Do you have a paper debunking Hoffman's energy requirements paper?

[Bonobo]

Thank you. I assume the debunkers must have a response to this paper. Could you please provide a link so I don't waste your time recapitulating old arguments. Thanks.

http://911research.wtc7.net/papers/dustvolume/volumev3_1.html
The North Tower's Dust Cloud

Analysis of Energy Requirements for the Expansion of the Dust Cloud Following the Collapse of 1 World Trade Center

by Jim Hoffman
October 16, 2003

[LARED]

1. I see you're digging through the archives of 9/11 woo,

There were a number a debunkings of Hoffman's paper about 4 or 5 years ago.

I'm surprised to see it resurrected... again.

[AZCat]

3. Nice timing. n/t

[Bonobo]

66. This was post #1. After days and dozens of post, nothing has yet appeared in this thread.

We have gone into several "branches" but nothing that could really be shown as a reasonably detailed response let alone a number of debunking from 4-5 years ago.

If this is a floating curve ball or even a whiffle ball, I encourage you to knock it out of the ballpark.

I am new to this "game" if that is what is what is going on. So I need a rule book or at least a record of last year's season.

So I asked for what has happened with the Hoffman paper. Was it rebutted? And I get crickets, insults and a couple of reasonable responses mixed in. Hard to process.

Can we restart and stick to either:

A. A link to a specific rebuttal of Hoffman.
B. A link to a previous DU substantive argument.
C. A substantive argument (like with details. Just spend the time you would otherwise spend on snark and it will free up some room!)
D. Other. Please explain (Snark-free (TM))

[SDuderstadt]

68. I believe you have been given adequate substantive rebuttal...

and I concur with at least one other poster that the problem is your failure to comprehend what you're being told. This illustrates the challenge of trying to discuss highly technical issues with non-technical people. With all sincerity, I don't think this is likely to change until you your confirmation bias goes away. As I have observed before, you seem to have chosen the outcome you like and are apparently trying to work backwards to rationalize it. There are a number of engineering heavyweights out there (members of ASCE, for example). Why aren't they flocking to Hoffman's position?

[Bonobo]

76. Please see #75.

If that is the best response to Hoffman that you guys can supply, that is fine. We will leave it as is for the time being. I am glad that you couldn't come up with better.

WRT your pop-analysis of my confirmation bias, it is a 2 way street that bias thing. I am well aware and trying to stay on the right path but thanks for the reminder. Make sure you take the same advice.

Anything not relating to a rebuttal of Hoffman such as your comments about my not understanding or my bias are pretty much unnecessary and off topic. I will ignore them because it shouldn't affect how I respond.

I asked for links to a rebuttal of Hoffman because I am trying to study both sides. If I had just read Hoffman and then NOT asked for a rebuttal or links to a previous conversation, than you could be certain that I have no interest. That is not the case.

Anyway, if the below summary I gave of AZcat's rebuttal is the best you have, I will leave it there and see if I can rebut your points or get Hoffman to do so. What I cannot do is accept them without more than "you wouldn't understand" or "I am an engineer, you are not so believe me."

I will take the summary as is in #75 if nothing more is added and consider that the dungeon's best response to Hoffman. I think it is weak stuff though -but as you know, I am not qualified to judge anything.

So please do indulge me with a little time to formulate a response to your BEST defense against Hoffman's paper. We dumb people are slow.

[AZCat]

69. Bullshit.

I have pointed you to the post where I made several criticisms of Hoffman's work. A detailed response isn't necessary because, frankly, his paper is garbage. Considering that it was post #9 of this thread, I think your complaint about dozens of posts without a response is off-base.

[Bonobo]

78. As I say in #75, I will take your points and consider that your best response.

Please let me know if I let anything out that you wish to include.

[AZCat]

2. Why is it necessary to have a paper "debunking" this?

Hoffman's mistakes are quite obvious (and quite plentiful) and even a cursory inspection of his work reveals several of them. A paper simply isn't necessary to refute his work.

Also, if you had simply searched for some basic terms you would have found previous threads here in this sub-forum discussing Hoffman's paper. Why were none of those sufficient?

[OnTheOtherHand]

4. maybe you could link to one that you "like"

I'm pretty new to this issue myself, so if I had just come across the paper (and offhand couldn't tell whether anything was wrong with it), I might be reluctant to just search the archives and see what I "hit."

[AZCat]

6. A good thread to check...

is also one of the earliest. It's short, but gives you an idea of some of Hoffman's mistakes. A lot of the later threads devolve into tangents (avoid any of them involving an ex-member named Christophera).

North Tower Dust Cloud Analysis started by demodewd on Fri Oct-10-03

[Bonobo]

8. OK, sorry, I was a moment late and posted first.

Thank you for the link. I see that you were kind enough to help. :)

[AZCat]

10. No sweat.

I know it is difficult for laypeople to slog through technical articles. Sometimes it can be difficult for technical people also, if the paper isn't well-written.

[Bonobo]

17. OK, I read through the thread and didn't see much.

Could you tell me what in that thread was a substantive complaint about Hoffman's analysis? The 60 micron average? It didn't look that far off to me. Certainly no more than 10% or 15% and by no means orders of magnitude for that particular number.

[AZCat]

20. Hoffman's number for energy consumption...

for the pulverization of concrete is strongly dependent on his choice of average particle size.

[Bonobo]

79. I understand. You think 60 microns is too large.

The study linked to doesn't seem to agree with you. Could you show me where the 60 micron size is challenged? Thanks.


This is the 4th or 5th time I have asked the same thing.

[AZCat]

129. No, it's clear you don't understand. n/t

[Bonobo]

134. Boy, you nailed me! Again!

Gosh, you're good!

[AZCat]

138. "Nailing" you wasn't the purpose.

Responding to an incorrect post was.

[Bonobo]

7. I tried the search you suggest...

Even "narrowing it down to 'from 2007' yielded so many threads that I could not possibly differentiate what would lead me to an efficient debunking of Hoffman.

So I asked on the 9/11 forum to my 'elders' to see if I could get a link and I am, once again, met with mostly attacks and unpleasantries.

Could you just assume I am trying to catch up and inform myself. I read the Hoffman paper. Now I want to read a good debunking of Hoffman. I assume the subject has come up and I could not find it after searching.

Anyone have a link? Please?

[AZCat]

9. I don't think anyone's bothered to formalize their criticisms.

Hoffman's mistakes are all over the place: he assumes all the concrete in the towers is fragmented, he assumes too small an average particle size for concrete (see the Lioy study), he simplifies the dust cloud as an ideal gas and uses the expansion to determine an increase in temperature (and therefore an increase in energy), he assumes the powderized concrete increases in temperature by the same amount. These are quite obvious, and any "paper" with mistakes like these doesn't warrant a formal response. It would be like writing a rebuttal to an paper written by a fifth grader.

[Bonobo]

12. He at least claimed that his errors were factored in in such a way that his results

would be well under the levels of that which could be forgiven. He is talking 'factors' of difference. I don't want to get into the arguments here because, as I said, I don't feel at your level yet and I want to read whatever you might have that would rebut Hoffman's numbers. Failing that, I would have to say that it is simply not enough to SAY that it is at the level of a 5th grade child.

Ultimately, if you have no substantial papers that specifically rebut the numbers he used in his calculations, we will have to argue it or agree to disagree I guess. Or perhaps we could start to argue whether you think his methodology itself is wrong in addition to his numbers and if so, why?

BTW, I started to read Mackay's critique of David Ray Griffin and it is a pain because much of it stuff that is not germaine to a scientific discussion, and it is loooong. Anyway, do you agree, for example, with the general approach of determining what would be 'energy sinks' and than compare to the estimate of total potential energy that existed in the building standing?

[AZCat]

14. He is incorrect.

It is not surprising, considering how poor his assumptions were. He is off by orders of magnitude. This is not an insignificant error.

I don't need "substantial" papers rebutting his numbers, because his mistakes are plainly obvious to most people in the scientific and engineering communities. We don't write papers for laypeople and there's no point in stating what everyone already knows, so I'm not surprised no-one has written a response.

The general approach is fine, it's Hoffman's application of it that's all wrong.

[Bonobo]

15. So for you, this discussion can only end in...

"I would like to point you to a paper that rebuts his points, but no serious person would bother. Similarly, since you are a layman, I can't/won't bother to explain to you since you could understand."

If that is your position, could you lay out how he is off by magnitudes? I know you explained generally above about the size of the dust calculation being wrong, but are you prepared to substitute a reasonable number and then crunch the numbers? Can you offer other numbers? If not, I do not see how this can be fairly evaluated. Surely you can see the problem from my POV.

[AZCat]

19. Look - this isn't my first time on the dance floor.

The internet isn't the ideal place to explain technical topics to laypeople in the first place, but when they're predisposed against your explanations it becomes much worse. I have found it to be an unrewarding and frustrating experience, and therefore am not inclined to waste lots of time trying.

The simplest, most accessible explanation I can offer is that Hoffman's conclusion regarding energy expenditure is significantly larger than what he calculates the available energy is, yet he doesn't stop to consider this other than waving his hands and proposing a 'god of the gaps' explanation. This is an egregious departure from the scientific method that should be obvious to you.

