I'm lost on terminology; i.e. free fall

[Nuclear Unicorn]

OK, it was a mistake to come here. I saw the forum title "Offbeat" and thought it referred to more humorous postings ala The Lounge.

Anyhoo --

I keep reading that people have been compelled to admit WTC 7 was in "free fall" and free fall is taken to prove "controlled demolition."

Now, unless I've missed something, "free" means "unhindered" or "unaided" or "unattached." When I think of free fall I think of parachutists plummeting unpropelled through the ethers as fast as gravity will have them. If I have a stack of wooden building blocks and tip them over they too fall, freely. In fact, everything would fall freely according to the claims of gravity unless some other force causes the object to accelerate.

But this is the opposite of what the CTers are claiming. Wouldn't a 9/11 CT be contingent upon claiming the towers were collapsed because they demonstrated a speed for which natural phenomenon could NOT account?

BTW -- don't post links to youtube videos. They won't be watched.

[TheWraith]

1. You're right. But some people here apparently believe buildings are supposed to collapse slowly.

And drift down to the ground gently, like a person lying down on the ground.

The reality is a very heavy steel frame building is a machine for holding itself up. It's usually designed to work on the assumption that the whole building is intact. When part of it fails, usually the whole thing goes, and pretty quickly. The heavier the building, the more likely that is to be the case.

[jesters]

4. Lol. Um, no.

"When part of it fails, usually the whole thing goes, and pretty quickly. "

What other buildings have done this?

[William Seger]

19. Skyline Towers, Baileys Crossroads, Virginia, 1973

Sampoong Department Store, Seoul, South Korea, 1995
Lulu'at al-Khair Hostel, Mecca, Saudi Arabia, 2006
125th Street and St. Nicholas Avenue, Harlem, New York City, 2011
Etc. http://en.wikipedia.org/wiki/Category:Collapsed_buildings

You're supposed to ask, "What other steel-framed skyscrapers have done this?" The logic is still faulty, but at least the answer will be "None," which will be less embarrassing.

[jesters]

27. Which, if you had read the post I was replying to

was already assumed.

But nice investi-googling. I feel like I'm on JREF.

Can you tell us more about the 2011 Harlem building collapse? Because all I can find is that it was a partial collapse, of the facade. And the building was already under demolition, lol.

[William Seger]

32. Wrong again

Not just the facade and not already under demolition:
http://blogs.wsj.com/metropolis/2011/09/20/building-collapses-onto-bus-in-harlem/

[jberryhill]

2. Free Fall

A "free fall" is a term of art in the truth industry. It's when someone falls for the goofy theory in your book without actually buying a copy.

[Nuclear Unicorn]

3. I chortled. n/t

[deconstruct911]

5. Everyone says "near free fall"...

At least I didn't say NYC is a vacuum.

[OnTheOtherHand]

6. no, I don't think free fall is inherently contrary to a controlled demolition hypothesis

(Probably it's better not to use "CT/CTer" in this context; it's more specifically about CD, I think.)

The basic question about WTC 7, in your terms, is: why is the top of the building plummeting like a parachutist, when there is an entire building underneath it? It didn't happen with the Twin Towers (although you'll still find some people who seem to think it did), so why with WTC 7?

I guess the CD hypothesis is that various parts of the building must have been sabotaged so that it could no longer provide resistance to the falling mass. That's not the only hypothesis, and I don't believe it, but at least it's consistent with free fall AFAICS.

[jesters]

7. "...(although you'll still find some people who seem to think it did).."

As far as I know, Zdenek Bazant is the only one who posits a free fall drop of top portion C onto lower portion A.

[Bolo Boffin]

8. Still exhibiting your lack of understanding about Bazant Zhou?

Very sad.

[jesters]

9. Still claiming that he doesn't?

Oh right, you never answered me the first, second, and third times, so you don't have to ever actually confirm or deny that -- even for yourself.

