with no mention of any other energy source. To answer FAQ #11, NIST must include all importantly contributing energy sources. NIST lists only gravity as an energy source for the collapse. Gravity, in short, is NIST’s only energy source enabling the collapse of the building, right through the intact structure, right through what is called “the path of greatest resistance” and causing it to fall “essentially in free fall.” They also say that this free fall can be seen in videos. Other means were also used to measure the collapse time. These corroborate the video timing.

They say more than this in that short FAQ answer but we only need to call up those three aspects of their statement.

Each of my analyses is done by simplifying the building to eliminate the complexity that was claimed made it impossible to analyze the collapse by computer. I chose the simplifications carefully. Each model calculates a collapse that happens faster than it could happen in reality.

The first model is made just to see generally how this kind of a thing might go. It starts with the roof falling on the next floor down, the third floor down being moved to rest atop the forth so that the two now joined and falling floors hit another doubling mass, and so on to the ground. This model generates a collapse that takes 12 seconds. The second models a collapse that is closer to what actually happened. A block of 12 floors falls onto the 13th down, they “stick together” (one rests on the next down) and fall gathering floors sequentially until the block of 12 is sitting on the ground, not yet collapsed itself. This model finds a collapse that takes about 15 seconds. Bringing the roof of that block of 12 floors adds another half second to the collapse time. The third model adds to the second but includes the process of mass being lost during the collapse. This model is even closer to reality, and calculates a collapse that takes a little longer.

Since each model is of a collapse that would happen faster than is actually possible because I removed the strong supporting structure from the building—everything that held the floors in place above the ground—it shows that the actual collapse had to have had added energy to enable it to collapse as fast as it did. In the real collapse of WTC1, because it happened in only 11 seconds, added energy was needed to remove the support structure and most of the floors below ahead of the collapsing material we see in the videos in order for any of the three buildings, WTC1, WTC2 and WTC7, to fall as they did straight down, and as fast as they did. My conclusion is that NIST’s explanation is incorrect. This paper is dedicated to showing you why that is true in a way that is naturally understandable.

The Physics

My analysis relies on physics. The physics we will use here is basic and easy to recognize and use. You may discover that you are already aware of these physical facts and processes in one form or another and may even have played with them yourself in a way that is applicable to our discussion here. This is not difficult to understand and it is useful not only here but in everyday life.

You may find that this presentation is incomplete in some ways. I’m trying to introduce no more than what is needed. Some things will be left out or left dangling. This is not a physics course, something for which you’ll likely be thankful, and something I have to keep reminding myself. If an aspect isn’t clear, ask about it and I’ll elaborate on it if I can. I apologize for redundancy in the presentation and for things included that are unnecessary to your understanding of the event and my approach.

A list of the physics principles involved

  1. Newton’s first law of motion: a body will remain at rest or in motion until acted on by an external force.
  2. Newton’s second law of motion: Force = mass x acceleration.
  3. Newton’s third law of motion: “Action/reaction”: Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object.
  4. Momentum. This is similar or to, an application of, Newton’s first law.
  5. Conservation of momentum: this law describes what happens when moving bodies interact and combines or is a consequence of Newton’s laws of motion.
  6. Gravity: For our purposes, that it accelerates any mass at the same rate. Either a feather or an anvil (both in a vacuum, for example, to eliminate forces due to air resistance which will be different for either) will gain speed at the same rate when accelerated by the same gravitational field at the same location.
  7. Kinetic Energy: The energy of motion. A moving object has kinetic energy. This is not the same thing as momentum and this fact will appear briefly in our consideration as something that is also involved in these interactions.

The physics aspects of this discussion will be engaged as we go along. This might not be the best way to present this but let’s see how it works. Conservation of linear momentum is the fundamental working element of this analysis so we I’ll begin with an introduction to momentum.


The Greeks recognized that there was something consistent about objects in motion with respect to other objects. The moving body had a property they called “Impetus” and through measurement it turned out consistently to be equal to the mass of the moving body times its velocity. This relationship is written mathematically as p = mv. The p comes from the word impetus, m, is mass, and, v, is velocity.

Bodies moving in a straight line have this property (linear momentum) as do bodies that are rotating (rotational momentum.) An example of the rotational case is a bicycle’s front wheel removed from the bike’s forks. The wheel spinning on its axis wants to keep spinning. If there were no friction in the bearings and no air and no other interference, it would spin forever until another force acts to change its rotation. Rotational momentum does not come to play in my treatment of the collapses of WTC1. We need only concern ourselves with linear momentum.

But to mention it so we can set it aside, rotational momentum does come into play when looking at WTC2. If you look at videos of the collapses, you’ll see WTC2 shown prominently. When WTC2 collapsed, first the top 400 feet of it began to rotate. Dr. Crockett Grabbe looked at this critically noting the odd disappearance of that rotating body into the cloud of dust that enveloped that building during its collapse and that it didn’t fall to the street beside the rest of the building as it should have. He asks, “How could that have happened?” The energy measured in the block’s rotational motion was huge and it all just seemed to have vanished or to have been somehow overwhelmed which didn’t fit with the NIST formal explanation. His observation and questions are similar to mine. I think mine are easier to understand and teach, so WTC1 became the object of my analysis.

Conservation of momentum

The backbone of this analysis is about conservation of momentum and I think we’ve covered it sufficiently by now. Our uses of conservation of momentum may be a little more subtle than the simple p = mv relationship but it is shown well in the skating examples below as you become familiar with the use and value of the selected system boundary. Establishing an imaginary, convenient (and valid) system boundary helps isolate an event so it can be more easily studied. A system boundary is chosen such that within that boundary, a boundary no mass or energy crosses, mass can be moved from player to player and velocities will change according to the law that the sums of the momentums of the objects before the interaction will be equal to the sums of the momentums of the bodies within the system boundary after the interaction no matter what happens in the interactions. The simplest interaction is when the masses are moving in a straight line and meet and stick together. This is what happens when a skater grasps another and they move off together. It’s also what happens when a building’s floor falls to rest atop another floor further down as happens in the sequential cascade of floors of the WTC1 collapse NIST would have us believe happened.

The idea of a system boundary and a closed system may be shown as follows. Consider the common experience of skating on a pond, my singular example explaining and relating all the physics I use in these models. The two skaters, one traveling, the other stopped, are both to be considered in a closed system, within the system boundary, a system chosen in such a way that no energy or additional mass enters or leaves. Things are as they are momentum-wise with respect to just the two skaters before and after they interact. There are many objects both stationary and moving on a good skating day on the public pond. We choose to look at only the two skaters for our purposes so the system boundary is drawn just around them excluding everything else.

Velocity and mass

A body in motion has two properties importantly related: its mass (or its weight, for our purposes) and its velocity (speed, again for our specific purposes) with respect to another body. The simple product of these two properties is the body’s momentum as we’ve said.