[Bonobo]

21. Well are you just here to beat people up then?

I'm not that predisposed to not listening. I am actually looking for understanding. I would be relieved either way. You can choose to believe or not, but compared to my friend, I am really very open minded. I do know what you mean about it being hard to explain.

In fact, when I get great responses like yours, I talk to friends of mine that have a better technical background than I do and convey your responses, seriously. I will try to get answers to your responses from people better suited than me to do it.

[AZCat]

22. That's a strange conclusion to draw.

Do you think I've been trying to "beat up" on you? This is the internet, not a bar in Texas.

[Bolo Boffin]

23. Oy! n/t

[AZCat]

24. Hah! I wondered how long it would take you to respond. n/t

[Bonobo]

25. So far the only criticism I have seen of Hoffman is the 60 micron particle size estimate.

But when I look at this:

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=125&topic_id=3500#3518

I see that the numbers don't look wrong at all.

Can you explain so I understand?

[AZCat]

26. Then it appears you missed...

this post of mine in this very thread. I list several criticisms right there.

[Bonobo]

27. I saw it.

I will get back to you.

[AZCat]

30. I won't be holding my breath. n/t

[Bonobo]

34. Why are you being rude?

That is why I ask about your "are you here to beat people up?"

I mean, are you here just to be "like THAT"? Can you possibly see why it is at bare bones unpleasant to deal with you when you do shit like that?

It's like talking to a teenager who twists their hair and chews bubblegum while you are talking...

[AZCat]

36. Perception is everything.

Perhaps you should consider why you take such offense to a simple remark?

[Bonobo]

45. You said "I won't hold my breath".

So you are saying either what greyl is implying -namely that I am not serious or I am pulling your leg about getting back to you in order to fulfill some kind of adolescent agenda, It is not true. But you are beginning to wear me down for no good reason with personal snark. I am just asking you to refrain please.

[AZCat]

55. No, I didn't.

I said " I won't be holding my breath." It's right there, a couple of posts above yours. If you're going to quote me, at least take the time to do it right.

You present a false dilemma. Please refrain from logical fallacies.

[OnTheOtherHand]

56. PMJI

My perception has been that you've started a lot of threads, raised a lot of issues, left a bunch of them hanging. I've sort of been wondering to myself why you don't finish one discussion before starting the next. I don't have any dark speculations about your agenda; I just don't see how this works. If we're trying to build trust, chasing each other all over the forum probably isn't the best way to do it. I assume you're not deliberately feeding that dynamic, which is why I took the time to point it out.

(By the way, I hope you'll bear in mind that when you cite something from 2003 -- which is perfectly reasonable -- some folks are wincing to themselves about all the stupid fights they've been in about that subject over the intervening six years. It may not be fair, but it's human.)

[Bonobo]

59. OK...

What have I left hanging and why would it be surprising anyway?

I am entering a field of research anew. Is that ok?

So I start a thread and reach a roadblock because A) I am stymied and cannot proceed any further along that angle because I don't have the ability to argue the point well or my knowledge on the subject has reached a limit. This type of investigation and research makes me think and try different avenues of enquiry. Isn't this what should be expected? I am at a loss for why this would be surprising.

As for as the building trust and the oldness of this paper... I am starting with what I run across that seems fundamental to the case. If it is ground that has been run over many times before, I do not want to waste anyone's times (or insults), so I ASKED FOR A LINK. Please read my OP. I do not want to discuss things that are old for you guys and new to me. I JUST WANT TO CATCH UP BY READING WHAT HAS BEEN DISCUSSED. I tried a search and it was frustratingly difficult to get to the meat because there is so much CRAP and NAME CALLING in the dungeon.

BECAUSE even a simple request, politely worded for a link, results in this kind of bullshit. Do you now see my frustration?

I just don't like being treated like this when I am asking for simple things. I can and will deal with it I guess, but it is really unpleasant and it is not my goal in being here. It makes me wonder if others are here because they enjoy feeling superior.

[OnTheOtherHand]

72. of course I see your frustration

And I'm probably more sympathetic to it than many of your interlocutors. But, y'know, everyone here is frustrated, take a number and wait your turn. ;) You know that your buttons are being pushed, but you're (naturally) less aware of the extent to which you are pushing other people's buttons. This has little to do with your intentions and much to do with knowing what the buttons are.

For instance, what you're experiencing as a process of thinking through questions, where one question leads to another, may come across to others as a sort of kinder-and-gentler Google-bombing. As a related matter, many of us have had the experience of arguing with someone who seems unwilling to pursue any one line of argument, but if one line seems to be going badly is quick to hop to another, sort of like Whackamole. In fact, I'm having that experience in another forum right now. I don't think you're doing that, but I think you're inadvertently triggering the reflexes of people who feel that "they've seen this all before," and in fact have seen a lot.

Another button is accusing people of suppressing discussion. I'm not entering into the merits of any recent post here, but I can tell you that everyone of a certain 'age' on the board has had the experience of posting a detailed response to some inaccurate factual claim, and being told that s/he is suppressing discussion. It may not be fair, but using that language when you could just say "Please cut the snark" is probably not likely to get the results you want.

[Bonobo]

80. I am open to suggestions beyond that.

If you reread my posts (particularly my OPs) recently in light of what I tell you is my sincere attempt to be accomodating in every way, I think you will see how I am trying.

In the case of Hoffman, in particular, and the geometry angles of descent thread, I am trying to get us all to lay off the personal responses and just not assume negative motivation.

I started this thread literally just to get links and NOT discuss the Hoffman article. Not only do I not get a link, but I get all the personal stuff. It is just frustrating where it seems so unnecessary.

But anyway, I really appreciate your post. So thank you very much for that anyway. I just am trying my best and wow, I can't believe how hard it is. Nevertheless, I will keep trying. Sometimes, as you see, I pop in frustration.

[greyl]

31. Could you say that 2 more times real quick?

I'm trying to complete my collection of a dozen.

[Bonobo]

33. You want me to answer off the cuff?

I asked for links to Hoffman rebuttal because I assumed you guys in the dungeon have talked about it for years.

If you could have just linked me to substantive criticism, I would be reading through it. I would take my time. If I say "I will get back to you", it means I am weighing what you said. I am taking it seriously. OPn the other hand, if I responded knee jerk, it would be a demonstration of a person who does not deliberate. There is no need for your snark, Greyl. It isn't funny and you aren't funny.

[greyl]

37. No, but I'd like to see your deeds match your words at some point.

The "I'll get back to you" & "Why is everyone else so impolite?" is difficult to take seriously anymore.

Seems to me that you spend more of your time here regurgitating old BS than you do honestly considering the thoughtful posts offered to you.

[Bonobo]

44. Seriously, I am finished with you.

You are useless as a discussion partner because you cannot discuss things without being insulting.

I know it is no skin off your nose, fine. But it is none off mine as well. This is the 2nd time recently you have pushed me to this point. I don't see why you find it necessary. You are the one who chooses to post on my threads. You can't just do so or not do so without being an asshole?

[lovepg]

114. Fill in the blank (It seems like some peoples --- to say the things they do). nt

[Realityhack]

74. Then why did you lie about only having seen 1 criticism? n/t

[OnTheOtherHand]

77. seriously, there is seeing and then there is seeing

I doubt that he has figured out yet how many discrete criticisms AZCat's post incorporates. Probably his statement shouldn't be interpreted as a lie about which posts he has read, but more as meaning that the 60-micron argument is the only one he has registered so far. I've had the experience that people sometimes can't see my arguments until I reframe them in a way that they can perceive (never mind evaluate!).

It can be really hard to communicate with people who are missing vast swathes of relevant knowledge, even when they acknowledge and try to allow for the lack. I know I've been on both sides of that divide.

[Realityhack]

83. Fair enough. n/t

[Bonobo]

81. You have jumped to the conclusion that I am deliberately lying now?

Seriously do you even want to talk to me? What is the point? I don't know what I have to do, but if you think I would lie in that way, I don't see us as having much of a meaningful conversation.

[Realityhack]

84. I retract that statement.

You may not have been lying. You may just not be reading the responses to your questions very thoroughly. Slightly less bad but still fairly silly.

[Bonobo]

87. I am actually busy replying and keeping up.

I think I felt that AZcat's responses were broad but not deep and that were lacking specificity.

I will accept them as they are if you all feel that it is the best that can be done to frame the rebuttals.

[Bonobo]

89. Right after you wrote that...

You replied the #3 "You wouldn't understand the answer anyway".

Do you retract that as well or are you just unable to sheath your claws?

[Realityhack]

96. No that statement I stand by.

I was wrong to assume you had KNOWINGLY misrepresented what AZCat posted.
But I think I have plenty of grounds on which to make an educated statement that you would not (at least not fully) understand the implications of a particular particle size being the correct 'average'. In fact I think it is inherent in your question which seems to indicate that such a number would be meaningful at all.

[Bonobo]

98. OK, but it doesn't absolve you of the responsibility to give me SOME range

of numbers to use as replacements.