[Bolo Boffin]

14. Sigh.

Does Bazant Zhou make the claim that they are modeling the precise way the Towers fell?

Or does it make precisely the opposite claim?

No peeking.

[jesters]

17. A free fall drop

is not only unrealistic and does not match observables, but it is most certainly not a "best case scenario" for collapse arrest.

[Bolo Boffin]

18. Sigh.

Did Bazant Zhou claim to "match observables" or did they do precisely the opposite?

[LARED]

10. One wonders if it is a

willful act of ignorance or just an inability to understand.

[jesters]

11. You don't have to wonder.

You can simply look it up yourself. Radical as that may sound.

[LARED]

12. Look what up?

Bazant's paper?

I read it a number of times.

[jesters]

13. Good for you.

So what rate of acceleration does Bazant posit for the initiating drop of Part C onto Part A?

[Ace Acme]

48. Ding! Ding! Ding! nt

[Bolo Boffin]

15. I'm thinking inability to understand.

Judgment clouded by the hopelessly wrong answers to a terminal degree.

[jesters]

16. Heh.

Eight posts and still can't answer the question.

So, anyway, Nuclear Unicorn, just so you know, Bazant is the only one positing free fall for the towers.

[OnTheOtherHand]

20. status: false

(1) Bazant and Zhou say this:

For our purpose, we may assume that all the impact forces go into the columns and are distributed among them equally. Unlikely though such a distribution may be, it is nevertheless the most optimistic hypothesis to make because the resistance of the building to the impact is, for such a distribution, the highest. If the building is found to fail under a uniform distribution of the impact forces, it would fail under any other distribution.

I don't know how they could make it any more obvious that what they're modeling here isn't what they think happened -- unless, perhaps, they also commented on some of the specific differences between reality and this model ("For example, the upper part of one tower is tilting as it begins to fall...&quot . Oh, right: they did that, too.

(2) In this scenario, Bazant and Zhou say, "the upper part may be assumed to move through distance h almost in a free fall," and they give a reason. Even if you don't understand the reason, and even if you don't understand the preceding point, it's hard to think how you can fail to understand "almost."

They can use g in their expression (1) because it's an estimate of the overload ratio, which works out to 31. They can assume that their professional readership understands that replacing g with, say, 0.9g won't drop the overload ratio below 1.

Near the end of the main paper, Bazant and Zhou do appear to lowball the collapse times (while still setting them higher than they would be in free fall). I have no idea how that could be construed as good news for a CD hypothesis, unless being able to show that B&Z were wrong about anything whatsoever as of September 2001 somehow strengthens the case for CD.

(3) Meanwhile, it took me ten seconds with Google to find a YouTube video titled "Twin Towers 10 Second Free-fall" -- posted in 2008, never corrected. I myself have talked with people who told me that the Twin Towers collapsed in free fall, so I know they exist.

(4) Way to derail the thread, jesters.

[jesters]

21. OTOH says "False!" and then proceeds

to demonstrate exactly why what I've stated is true. Gotta love self-debunking "debunkers".

Assuming free fall for the initiating drop is most favourable for collapse progression, not collapse arrest. So this b.s. about his model being a "limiting best case" is not supported by reality.

As far as google-mining for quotes, I'm sure you can find a lot of anonymous and erroneous claims of free fall for the twin towers. The fact remains that no known 9/11 researcher who is presenting information using his or her real name, independently or on behalf of an organization, is claiming that the towers fell in free fall. Only Bazant is doing that.

[LARED]

23. Once again demonstrating for all

You have no clue what Bazant was positing.

[OnTheOtherHand]

24. I note that you didn't respond to any of my points

It's good to know how this is going to go.

Your "reasoning" here has no logical limit. Why don't Bazant & Zhou just assume that the towers didn't fall down, since surely that would be an even worse case?

Only Bazant is doing that.

Only I just demonstrated that he isn't.

Way to derail the derail.