The collapse of a building as modeled simply is a series of these closed system interactions. The interactions are linked in that the immediately previous interaction provides the initial conditions for the interaction that follows. In my models of the collapse, this series chains on down, repeating, until the entire building has collapsed.

In our case, in a system where there are two masses, one moving, the other stationary with respect to it, if the moving mass strikes the stationary one straight on so that there is no tumbling introduced and sticks to it, conservation of linear momentum rules and the products of the speeds of the two individual masses and their combined mass will be the same after the impact as it was before the impact. This means, for a simple example, that if these masses are equal, the doubled mass right after impact will depart the impact site at half the speed the moving one had initially, the total momentum of the “system” remaining the same and therefore “conserved.” The familiar example of skating on a pond will illustrate this and is presented below in Figures 1 and 2.

An odd aspect of the NIST presentation of the towers’ collapses

NIST analysis as shown us in its Answers to Most Frequently Asked Questions presented above includes a body’s speed and mass for the moving body (the falling floors) but selectively and oddly ignores the mass of the body being struck (the yet-to-be-hit floors,) treating it as though it were zero. Of course, if the floor to be struck has no mass, there is no conservation of momentum consequence of accelerating that stationary mass by the falling mass and, so, the event proceeds at free fall. But, again, for this to happen, the lower floors, in the case of the building, or of the second skater in that instance, would have to have no mass (or to already be moving along that line, but if so, there would be no impact.) All the floors, falling and stationary, have mass and all skaters have mass and therefore there must be conservation of momentum physics happening with each collision and the colliding bodies’ progress downward must slow or there has to be no collision. Try this in a supermarket. Push your initially empty cart from zero speed to a walk and note how much effort you had to put into it to move it. Later push the filled cart from stopped to a walking pace and note how much effort it takes it to get it moving when its mass is greater. In terms of Newton’s third law of motion the cart resists being accelerated precisely as much as it is pushed and does so because of its mass.

“Free fall”

It is common to hear of something falling at “free fall speed.” This is misleading and we’ll talk about it in a moment. “Free fall” is the condition of unimpeded fall with gravity accelerating the falling body. That means it is not allowed to hit anything and it is not allowed to be pushed by anything. The simplest example is of an object falling in a vacuum where even air, which slows things due to drag, is excluded. This is a simple value to calculate as there is so little involved, only gravity and the falling object. It establishes a fastest fall time and rate, a time and rate that are faster than can actually happen in air. Anything that falls “at free fall” is falling with no interactions with any other mass during its journey. In reality, objects falling in air can only fall close to “free fall”. Any object falling freely near the surface of the Earth (but in a vacuum) will gain speed at 32.174 feet per second every second that it is falling. If it’s falling freely but in air near the surface of Earth, which would be more usual, friction with the air will slow it down to some extent depending on its shape and a few other parameters such as the density of the air. It will never be able to fall as fast as in a vacuum.

Falling in the real world…through air: Terminal velocity

Human bodies, for example, that fall long distances in air, are slowed by the resistance due to the air and finally reach what’s called “terminal velocity” where the drag resistance due to air equals the force of gravity and the falling body can no longer gain speed. Terminal velocity for a falling human body is somewhere between 90 and 120 miles per hour. The free fall calculation of an object falling in a vacuum from the top of WTC1 shows that the object will reach about 250 miles per hour by the time it reaches the pavement 1368 feet below. In reality those speeds are not reached and, so, the time a real object will take to fall from the top of WTC1 will be longer, and the speed reached slower, than the free fall calculation determines. If an object falls in a time “essentially in free fall,” it will have met very little resistance, if any, to its fall.

Free fall speed

The concept of, “free fall speed” introduces an unnecessary complexity such that it is usually confusing. Free fall denotes a state of motion where the moving object’s speed is always increasing, that is, always changing. There is no actual overall “free fall speed.” A “free fall speed” or a speed during free fall, might be measured at any single, specific moment in the journey of the falling object. Gravity provides the push (or pull) that keeps the falling object’s speed increasing. Free fall on the moon, for example, will be different than free fall on Earth due to the moon’s lesser gravity. It even varies a tiny bit on Earth, mostly depending on altitude.

Free fall time

“Free fall time” is another common phrase used when speaking of falling things. This is more straight-forward. “Free fall time” is the time an object takes to fall from a given height usually to the ground or to some other marker, the time it would take the object to fall unimpeded even by air. It is the shortest time for an object to fall said distance with gravity providing the only force causing the fall acceleration. No object actually falling on Earth, in Earth’s atmosphere, with gravity providing the only event energy can fall in this short a time because of the resistance due to air but it can come close.

The free fall calculation will provide the absolutely shortest time for a given fall. It establishes a limit. I calculate the free fall time for an object dropped from the roof of TWC1 to establish that limit and help us put WTC1’s collapse in context with what is possible (with gravity providing the only collapse energy) and what is not.

Ice Skater’s Pleasure: An everyday example of the physics

If you ever ice skated on a pond you probably performed the experiment that demonstrates the conservation of momentum law I use in my analysis.

Remember when you were about seven years old and had a sibling or friend your same size. You both are on the ice. Your friend is standing still on the ice and you are skating up behind him or her going not so fast that you’d knock them down when you contacted them but fast enough to play a game with them. (Fig.1) You skate up and grasp your friend from behind, hug them and the two of you glide off across the ice together propelled by the energy of your momentum alone. (Fig.2)

figure 1 0bf77figure 2 a7c07

You had a speed when you got to your friend and you had a momentum. Your friend’s momentum can be considered to be zero with respect to yours as he or she wasn’t moving. Together the two of you comprised a closed system and that system had a momentum, yours. When you were gliding off hugging your friend, the two of you together had the same momentum you had alone as you approached your friend but a different, slower speed. If you were the same weight, the speed the two of you had after the “event” of hugging your friend would have been half the speed you had just before you grasped your friend. Half the speed, twice the weight, same momentum.

Momentum is conserved

If you had a little brother on the ice and did this to him, the two of you will have glided off after you gathered him up at a speed much closer to the speed you had alone just before you grasped him. If your little brother tried to do this with you, the two of you would have moved off very slowly indeed. He would have hardly been able to move the two of you together. This is obvious to you and you would have said, “Of course! I weigh much more than he does,” the correct reason. Per conservation of (linear, in this ideal case) momentum, the product of the speeds of the bodies and the masses of those bodies must be the same before and after the interaction. If the interacting masses are equal, the speed after the meeting and sticking together will be half the speed of the moving object, the product of these always being the same, the system momentum conserved. If the mass of the moving object is less than that of the stationary object it is about to stick to, the speed of the two masses together after the impact will be slower than if the masses had been equal. The opposite is true if the mass of the moving object had been greater than the stationary object, in all cases momentum is conserved, ideally nothing lost and nothing gained.

As we said earlier, the property of a mass’s momentum alone is represented as: p (momentum) = m (mass) times v (velocity, or for our use here, speed,) and is familiar to physics students as: p = mv.

