# Kuttler's paper: Estimates for time to collapse of WTC1

I suspect that qed's 'level of understanding' of the higher physics in that paper is no higher than my own.

The paper is not higher physics. Nor is Tony's. They are both really simple. Very little math at all!

The paper is not higher physics. Nor is Tony's. They are both really simple. Very little math at all!

Should be easy for you to produce your own paper then, showing where they have both been going wrong.

But of course that would be unfair to ask of you.

Should be easy for you to produce your own paper then, showing where they have both been going wrong.

But of course that would be unfair to ask of you.

No its not.

But only in the same "journal".

Ok.

The first two models in the paper fall within the quoted estimates, so they agree with progressive collapse.

So that leaves only the third model which includes the energy required to smash through the floors.

From my reading of page 6, this energy is calculated as the energy required to pulverize a slab of concrete lying on an immovable surface.

The value that should be used is the value required to crack a slab of concrete lying on the metal floor linkage. This is the value E1 in the NIST report.

But what is your response to my objection.

But of course those 'others' would then have to give you the ammunition to demonstrate that using realistic assumptions, the standard calculations would confirm the official fall times. You imagine a strawman that doesnt exist. Its a logic consequence of the first part. You can't just say something is wrong without proving that claim.
If Kuttler's paper is found to be fundamentally flawed, then there's no reason to expect it to give a correct prediction/expectation. Isn't that right? If it happened to match up to reality, then all you can say is "happy coincidence." If it didn't match reality, then no claim of discrepancy can be made on the basis of his calculations.

Done. All that's needed is to show Kuttler's work to be sufficiently flawed to render discussion of his paper moot. There's no need to go beyond and produce some 'standard calculations' to confirm the official fall times. It could even be impossible to do so and yet it would have no effect on the legitimacy or usefulness of Kuttler's work, which stands or falls on its own merit. It remains to be seen whether Kuttler's work can be dismissed, but your goalposts are positioned such that it won't matter if it is. You are the person who introduced Kuttler's work and appear to be one of two saying it's worth consideration. The work of showing his model inadequate would carry no reward to the person doing it other than satisfying themselves that they can indeed type what's on their mind.

I would suggest that you don't waste all our time regurgitating JREF input in here ...
Why not? If a post or thread at JREF involves a satisfactory analysis leading to refutation of Kuttler's paper, why shouldn't it be admissable? Why wouldn't it be sufficient? If a linked analysis is correct, it's reasonable to expect that a correct analysis independently performed here would have overlapping elements, if not be virtually identical. It seems not only are you rejecting counterarguments out of hand but are petulantly demanding someone whip up the same three course meal for you right here. So you can send it back???

The JREF link to Dave Rogers' post contains a counterargument to Kuttler, and Dave Rogers presumably has a PhD in physics. I think the proper thing for you to do is refute Dave Rogers' counterarguments before asking someone to jump through any hoops. If you can't, we're done.

Having said that, I can make a much better argument than Rogers (as is typically the case). At this point, I see no reason to expend the effort.

But what is your response to my objection.

Forgive me, but didn't people in here spend much time claiming that his first two models were based on unrealistic assumptions and were therefore to be discarded. Mick even said that - quote -" I introduce absurdity because it is absurd."

But you now wish to accept his 'absurd assumptions' in the first two models because they enable the calculations to almost agree with the official fall times, despite them being absurdly unrealistic in ignoring column resistance in the calculations, and assuming absurd 'floating' floors.

Then, when he introduces more realistic assumptions you wish to return to some kind of 'pancake' event involving just the progressive cracking of slabs, and ignore the enormous cloud of dust all over Manhattan. Surely, if NIST used a value only sufficient to crack a slab then that is also unrealistic, as they would be ignoring the massive amount of dust created, and the energy required to produce that.

Seems to me that you wish to accept information- however absurd - that tends to agree with your theory, and then reject information that is more realistic than NISTs assumptions.

The point of Kuttler's contention was that even by making absurd assumptions in favour of a rapid fall time he couldn't achieve a time to match official figures. So far you have just accepted the accuracy of his first two models, despite them being illogical, because they almost confirm the times reported. But when he takes away the illogical assumptions to carry out other calculations you say that he is incompetent because the result isn't to your liking.