[William Seger]

22. Wrong again

Actually, Bazant is one of the few analyses I've seen that DOESN'T try to calculate the impact energy from the velocity of the falling mass. Just so you know, here's what he really does:

After a drop through at least the height h of one story heated by fire (stage 3 in Fig. 2 top), the mass of the upper part of each tower has lost enormous gravitational energy, equal to m g h. Because the energy dissipation by buckling of the hot columns must have been negligible by comparison, most of this energy must have been converted into kinetic energy K = m v^2 / 2 of the upper part of tower, moving at velocity v.

In other words, since he is constructing an energy analysis, he starts by assuming that a mass m at a height of h has a gravitational potential energy of m g h which must go somewhere if that mass falls h. In terms of the energy, it doesn't matter how fast the fall is; Bazant is saying that much potential energy must be accounted for. He then says that the energy required to buckle those first columns was negligible by comparison, and seeing no other energy sink, he assumes that it was converted to kinetic energy, and you could use the formula he provided to calculate the velocity. In other words, you could say he derived the velocity from the energy, not the other way around, but it's the energy he's concerned with, anyway.

If you would like to say he is wrong, you will need to explain where the energy disappeared to.

[jesters]

25. Doesn't matter how he derived it

or what his rationale is. It's still what he claims.

[William Seger]

26. Here we go again...

I just explained to you that what he claims is that most of the gravitational potential energy MUST have gone into kinetic energy, because the only loss was the negligible amount that buckled that first set of columns.

If you have no explanation for where the energy went, then you have no refutation whatsoever of Bazant's actual argument. In that case, it might be best if you keep your fingers off the keyboard until you've given it some actual thought.

[jesters]

28. Pay attention.

I'm not, in this thread, refuting Bazant's argument. I am stating that he is the only 9/11 researcher who is claiming free fall for any portion of the twin towers' collapse.

This is a fact.

[William Seger]

29. Oh, so it was just another pointless red herring, devoid of any actual argument?

I shoulda guessed.

[jesters]

31. Not really.

Since the thread is a question about free fall, and OTOH is the one who claimed that it's "truthers" who still claim free fall for the towers. Just pointing out whose side this claim belongs to.

[William Seger]

33. Some "truthers" DO claim free fall in the towers...

... and not just for the first floor, but Szamboti for example assumes free fall of the first floor in his "missing jolt" paper, so you are simply wrong about that, too, in addition to misrepresenting Bazant.

[OnTheOtherHand]

35. "it's 'truthers' who still claim free fall for the towers"

Whisky Tango Foxtrot, dude?

What I wrote was that free fall "didn't happen with the Twin Towers (although you'll still find some people who seem to think it did)."

Everyone can see that that is what I wrote. What could possibly be the point of telling people that I wrote something else?

[Bolo Boffin]

36. "I am stating that he is the only 9/11 researcher who is claiming free fall"

Except for the tiny facts that Bazant is not claiming this at all and that other 9/11 Truth advocates do, you're absolutely correct.

Sigh.

[jesters]

37. omfg. How ridiculous does this need to get?

Is it embarrassing for you that Bazant claims free fall for the initiating drop? Do you think maybe he shouldn't be doing that? Do you, furthermore, think people are somehow not able to just go find out for themselves??

I don't understand how your minds work. What possible interest could you have in attempting to deny this simple, easily verifiable claim?

Is this what "debunking" has been reduced to in 2012? Sad.

[Bolo Boffin]

38. There is nothing for me to be embarrassed about here, particularly in regard to Bazant.

Feel free to provide links to mainstream papers debunking Bazant. Any day now would be nice.

Again I repeat my question: do you think Bazant Zhou was modeling exactly what happened, or did the paper precisely say the opposite?

[jesters]

39. Bolo boffin,

look at the thread title. Is this a thread about debunking Bazant's model? No, it isn't. It's about the question of free fall. OTOH made the comment that some people still think that free fall occurred in the towers. I pointed out that Bazant is the only one we know who has officially stated this, because he uses a free fall drop for his upper block motion.