[LARED]

5. This error in the begining all you need to know to dismiss the whole paper

It is well documented that nearly all of the non-metallic constituents of the towers were pulverized into fine powder. The largest of these constituents by weight was the concrete that constituted the floor slabs..............Based on diverse evidence, 60 microns would appear to be a high estimate for average concrete particle size,

This is not documented at all. In fact all the documented analysis performed on the dust indicates this is not true.

http://www.ehponline.org/members/2002/110p703-714lioy/lioy-full.html

[Bonobo]

11. You are objecting that it should be a few microns larger and that would still allow enough mass...

For the legendary sledgehammer to continue to smash down through 90 floors of reinforced steel columns and core (that all degraded at the same rate) at nearly free-fall speeds, while ejecting massive walls outward at 50 mph and still transmitting all of its force down wards?

That is a pile driver that puts the magic bullet to shame! It dissolves into visible debris as soon as the initiation of collapse begins and yet it continues to smash down (while dissolving) into the 90 floors below it, pulverizing everything in its path. Remember now. Most of this dust was the same size. Why? Wouldn't the stuff on top be less pulverized then the stuff on the bottom? Why do I "see" the thing falling apart and stuff being ejected, leaving what looks like a fireworks display of debris coming out and yet at the same time have to believe that the same energy is simultaneously driving down?

Anyway, I don't see how the link is a very good indictment of the Hoffman numbers.

[AZCat]

13. Let's get back to basics.

First, the core wasn't necessarily destroyed during the floor pancaking. There are numerous photos that show remnants of the core still standing moments after the floors have collapsed.

Second, the mass of the building was transmitting all its force downwards because that's the direction of gravity. Mass was ejected away from this vector by collisions between the components in the collapsing portion and the rest of the building, but the energy used (or the mass lost) was not significant.

Third, the collapse didn't pulverize everything below the collapse initiation zone. It is likely most of the columns failed by buckling, and very unlikely any of the steel was pulverized. There was a significant amount of wallboard in the towers, though, and that can be pulverized quite easily.


Check out the breakdown of particle diameters in the samples for an idea of how far off Hoffman's estimate of 60 microns was.

[Bonobo]

16. Here. I would like you to take a look at this link.

http://doujibar.ganriki.net/english/e-01a-wtc1upperfloors-1.html

Can you look at the pictures and analysis and still maintain that there was a significant pile driver?

[AZCat]

18. The person who made that web page...

doesn't know what he is talking about. I recommend against relying on internet sites as your source for engineering analysis.

[Bonobo]

28. That is not a valid criticism. nt

[AZCat]

29. Then why don't you show it to some of those technically minded friends of yours?

See what they think of it. Here's a hint: where does the author of that atrocity of a web site think the mass above the collapse initiation zone went? Does he think it just disappeared? I know you've said you're not technically savvy, but surely you're aware that it takes a loooooot of energy to make mass "disappear".

[Bonobo]

32. That is precisely what he finds odd. It is being ejected.

He demonstrates it visually. You call it dumb with no real substance behind your remark. If you are content to believe you have won an argument by saying "he doesn't know what he is talking about" then fine. But you are on a discussion board. Being disinclined to discuss a subject, offer reasons for your rejection of people's arguments, et, does not really advance anything, not even "discussion".

[AZCat]

35. Hmmm. No, it isn't.

It should be quite obvious there isn't nearly enough ejecta.

[greyl]

38. It's valid if it's true, and you're totally ignoring his recommendation

"I recommend against relying on internet sites as your source for engineering analysis."

His other statement is indeed a valid criticism, but it doesn't qualify as an argument, technically. You still need to realize that the site you linked to in your OP isn't a valid argument.

[AZCat]

39. I don't think he has the ability to differentiate...

between a bad technical argument and a good one. The site he linked to is crap, but he doesn't seem to be able to recognize that on his own. I think his best bet is to talk to his friends - they are in a better position to explain this to him than we are.

[Bonobo]

46. Not substantial, but you did manage to sneak in another "I don't think he is smart enough"

statement.

Do YOU have anything of substance or just that?

[Bonobo]

62. I would need more than an anonymous person saying "that site is crap."

I wouldn't be a very rational person if I just accepted that as proof, wouldn't you agree?

My "more technically savvy friend" doesn't think it is crap. Reasons would be nice.

[AZCat]

130. Then your friend isn't technically savvy at all.

If he can't see why it's crap, then he's not reliable as a source.

[Bonobo]

135. I won't honor that waste of a time statement with a reply either. nt

[AZCat]

140. Fine. Depend on someone who doesn't know his ass from a hole in the ground.

What do I care that you're being led astray?

[Bonobo]

142. I never imagined or hoped that you cared.

But I thought a discussion without childish behavior might be possible.
Failing that, one could just say nothing.

Thanks for what you DID offer. I will pass it on as I say and truly give it the due and consideration that it deserves (meaning that I really will think about it. It will take me some time, as you pointed out correctly, to even fully understand what you mean if such a thing is possible with the limited verbiage you offered me.)

[AZCat]

145. Whatever you do, don't give it to your friend.

He'll just fuck it up. Try finding someone else to rely on.

[Bonobo]

148. OK, thanks!

[LARED]

42. Let me ask a question

Do you think it's possible that as the top section collapses, it's mass is moving into the upper floors while the perimeter wall remain intact for a few moments?

[Bonobo]

47. Of course I do. I think it is possible.

It would be unreasonable to dismiss that statement.

[LARED]

50. Ok, so the fact the this is completely ignored in the

video you posted does not influence your view as to the validity of the video's authors assumptions.

[Bonobo]

60. What video did I post? This OP is about asking for rebuttal of Hoffman. nt

[Realityhack]

63. Um... this is all stills from a video

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=265855&mesg_id=265872

I think that is what is being referred to.

[Bonobo]

64. OK, so let me try to understand the point Lared is making...

Lared,

Just to recap what you are asking me. Here is a summary. Is this right?

You said ""as the top section collapses, it's mass is moving into the upper floors while the perimeter wall remain intact for a few moments"

Then you asked me if I thought that such a thing was possible. I said certainly it was.

And now you are asking me if I should throw out everything this author says because he doesn't address that specific possibility, is that correct?

You think that from this point, everything that he says or has said is "junk" that shouldn't even deserve consideration?

Is that how difficult you will make the process of discussing things here? It seems, well, a little over the line in terms creating a reasonable standard for engaging in a conversation. Particularly when the point of this OP was merely to ask for links to a rebuttal of a paper that came out 6 years ago (i.e. Hoffman) that I STILL haven't gotten a decent response to ion this thread.Just the 60 micron quibble which certainly is not proven wrong from the paper you cited and would not represent orders of magnitude of difference in any case.

It has been agreed by AZ that the approach is reasonable, so we should be able to go beyond that to discuss numbers or application problems, no?

Why is it taking so many responses to get to what I asked for. Either a well-written response to Hoffman that has been done in the last 7 years or at least something written in the past few years on DU. I haven't seen it yet.

[Realityhack]

65. "...that I STILL haven't gotten a decent response to..."

Of course you have. It just doesn't meet *YOUR* criteria for 'decent' which are quite silly. The responses you have received are more than enough for any reasonably informed person who has the requisite background knowledge to analyze the paper to understand the issues with it.

You are intentionally ignoring the clear counterpoints made by people against the Hoffman paper and then asking for a ridiculous burden of proof where people convince you specifically no mater how ignorant you choose to remain regarding the physics/math/engineering or other subjects involved.

[Bonobo]

67. Let's meet at post #66.

I think I am asking for very little.

Please show me the decent response that I have been given and we can discuss why it seems insufficient?

I agree that our perceptions of what is going on here seem at odds. TO me, it seems I am asking for relatively little and you see to perceive quite the opposite.

Show me what I am missing. Please.

[Realityhack]

73. here goes nothing...

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=265855&mesg_id=265864

AZCat
Hoffman's mistakes are all over the place: he assumes all the concrete in the towers is fragmented, he assumes too small an average particle size for concrete (see the Lioy study), he simplifies the dust cloud as an ideal gas and uses the expansion to determine an increase in temperature (and therefore an increase in energy), he assumes the powderized concrete increases in temperature by the same amount. These are quite obvious, and any "paper" with mistakes like these doesn't warrant a formal response. It would be like writing a rebuttal to an paper written by a fifth grader.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=265855&mesg_id=265921

LARED
It is well documented that nearly all of the non-metallic constituents of the towers were pulverized into fine powder. The largest of these constituents by weight was the concrete that constituted the floor slabs..............Based on diverse evidence, 60 microns would appear to be a high estimate for average concrete particle size,

This is flat out wrong by a large margin. This is a foundational assumption that large parts of the paper depends upon. If this is wrong the paper is worthless.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=265855&mesg_id=265860

LARED
It is well documented that nearly all of the non-metallic constituents of the towers were pulverized into fine powder. The largest of these constituents by weight was the concrete that constituted the floor slabs..............Based on diverse evidence, 60 microns would appear to be a high estimate for average concrete particle size,

This is not documented at all. In fact all the documented analysis performed on the dust indicates this is not true.

http://www.ehponline.org/members/2002/110p703-714lioy/l...

I do not expect you to understand what Lared and AZCat (both engineers) are pointing out. You have admitted you do not have the requisite foundation to comprehend their answers. But they HAVE provided very good answers to your initial question wither you choose to accept those answers or not.