Kuttler, page 6. Do I understand correctly that he calculates the energy required to crush ALL of the concrete of the upper section on each story iteration? That is, the energy for pulverization of the entire upper section is subtracted at the crushing of each story, instead of the energy required to crush the current story. Looks like it. Can anyone check that?

No, he doesn't.

But you now wish to accept his 'absurd assumptions' in the first two models because they enable the calculations to almost agree with the official fall times,

What official fall time?

Against my better judgement, I spent some time analyzing section 1.4.3 (Energy loss to crushing of concrete, pp 5-7) of Kuttler's paper in detail. In a nutshell, he crushes far more concrete than there is in the building.

It was somewhat difficult to unravel what was going on; the mechanics were a little screwy for a variety of reasons, and the poorly written program didn't help a bit. I first ported the program to a more friendly (to me) language and refactored and renamed to make things more understandable, all the time verifying I got the same results as Kuttler. Then I inserted other statements to perform intermediate calculations and watch the quantities being calculated by Kuttler to try to determine what was up.

Turns out none of this was necessary. All of the necessary information is right there in the text:

Letting E denote the energy required to crush (1 - r) (M + 1) kg of concrete which is what gets crushed between the collision with floor j - 1 and the collision with floor j...
Content from External Source
and

Running this program for the value r = .99 and 100(micro)m dust as indicated above, it follows the remaining mass is 66.73...
Content from External Source
Note that Kuttler uses normalized masses for the stories (total tower mass = 110kg), which is fine. While r (the mass retention fraction at each collision) seems quite conservative on the surface with only 1% of the crushing mass lost at each impact, in fact it leads to total mass shedding of (110 - 66.73)/110 = 39.3% by the end of collapse. I have no problem with that, whether it's reasonable or not.

Where he goes wrong is equating mass lost by shedding with the mass of pulverized concrete, something I've verified by inspecting calculated values while the program runs. The quantity (1 - r)(M + 1) pulverized at each steps sums to the 39.3% figure. The problem is, there wasn't that much concrete in the towers. According to the Greening citation (ref #3), the mass of concrete in floor slabs was 48,000,000 kg and total tower mass 510,000,000 kg, which is 9.4%. Even lowballing the total tower mass to 300,000,000 kg gives 16%. So he is pulverizing roughly 2.5 - 4.0 times the amount of concrete available.

It's not like that's the only problem, but it's a biggie.

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I think there might be some value in setting up a model in an an accessible, forkable, and collaborative framework like jsfiddle, that could be used to demonstrate things like the above.

Suddenly, quiet.

The point of Kuttler's contention was that even by making absurd assumptions in favour of a rapid fall time he couldn't achieve a time to match official figures.

Here's a critique of Kuttler's paper from Dave Rogers.

What he has to say about section 1.4.3:

Rogers said:
Section 1.4.3: Kuttler neglects conservation of momentum and assumes 100% crushing of concrete to 100µm dust. This is physically unreasonable because (a) it has not been established satisfactorily that all the concrete was crushed (see above), and (b) the transfer of energy from kinetic to fracture energy must be limited by conservation of momentum otherwise Newtonian mechanics are violated. Indeed, it is the loss of kinetic energy due to the requirement that momentum is conserved in an inelastic collision that is the source of the fracture energy required for pulverisation, so by neglecting that effect Kuttler is failing to make any attempt at realistic modelling of the physics of pulverisation. The value of 100µm comes from Lioy et al, a paper concerning the sampling of airborne dust at remote sites downwind of the Twin Towers, a sampling technique which would automatically place an upper limit on the dust particle size collected; these samples were therefore in no way representative of the debris from the collapse as a whole, which could have a very much larger particle size distribution. In fact Kuttler himself comments that there was insufficient energy in the collapse to achieve the level of pulverisation he requires, which should alert him to the problems with his own modelling.

Told you I could do better.

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I think there might be some value in setting up a model in an an accessible, forkable, and collaborative framework like jsfiddle, that could be used to demonstrate things like the above.
Agreed, and thanks for turning me on to that site.

Told you I could do better.
Not a difficult task for you, I'm sure. Nor particularly interesting, either.