In conservation of momentum in a before impact and after impact representation, the equation becomes, pi = pf or initial momentum equals final momentum. This is the law of conservation of momentum symbolically presented. It is then also represented as, mivi = mfvf , or the initial mass times the initial speed is equal to the final mass times the final speed. We can imagine the equals sign being the impact event. In the case of the falling floors, the initial mass is the falling mass before an impact. The final mass will be the initial mass plus the mass added during the impact just like the skaters on the pond.

In the interactions that concern us, there are only the moving floor or floors and the stationary floor about to be hit and that they all stick together. These are relative motions, motions relative only to the objects of our immediate concern. Of course, everything is moving with respect to other moving objects. We’re all doing 25,000 mph as the Earth rotates on its axis, for example, but that cancels out since those general motions are the same for all these objects. The laws we’re talking about apply to relative motions of bodies around which one can construct a convenient boundary across which no unbalancing force or mass crosses. The skaters on a pond are a good example of this.
On the ice, you were a mass that had a speed at the moment of impact. In the case of your hugging your same-weight friend, after the impact the mass had been doubled and the speed of the new, doubled mass, will have been cut in half. After you two connected, you glided off across the ice more slowly than your own speed just before contact.

Does gravity interfere with the momentum laws?

This question introduces a variation. Does gravity makes a difference to the conservation of momentum law, perhaps invalidating it, when a body is being accelerated by gravity at the same time the impacts occur?

It does not. Here’s why.

Say that your little brother wants to push you rather than let you skate up behind your friend on your own power. So you stand there and he begins pushing you. At first you have no speed. Then, as he pushes you, you gain a little speed, then a little more. Your little brother—whose nickname is Gee, by the way—pushes with a constant force and you gain speed at a constant rate. Faster and faster you go. As shown in Fig. 3, just at the moment you grasp your friend, Gee is joined by his friend and together they push the two of you. When you grasped your friend, your speed is instantly cut in half. Gee’s friend’s help enables the two of them to accelerate the two of you (the doubled mass) at the same rate as little brother could accelerate you before you grasped your friend. This is graphed in Fig. 4.

In vertical, driven by gravity, interactions like this, gravity instantly supplies the second little brother to help just when it’s needed. Gravity accelerates all masses at the same rate (within reason for our needs…tiny masses compared to the Earth) and conveniently supplies all the little brothers needed the instant they’re needed. This, by the way, is why we don’t have to know the actual mass of the floors. If we know that the floors were all the same, as they were, then it’s sufficient to know just the number of floors that accumulate and stick together as the collpase unfolds all the way to the ground. They or whatever combination thereof will always be accelerated at the same rate. During the moments of mass interaction, things get shuffled and changed. Another way to look at this is to see that a mass interaction happens for a duration of virtually no time and, so, we can separate the action of gravity and what happens during an interaction.

figure 3 e2ca9figure 4 99547Conservation of Linear Momentum

In Fig. 5 the velocity differences between the first pushed skater (undergoing constant acceleration) and the skater who shared momentum with another skater, the two together being pushed as powerfully as the first was alone are shown. At time, T, the single skater would have been traveling at speed V2, whereas if the first skater’s momentum is shared by gathering up another skater (i.e. adding mass,) the velocity of the two skaters at the same time, T, is only at V1. If more skaters are encountered and gathered to glide off together (and more little boys and girls to propel them, one per new skater added,) there continue to be sudden drops in speed followed by increases as before. In such a case, the graph would have a saw tooth appearance with each gain in speed followed by a loss with each new impact and gathering of another skater while the unimpeded skater keeps right on speeding up. That one skater propelled by one little boy would far out-pace the ever gathering line of skaters and skater-pushers.

When Gee pushes you and your speed increases, you will have been subjected to acceleration due to Gee. If this sounds familiar, it may be because you’ve had a basic physics course. Gee is wearing his favorite T shirt under his winter coat, the one that has “9.8m/s2”on the front and “32.174 ft/s2” on the back, the values for acceleration due to gravity, g, at sea level in international (SI) units on the front and in English units on the back. When a body falls at (or near) sea level it gains speed downward at nearly “free fall,” which in English units, is an ever increasing speed per the acceleration due to, g, 32.174 ft/s2 , that is, gaining speed at the rate of 32.174 feet per second (about 22 mph) for every second it is falling. The speed of a body being accelerated by gravity (in a vacuum) is always increasing and always at the same rate. At the moment of impact with another body, the laws of momentum come into play. The fact that the falling body was increasing in speed just before the impact does not change the momentum interactions. They happen at the same time as, and independent of, the effects of gravity.

When dealing with the falling floors of the WTC buildings, we calculate the speed of the falling floor right up to the moment of impact. The impact occurs, mass is increased and downward speed is slowed according to the conservation of momentum law. The impact—the increase in mass and decrease in speed—is considered to take no time. We continue calculating increasing speeds after the impact after the results of the law of conservation of momentum have reset the downward speed. Everything happens in the vertical case the same as in the horizontal case shown on the ice with Gee and his friend pushing as described above.

A graph of your speed profile as you progressed across the pond would show your steadily increasing speed, the instantaneous halving of your speed as you gathered your friend followed by your continued increasing speed afterword as shown in Fig.4 and Fig.5. That increase in speed would be at the same rate as yours was before you gathered your friend. This is what happens when, under the influence of gravity, one floor of a building falls upon the next floor down and that floor is released from its support structure at the moment of impact. The combined floors will be slowed. Then their speed continues to increase from the new slower speed to the next impact with an awaiting floor, and on down the sequence goes. In the end, the slowings all add up and this sum is significant.

The physics as it applies to falling bodies

The closest representation to the falling mass of a top-down collapse of a building is the case shown in Fig. 3 and graphed in Fig. 4 and Fig. 5. A falling floor or block of floors impacting a floor further down will “stick to” that floor by resting atop it. From there, the assembly of floors—if there was enough energy in the first falling floor to tear the second away from the structure holding it up (an energy-absorbing action that will also slow the whole event down…to an unknown extent so I don’t include it in my models)—will fall leaving the impact site at a velocity that is slower than that of the falling floor or block of floors before the impact. As floors fall they will, in an imaginary scenario, gather more floors as the building continues to collapse. At each interaction or impact, mass is gained per the basic conservation of momentum relationship and speed is lost. Between each impact, the falling floors gain speed normally as they are accelerated by gravity, g. The overall result is a collapse that must be slower than the length of time the roof, for example, would take to fall to the ground alone or the time it would take for a rock dropped from the roof to fall the same distance.

Note that the tearing away of the floor from the support structure will further slow the collapse. This is because that action takes energy away from the collapse/event, away from gravity if gravity is providing the only event energy. The support structure resists the impact and eats into the collapse energy. The stronger the support structure, the more energy it takes away from the gathered floors falling upon it. Imagine a support structure strong enough to fully resist the falling block of floors. This would stop the collapse. Every real aspect of such a collapse slows it down, the question is: how much?