It has already been explained to you in another thread why engineers can not necessarily provide a simple answer to a simple question (remember the post about why the sky is blue?). You seem to be intentionally ignoring that information.

Edit for missing link

[Bonobo]

75. Thanks for the reply.

I will ignore the unnecessary (but expected) statements of "I do not expect you to understand" blah, blah. They have no place in the conversation. It is ironic though. I am about to say the other thing that you do not want to hear which is that I will get back to you soon.

BUT wrt to what you sent above, even at a cursory glance I see that all you did was repost highly unsubstantative posts with no details and then even the same link twice in a row.

You did not address the fact that I called the 60 micron complaint untrue and that seems to be the largest of your complaints with Hoffman's work.
So what is it that you don't think I am understanding? What am I ignoring?

YOUR QUOTE:
"It has already been explained to you in another thread why engineers can not necessarily provide a simple answer to a simple question (remember the post about why the sky is blue?). You seem to be intentionally ignoring that information. :

This is what you mean when you charge me with 'ignoring' information. The sky is blue analogy amounts to "you are not smart enough to understand the answer, so don't ask."
Are you asking me, in effect, not to ask because I am too unschooled? I am a well-educated liberal arts person. I have learned how to delve into new subjects and look for evidence. I have learned, in sort, how to learn.

Below is a summary of AZCat's stated complaints with Hoffman.

1. (Hoffman) assumes all the concrete in the towers is fragmented,
2. (Hoffman) assumes too small an average particle size for concrete (see the Lioy study),
3. (Hoffman) simplifies the dust cloud as an ideal gas and uses the expansion to determine an increase in temperature (and therefore an increase in energy),
4. (Hoffman) assumes the powderized concrete increases in temperature by the same amount.

I think you have been unable to really support #2. I think it is unclear what you mean by #1. What do you mean by "fragmented"? Please explain. I think #3 was done because Hoffman stated he does NOT believe there was a bomb, so he assumes that only the expansion of natural gases could explain the expansion of the dust cloud? Isn't that true? If not, please correct me as to how I should explain it. Hoffman was looking for energy sinks and if the cloud expanded, it means a certain amount of energy went into the heating of those particles and the expansion of the cloud. The answer is how much. If you object to his numbers, I think it only fair to supply other numbers or a more pointed criticism.
In any case, as I said, I will attempt to get an answer to any questions submitted here directly to Mr. Hoffman. So if you have anything to add, I would like you to please cut and paste the above 4 points into your reply and add some more.

[Realityhack]

92. let's see here.

BUT wrt to what you sent above, even at a cursory glance I see that all you did was repost highly unsubstantative posts with no details and then even the same link twice in a row.

Nope two different links. They did start out with the same quote and were both posted by Lared but they are different.

This is what you mean when you charge me with 'ignoring' information. The sky is blue analogy amounts to "you are not smart enough to understand the answer, so don't ask."
Are you asking me, in effect, not to ask because I am too unschooled? I am a well-educated liberal arts person. I have learned how to delve into new subjects and look for evidence. I have learned, in sort, how to learn.

It is a simple fact that you can not begin to explain advanced calculus to a person who has never seen algebra. Sometimes you need to go out and do your own research and ask simpler questions before tackling the ones you want to. If you know how to learn than you know that. Nobody is saying don't ask, they are saying 'why should I bother with a long detailed explanation you won't understand?' You simply have not shown that you have the requisite understanding to discuss these topics intelligently, and you have essentially refused to educate yourself.

...I think it is unclear what you mean by #1...

If you want an explanation of what AZCat means by something he types I would strongly suggest you ask HIM.

1. (Hoffman) assumes all the concrete in the towers is fragmented,
2. (Hoffman) assumes too small an average particle size for concrete (see the Lioy study),
3. (Hoffman) simplifies the dust cloud as an ideal gas and uses the expansion to determine an increase in temperature (and therefore an increase in energy),
4. (Hoffman) assumes the powderized concrete increases in temperature by the same amount."

1. I believe what AZCat is getting at here is that not all of the concrete in the building was turned into dust. But Hoffman assumes it was in his calculations.
2. You claim 'we' have not backed up the criticism of the particle size. This is not true. Links have been posted more than once, your quote includes a source to check. I have not seen you point out a specific error in any of these sources much less all of them.

[Bonobo]

97. It seems from your reply that the best that you and everyone else has as a rebuttal is:

1. (Hoffman) assumes all the concrete in the towers is fragmented,
2. (Hoffman) assumes too small an average particle size for concrete (see the Lioy study),
3. (Hoffman) simplifies the dust cloud as an ideal gas and uses the expansion to determine an increase in temperature (and therefore an increase in energy),
4. (Hoffman) assumes the powderized concrete increases in temperature by the same amount."

I will ask once again to you, and leave it open for another few hours:

Do you have anything else to add to these that were supplied by AZCat?

Otherwise I think it is fair to assume that anyone participating in this thread has no other substantive complaints (i.e things to say that DON'T talk about how uneducated and incapable of understanding anything Bonobo is.) and I will pass these along to my friend who says he hopes to get a response from Hoffman. OK?

[Realityhack]

105. Sure.

Hoffman fails to establish a distribution of particle sizes or show why an average is acceptable for his calculations.

[AZCat]

132. Wow, this is really getting deep fast.

You don't understand my criticisms of Hoffman's work, so you handwave them away. Fucking brilliant. Who knew that you could win arguments by being ignorant?

[Bonobo]

133. YOU are the only person that offered anything at all.

I am not handwaving your contribution. In fact I am trumpeting it, I am championing it as the very best that DU has to offer on the entire subject of Hoffman's paper.

Again, for the last time. the list in #75 is what you offered as a rebuttal of Hoffman's paper. I think it is possible I might get Hoffman to respond to substantive criticism, so I wanted to be sure I collected the full weight of DU wisdom on the subject. Now I am convinced I have seen and heard it all.

But in case I am wrong, do you have anything to add to the list in #75 that you offered?

If not, I guess I will bow out of this thread for the time being while I see if I can come through with something such as a direct response from Hoffman or a more satisfying response to the criticisms you made from someone you would respect.

[AZCat]

136. In all honesty, I don't care if Hoffman responds.

Based on what I've seen of his work so far he's not going to have anything interesting to say. Best case is that he'll try to defend his calculations, except that they're not really defensible - they're crap.

[Bonobo]

141. OK, great. I guess we're done. Thanks for everything.

Now I know that it doesn't matter what he says. What a great scientific attitude. He could literally say anything and it wouldn't matter.

Gotcha. Consider me out of the thread.

The thread officially ended when you, the only person to offer ANY rebuttal of substance, declared that no answer would suffice. Even though you said that Hoffman's approach was sound but that his application was wrong.

When offered a chance to substitute a new number, it was said that the idea of an average itself was pointless. When a range or whatever was asked for, that too was denied. When it was pointed out that there was plenty of room for error in the equation but this was dismissed without any calculation as being an order of magnitude off.

So congratulations of the thread ending, but I have to say that as I go on and actually see how you all operate, I am losing my fear and respect. You are actually rather hollow shells that break apart as fragilely as the top of the old pile driver. And the funniest thing is that you display far greater paranoia than I do.

Some people on this thread, although disagreeing with me, were able to do so in a reasonable manner that will continue to facilitate mutual communication. Others have cemented, for me, reputations that had up until now been somewhat in flux.

Rest assured I will pass on these rebuttals listed in #75 as representing the full weight of the authority of the DU debunker commission.
I hope I can get an answer soon (even though I know "itdoesn'tmattercausenothingwilchangemymindsothere!!blahblahblah" LOL.

[AZCat]

143. Oh, for fuck's sake - take your drama queen bullshit somewhere else.

Next time try reading for comprehension. You may not have a technical background but surely you can at least accomplish that much. It would also help if you avoided making strawman arguments, or if you managed to stop whining about our vicious treatment of you (:eyes:).

[Bonobo]

150. OK thanks for everything! nt

[LARED]

71. Here's the problem

Serious and fatal flaws in Hoffman's paper have been shown to you. Of which you either do not understand or refuse to acknowledge. I'm guessing you really don't understand based on this

would not represent orders of magnitude of difference in any case.

Yes it could. The energy required to pulverize something is not linear. Not at all. Particle size has a geometric influence. Add that to his incorrect assumption about the mass of the particles and it becomes bird cage liner in short order.

The flaws are so obvious to those with the proper background that it is silly to consider some sort of "formal rebuttal".

You seem disturbed that no one what to discuss this on your terms. Frankly your terms are terms derived from ignorance. Don't expect serious people to have serious discussion about nonsense. Hoffman's paper is nonsense, you just can't see it and refuse to listen to those that have been trying to educate you.

[Bonobo]

82. Again, "you are too dumb".

What is your number for the average particle size?

Please just answer that.

You can't just say the flaws are so obvious that you must be dumb and since you're dumb it would be a waste to explain.

Surely you can see the problem with that, Lared, no?

[Realityhack]

86. "What is your number for the average particle size?"

Seems to me that that is not necessarily a properly formated or relevant question.