Not a difficult task for you, I'm sure. Nor particularly interesting, either.
Indeed, not so interesting. Shooting fish in a barrel, basically. I knew there was a reason I never gave this paper the time of day before. Remains to be seen what sort of reaction Hitstirrer, being only the messenger, will have. So far, it looks like none, but time will tell.

Tony and gerrycan... how many days before a discussion can be considered abandoned?

I'd say a week qualifies.

Hitstirrer, any reaction to the critique of Kuttler? That is, before we move on to the next set of questions.

OWE. Ive been in Spain since that saga and using Hotels flaky WiFi to try to at least keep up with domestic emails. Basically I have been out of touch with the world other than that -- so I would have to scroll back a while. But as I said before, it was turning into an academic dispute where I was being asked to believe both Kuttler and yourself without the tech knowledge to check either of your assertions. I suspect that reading the thread for the last few weeks won't help either. You will recall that I only introduced it as it came to my notice, to see if it would cast any light on the topic. Seems that it was like rubbing Alladin's lamp as it brought you into the fray at the request of your sycophantic 'likers'.

Much that goes on in here falls into that catagory though. He says - She says. Where us lesser mortals are asked to pick sides based on whoever seems to be the most arrogant, or should I say - seemingly confident, with their input. But thats how 'appeal to authority' works isnt it.

OWE. Ive been in Spain since that saga and using Hotels flaky WiFi to try to at least keep up with domestic emails. Basically I have been out of touch with the world other than that -- so I would have to scroll back a while.
I can summarize a specific problem for you. Kuttler inadvertantly crushes far more concrete in his calculations than is available in the tower.

But as I said before, it was turning into an academic dispute where I was being asked to believe both Kuttler and yourself without the tech knowledge to check either of your assertions.
If that's a problem, it's always going to be a problem. It could very well be a problem with this latest series of questions.

I suspect that reading the thread for the last few weeks won't help either. You will recall that I only introduced it as it came to my notice, to see if it would cast any light on the topic. Seems that it was like rubbing Alladin's lamp as it brought you into the fray at the request of your sycophantic 'likers'.
That's the impression you have of someone answering your question? Okay. Does not encourage further answers. If that's the mission, then mission accomplished.

Much that goes on in here falls into that catagory though. He says - She says. Where us lesser mortals are asked to pick sides based on whoever seems to be the most arrogant, or should I say - seemingly confident, with their input. But thats how 'appeal to authority' works isnt it.
Yes, it seems that way. I have to wonder about the motivation behind asking questions or introducing subjects if you expect the ensuing discussion to be out of reach. I'm going to tell you the same thing I've told others: when I started looking at the subject of the collapses, I didn't know anything. I have a BS in physics under my belt, which is a very helpful foundation. But, as I've also noted many times, enough years have passed that anyone interested in the subject could be in post-doc physics studies by now, starting from scratch.

I'm sorry I'm not going to let you off that easily. This is not that hard.

1) Kuttler states the mass of concrete in a tower
2) Kuttler states the relative amounts of mass ejected/retained in his calculations
3) Kuttler states that all mass ejected is assumed to be pulverized concrete
4) The fraction of mass he assumes ejected exceeds the mass of concrete he reports
=> His calculation crushes more concrete than even existed in a tower.

1, 2 & 3 involve no math or physics at all, where 4 only involves arithmetic. His calculation of the concrete mass errs on the high side because he takes floor slab area as equal to the entire footprint. Even so, he exceeds this amount. When a more accurate value is used, it is found that he crushes 2.5 - 4x the amount of concrete available.

That wasn't so hard, was it? You can dispute any of the four points I've listed, but three of them are resolved simply by reading the paper. When you introduced this paper for discussion, you said "Please take time to read the paper." Now I'm going to ask the same of you. It takes a bit of discernment to go from what he wrote to the distilled bullet points above, but I've given you a cheat sheet of what to look for. If you can establish that the first three points are indeed correct, you can undoubtedly divide two numbers and then multiply by a third number. At that point, you will know whether I'm right or wrong and this will no longer be a matter of appeal to authority.

I'm sorry I'm not going to let you off that easily.