A Look Ahead

Perhaps you are now asking yourself how, then, could the collapse of the WTC towers have happened so that they fall essentially in free fall only due to the force of gravity? Something here just doesn’t fit. Mass just being in the way slows an impact sequence, and critically as we’ll see through the lens of the models. If it looks like this event would have had to have been quite the complex dance by whatever mechanism or influence that could cause it, then you are seeing what is happening here.

Where did the extra energy come from required to break the strong connections between the floors and fold up the structure holding all the floors in place? How did the top 12-floor block of WTC1, for this example, fall so quickly? Physics suggests—and we’ll show—that the mass below that falling block simply could not have been there when the top block fell apparently on top of it. And another question follows: how did that event-slowing, uncontrollable, wants-to-tilt mass below the falling block move out of the path of the falling block so that it was not there when the falling block came down, and especially without anyone recognizing that that was happening?

In reality, an impact is a complex happening

Bodies distort, sound waves are set up, the bodies heat up as energy is exchanged and dissipated, bodies are broken up, some reduced to dust, material absorbs some of the impact energy elastically and releases it throwing pieces of broken materials up, down and everywhere, steel beams are bent absorbing collapse energy and more. All those small interactions, especially the pulverization of concrete and the distortion and breaking of materials and the throwing of materials other than straight down, will absorb energy from the interaction and, if gravity is the only energy source as is claimed by NIST, then that energy lost to do other work of the collapse energy will slow the collapse. Note that bodies also heat up as energy is exchanged and dissipated. That is discussed below when we look at what happens to kinetic energy—the energy of a moving body—in these interactions.

The simplifying assumptions and Critical Thinking

Initially I had critical thinking as a separate bold item. This entire analysis is the application of a series of critical thinking techniques. In general, critical thinking is the backing away from an interest to view it from a broader perspective. Critical thinking stems from an attitude and intention to do independent research regarding that interest to establish context within which the interest is couched.

In the analysis of the collapse of WTC1, we are met with assertions about the collapse by a trusted authority, NIST, and we wish to examine these assertions. One is unquestionable: the near free fall time of the collapse. The other two I listed are available to be tested using critical thinking techniques to see whether or not they are consistent with what we know to be factual about the collapse, the rapidity of the collapse.

A short list of critical thinking applications used in this analysis will include the establishing of fall time boundaries, the fastest possible and the slowest possible. The simplification of the building to enable a simple mathematical model to be designed and tested and compared to the actual collapse is another critical thinking technique. Directly below we will examine the two ways to establish the fastest time to collapse for WTC1 and what I call the “slowest complete collapse” which was done by an independent researcher and published as “The Billiard Ball Example” and is also described below.

I have combined simplifying assumptions and critical thinking here because almost all of my critical thinking techniques involve simplifying assumptions.

In order to do the analysis we make simplifying assumptions. The rule is that no simplifying assumption that can slow the model collapse is allowed, only those that will enable it to happen faster are permitted. Because the support structure is so hard to model (because of its complexity,) and though it would, due to its great strength, slow any collapse, we eliminate that structure and float all the building’s floors and roof in place above the ground. We run this model to see what it can teach us about how these collapses can and cannot happen. We run a model like this as a critical thinking exercise, an exercise.

It is assumed that the structure does not slow the collapse and we proceed handicapped in this way to see what it might teach us about these kinds of collapses. In this way we will establish more boundaries within which the real collapse must happen. Let’s establish the fastest time to fall from the roof of WTC1 not including the radio mast. It’s a simple calculation of an ideal event that we’ll work out just below.

Recall that the height of WTC1, d, was 1368 ft., that there were 110 floors and they are taken to have been evenly distributed in the building, 12 ft. apart (with a mezzanine at the lower floor we won’t consider because, by the time the falling material reaches that low level, it’s moving so fast the consideration yields very little time difference in the fall.) We wish to know the shortest time for an object to fall from the roof of WTC1. If one distrusts formulas, as I do since I didn’t derive the formula, one may start with what we know about objects accelerated by gravity. They gather speed straight down at 32.174 feet per second every second. Making a table, it’s fairly easy to figure out how many seconds it will take that object to fall that far (at sea level.) It turns out to be about 9-1/4 seconds interpolating on the table. I did this but using the formula is more precise and easier.

The formula for this distance to drop is d = 1/2gt2 where g = 32.174 feet per second per second. Rearranging the elements of the formula we find that t = (2g/d)0.5 or time to fall = the square root of 2g divided by d. The answer rounded back to three places is 9.222 seconds. This is the fall time for an object falling at sea level a distance of 1368 feet in a vacuum. In air, the resistance of the air would slow the object somewhat pushing the time out to be closer to 10 seconds. To be as fair as possible, we’ll use the 9.222 seconds as our fastest time to fall that distance. Remember that any object falling in a vacuum as above will take that time, a feather or an anvil, the floor of a building or anything else that is small compared to the Earth.

The Billiard Ball Example is a similar critical thinking exercise and shows us a time that the collapse might not be longer than provided it did go all the way to the ground and didn’t run out of energy part way down. The BBE generates a fall time of about 97 seconds. The model has the top floor, represented by a billiard ball, falling and causing the release of the next floor/billiard ball down as it passes it. That next floor, then, does not have the push from the impact of the upper falling mass. This generates a time that, if the collapse went all the way down (something that is not entirely certain, but, just saying…) might be termed a simplified “slowest complete collapse.” It is an important member of the critical thinking exercises available to us to help us corral the collapse events as we examine what can and what cannot happen in such a collapse.

The fastest collapse requires that all the falling mass land within the building’s “footprint”

We assume, for the first calculation, that all falling floors coming down land within the building’s “footprint.” We assume that all of the falling material lands on the lower awaiting floors so all of its momentum can be shared. If falling material misses the floors below, something that can be seen happening abundantly in videos of the WTC collapses, that material’s energy of motion cannot help power lower floors downward and the fall time drifts toward the BBE end of the timeline.

For my third calculation we add in the real complication of mass falling wide of the footprint of the building. Dr. Gregory Jenkins calculated that in the end of the collapse of WTC1 and WTC2, half of the material did, in fact, not land on the lower floors but was thrown wide and had missed. In videos of the WTC1 and 2 collapses you can see this happening as material falls outside the buildings’ walls.

For our purposes we will evaluate imaginary impacts in which we make some assumptions that enable us to calculate that simplified interaction. All assumptions are made in favor of a faster collapse. Again the greatest simplifying assumption is that there is no support structure and that all the floors are floating in space waiting for floors falling from above.

This is a race. We want to see if our faster than real life collapse will beat the actual collapse to the ground. If it does, then the real collapse could—maybe, and it’s still a huge maybe with all the rest of the energy sapping things that happened—have happened as fast as it did with gravity as the only energy source.