1. Which type of average? Mean? Mode? etc.
2. Because the energy required does not vary linearly with the partial size you can not just take the 'average' particle size and start throwing it into formulas as if all the particles were of that size. This is especially true if you have large 'spikes' where a significantly greater mass of particles are of a particular size.
3. You wouldn't know what to make of the answer anyway.

[Bonobo]

88. I would have replied but then I got to #3 and decided why bother.

Would you respond if someone wrote that to you?

[Realityhack]

93. You have previously admited...

that you are not good at math. You also showed that you did not understand what would be required to result in a difference of an order of magnitude in the energy being discussed.

Given an average particle size of X I stand by my statement that you would not know what the implications of X as an average size are.

[Bonobo]

95. Look, why don't you supply a number then?

Hoffman supplied a number. You criticized it and said that a small change could lead to a magnitude of difference, right? If so, show me. You choose an upper limit factor for a particle size that would be able to result in an expanding dust cloud (hint: a 8x8 steel girder cannot be consider part of a dust cloud) and show me that your defensible number would result in an order of magnitude difference.
The fact is that Hoffman's energy equation, if you would give it a chance, has so much room for error that it at least deserves to be given consideration and not short shrift.

In any case, your projections that I cannot understand the implications of a number (true or imagined) do not bear directly on the issue, nor on your burden of supplying another number in lieu of, as yet, unclear critique of the originals.

[Realityhack]

100. please refer back up thread to where...

I pointed out that I do not think a single 'average' particle size would necessarily be meaningful for this calculation.
Also consider that there are other flaws that could drastically influence the outcome.

You state that:
"...Hoffman's energy equation, if you would give it a chance, has so much room for error that it at least deserves to be given consideration and not short shrift."

On the contrary. I think the fact that he came up with an energy estimate of more than 10 times the available PE would make any sane person go back and question his assumptions carefully. Which of course results in the problems pointed out by AZCat and Lared.

[Bonobo]

104. First of all, it is NOT 10 times the available PE

Available PE = + 111,000 KWH falling of mass (1.97e11 g falling average of 207 m)

- 135,000 crushing of concrete (9e10 g to 60 micron powder)


So why do you say 10 times?

[Realityhack]

106. From the conclusion of Hoffmans paper.

"The amount of energy required to expand the North Tower's dust cloud was many times the entire potential energy of the tower's elevated mass due to gravity. The over 10-fold disparity between the most conservative estimate and the gravitational energy is not easily dismissed as reflecting uncertainties in quantitative assessments."

You only included one of the line items in his calculation. I was including all of them... because that is what his paper does.

[LARED]

102. My answer to average particle size.

I don't have a clue other than it is far greater than 60 micron. Years of experience in the business of milling and crushing resins tells me that. In case you don't know 60 microns is barely visible to the eye as a discrete particle.

Again using the average particle size tells you little about the required energy because the energy needed to pulverize to different sizes is not linear.

[Bonobo]

112. Well. If it isn't linear, than the only approach you would accept would be a range then, yes?

It still wouldn't place this conversation outside of what we should/could discuss AND

it does not establish your claim that he was off by an order of magnitude.

As to your personal experience of milling and crushing resins, I will have to say that an anecdotal claim like that does not hold much weight. But the good news is that it shouldn't be THAT hard to get a range of estimates of dust particle size. I bet it has been done, or you are willing to do it. But I cannot see any argument for NOT proceeding with this type of argument if we could come to an agreement about proper calculation methods, right?

The results could establish an argument for EITHER side.

You claim it should be a greater average particle size, right? Based on your experience with resins? Okay, but can you give me the range YOU wish to calculate? Or if I do research and find that the number is supported by other claims of avg. cloud dust size or something than would you come back and revisit this Hoffman?

[Realityhack]

113. Not a range. A distribution.

There is a huge difference.

[vincent_vega_lives]

43. all the crush up did

was eliminate all the empty space and volume of air in the upper part. The amount of mass lost outside the perimeter of the building was 20-25% at most.

[Bonobo]

48. So are you saying the 'crush up'

was a kind of pancaking of upper floors or a shedding of massive amounts of mass out to the perimeter?

[vincent_vega_lives]

54. Pancaking of the floors

and shedding of the perimeter columns IMO.

[Bonobo]

61. OK, thanks.

[LARED]

41. Lets try to stay on subject

The point is that a foundational assumption made by Hoffman is just plain wrong. Not just a little wrong, wrong by probably orders of magnitude.

Hence, just about everything following in the paper is based on a faulty assumption.

Do you understand this?

[Bonobo]

49. Which assumption do you mean? nt

[LARED]

52. This one

It is well documented that nearly all of the non-metallic constituents of the towers were pulverized into fine powder. The largest of these constituents by weight was the concrete that constituted the floor slabs..............Based on diverse evidence, 60 microns would appear to be a high estimate for average concrete particle size,

This is flat out wrong by a large margin. This is a foundational assumption that large parts of the paper depends upon. If this is wrong the paper is worthless.

[Bonobo]

58. What's wrong with the numbers?

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=125&topic_id=3500

Please see the table you posted. What is wrong with the 60 micron size estimate?

[LARED]

70. I have gotten out of the habit of spoon feeding but here goes

1. The table clearly shows the three samples as having a size greater than 75 micron for at least 63% and up to 72% by mass.
2. Two of the samples were taken at least a block away from the main collapse area and one was 0.7 kilometers away. This is rather important as only lighter and smaller debris will travel those distances. The heavier and denser materials will fall close to the collapse zone.

Or as I said nearly six years ago regarding Hoffman's paper here and linked above for you to read.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=3500&mesg_id=3518

Also you seem to assume the concrete particle size distribution stayed somewhat uniform regardless of the distance from the collapse, when in reality the heavier and larger particles (or chucks) would remain near the towers footprint while the lighter, smaller and more aerodynamic particulate matter would travel further. How much of the heavier concrete remained within or near the footprint of the collapse would greatly impact your energy calculation.

In short the mass of materials Hoffman believed (at the time) that would be pulverized to an avg of 60 micron is overstated by at least an order of magnitude.

Of course you will now ask for a rigorous justification for my statement regarding particle size distribution. To which I can only tell you to go educated yourself about topics like terminal velocity and particle size distribution for plumes. I've spent 25 years as an engineer and I can assure you my statement that he's off by only a single order of magnitude is being generous.

[Bonobo]

85. Thanks for the spoon-feeding, but...

1. The table clearly shows the three samples as having a size greater than 75 micron for at least 63% and up to 72% by mass.
RESPONSE: Not true. The table shows 2 types of samples; Aerodynamically separated samples and Sieved Samples. Naturally sieved samples will be larger (because they were sieved!) But among the aerodynamically separated samples, between 35-45% were between 10-53 microns and 50%-60% were between 53-75 microns. Nothing showing the ratio between the 2 types is visible to me in that table.

2. Two of the samples were taken at least a block away from the main collapse area and one was 0.7 kilometers away. This is rather important as only lighter and smaller debris will travel those distances. The heavier and denser materials will fall close to the collapse zone.
RESPONSE: SO what? Those larger masses are not part of the energy needed to form a dust cloud so throw them out. It is not part of the estimated sink that he is even talking about here. Throw those out if you wish, it shouldn't make a difference.

"In short the mass of materials Hoffman believed (at the time) that would be pulverized to an avg of 60 micron is overstated by at least an order of magnitude. "

REPONSE: More than an order of magnitude! How did you get that? I see no supporting evidence that that is true. You can't just SAY it and expect it to go unchallenged. Do you have other numbers? Oh, I see below. This is the part where we accept your statement because you say so and yet I am the unscientific one because I want to have more than that. You are an unknown on the internet. At least Hoffman published numbers. If he is off by more than a magnitude, it should be EASY to show that.

"Of course you will now ask for a rigorous justification for my statement regarding particle size distribution. To which I can only tell you to go educated yourself about topics like terminal velocity and particle size distribution for plumes. I've spent 25 years as an engineer and I can assure you my statement that he's off by only a single order of magnitude is being generous.

RESPONSE: So in other words, Hoffman is wrong by a magnitiude. I am too stupid to know that and you are too smart to waste your time explaining it. Is that about right?

Is that what I should have Hoffman respond to?

Can you go to #75 and tell me how I should append the summary of rebuttals that I will make to him? Shall I include your letter from those years ago? Did you never get a response?

[LARED]

99. No you're wrong

So in other words, Hoffman is wrong by a magnitiude. I am too stupid to know that and you are too smart to waste your time explaining it. Is that about right?

I am not too smart to waste my time. You are not stupid either. You admittedly do not have the background to discuss these matters as you would like to. Your responses thus far and defense of Hoffman clearly exhibits this for all to see.

1. You fail to understand why if you want to find an average size a sieve is the better method. You also fail to understand how using an average particle size is just about useless unless you have a distribution if one is trying to calculate the energy used to pulverize concrete.

2. You say so what? Saying that just reinforces to all that you don't understand. Hoffman uses the entire mass of concrete as a basis. The particle size distribution from ground zero outward is critical to quantify if you want to state the average particle size is 60 micron. I'll tell you what. If you want to see the impact of this, calculate how many 60 micron particles would fit into a 1 cm sphere of concrete. Then you will see the the difference in required energy.

If your background in math is insufficient to do this then you are out of your league.