We are not discussing why he uses it, nor why it's incorrect to do so. We don't care here about "limiting cases" or "simplifying assumptions" that are designed to favour collapse progression. That is not the purpose of this conversation. You are a host here; you should be able to recognize what conversations are about, and what they're not about.

You are the only one left who is still denying that Bazant uses free fall acceleration for his upper block motion, even though this information is easily found in any of his papers. If you are denying that he's using a free fall acceleration for the drop of the upper block, then please tell us what rate of acceleration he's using. If you can't do this, then the conversation on this point is over.

[Bolo Boffin]

40. As long as you keep misrepresent Bazant's work so egregiously

I'll keep asking you my question:

Was Bazant Zhou trying to model the fall of the towers precisely, or did they expressly state exactly the opposite?

Your chicanery surrounding free fall and the towers is part and parcel of your misrepresenting Bazant Zhou. Please stop doing that.

[OnTheOtherHand]

41. that is factually incorrect

Bazant neither thinks nor has officially stated that free fall occurred in the towers. Again, if you insist on getting the basics wrong, it's hard to have a serious discussion.

...Bazant is the only one we know who has officially stated this, because he uses a free fall drop for his upper block motion.

We are not discussing why he uses it....

That's ridiculous. That's like saying that if someone argues that air resistance can be neglected for the purpose of analyzing some event, s/he has officially stated that the event happened in a vacuum.

It isn't possible to determine what people "stated" -- "officially" or otherwise -- while refusing to look at what they said.

[jesters]

42. From Bazant & Zhou, 2002

Under: "Didn’t Plastic Deformations Cushion the Vertical Impact?"

" ... the time that the upper part takes to fall through the height of one story is, for cold columns, only about 6% longer than the duration of a free fall from that height, which is 0.87s. For hot columns, the difference is of course much less than 6%. So there is hardly any 'cushioning.' It is essentially a free fall."

[OnTheOtherHand]

43. again, this refutes your point literally on its face, and more thoroughly in context

Now you're actually citing a different paper (the addendum published in March), but whatever.

What this says, literally, is that the fall takes longer than a free fall. Really, that ought to be enough.

In context -- as you presumably noticed, since you copied the section title -- the topic at hand here is whether "the inelastic deformations of columns, analyzed in Appendix II of Bazant and Zhou (2002), might have significantly 'cushioned' the initial descent of the upper part, making it almost static." The conclusion is: no, the inelastic deformations couldn't significantly cushion the initial descent. That's relevant to Bazant and Zhou's topic, which they cleverly tuck into their title: "Why Did the World Trade Center Collapse?" Bazant seems to have become more interested in the timing question later.

[jesters]

44. No

because he's assuming "hot" columns, as he calls them. He says "essentially" free fall, and that's what his calculations also reflect.

[OnTheOtherHand]

45. "his calculations" of what?

You seem to think the paper is about estimating collapse times, but clearly it isn't. The point there is exactly as stated, and exactly as many in the truth movement have denied ever since: that the columns couldn't keep the towers from collapsing.

[jesters]

46. No.

His paper is not about estimating collapse times.

Are you just making stuff up now?

[OnTheOtherHand]

47. right, that's what I said

So, what do you accuse me of making up?

[Ace Acme]

50. Shyam Sunder said the towers fell in 9 seconds and 11 seconds, and he said that was freefall.

He said that was to be expected because there was so much air in the buildings.

[AZCat]

51. Can you calculate what the "free fall" time would be for a building resembling the twin towers?

What do you determine that duration should be?

[Ace Acme]

52. Why should I? Isn't Dr. Sunder's estimate good enough for you?

NIST said the towers came down "essentially in free fall". (Section 6.14.4)

If you don't believe it, take it up with NIST.