If, on the other hand, no matter what we do to make it faster, our model collapse following the laws of physics we’ve discussed always comes out slower than the collapse as it actually happened, the real collapse would have to have had energy added for it to have happened as fast as it did. If this is true, then there is a fundamental problem with the NIST explanation of the WTC1 collapse.

What about kinetic energy?

Kinetic energy is the energy of a mass in motion. It is similar to but different than momentum. We can keep in mind that this relationship was discovered by experimentation. Those experiments’ results are modeled with “the math” that describes it. If we look at the math we can predict what will happen. Kinetic energy is related to mass (weight) and velocity (speed) as described by the formula: K = ½ mv2. Notice that it’s a function of the square of the velocity. If the speed of a moving object is cut in half and its mass is doubled, its kinetic energy will be cut in half. Momentum is conserved but kinetic energy is not. In these impacts, critical energy needed to keep this process going is lost. You can work through that simple formula to see how it goes.

A floor falls and hits the next floor below it. The speed of the event is cut in half when the mass of the event is doubled. When there was one floor falling and being accelerated by gravity, now there is twice the mass (one floor “stuck to” another) and they are traveling downward starting at half the speed of the single floor the instant before it struck that next floor down. Momentum is conserved but kinetic energy is cut in half.

So what happens to the other half of the kinetic energy? Have we destroyed energy? That cannot happen so, no, we haven’t. Tests show that the rest of the kinetic energy has been turned into heat. That heat is distributed through all the materials involved in the impact which warm up a little and is radiated into the air and surrounding structure. It is quickly distributed and lost to the event elements. The heat is energy that is lost from the moving event and can’t be used to continue the event. The bodies continue to fall. As they do, they gather mass, lose speed, gain it again by acceleration due to gravity between impacts. The event continues to lose kinetic energy at each impact. The kinetic energy lost in each interaction in this case is energy that can only come from that given it by gravity. It is energy that the moving mass had but has been lost to heat in the impacts. The loss of this energy is in keeping with the slowing of the collapse per conservation of momentum requirements. Again: as a mass falls, it gains kinetic energy, energy available to impart to an object it hits as it falls. The impact slows the event per conservation of momentum requirements and heats the colliding objects essentially turning kinetic energy given them by gravity into waste heat. As far as the kinetic interactions of the colliding bodies go, that energy is lost and our energy and momentum conservation accounting sheets are balanced.

As an example, when snow falls down a mountainside in an avalanche, it gains kinetic energy as it accelerates but when it comes to a stop, it heats, the heat melts the mass to some extent and when it cools it solidifies into a more dense structure, closer to ice. This result is one of the things that make it so hard to recover people caught and buried in the avalanche. The same thing happens when a snow plow pushes snow aside to clear a road. The snow is energized by its velocity as it is accelerated by the plow. When it stops moving, its kinetic energy is turned into heat warming the snow mass. The heating changes the snow’s structure and as it cools it changes into a harder mass. A pile of snow newly placed there by a plow is easier to move than it will be a half hour later after it’s re-cooled. If you are a snowmobiler you’ll know that when you’ve run off the track and are bogged in deep powder, you must right the machine and then trample (I use snowshoes) a track for the machine to use to get going again. But you have to wait for it to “set up” so it’ll support the machine. It takes about 15 minutes for your trampled track to set up. These physics are going on around us all the time. We just rarely pause to think of what’s happening to notice and appreciate the aspect of the universe being demonstrated to us. If we wanted a stronger snowball to throw at our sister and her girlfriends, we should have made it ahead of time and waited for it to strengthen enough to stay together. Fortunately for all concerned we usually hadn’t figured that out and if we did, we usually didn’t understand why…or needed to, it just worked.

A collapse cannot afford to lose any energy of motion if it’s to win the race with an object undergoing near free fall like the dropped rock. This lost energy is another way to account for the effects of conservation of momentum in these impacts. We now can see where the energy is going and understand better why the gathered/impacted masses slow down.

A note about the fastest collapse possible

NIST tells us that WTC2 the South Tower, which was the same height as WTC1, collapsed “in about 9 seconds” suggesting perhaps between 8.8 seconds and 9.2 seconds, a reasonable margin, I think. You can now see that this is not possible. It has to be more than 9.222 seconds even without the support structure resisting the collapse slowing it and increasing the time to fall. NIST tells us that WTC2 may have collapsed in less time that a rock dropped from the roof could have fallen even without resistance to air considered. This cannot be correct but the observation by NIST that WTC2 fell “essentially in free fall time” is and we now see that there is a critical problem with this.

My first simple analysis

My first model was very simple and was done to give a general idea of how the mass impacts would tend to slow the collapse. During this modeled collapse, no mass is lost to the collapse. It all stays within the building’s footprint and helps drive the event down.

The model collapse is done by considering only mass doublings which makes for only a few calculations easily done by hand. It starts from the top block of 12 floors which, as we saw on TV and now in videos, fell as a 12 floor unit, the failure happening at floor 98 where the aircraft hit the building.

I move imaginary floors downward within the building to rest atop lower floors waiting for upper floor stacks to fall. The block of 12 floors falls onto the second block of 12 floors 11 of which I lowered 12 floors down or 144 feet to make the waiting stack of 12. (No floors are ever moved upward.) When the first block of 12 floors hits the second, mass is doubled and downward velocity is cut in half per conservation of linear momentum (in inelastic interactions…things that hit stick together) requirements. We now have a block of 24 floors moving downward at half the velocity that the first block of 12 had when it hit the second stack of 12 floors.

I next move the next 23 floors down 288 feet to make a stack of 24 to wait there for the now falling block of 24 floors. Gravity speeds the falling accumulation of 24 floors. The impact doubles the mass (the number of floors accumulated at that point) and halves the arrival velocity. Next, the now 48 gathered floors fall to meet the next 48 gathered floors waiting 576 feet further down. The 48 floors gain speed for this long drop and the impact with the awaiting 48 floors halves the downward velocity per conservation of momentum requirements. In reality such impacts would shatter floors and cast material wide of the building’s footprint robbing event energy but this is a simplified model ignoring such considerations.

The last drop is to the ground. It is a drop of the roof of the original block of 12 plus the remaining floors not yet hit by the falling block. The block has not been damaged during the fall and is still 144 feet tall. The distance from the roof to the ground is 312 feet. We do not consider any consequences in what will otherwise have to be a “crush-up” event of top block. For our analysis we allow everything to come down at free fall that last 312 feet. Here it is as though all the floors beneath the roof of the original block of 12 floors had vanished. The roof falls at free fall and is not slowed by any resistance to its advance. The total time to fall for the whole building is the sum of the times for all the drops.