[Bonobo]

119. Again, I invite you to offer a distribution of sizes to calculate from. nt

[LARED]

124. Do your own homework

Again I offer this simple mathematical experiment to assist you in understanding the particle size issue.

Calculate how many 60 micron particles will fit into a 1 CM^3 sphere of concrete.

[Bonobo]

125. I will take post #75 where I summarized the rebuttals to be all there is to say then.

I don't think there is any more point to this.

[Bolo Boffin]

40. An interesting feature of your link.

The paper was written in 2003.

At the top of the page currently is this statement.

This paper has been updated. Please see Version 4. The version on this page is archived for historical interest.

Yet when you go to Version 4, you find this message after a few paragraphs:

NOTE BY JIM HOFFMAN:
This paper is currently under development, taking into consideration critiques by various reviewers.

Going to the page source code you find the rest of the paper enclosed in HTML comment markup and the date <!-- December 15, 2005<br/> --> under Hoffman's byline. Are we to believe that Jim Hoffman has been four years taking into consideration critiques by various reviewers? What is the hold up? Has Jim Hoffman given up this line of inquiry?

Perhaps we should wait for the final version of the paper before commenting on it further.

[Bonobo]

51. I think that I could get an answer directly from Jim if you can offer some strong

points of rebuttal.

I know someone who can reach out to him, so I would be delighted if you could share some arguments and I could get a response. I think it could be an incredibly great conversation since you are such a worthy adversary to take the debunking side.

[LARED]

53. Seriously, do you not understand what others have said?

It is obvious strong points of rebuttal have been offered here, and elsewhere since his paper was published. He has not revised the paper in over four years. I seriously doubt Hoffman is patiently waiting for yet more strong points of rebuttal to yet again get his ass handed to him.

[Bonobo]

57. I am sorry that you don't want to try that.

"Seriously, do you not understand what others have said?"

I am underwhelmed. Very little has been said other than the 60 micron complaint and when I ask you to look at the study to cite and tell me precisely what is wrong with that estimate, all I hear is crickets.

[Bolo Boffin]

90. Has Hoffman ever calculated the amount of explosives needed to provide the energy

he says is required?

[Bonobo]

91. It is not germane to his paper.

In fact, his calculations assume there was no explosion since it has no part in the official explanation.

[Bolo Boffin]

103. The fuck it isn't. n/t

[Bonobo]

108. Can you take a chill pill and explain?

"Fuck it isn't" doesn't really communicate that much information surprisingly.

[Bolo Boffin]

110. I've had it with your act.

You're not here to listen and to dialogue. You're here to scold and to advance crap like Hoffman's bullshit on 9/11.

So the fuck a calculation of explosives needed isn't germane to Hoffman's paper. I agree that it's not at all helpful to Hoffman's goal, the spreading of bullshit about 9/11, but it definitely is germane to the subject of Hoffman's paper.

[Bonobo]

115. You are welcome to say whatever you want. Be done with my act all you want.

But you have shown your hand in my opinion. Fine. Do not post on my threads. You are precisely the type of person that cannot be spoken to. In my opinion you exhibit a decidedly UN-scientific point of view because you shut down conversations. If I am wrong, you will stay out of my threads. If I am right, I will continue to see the type of behavior you are exhibiting now with your baby-like cries of "The fucki it isn't".

The fact is, for whatever reason, you think I "have an act". This says loads more about where your head is than where my head is, brother. I have tried to be respectful, I have tried to be patient.

To a degree, I can understand motives. moods and intentions being misunderstood. But I have been trying to 'cool the air' before entering into discussion many times -the latest spur of which began only recently when SDuderstadt instituted a 'truce' in honor of Ted Kennedy. Since that time, I have 99% of the time tried to be respectful while I sit and READ the stuff I am talking about. After I read it and try to understand the "Truther" arguments, I present them here and ask questions. Sometimes I just ask for links as I did in this thread. What I get is a couple of people willing to share their objections and then I get people who just want to shut down conversation.

You show yourself here to be one of them. Despite numerous attempts at rational conversation (the point of the 9/11 forum), I get maniacal psycho shit like your 4 word rant above. WTF is with that? I realize that you have a rather ummm, "focused" view of the world but it doesn't make me a double secret agent. You are just being, well, nutso about that.

So don't respond to me anymore if that is what you think I am.

[Bolo Boffin]

116. That post is nothing but the "scold" part of your act.

Scold, scold, scold.

Meanwhile Hoffman hasn't calculated the amount of explosives needed to make up the difference in his energy requirements and blithely accepts a staggering figure like 14 tons and you're advancing his bullshit.

[Bonobo]

120. Buh-bye. I have no act and no desire to talk to you. nt

[Bonobo]

123. That was an unhinged post. Truly paranoid raving. nt

[Bolo Boffin]

126. LOL, you keep dreaming n/t

[Bonobo]

127. You have really disappointed.

You are smart but not cut out for looking for truth. Too closed-minded.

[Bolo Boffin]

128. Scold, scold, scold.

I won't sit idly by while you pretend to promote reasonable dialogue with the likes of Jim Hoffman.

[OnTheOtherHand]

149. yikes, c'mon, think about it

Bolo is sketching a proof by contradiction, or at least reductio ad absurdum. Hoffman postulates a humungous energy deficit. A bunch of people here are telling you that his calculations are bunk, but you don't know them, and you can't do your own. So, consider: if there's a humongous energy deficit, it would have taken a humongous quantity of explosives to balance the equation. What would it look like, what would it sound like, if that quantity of explosives were set off in whatever sequence would be needed to produce the collapse we see?

If someone is arguing that the accepted explanation is impossible, and you can't tell directly whether that argument is correct, it's eminently reasonable to ask whether his or her alternative explanation is facially more plausible or less plausible. If he or she refuses to offer alternative explanations -- or if the alternatives are strangely lacking in the specificity one would need to tell if they make a tinker's dam worth of sense -- then IMO s/he is in approximately the same boat as the person who argues that evolution is mathematically impossible. It's not logically impossible that s/he is right, but it probably isn't worth much time.

[Bonobo]

151. It's fine.

It is more than I asked for with the thread and I don't understand your point below:
"Hoffman postulates a humungous energy deficit. A bunch of people here are telling you that his calculations are bunk, but you don't know them, and you can't do your own. So, consider: if there's a humongous energy deficit, it would have taken a humongous quantity of explosives to balance the equation. What would it look like, what would it sound like, if that quantity of explosives were set off in whatever sequence would be needed to produce the collapse we see?"

First of all, I don't think Hoffman postulates a humongous energy deficit. He postulates that the heating and expanding cloud represents an energy sink. Do you disagree that it took energy to heat and expand a cloud of dust? He does not postulate explosives but finds after balancing the equation that the power differential he reports is off by a lot.

All I meant to do with this thread was to personally gather what had been discussed by way of debunking his approach. If you are satisfied that this thread is the best that can be done toward that end then I have to decide that this thread is finished.

It has served its purpose and it never really mattered if you all felt I was advanced enough to understand my answers. I was gathering info. This does not require that I understand everything, but I did my best.

Thank you everyone for helping me. I wish you could not be such assholes in general, but I guess that is what you get.

Thanks to OntheOtherHand for getting the "But I'm not an asshole" award for the thread.

[Realityhack]

152. "I don't think Hoffman postulates a humongous energy deficit."

"He... finds after balancing the equation that the power differential he reports is off by a lot."

That would be um... an energy deficit. And the one he calculates is unarguably humongous.

[Bonobo]

153. So you are saying he postulates too much energy is needed for the dust cloud.

Is that right?

[Realityhack]

155. Are you telling me you do not understand the conclusion of his paper?

At this stage in the discussion?

If his joke of a 'paper' was correct it would indicate that the energy needed to create the dust cloud alone was over ten times the amount released by the buildings falling.

Which should immediately set off alarm bells.

Fortunately his calculations are laughable so we don't need to go looking for what released the remaining energy (equivalent to 95 tons of TNT for each building).

[Bonobo]

161. Not at all! But, in his paper, even if I threw out the dust cloud completely...

I am left with an energy drain for pulverizing all that concrete that would demand more than the total potential energy contained in the building. Admittedly it is close, but that is not including the energy needed to throw material out to the sides.

Can you help me total what the expected number of energy drains would be in your opinion?

[Realityhack]

166. No.

I do not have the requisite data, time, or (depending upon how precise you are expecting to get) the requisite skills.

For example we do not even know what the distribution of particle sizes is for the concrete or what percentage was actually pulverized into dust. I CAN tell you it is not 100% as Hoffman assumes. I can not give you a figure that would allow you to calculate the exact energy expenditure.

[Bonobo]

168. I understand that such data is not available as well.

No distribution of particle sizes was available.

So I can understand the critique of his claim for 60 micron size average and I even understand your criticism that the amount of energy to push around debris does not increase in a linear fashion relative to size and so such a 'median size" is somewhat useless for calculation purposes.

So it sounds as if you feel that the attempt to nail anything down by doing a 'balance of energy' equation is basically useless since we cannot fairly estimate the factors involved.