[AZCat]

53. It's not me who has a problem with the NIST reports.

I just find it odd that you refuse to accept the bulk of the information provided in the NIST reports, but seem to find Dr. Sunder's statement unimpeachable, when it is a relatively easy exercise to calculate the "free fall" time independently.

That seems a bit incongruous. Shouldn't you be a little more consistent in your questioning of the work of the NIST? Why accept some of the NIST's work, but not other parts?

[Ace Acme]

54. Where do you get the idea that I have a problem with the bulk of the information

provided in the NIST reports?

I didn't say Dr. Sunder's statement was unimpeachable. I reported the fact that he said it.

You seem to labor under a whole lot of unjustified and erroneous assumptions.

[AZCat]

55. From reading your posts - that's where I get the idea.

You're using Dr. Sunder's statement to support your conclusions, which is a bit odd considering how little you trust the NIST reports otherwise. Why not just calculate the "free fall" time yourself? It's quite trivial. Then you don't have to rely on Dr. Sunder's statement at all!

[Ace Acme]

56. What conclusions are you assuming for me?

You're not reading my posts--you're hallucinating them.

Why should I calculate the free fall time when Dr. Sunder has done it for me? Do you consider NIST's estimates unreliable?

[AZCat]

57. Of course - why would you double-check a simple calculation...

when you could just accept the arguments of the NIST at face value? Except that's contrary to your whole schtick, isn't it? Why don't you just crank through the calculations yourself, then you don't have to rely on Dr. Sunder? Or is the problem that you don't have the technical chops to do it?

[Ace Acme]

58. Dr. Sunder is the expert. Do you think he's wrong?

NIST validates his statement when they say the buildings came down "essentially in free fall" and when they say WTC1 came down in less than 12 seconds. Popular Mechanics says ten seconds and 12 seconds.

If you don't think they're wrong, what's your point? If you do think they're wrong, explain how you know and why it matters. It doesn't matter to me. I don't care if Sunder is right or wrong. I said what he said, that's what he said; he said what I said he said. That's the end of it.

[AZCat]

59. Do you understand the concept of irony? n/t

[Ace Acme]

60. Why, no, not at all! I'm sure your understanding of it eclipses mine completely! nt

[AZCat]

61. That's what I thought.

Otherwise, how could you so unquestioningly promote Dr. Sunder's claims in this sub-thread while roundly rejecting the NIST's work elsewhere?

Of course, you could just do your own calculations for "free fall time" and verify (or contradict) Dr. Sunder's claim independently.

[Ace Acme]

62. What makes you think I reject NIST's work?

The problem is what NIST didn't do. They didn't explain how the buildings collapsed, they didn't analyze the collapses, and they did not rigorously explain how a collapse on one side of the tower propagated to the other side to bring down the entire building symmetrically.

I don't need my own freefall time. Neither do I need my own time zone or my own coinage. Some people find such exercises amusing. I don't.

I'm not unquestioningly promoting Dr. Sunder's claims. I'm simply reporting them. And you haven't answered the question. Is he wrong?

[AZCat]

63. Other than your repeated assertions that the NIST lied...

and that they are not trustworthy? That was sufficient for me to think you reject the NIST's work.

Again, I think it would be of interest to you to independently calculate "free fall time". That way you don't have to rely on Dr. Sunder, and possibly could challenge his claim with your own work. Considering how eager you are to dispute the work of the NIST, I think you would leap at such an opportunity.

[Ace Acme]

64. There is no reason for me to calculate free fall time.

That is a red herring.

We've been over this.

You are simply trying to create the illusion that you have a point.

[AZCat]

65. Because you can't? That's okay.

I kind of figured we'd end up here, based on your obvious unfamiliarity with physics fundamentals.

[Ace Acme]

66. It's trivial. "Won't = Can't" is a dumbass formulation. nt

[AZCat]

67. What is trivial? The calculation?

Then why not recalculate it yourself? In the face of your obvious discomfort, I am inclined to believe you can't. You certainly haven't shown any contrary evidence on this forum.