The lowering of floors like this, the 12 then the 24, then the 48 etc., is a gift to a faster collapse and is another CT technique. To show this, let’s do the following thought experiment. Imagine if a floor were moved all the way to the street level. This would be an even greater gift to a faster collapse because the moved floor would never be in the way to slow the collapse. There are 3 doublings possible in this model collapse, and 3 halvings of downward velocity plus the 312 feet of distance remaining to the ground. The total calculation of this faster-than-reality collapse results in a collapse of 13.31 seconds. The free fall of the roof of the block of 12 floors the 312 feet is obviously faster than would happen in reality because we really have removed all the floors below the roof all the way to the ground for this last drop so the roof is free to fall that last distance unimpeded. This means that, in this model we have not considered the mass of almost a quarter of the building.

Again this is not a collapse that mirrors what we see in the videos of the WTC1 collapse. It only tells us something about what can and what cannot happen in such an event. It gives us a better idea of what we’re dealing with. We are corralling the actual event. We might not be able to tell exactly how fast the building should have fallen but we will be able to narrow the range greatly and tell what could not have happened. A real collapse of WTC1, gravity the only collapse energy source, could not happen faster than 13.3 seconds if all the floors were in place during the collapse and, in fact, because we’ve made so many concessions to a faster collapse, could only happen even more slowly taking more time.

I could have stopped here. My thesis is proved. The buildings had to have extra energy added, energy needed to remove all the mass and structure between the bottom of the block of 12 floors ahead of that falling block and create all the dust we saw as well as throw beams 500 feet across the street hard enough to be embedded deep in buildings there, etc. NIST’s explanation is incorrect. But there is more we can do with our simpler-than-reality, models. There is more fun to be had.

My second model

The next analysis was with the 12 floor block hitting and gathering all the floors below it in sequence to the point where the block of 12 floors is sitting on the ground but with the roof still 144 feet from the ground. This model generates a collapse of about 15 seconds to that point. At that point the block is moving very quickly so, ignoring the resistance to collapse that would surely have been presented by the structure holding the 12 remaining floors in place, would have added about a half a second more. This, too, is not trivial. The total collapse time using this model is, then, about 15.5 seconds.

My third model

It should be clear by now that there’s no way the tallest buildings, WTC1 and 2, could have fallen as fast as they did with gravity as the only energy supplier provided all the floors were in place during the collapses. But there was one aspect of the collapses I want to add, that is that, in total, half the falling material was cast wide of the footprint of the building and, so, couldn’t have participated in the collapse of the building. This aspect of the event, some of which we can see happening in the videos, will further slow the collapse, but by how much, a lot or a little? Because Dr. Jenkins’ assessment was carefully done, this is something we can add in to our simple models.
For this presentation, I did this by hand. It was a long process and is still inflexible in that it’s too hard to modify anything and do additional model runs. It will be more sensible to do this in a computer model like Excel. At this writing, I have only the approximate collapse modeled in computer, the result of which is included in appendix C. It shows how such a collapse must happen as described earlier but without the addition of steady mass loss during collapse. That modeling is a future project.

I collapse the imaginary building starting from the 98th floor without moving any floors down—calculating for every floor as the falling block would have met it—and I remove material steadily as the building collapses so that at the end of the collapse half WTC1’s material will have missed the floors below. There are 98 levels to calculate and four calculations per level. I will not calculate or model the collapse of the roof in the “crush up” phase because there are too many unknowns in the collapse of those first 12 floors. I’ll carry the roof down to the ground as though the floors below it were not there and would not slow its progress. After all, the block of 12 floors would be traveling quite fast by the time the 98th floor reached the ground. From the above model, we know that it will take about half a second (in this case, a little under half a second) for the roof of the block of 12 floors to travel the last 144 feet ignoring crush-up resistance to collapse.


Below are details I came to appreciate as I dug more deeply into the collapse analysis that I think you will ask about as I did. Some are peripheral and just interesting. Others apply directly to our inquiry.

Why we don’t need to bother ourselves with the sizes of the floors

This is because gravity accelerates anything at the same rate regardless of its mass. We assume all the floors were the same weight/mass. They were massive and all built the same and anything placed on them office-style would not appreciably add to their mass. Also many of the floors were unoccupied at the time of the collapse, the floors being bare. We ignore air resistance for these analyses which would only slow things down. We only need to know the height of the building, the number of floors, their placement or location in the building and that the floors can be assumed to be all approximately the same mass.

If conservation of momentum is violated by the formal story, are other physics aspects of the collapse also violated?/ Here are a few aspects of the collapse of WTC1 that also violate physics as well as a parallel example of the collapse of the small upper block of floors and structure onto the larger block below it. We know it was less strong floor to floor than the structure below but not because it was smaller. The WTC buildings were built such that the top most structure was lightly built, only needing to support a few floors and more robustly as one goes further down the building. Each lower floor’s columns have to support everything above it. The thickness of the steel box beam columns at the lowest floors of the building were massive indeed with steel 4 inches thick all around to make up the box-beams. At the top they were much thinner. That the buildings were cantilevered structures with respect to winds is considered just below. This also dictates that the structure be stronger the lower down you go.

How strong was the 12 floor block that drove WTC1’s collapse?

The structure’s wind resistance and construction safety factors/ The buildings were designed to withstand 145 mph hurricane winds. Additionally, they were designed with a standard-practice 3 to 5 times safety factor over that needed to actually survive those winds; the buildings were strongly built. This makes the buildings a cantilever firmly fastened into the ground causing the structure to be most lightly built at the top and stronger as one descends in the building just as with the requirement to hold sequential floors up as one goes down in it. The blow dealt the structure below floor 98 of WTC1 by the upper 12 floors (if it could happen, see below,) would be a little like a Tin Lizzy hitting an eighteen wheeler.

The “hammer” blow

Note: Someone raised the question about whether a hammer blow could shatter the supporting steel structure throughout the building. I present this in greater detail in Appendix B discussing impacts with steel at relatively higher velocities such as when nails are driven either by a hand-held hammer or nail guns and in automobile accidents. For now, let’s stay with the small car vs truck example. Appendix B inclusion is the result of input from one of my checkers/readers for this paper.

The 18 wheeler is going to be damaged but the more lightly built car far more severely yet we see the heavily-built lower structure being demolished apparently by the more lightly-built, falling upper structure. One should ask, “What’s with this?” Below, this example is explained a little further. Newton’s third law, the action/reaction law says that the lower block will hit back as hard as it was hit and we know it was more strongly built.

Watch the videos of the WTC1 collapse. You’ll see that the top 12 floor section comes down with no visible damage done to it while the lower structure falls away like it’s offering no resistance. There’s something wrong with this as there is with almost everything else about this collapse. The same applies to the other collapses, WTC2 and WTC7 but for slightly different reasons.

Another way to view the falling block of floors hitting the lower structure of WTC1

Exercising another critical thinking technique, imagine an accident between a fast moving truck and a stationary car. The truck is ten times the size of the car and more robustly built. When the truck hits the car, the car goes all the way through the truck, flattening the truck front to back piling it against its back wall! There is something wildly wrong with this picture, but it’s what we see happening with the collapse of WTC1.