Can we agree in general on what the energy drains would be even if not how to calculate them? Does Hoffman get ANYTHING right? Are his energy drain 'topics' correct in your opinion at least (other than the cloud which I now understand you as saying that it required none or very little energy since it did not heat and expand).?

[Realityhack]

173. Well lets see.

"So it sounds as if you feel that the attempt to nail anything down by doing a 'balance of energy' equation is basically useless since we cannot fairly estimate the factors involved."
That would be my assessment yes.

"Can we agree in general on what the energy drains would be even if not how to calculate them?"
Maybe but I am not sure I see the point given the above.

"Does Hoffman get ANYTHING right?"
I think we would have to agree on what you mean by 'right' and what constitutes a substantial enough item to be listed. I noticed he used several complete sentences and as far as I saw did not misplace any decimal points.

"Are his energy drain 'topics' correct in your opinion at least (other than the cloud which I now understand you as saying that it required none or very little energy since it did not heat and expand).?"
Glancing back at the paper all I see listed are:
Crushing of concrete (takes up energy sure, but his calculations are silly)
Heating of cloud (you already accept this is a poor calculation at best)
Heating of concrete in cloud (same as above)

Of course there were other things, mangling of nearby buildings, the pulverization of wallboard, the twisting of steel supports, etc. etc. etc.

All of which is why this is a pointless calculation. Anything it might 'reveal' would be orders of magnitude below your potential error for any reasonable confidence interval.

[Bonobo]

175. OK, but...

"Anything it might 'reveal' would be orders of magnitude below your potential error for any reasonable confidence interval."

You seem so confident of this conclusion that it is hard to avoid the feeling that you would throw away any calculation that didn't come out that way you expect if you were to even attempt it or allow someone to attempt it.

In other words, it sounds as if your definition for rejecting the data out of hand is based on the fact that the conclusion would imply added energy and therefore COULDN'T be true.

So any bias before crunching the numbers is unfair, no? It just seems you are prejudging it based on what you have already decided must be true. Maybe the same is true of Hoffman, I don't know.

[Realityhack]

181. I disagree.

Let's assume for a second that we are looking for explosives.
Take a look at the figure for how large the PE of the WTC towers was. Then we can go and add up some, but not all, of the energy released in the collapse, with a huge margin of error (say 10%) because there are way WAY the hell too many things we don't know.
Then look at that 10%. It is still a staggering figure. So we could potentially rule out a nuclear blast or tons upon tons of explosives. But we can do that already from the video etc.

Say you want to find a death ray, or thermite, or whatever. How much energy would be needed to initiate a collapse (even without aircraft damage) as a percentage of the PE? It will be a minuscule percentage, and since we know we will have a very large margin of error, we know we won't be able to learn anything from what we calculate.

The only way we could learn something is if there really was two or three times the expected energy, but do you seriously think that much energy would not be recorded in other more obvious ways?

[Bonobo]

183. That is a really good point. nt

[Bolo Boffin]

157. That is his argument against gravity being able to do it.

Gravity isn't enough by a humongous amount. But the amount of explosives (his suggestion) needed to make up the deficit is a staggering amount. Hoffman doesn't blink at a 14 ton amount - and I showed you what 364 POUNDS sounds like.

And yet all I get is scolding because I roll my eyes at Hoffman's bullshit and your attempt to spread it here in a polite and rational manner. Oy.

[Bonobo]

163. Thank you.

[Bonobo]

164. Here is your error.

You ascribe motives to me that are untrue whether you believe it or not. And it is really borderline offensive and against DU rules for you to suggest that my motives are for spreading lies and "bullshit".

Stop impugning my motives, stop being rude and we will get along fine. Otherwise just don't respond. I really would prefer that, but I recognize that you will do as you please in the end.

[Bolo Boffin]

170. Thank you, Bonobo.

May I have another?

[Bonobo]

172. No, I have nothing to add.

Just please... you know?

[Bolo Boffin]

154. I disagree that it took heat energy to expand THAT cloud of dust.

I see a cloud of thick dust that goes DOWN until it reaches the ground. At that point, it begins to flow out, behaving for all the world like the density flow that it is.

Hoffman's assumption that it is heat energy expanding that dust cloud is unwarranted.

[Realityhack]

156. Seems a lot of his assumptions are unwarranted. n/t

[Bonobo]

159. I would love it if you wouldn't mind elaborating.

I know, I am faking and it is an act. But I still want you to prove Hoffman wrong and silly so I too can dismiss it with prejudice!

[Realityhack]

160. AZCat gave you a starter list

We added to it. The assumption that the calculation could be performed with an average particle size, the assumption as to the mechanism of cloud expansion.

Hell just click the link to see what post I replied to. It was quite specific.

[Bonobo]

162. Thank you.

[Bonobo]

158. I sure understood that!

Okay, what can I say to that? Great point. To prove that you are wrong about that, I would need to demonstrate unequivocally that the cloud expanded before it hit the ground I suppose! Great!

I love a nice clear point like that, so thank you.

[OnTheOtherHand]

176. well, I think the thread is sort of a train wreck

Just to situate myself here, I've been the person in a position to say, 'Frankly, this is so bad that when I try to explain the bad, my teeth hurt.' I'm sure it comes across as very sour, and I try to walk through the critique whenever I can, but sometimes a close analysis is just painful, like listening to really bad karaoke, so bad that it threatens to annihilate the memory and prospect of actual music.

That's with respect to survey research and other poli sci stuff. I'm no engineer -- I didn't study physics beyond high school -- so my initial reaction to the paper you linked to is that I know I could figure out the math, but I wouldn't necessarily pick up on the crucial questionable assumptions, if any. AZCat succinctly outlined some of those, and his points seemed plausible to me, as did points made by others.

Truthfully, I've learned enough respect for AZCat as an analyst and a person that if he has that sort of "so bad my teeth hurt" reaction to a piece of work, I'm inclined to go with it, all the more because he did succinctly enumerate a host of conceptual flaws. The fact that I can reason to a similar conclusion without even considering the math pretty much seals the deal. (There's also the fact that Hoffman has withdrawn the article you linked to, and that his Version 4 doesn't have any actual analysis yet, unless I'm missing it.)

I think I may be missing your distinction between "postulates a humongous energy deficit" and "finds... that the power differential is off by a lot." If you mean that he came to this conclusion after doing some work, rather than assuming it and circularly confirming his assumption, I agree (at least formally -- I have no way of reconstructing his thought process). I have no reason to think that he willfully butchered the analysis, any more than I think that the people who beleaguer mathematicians with their angle trisections have malicious intent. But I have good warrant for thinking that this line of analysis is extremely unlikely to pay off, at least in anything like that form.

I daresay someone could write a blow-by-blow rebuttal of this piece, so in that sense this thread isn't the best that could be done. But, again, considering that Hoffman has withdrawn version 3, it could be time to move on.

[Bonobo]

177. After this train thread of a wreck, I am not sure I disagree with what you said.

The fact is that I have learned a lot through the process of reading his work and trying to understand everyone's reactions.

Some of them perhaps seemed over the top to me because I do NOT have the background of AZCat for example. But that should not mean that I have to not try to learn or that I should be treated rudely.

Anyway, I have learned a lot.

[OnTheOtherHand]

184. I guess part of what I am trying to explain

is that people have visceral reactions to the bad*, and part of the reaction that you perceive as directed at you personally is more like, umm, spontaneous projectile vomiting. When I read post #2, I had a ferocious moment of empathy both with AZCat and with your likely reaction, so I jumped in. For one silly moment I thought I had really accomplished something. Oh well. :) Stuff gets personal on the Internet amazingly fast -- I used to think I was patient, but the record indicates Not So Much.

* ETA: It's partly to the bad itself, and partly to lousy memories of crazy-ass arguments about the bad. I do think people are sometimes 'guilty' of knowing what you're going to say next when you actually aren't, just because they feel like they've seen it so many times before. I know I get like that on the issues I know best.

[Realityhack]

Very very well written OTOH

So many good points.

[Bonobo]

179. I totally agree.

I am sorry it was so hard to get to this point, but maybe it is the best I can expect.

[OnTheOtherHand]

180. *blush* n/t

[Realityhack]

94. I did.

According to the numbers he gives he would need the equivalent of 95+ tons of TNT per tower.

regardless of where he does or does not think that energy came from it is a lot of energy.

[Bonobo]

101. Yes that is true. And Hoffman does in fact say this:

"Only the detonation of large quantities of explosives could have driven the third source of expansion. A commentary of version 3 of this paper by an anonymous author calculates that it would take 14 tons of the high explosive amatol to produce the expansion."

Remember now, he is working backwards attempting to identify, as I understand it, 'energy sinks' in order to determine how much energy as a total was expended. Do you agree that the expanding and heating dust cloud would require a certain amount of work to be accomplished? Of course you do. So the question is what size particles would define the dust cloud and then how do we define the dimension and speed of growth of the dust cloud. This is common sense.

You are objecting to his choice of particle size, but in the quoted table, there are 2 types of samples that we taken. One was airborn and the other was taken through a sieve. Both had the micron size calculations and, as expected the airborn ones were mostly smaller than 60 microns and the sieve ones were mostly larger. How do we arrive at a fair number? Hoffman gave 60. What do YOU want to replace it with. Let me quote from Hoffman:

"The quantity for the crushing of concrete appears to be conservative since some reports indicate the average particle size was closer to 10 microns than 60 microns. The quantity for the heating of suspended concrete has a large amount of uncertainty, but the energy imbalances remain huge even when it is ignored entirely. All of these energy sink estimates are conservative in several respects.