Let me get this clear. You actually think that you are in a position in an open forum to berate me and demand that I jump through hoops to placate you ?
Trust me, I have no inclination to undertake a degree level course (to match your own) if that just turns me into a bombastic bully who prints bare assertions to impress acolytes in a chatroom. The mystery to me is how your impolite replies remain unedited but whenever I respond to impolite people in kind then Mick invariably deletes my comments. To move on.

You seriously expect me to accept that Prof Kuttler's paper concludes that more pulverised concrete was ejected than was actually in a tower - by a factor of 2.5 to 4 ? And he never noticed ? More to the point - no-one else noticed until now.

Earlier you indicated that his paper has been extensively debated in that well known unbiased forum JREF. Odd that you are the only one to have eventually discovered such a basic flaw in the paper when it has been crawled over by many others. You offer no calculations to support your claim but expect me to just roll over and accept your bare assertion. Forgive me but I must decline that kind invitation. In the 'appeal to authority' stakes a Professor publishing a paper trumps a physics degree bare assertion in a forum.

Others here have selected various lines in Kuttler's paper to ridicule. Totally failing to understand that the ridiculous assumption that they refer to was deliberately chosen in order to attempt to get the maths to agree with tower fall times that have been accepted by NIST. And he consistently failed to achieve that.

Some just focus on one or other of his scenarios to discredit. One even scoffed because he once used an assumption that all concrete had been pulverised - disingenously saying that he used that for all the scenarios. Again, failing to understand ( or more likely choosing to not understand) that Kuttler used many totally unrealistic asumptions in many ridiculous scenarios quite deliberately - and fully explained his reasoning at each stage. At every turn he attempted to always err on the side that would enable a rapid fall time. People ( without another agenda ) who actually read that paper will understand the lengths that Kuttler went to in order to discover a situation where the maths could agree with the times - but failed. Whatever he 'assumed' always made the fall time far too long.

Let me get this clear. You actually think that you are in a position in an open forum to berate me and demand that I jump through hoops to placate you ?
I asked you to read the paper. If you don't want to read the paper you beseeched others to read, why'd you bring it up? Why stroll into a discussion to inject something into it with no intention of actually discussing it yourself?

Trust me, I have no inclination to undertake a degree level course (to match your own) if that just turns me into a bombastic bully who prints bare assertions...
Oh, now, they're hardly bare assertions. I told you specifically what was wrong and why.

You seriously expect me to accept that Prof Kuttler's paper concludes that more pulverised concrete was ejected than was actually in a tower - by a factor of 2.5 to 4 ? And he never noticed ? More to the point - no-one else noticed until now.
Absolutely.

Earlier you indicated that his paper has been extensively debated in that well known unbiased forum JREF. Odd that you are the only one to have eventually discovered such a basic flaw in the paper when it has been crawled over by many others.
It's not that odd. I even predicted in advance I could do better than Dave Rogers, who's one of the sharper tools in that shed. And I did.

In the 'appeal to authority' stakes a Professor publishing a paper trumps a physics degree bare assertion in a forum.
In the real world, publishing a paper in a non-professional "journal" run by a cadre of buddies doesn't count for anything more than a post in a forum. You do realize this is Journal of 9/11 Studies, right? The same group who allegedly reviewed and published Szamboti's The Missing Jolt and never noticed he used a completely made-up formula to calculate acceleration over an interval. I noticed it, and after convincing Tony of his error (which was exactly like pulling teeth), he fixed it and issued a revision. That time, too, JREF members as well as many others were poring over the paper.

Others here have selected various lines in Kuttler's paper to ridicule.
That would be their business.

Totally failing to understand that the ridiculous assumption that they refer to was deliberately chosen in order to attempt to get the maths to agree with tower fall times that have been accepted by NIST. And he consistently failed to achieve that.
Yes, whatever. Nice dodge.

Again, failing to understand ( or more likely choosing to not understand) that Kuttler used many totally unrealistic asumptions in many ridiculous scenarios quite deliberately - and fully explained his reasoning at each stage. At every turn he attempted to always err on the side that would enable a rapid fall time.
Attempted, yes, but failed miserably on that point.