The above is the description of the collapse of WTC1 with a simple legal change physically. Instead of having the car (upper block of 12 floors) hit the truck (the lower 97 or 98 floors,) I turned that around and have the lower block hit the small and more lightly built upper block.
Physically it doesn’t matter which mass is moving, the car or the truck, the small, lightly-built block or the massive lower block anchored to the ground, the results are the same. If you are sitting in the car and have no other references and can’t tell it’s you and the car that are moving, it appears that the truck is moving. If you’re in the truck with the same restrictions, it seems as though the car is moving.

Here is a perhaps stranger but equally valid comparison. If a body is moving at 4000 feet per second, the muzzle velocity of a high-power rifle bullet, toward a bullet suspended in the air, and the air is moving with the body, the resulting impact will be the same as if the bullet is moving toward the stationary body and through the stationary air; same thing, same result. So if it seems to be ridiculous that the car can blast its way right through the truck—which is far more massive and more sturdily built—why do we accept that a more lightly built block of 12 floors can collapse the more massive and more sturdily built lower structure right to the ground? Even if we ignore the relative strengths of the structures themselves, the very mass of the objects deny that result. Both structures will be damaged, the car much more so, being the more lightly built…and the event won’t proceed far. That the top 12 block of floors can hit and crush the lower, more massive, structure and remain undamaged defies Newton’s third law. That lower structure would have hit back just as hard as it got hit…if it could have. It didn’t. Why didn’t it? There’s a reason. This question might be the most important of an inquiry into the events of the WTC collapses on 9/11.

If you’re feeling the confusion and discomfort called cognitive dissonance considering these rational collapse elements discussed in the context of NIST’s answer to FAQ #11 with which we began this exploration, it’s because you may have not yet come to recognize that NIST is either incorrect or insincere in its answer to that FAQ. NIST, for me, an engineer, was the gold standard of all things engineering and scientific as I was growing up in an engineering family and as I earned my engineering degree and also through my career as a designer (basically doing applied science, each project a physics experiment.) I’d never have thought to question the NIST. That is partly why it took me such a long time (3 months) to finally believe what my own physics analysis told me was actually the case.

Acceleration by gravity is an energy starved process

Gravity can only accelerate an object as fast as it can and has no extra energy to do anything else. It can’t accelerate it faster (or it would) and it especially can’t maintain its rate of speed increase and do extra work on the mass it is accelerating at the same time. Its energy is already fully occupied, already being fully expended the moment it’s available. If the falling mass must also accelerate more and more mass as it meets unfallen floors within the confines of the building’s shell, the exterior of which is all we can see, energy will be stripped from gravity to do that extra work and the cost will be seen in the collapse time; it must stretch out.

What was going on inside WTC1?

We were not seeing what was happening inside the building. There, mass had to have been cut away and dropped before the event front reached it to allow a collapse from the top down that happened “essentially at free fall.” This leaves only the shell to be accelerated. Even that relatively light structure had to be accelerated and that did slow the event a little, and even that process was quickly hidden from us as the cowl of mass falling alongside the building fell just a bit faster than the event and shrouded it. You can see all this happening as you watch the videos of the event but you have to know what you are looking at. The building didn’t fall exactly at free fall, but a little more slowly, and only a little because it wasn’t encountering much mass, just the already empty shell. Real floor to floor interactions would have slowed the collapse way down and that’s only the start of the things that would slow the event and distort it. Looking at the models now, I’d like to suggest that without massive additional energy added to control and basically enable every element of the collapse of, for our purposes, WTC1, the collapse wouldn’t have continued to the ground and, in fact, wouldn’t have gone much of anywhere at all. …Actually, if there were no other means to collapse WTC1 but the damage done at floor 98 and the fire, because of what I know about the thermal aspects of structural steel, discussed next, I think the fire would have smoldered and gone out and nothing would have collapsed.

Strength of structural steel vs temperature

Steel softens as it is heated. A curve that includes the strength of structural steel vs its temperature is attached at the end of this write-up and included in Appendix E. Look at the green curve (structural steel) and think about what you see in the videos of the moment of the start of the collapse of WTC1. We see an abrupt, uniform failure all around the building and the top structure coming straight down suddenly onto the lower section. For this to happen due to weakening due to heating at this scale we’d need a broad region in the strength vs temperature curve that predicts a sudden loss of strength. If that’s not there, we’d see the structure weaken as it warms and settle slowly down onto the structure beneath. That would be for an absolutely straight down collapse. But there is no such broad region of instability and unpredictability of strength vs temperature in steel’s physical characteristics.

A straight-down collapse is almost impossible in reality

The about-to-fall upper block would tilt and then tilt more and tumble…if it were able to break free. More realistically, it would tilt and settle and the fire would go out leaving a cocked 12 floor hat on the still standing 98 floors. We do see this beginning to happen to WTC2. Watch the first part of that collapse. What then happens to that building is absurd; it vanishes into a cloud of dust. What would produce such a cloud? That top should just have fallen over and landed in the street below leaving the rest of the building standing.

More realistically, since the building was damaged asymmetrically, the aircraft entering one wall obliquely and off-center and exiting not straight through the building but out an adjacent side (https://www.youtube.com/watch?v=h3shmfKOZ9g), we should see an asymmetrical collapse with the weakest area failing first, tilting the falling block. In all cases, the steel softens slowly. There is no abrupt (or broad or confusing or odd) change anywhere in the strength vs temperature curve of the steel. The steel heats from room temperature and actually gains strength for a while. Then that strength falls back to its room temperature strength at about 700 degrees F and then falls off from there smoothly and at an even less steep rate as it warms further. Any failure would have happened gradually as the steel heated. It doesn’t suddenly lose all strength but that kind of thing is what we see happening in the videos.

The chaotic nature of fire at the human scale

At sizes with which we are most familiar, the sizes of our bodies and an order of magnitude on either side of our scale, fire, for example, presents as a chaotic event. Flames flutter. Air currents tumble. Unless the flame and fuel feed rate, flame shape and other parameters are carefully controlled, such as in a jet engine, the flames will heat unevenly and inefficiently. The fuel that burned was distributed in the building unevenly owing to partitions and the off-center and oblique and tilted nature of the aircraft’s trajectory and destruction. Some fuel, we were told, flowed down to lower floors. And it has been estimated that the fuel could have burned for only 6 minutes or so. If distributed evenly across the acre of floor, something required for an even heating of the columns, it would have been less than 3/16ths of an inch deep and such an even distribution is not possible given the partitions within the building on each floor separating offices . Also consider that the fire, such as it was, was only on the inside of the building. The outside of the building’s structural shell was not being heated. Any flames there would have disbursed the oozing smoke we did see.