They are based on an estimate of dust cloud volume at a time long before the cloud stopped growing.
They use a liberal estimate of the contribution of mixing to the volume.
They ignore thermal losses due to radiation.
They ignore the resistance to expansion due to the inertia of the suspended materials, and energy requirements to overcome it."

[Bolo Boffin]

109. 14 tons of explosives!!!!!!!!?????

The Landmark Tower demolition in Fort Worth used 364 POUNDS of explosives.

http://www.dhgt.com/PDF/A%20talented%20team%20of%20demolition%20experts.pdf

And it sounded like this!

http://www.youtube.com/watch?v=79sJ1bMR6VQ

And you still defend Jim Hoffman?

[Bonobo]

117. Your point is unclear.

"The Landmark Tower demolition in Fort Worth used 364 POUNDS of explosives."

All explosives are not the same, what is your point?

Look, Hoffman said that a certain amount of energy was needed to produce the clouds. He said it would require 14 tons of a CERTAIN explosive. He said this to try to estimate a number. What is the problem. You are trying to obscure the issue.

[Bolo Boffin]

118. Only to people without ears and people without the desire to hear. n/t

[Realityhack]

111. Bonobo...

you keep coming back to average particle size as if it has some meaning in this calculation. It does not appear to me that such a simplification is warranted. Hoffman also assumes all the concrete in the building was broken down to this 'average' size, and makes some other errors (see AZCat's post). These are not small insignificant issues with his paper. They undermine the very foundation of his calculations.

[Bonobo]

121. Understood. I will go with #75 as being the total rebuttals. nt

[Realityhack]

165. BTW this is what the deficit Hoffman 'calculates' would look like.

http://www.youtube.com/watch?v=7VANyY87-_Q

100 tons of TNT PER BUILDING.

[Bonobo]

167. It seems misleading to claim that Hoffman postulates explosives at all.

I understand your point. He says that he has found an energy deficit and you are taking this to imply that he concludes there were explosives but that seems reverse thinking.

You are rejecting his figures based on the idea that you don't like the conclusion it implies, but to do so on that basis seems to be putting selecting data that you want to use based upon obtaining the results that you want.

[Realityhack]

169. Not quite.

You are correct that he does not specifically postulate explosives.
However, I think the video might help people who are not used to the amounts of energy we are talking about understand what he is implying.

It doesn't matter if the energy came from burning newspapers, the energy deficit is enormous.

As for wither we are doing it backwards... not quite.
The issue here is that Hoffman's calculation is out of the ballpark. It would be like doing a whole bunch of math to estimate the number of homeless in NYC and getting a figure like 30 Million. You don't start out by looking for the secret layer all those homeless are living in. You start by checking your calculations, assumptions, and methodology because your result makes no friking sense.
Then if you couldn't find any problems, and your peers couldn't, you might start looking for where they were hiding. In this case the flaws are numerous and obvious.

[Bonobo]

171. I understand. Thank you for that reply.

It may be frustrating for you all, it may even appear to you that such a person like me cannot exist. You may say I am running an act, being a drama queen.

You may say I should read more, not rely on the internet, do my own homework, etc.

You may think I am stupid, out of my depth, etc.

But if you knew me, and if we could talk eye to eye, you would find me a reasonable person. And I am honestly making an attempt to listen. So if you have any desire at all to continue explaining things even when you are frustrated, I promise to listen.

I do not promise to not ask questions or stop having a skeptical POV.

[Realityhack]

174. I certainly hope you do not stop having a skeptical POV.

As for the rest I can assure you that your looking things up and admitting when you may in fact be out of your depth will help you both in learning more and in getting along here.

[Bonobo]

178. Believe it or not, it is what I am trying to do.

NOT trying to spread untruths.

So thanks for your help and I hope to continue polite conversations with you if possible.

Thanks.

[tenseconds]

185. "out of the ballpark"

If the flaws in his calculations are numerous and obvious then lets hear some.

You have to come up with something well calculated in return. You can't sum up without a well constructed rebuttal.

You have none. Other than Hoffman's figures are "out of the ballpark"

Whatever the energy "sink" it certainly would slow down the time of collapse well beyond free fall times IMHO.

[Realityhack]

191. It doesn't look like you are even trying to follow along.

Hoffman's terrible paper does not deal with the collapse TIME at all. Not in any way.
People have offered quite substantive criticisms of his work. See post 9 for example.
Actually there is no requirement to come up with something 'well calculated' in order to criticize a bad paper. If you followed along you would know the approach itself is highly flawed.

[LARED]

107. Amazing

Bonobo is defending a paper the author seemingly won't even defend. And then to boot is upset because his ignorance gets no respect.

So amazing it make me wonder what this is really about.

[Bonobo]

122. Misplaced attack on me (again).

You guys amaze me. I asked for rebuttals and I got #75. Everything else is masturbation. I will leave this thread alone now while I attempt to get an answer from others. Yes, now you can criticize me for saying I will get back to you and then you can pretend that you think I am doing an act and all that....


I just don't get it. Thank god for SOME reasonable people on your side, but many of you don't really hack it in the people department.

[AZCat]

131. Really, LARED? It should be obvious...

what this thread is about.

[Bonobo]

137. Well tell me! I am dying to know what's cooking in that noodle of yours! nt

[AZCat]

139. Whatever.

This thread (and your behavior) is pathetic. You had a decent response at post #9 yet you couldn't shut the fuck up and walk away.

[Bonobo]

144. Same here.

Like I said, I came to collect rebuttals. I tried my best to draw as much info from you could about the specifics of your criticism of Hoffman and I don't think I got much. I was disappointed.

But I will take what you gave me with gratitude and move on.

I just don't understand the need for your contemptuous attitude. Does it make you feel better about yourself?

[AZCat]

146. I'm sorry we couldn't spoon-feed you all the information you required.

Heaven forbid you do a little fucking work yourself.

[Bonobo]

147. Nice french! nt

[Bonobo]

182. Thank you everyone for a very informative thread.

I learned a lot.

[vincent_vega_lives]

186. please explain what you have learned exactly

I am interested.

[Bonobo]

187. Well...

I don't know if this is all or exactly, but...

-I learned to understand what the justifications for rejecting Hoffman's paper were. I learned to understand the meanings behind those concepts.
-I learned that, as an approach, doing balance equations is acceptable as a concept, but given the massive numbers and unknow variables, it would be difficult to prove anything within the rather large margin of error that would exist. Still, I do think that a line of enquiry involving ballistics and angles of descent makes sense in order to prove or disprove any ideas about explosives, squibs or other phenomena.
For example, I have a thought experiment idea that I think would prove/demonstrate something. It would potentially rule in or out whether the top was "exploded". Interested? Okay here goes:

-We would be examining the large pieces of perimeter wall that could be described as peeling off the building as the additional building mass basically collapses internally (WT1,2). The perimeter wall could also be described as 'sloughing' or sliding off I think you might say. Are you with me so far? People who believe that there are explosions forcing those same perimeter walls outward would not describe them this way, but rather as being blown out to some degree. The speed at which some of them 'expelled' was calculated at a certain mph already by one guy I read, so we could check this by doing a ballistic analysis of the visible wall trajectory.
-It is my idea that by using the building side as a straight line and then reversing just the collapsing tower in the video to where it had begin standing a number of seconds previously (allowing for gravity?) and then measuring the angle of the wall section, it should be clear whether the exiting debris was 'sliding off' or 'exploding out and up in violation of gravity'. Isn't this true? I just thought of this the other night as an idea and I don't believe it has been done -not to my knowledge anyway. I do have a short ppt file that shows the particular piece of wall section though and measures it's distance and expected exit speed. But without doing a further analysis, I don't see what use that knowledge is (as I believe YOU pointed out -unless another energy balance equation could be set up but I believe it would be not very useful for the MOE reasons stated above).

[LARED]

188. Your thought experiment is reasonable except for one thing

during the collapse the materials that fell into the building not only collapse the floors beneath them but they also "collect" debris inside the volume of the tower. Meaning there was likely a mass of materials, perhaps ten stories worth or more, inside the structure acting as a chaotic mass in both a downward and horizontal direction. The effect of this is to act as a force pushing the perimeter walls outward as they were forced off or were sloughed off.

This outward force must be accounted for if you want a "balanced equation" I know of no way to quantify this force. Many CT'er already assume any horizontal force observed is proof of explosives.

[Bonobo]

189. OK, I see...

So in theory, couldn't you assume that any debris that wasn't clearly going outward initially was then going inward and became the 'outward force' you describe? So if you could estimate the mass of the top, say 40 floors or whatever and then make an estimate of what percentage of the mass was coming out and down (let's call that external debris) and what percentage was coming in and then forcing stuff out...???

Or strike that, maybe that's dumb... Well maybe it's not... Is there anything salvageable in what I just said?

[LARED]

190. anything salvageable?

Honestly no. It gets back to the issue of far too many unknown variables.