Let me get this clear. You actually think that you are in a position in an open forum to berate me ...
I have long lost my patience for those who can't distinguish between a well-formed, rigorous and complete argument and a bare assertion, yet boorishly inject distractions into a discussion with no ability or even intent to discuss them. I sort of assume that, in a discussion about collapse times and rate of fall, the participants can do simple arithmetic. Is that too much to ask?

I don't know what it is about 9/11 that makes people think they can discuss physics-oriented topics with no knowledge of physics, nor any intent to lift a finger to obtain it. Yet, it happens all the time, all over the place, so I've long since adjusted my argumentation style to be drastically dumbed down and to avoid equations (even simple arithmetic) wherever possible. For this, I hear:

You offer no calculations to support your claim but expect me to just roll over and accept your bare assertion.
I tried to make it simple for you. If it's simple enough that you might understand it, it's called a "bare assertion". If it has calculations, you won't understand it. Right? You said:

...it was turning into an academic dispute where I was being asked to believe both Kuttler and yourself without the tech knowledge to check either of your assertions. I suspect that reading the thread for the last few weeks won't help either.
Ah, so it's damned if I do, damned if I don't.

I'll have some time later to hold your hand all the way through this wicked addition, subtraction, multiplication and division. It won't be a bare assertion (any more than it has been). If you can't follow it, 1) don't blame me and 2) you might want to rethink your participation in subjects you don't begin to understand.

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And, by the way, I suspect one of the reasons no one caught this before is that it's a poorly written paper with funky non-standard ways of doing the mechanics, and is implemented by virtually unreadable hacked-out spaghetti code. Plowing through this and following his argument is painful and tedious, not many are going to do it absent a compelling reason. No one is getting paid, and placating ingrates is not a compelling reason.

I have just independently repeated the analysis outlined by @OneWhiteEye .

• I will post a full analysis shortly (am busy). Promise.

But I will put my head on a mathematical block for now, that Kuttler ejects an increasing amount of concrete for each floor even though the collision dynamics are the same.

Assume each floor masses 1 (normalisation).

If M is the mass of the original upper levels, then hitting the first (critical floor) eject 0.01M.

The new M is (0.99) M + 1. The remainder plus the mass of the next floor.

You will see this in the anaysis on pg 3 and in the code on pg 4, i.e., M = (0.99)M+1.

Hitting the next floor ejects 0.01((0.99)M+1) , but (0.99)M+1>M hence more concrete ejected than before.

The problem compounds recursively floor by floor.

I have to solve the difference equation to mathematically calculate how badly wrong Kuttler is, but the solution can also be determined by running an amended version of the code, which is what @OneWhiteEye has done. I bet his number is correct.

Well done @OneWhiteEye

• Can anyone see why more matter should be ejected for each floor?

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What is it with these "peer-reviewed" "papers" being wrong?

Thank you.

What is it with these "peer-reviewed" "papers" being wrong?
I have to call a spade a spade. Written by incompetent researchers, reviewed by incompetent peers (if at all, 'rubber stamp' is more like it). You saw in the other thread how Tony Szamboti was not aware of what the citations in his own paper said. These are people who don't even bother to read the works they cite, who submit their 'articles' to their friends who share the same confirmation bias, then go on clucking about their "articles in peer-reviewed journals". I guess that technically they are correct; anyone can call anything a journal (a PDF doc makes it official!) and once a peer has skimmed an article ....

.

To normalise - let 10kg be the mass of concrete in each floor and let there be 10 'upper block' floors and 100 'lower block' floors. A total concrete mass of 110kg at initiation. Then - initial mass to begin movement is 10 x 10 = 100kg. At impact 1kg is ejected as dust and 99kg moves on to incorporate the next floor leaving 109kg to move down. At impact with the next floor, 1.09kg is ejected and 107.91kg moves on to add to the next floors 10kg, making 117.91kg to impact. There, 1.1791kg is ejected leaving 116.7309kg to add to the next 10kg, and so on. A simple enough concept

Justify.

@qed, Kuttler calculates the ejected mass as a percentage of the total falling mass, which seems fairly reasonable. I don't think your objection is valid. Kuttler's problem here is as @OneWhiteEye pointed out, he's crushing more concrete than exists, by saying all the ejected mass is crushed concrete, and not because of a mathematical error.