A smoky fire is a cool fire not a hot one

This you really can try at home or you may already be familiar with this from camp fires and cook-outs. A hot fire is a bright and vigorous one and little smoke is produced. Take a look at the videos and note the lack of visible flames and the abundant smoke drifting from the building. This presentation does not make a convincing argument for a hot fire. For comparison look at the Windsor Tower Hotel, Madrid, Spain, fire in February, 2005. There are videos and images of that fire on the Internet. Here’s one: https://www.youtube.com/watch?v=SSybd_kLctE And another: https://www.youtube.com/watch?v=eKvgD9NyIi4 The images seen here show a hot fire. The Windsor Tower Hotel burned fiercely for 17 hours lighting the Madrid night sky through the night. Notice the lack of visible smoke and the abundant sheets of nearly white flame. This building, a similar structure to the WTC towers, did not collapse due to that fire.

Pool anyone?

Our model is simple because everything happens in a straight line as dictated by gravity, something, by the way, that is hard to achieve in reality. Try this on a pool table. It’s hard enough to hit a single object ball with the cue ball and keep everything going in a straight line. The hit has to be precisely on that straight line. Hitting two balls such as in a combination shot is harder still and hitting three, well…. And this is with billiard balls, a simple situation. An acre area of floor must fall precisely flat on the next floor down in order for the next floor to be driven exactly straight down and not rotate or tilt some. In the collapse of WTC1, this precise sequence of impacts has to happen 98 times in a row, perfectly or the collapse tilts then tilts faster and further. This is so unlikely that demolition professionals always positively control the collapse. That method is called “controlled demolition.” Controlled demolition uses energy carefully with carefully timed explosives and cutting charges to bring a building down in a safe (controlled) manner. If it’s not carefully controlled, the likelihood of it going astray is high. Just take a look at videos of failed controlled demolitions on the Internet. It’s easy to screw up a building demolition even when explosives are used. That a perfect collapse should happen completely uncontrolled as we are told by NIST is more than a stretch.

A third building fell that day, one most don’t know about: WTC7

WTC7 collapsed at 5:20 that same afternoon. It was a shorter and broader structure than WTC1 or 2 and collapsed in just over free fall time. NIST reports that it fell because of a few office fires ignited by falling debris from the WTC1 and 2. No aircraft had hit it.

Some of that collapse was timed from a frame to frame visual analysis of the collapse using videos and finding a clear location on the building as a marker, work done by David Chandler. The beginning and end of the collapse were slower than free fall but the major part of it was at free fall. NIST did a partial computer analysis of the collapse. Their modeled collapse covers only the initial phase. It does not go to completion. A PhD student computer lab team lead by Dr. Leroy Hulsey at the University of Alaska in Fairbanks has completed a full finite element analysis of that collapse. Their study of the NIST work using the drawings of the building has already yielded good information about the collapse. Their project is illustrated in the film, “SEVEN.” Their work may be found from this website: www.WTC7evaluation.org.

Another way to think of the WTC1 collapse: Mr. Li’s urban renewal idea

Some of this is true. I have a friend in Singapore. His name is Yan Wong. He went to England for his architectural studies and met his wife, Sheila, there. His firm designs large public buildings like city halls. Yan has a friend in Shanghai, China, where Yan also has relatives. I know him as Mr. Li. Mr. Li is a successful industrialist and had a replica of one of the tall WTC buildings made for his company built in the mid to late 70s. For a while he had luxury apartments for guests on one of the upper floors. After 9/11, customers told him they were afraid of entering the building because it had been shown to have serious design flaws regarding fire safety. This has become such a problem that Mr. Li plans to have the building replaced with a safer and more modern building that his customers will enjoy and that will enhance his business. He sent out for quotes to traditional controlled demolition companies.

The quotes to demolish that building in the traditional way as has been done for over two hundred years came in at over a million dollars. A sharp and innovative business owner and engineer, Mr. Li thinks he has a cheaper way to bring his building down. He had seen it all on TV. He’s planning on having some columns at the 98th floor damaged (or removed entirely) as they were in WTC1 on 9/11, load some 5000 gallons of kerosene on the floor—that fuel will come to a little under 3/16 inch deep spread over the acre of the floor, distributed uniformly to produce a uniform fire all around—and set it alight. He expects to watch the building fall straight down in under two hours as happened on 9/11. He figures he can have the building brought down this way for less than 100,000 US dollars. “It worked beautifully in New York,” Mr. Li is quoted as saying. “New York, Shanghai, there’s no difference. Steel is steel everywhere. It will work just the same and it is much cheaper, straight down, completely safe.” He also noted that he is now surprised that controlled demolition companies still can do business the old way, with explosives. “This is so cheap, I am surprised that I could even get quotes,” he said.

Yan asked me if I’d take a look at Mr. Li’s idea. What do you think? How do you think Mr. Li’s project is going to go?

But we saw the building come down all the way

We didn’t see all of what happened. It’s important to realize that we were told what we were seeing by a trusted authority and what we were told was incorrect intentionally or otherwise.

In my opinion we saw a closely directed and narrated theatrical performance, a carefully arranged, awesome and horrific magic act. It would be the equivalent to being told that seeing the car plow through the truck was true while actually the truck’s innards had been cut up and dropped out of the way so the car could make it all the way through what we were told and believed to be a solid truck undamaged, much as we see the block of 12 floors undamaged as it descends “through” the lower building collapsing it. We believed what we saw because what we saw was so far out of our experience, so we turned to trusted others to explain it.

I’d certainly like to have your feedback as to how my presentation works for you and your ideas of how to improve it.

I’d come to you through others as I was trying to find out why journalists have ignored what I think is the greatest news story this century. As I have been saying, though this has been a long presentation, it’s the words that are the problem, their linear nature, not the subject itself. Anybody who has ice skated would understand what I’ve presented instinctively. Perhaps they didn’t think to apply it to the events of 9/11. Perhaps they were too automatically, naturally, subconsciously frightened to do so. But I don’t believe journalists didn’t know or couldn’t figure 9/11 out fairly quickly. The question remains, however; why the silence? How did that happen and how has it remained? I’m thinking this is an important story and not a pretty one. What else could I think but that the media have been muzzled about 9/11? I wonder how that could happen in America today. Thinking that leaves me sad. You have my long-winded, half a physics lesson proof before you. Please take it to your favorite physicist to check it out. Let’s see what she says. If you and she can refute it, I need to know that refutation. I need to see the counter arguments, but I don’t think they exist. I think we’re staring at a monster so big one has to back away from it to get a glimpse of the whole breathtaking thing.

I’m sure there are lots of state’s secrets that enable us to survive in a world few understand well enough to be safe in it. I think everything we see has a temporarily cobbled-together back-room deal yielding a bride-perfect, happily ever after showroom presentation. Perhaps this is one of them, but if it is it is a horror. As I said, if it is, a new 9/11 can happen anytime and anywhere, limited only by the imaginations of the horror’s creators. Some have argued that the events of 9/11 that I’ve analyzed above show that the very Constitution of the United States is at risk. I can see that argument but I’m not a good enough student of history or government to understand it well.