[Ace Acme]

68. Yes, the calculation is trivial. The demand that I perform it is insulting.

There is no reason for me to do it. NIST said the building came down "essentially in free fall".

Do you dispute that?

[AZCat]

69. Insulting? Really? That's one of your more ludicrous claims.

Of course there's a reason for you to do it. By independently calculating the "free fall time" you don't have to rely on Dr. Sunder's authority. Otherwise why are you questioning the results of the NIST reports at all? Isn't the rest of Dr. Sunder's work sufficient for your acceptance?

[Ace Acme]

70. I am not relying on Dr. Sunder's authority. You are.

You're the one that claims we don't need new investigations.

If you don't know why I'm questioning the NIST report, you haven't even read my posts. The NIST report is only half a report. It ignored the ten essential mysteries of the collapses.

[AZCat]

71. Oh really?

I'm not the one who repeated his claim multiple times, nor am I the one who said that he was an expert and that the NIST validated his claim.

I've read your posts - hence my confusion why you're so resistant to freeing yourself from a reliance on the authority of Dr. Sunder. You yourself said the calculation is trivial, so why not just do it? Show your work, of course - we've seen how sloppy you get when you skip that step.

[Ace Acme]

72. I repeated his claim because that is the official time.

The official reports validate it, and it has never been corrected.

There is no reason for an anonymous internet poster to do independent work. That's silly. Anyone with any knowledge of science understands that.

[AZCat]

73. Well, then, I guess that's the end of the internet (at least for your type).

There is no reason for an anonymous internet poster to do independent work. That's silly. Anyone with any knowledge of science understands that.

Coming from a supporter of conspiracy theories, this is a surprising statement. I'm going to have to save this for posterity.

[Ace Acme]

74. What gives you the idea that I support conspiracy theories? nt

[AZCat]

75. <error> Internet not found. </error>

[Ace Acme]

76. IOW, nothing. You made it up. nt

[AZCat]

77. Why are you still here?

According to you, there's no reason to be doing independent work. Shouldn't you just close up shop and go home then? Or are you so captivated by our winning personalities that you can't quit us?

[Ace Acme]

78. I could ask you the same question.

It appears that your purpose here is to inhibit discussion of a vital issue of our day, using the technique of implying that you have vast knowledge of everything and intimating that everyone who has any questions is stupid, deluded, incompetent, or all of the above.

It appears that you and your teammates have managed to drive away everyone and make a ghost town of this group.

[AZCat]

79. I'm here for interesting discussions of the collapses...

with competent persons. You, however, don't seem to meet that criteria.

Your failure to demonstrate familiarity with basic physics concepts coupled with your hostility to admitting ignorance means you're not an interesting discussion partner.

Somehow I find it difficult to accept blame for your incompetence and arrogance.

[Ace Acme]

80. You neither demonstrate your competence nor my incompetence. You make empty claims. nt

[AZCat]

81. I don't have to demonstrate your incompetence - it's demonstrated in your posts.

Over and over again, you've failed to display competency. What's amusing is that you're so adverse to admitting your ignorance. If you weren't so hostile we'd probably be more willing to work through the problems with you, rather than waiting for you to see your own mistakes (which increasingly seems to be unlikely in the near term).

[Ace Acme]

82. Empty claims from a guy who claims to be a cat. nt

[AZCat]

83. Does your post have a point?

Either demonstrate the ability to do the calculation you claim is trivial (yet refuse to do) or provide yet again more evidence of your incompetency.

[T S Justly]

30. Free fall ...

Last edited Tue Jan 10, 2012, 07:01 AM - Edit history (1)

The time it took and the way in which the Bush Administration's Official Story collapsed.

[William Seger]

34. Zero G

The weight of "truther" arguments based on imaginary physics.

[Ace Acme]

49. Unintentionally tautological, Seger refutes himself yet one more time. nt