The following Pen duplicates the calculations in 1.4.2 wtcA and 1.4.3 wtcB

The only tweakble thing of interest is the Ratio (r) which is set to 0.957 for the wtcA code, and you should set to 0.990 for the wtcB code.

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At the instant that I released that post I remembered the old Chinese proverb where a philosopher asked his Emperor for payment by an unusual method. He produced a chessboard and asked for payment by a single grain of rice on the first square and to double each squares amount, on each subsequent square for the whole 64. The resultant rice to be made in payment exceeded the worlds supply. It made me pause to ponder.

As I have told you here before, my own expertise is not in physics /maths/chemistry. As such, much of the tech info in the physics field has to be accepted as read. That doesnt mean that I simply accept everything that I am told. Not by a long shot. But if/when I discover that ones I trusted have feet of clay then I have no difficulty in amending my stance. All that I ask is that highly technical explanations are not aimed at peers, but at a level understandable by others. Anything else is self defeating. Especially as many people just swallow what they are told without confirmation. That means that it becomes a lottery as to which 'expert' view is accepted. I do try to avoid that trap.

The problem in here is that people prefer to blame me for failing to understand technically troubling issues, rather than themselves for their inability to clearly explain. In this case, the Chinese proverb caused me to consider further and take my own advice by going away and programming a simple Excel spreadsheet using normalised figures to set out a similar scenario. I will either justify -or confirm an amended stance - once I have done that.

A 'back of envelope' initial overview still seems to indicate that a 1% increasing ejection of mass at each impact will still be unable to total more than the original mass, but a spreadsheet programmed to do the maths should easily do that. It may help if you match my own intended normalised figures so that a double check can take place.

I intend to assume 110 floors - each 10kg of concrete making a total concrete mass of 1100 kg at initiation.

Then use the 'Bazant' crush down/crush up theory. With the crushing 'upper block' being 10 floors that remain constant mass until the meet the floor when they crush themselves. And 100 floors in the 'lower block'.

Kuttler ejected 1% at each impact. So the first impact would be 10 x 10kg = 100kg -ejecting 1kg and leaving 99kg to impact the next floor where the new total of 109kg would impact the next floor. There, 1.09kg would be ejected leaving 107.91kg to move on. Adding the next 10kg means that the next impact would eject 1.1791kg and 116.7309kg moving on etc etc.

My 'back of envelope' calcs still tells me that a total of some 600kg would eventually be ejected which is not an excess over the initial 1100kg. A spreadsheet will fine tune that 600kg 'estimate'.

Your own duplication of my simplistic plan would assist here.

I see your post then (courtesy of qed):
To normalise - let 10kg be the mass of concrete in each floor and let there be 10 'upper block' floors and 100 'lower block' floors. A total concrete mass of 110kg at initiation. Then - initial mass to begin movement is 10 x 10 = 100kg. At impact 1kg is ejected as dust and 99kg moves on to incorporate the next floor leaving 109kg to move down. At impact with the next floor, 1.09kg is ejected and 107.91kg moves on to add to the next floors 10kg, making 117.91kg to impact. There, 1.1791kg is ejected leaving 116.7309kg to add to the next 10kg, and so on. A simple enough concept

and I see your post now:

Is it because it occurred to you afterwards that this "simple enough concept" ends up crushing nearly 40% of the total mass? Good guess?

In your scenario, the building is ALL concrete, so there's still 1.5x that much concrete left to crush, which would leave nothing. But, in the towers, where the fraction of total mass represented by concrete is taken by Kuttler to 17.3% (and better estimates go lower than 10%), more gets crushed than is available. Do you get it now?

Kuttler's error is treating mass ejected and mass pulverized as the same thing. He, too, undoubtedly thought r=0.99 was an extremely conservate figure. Not with a recursive process. It causes his calculations to crush way more than even he calculates is available. This error could've been caught by doing a simple sanity check for consistency. Elsewhere, he calculates the steel to constitute 22 mass units (20%) and concrete to 19 mass units (17.3%), which accounts for only 41/110 = 37.2% of the total mass, leaving 69 mass units in other stuff. Then he proudly announces "the remaining mass is 66.73" and considers it conservative that he did not come anywhere close to his goal:

Kuttler said:
Note also that the remaining mass, 66.73, is nowhere near 22.01, the mass which would result if all the concrete were crushed.
No, baby, that's what's left if you crush everything BUT the steel. Right there, he's implying the mass of concrete - which is all he's trying to crush - should be 110 - 22 = 88 units. But he's already calculated it to be 19.

Hitstirrer said:
You seriously expect me to accept that Prof Kuttler's paper concludes that more pulverised concrete was ejected than was actually in a tower - by a factor of 2.5 to 4 ? And he never noticed ? More to the point - no-one else noticed until now.
Yes. It's absolutely ******* astonishing, isn't it? Something tells me you've noticed by now. Correct me if I'm wrong.

Haha, cross-post. Let's see if you do get it or not...

At the instant that I released that post I remembered the old Chinese proverb where a philosopher asked his Emperor for payment by an unusual method. He produced a chessboard and asked for payment by a single grain of rice on the first square and to double each squares amount, on each subsequent square for the whole 64. The resultant rice to be made in payment exceeded the worlds supply. It made me pause to ponder.
I've only read this much. YES, you get it!

You are correct @Hitstirrer, however that's not really what is being claimed by @OneWhiteEye . The problem is that it crushes more concrete than exists, not that it crushes more than the weight of the building. @qed took issue with the increasing amount, presumably because he was thinking the ejected mass would only come from the newly crushed floor, but some of the falling mass would be crushed as well.

Oh, and use a mass of 1 (kg) per floor, as that's what Kuttler does.

As I have told you here before, my own expertise is not in physics /maths/chemistry. As such, much of the tech info in the physics field has to be accepted as read. That doesnt mean that I simply accept everything that I am told. Not by a long shot. But if/when I discover that ones I trusted have feet of clay then I have no difficulty in amending my stance. All that I ask is that highly technical explanations are not aimed at peers, but at a level understandable by others. Anything else is self defeating. Especially as many people just swallow what they are told without confirmation. That means that it becomes a lottery as to which 'expert' view is accepted. I do try to avoid that trap.
All of that is perfectly fine.

The problem in here is that people prefer to blame me for failing to understand technically troubling issues, rather than themselves for their inability to clearly explain.
You see, I disagree with that. If your premise were true, then ANY subject of ANY depth or complexity could be adequately explained to any moron if only the explainer were "good enough." That simply isn't true. Most people could not complete an introductory course in quantum mechanics no matter how hard they tried and no matter who did the explaining.

This is engineering mechanics were talking about, after all. To put an inability to understand exclusively on the shoulders of the explainer is quite unfair. To do Kuttler/Greening style stepwise mechanics is comparable in difficulty to an introductory course in special relativity. There's no shame in not understanding it, but being quick to blame the instructor seems pretty screwy on the face of it.

I tried to make it as simple as possible. Once you do understand, then go back and read my initial critique and then tell me where you think the blame should be placed on a failure to comprehend.

In this case, the Chinese proverb caused me to consider further and take my own advice by going away and programming a simple Excel spreadsheet using normalised figures to set out a similar scenario. I will either justify -or confirm an amended stance - once I have done that.
Bravo. No sarcasm; it's the absolute best thing you could do.

Kuttler ejected 1% at each impact. So the first impact would be 10 x 10kg = 100kg -ejecting 1kg and leaving 99kg to impact the next floor where the new total of 109kg would impact the next floor. There, 1.09kg would be ejected leaving 107.91kg to move on. Adding the next 10kg means that the next impact would eject 1.1791kg and 116.7309kg moving on etc etc.
Correct.

My 'back of envelope' calcs still tells me that a total of some 600kg would eventually be ejected which is not an excess over the initial 1100kg. A spreadsheet will fine tune that 600kg 'estimate'.
Read my post above and see if you still think you need to bother with the spreadsheet.

It's not a matter of ejecting more mass than there is in total, that cannot happen because it's always a fraction less than one at each step. The problem is with the accumulated mass crushed exceeding the total mass of concrete available, by Kuttler's own reckoning, and by a huge margin.

Like I said, that's only ONE problem amongst many, but it's a biggie.

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