Can 15 floors crush one floor?

[000063]

The potential energy of each twin tower was also the energy equivalent of 14.25 tons of chocolate chip cookies.

Chocolate chip cookies have 8 times the energy density of TNT, as you should know Dave, since I told you this last year after you used this same argument in your debate with Richard Gage and Niels Harrit.

The difference between explosives like TNT and other more energy dense but less powerful items is that the high explosive releases all of it's energy in a millionth or two of a second, so it is much more powerful. It is really power and the ability to do a certain amount of work in a specified period of time which should be the measurement here.

You still lose even with a more technical definition, so stop quibbling over a term used to give laymen a broad strokes idea o--

Wait a minute.

You only posted when there was something other than the OP to respond to so you could nitpick instead of addressing the primary point.

Clever boy.

 

[Bell]

2 out of 2 truthers dodge the OP question.

As far as I recall, no truther ever answered my (this) question:

Can this floor...

... stop this...

 

[Tony Szamboti]

You still lose even with a more technical definition, so stop quibbling over a term used to give laymen a broad strokes idea o--

Wait a minute.

You only posted when there was something other than the OP to respond to so you could nitpick instead of addressing the primary point.

Clever boy.

Okay, you shamed me into addressing the OP, but first I have to help the question to be more relevant. It should really be asking

Can 15 floors crush one beneath them designed to hold up at least 45 floors?

My answer is: sure they can if they fall from a distance and decelerate sufficiently in the impact to generate an amplified load great enough.

 

[R.Mackey]

Please don't accuse me of a strawman attack in your answers.

Okay, you shamed me into addressing the OP, but first I have to help the question to be more relevant. It should really be asking

Can 15 floors crush one beneath them designed to hold up at least 45 floors?

Bzzzzt, thanks for playing.

 

[000063]

Okay, you shamed me into addressing the OP, but first I have to help the question to be more relevant.

You're going to strawman it into a different question and answer that.

It should really be asking

Can 15 floors crush one beneath them designed to hold up at least 45 floors?

Considering that the load was being held up by the columns and walls, not the floors, and no floor was designed to hold the weight of 45 floors above it, much less in an asymmetric dynamic load, this is a strawman.

My answer is: sure they can if they fall from a distance and decelerate sufficiently in the impact to generate an amplified load great enough.

Someone in a now-defunct PoliticalForum thread did the math; the collapsing section of the building hit with several times the force of the entire building. Of both towers together, in fact.

You still have not answered the OP question. And I doubt you'll answer Bell's in #62 either.

 

[Travis]

Wait......was that an attempt to answer while still dodging the question?

 

[Oystein]

Okay, you shamed me into addressing the OP, but first I have to help the question to be more relevant. It should really be asking

Can 15 floors crush one beneath them designed to hold up at least 45 floors?

My answer is: sure they can if they fall from a distance and decelerate sufficiently in the impact to generate an amplified load great enough.

What would that distance be, at a minimum?
And what deceleration would be sufficient?



(I hope you are aware that this "fall from a distance" is just an easy to visualize way of stating the more abstract concept "has momentum" or "center of mass has downward velocity" - the important value is the momentum/velocity, not the distance

I also hope you are aware that the mass of the 15 floors, when they come down on the intact structure below, will mostly bypass that part of the assembly that is "designed to hold up at least 45 floors", the vertical, fully braced columns, and instead hit elements designe to hold much less.

Please do not fail to indicate that you are aware of both considerations in your reply)

 

[ozeco41]

Gawd can we at least decide what we are talking about?

This is the relevant bit of the OP:

....do you think a 15 floor block of building can crush one floor underneath it?...

Which is three way ambiguous and AFAICS no-one has decided which case they are addressing and stated so explicitly.

The three are:
1) Travis is referring to the WTC Towers and by "crush one floor" he means crush the complete floor level including columns a la Bazant and Zhou. My answer in that case is "Yes. Bazant got it right! as a limiting case even though that is not how the Towers actually collapsed"; OR
2) Travis is referring to what actually happened with the Twins on 9/11. My answer is still "Yes - because it actually happened"; OR
3) Travis is referring to any generic building. (He does not say WTC OR 9/11) In that case my answer is "It depends..."

So at least everyone now knows which one I'm addressing. You have my answers for all three. And, if anyone thinks that, like most others here, I have ignored the qualifier constraint:

...Truthers or those with Truth Movement sympathies do you think...

Well I'm not a truther BUT I do have "Truth Movement sympathies..." I'll leave it to you all to decide what those sympathies may be....


[/legal_pedantry]

 

[leftysergeant]

You crush a structure as tall as the WTC the way you eat an elephant. ONE BITE AT A TIME.

 

[ozeco41]

As far as I recall, no truther ever answered my (this) question:

Can this floor...

[qimg]http://www.internationalskeptics.com/forums/imagehosting/11696474df7b2e709f.jpg[/qimg]

... stop this...

[qimg]http://www.internationalskeptics.com/forums/imagehosting/11696474df7bfd686f.jpg[/qimg]

A rough bit of graphics I first posted 26 November 2007

...about a week after my first ever Internet post.

...I'm certainly not an artist.

 

[Oystein]

Gawd can we at least decide what we are talking about?

This is the relevant bit of the OP:

Which is three way ambiguous and AFAICS no-one has decided which case they are addressing and stated so explicitly.

The three are:
1) Travis is referring to the WTC Towers and by "crush one floor" he means crush the complete floor level including columns a la Bazant and Zhou. My answer in that case is "Yes. Bazant got it right! as a limiting case even though that is not how the Towers actually collapsed"; OR
2) Travis is referring to what actually happened with the Twins on 9/11. My answer is still "Yes - because it actually happened"; OR
3) Travis is referring to any generic building. (He does not say WTC OR 9/11) In that case my answer is "It depends..."
...

ozeco,

sometimes distinctions make less of a difference than you might think.

To start with last: 3) I am pretty shure that Travis has the WTC North Tower in mind. Which version - the actual one that collapsed or the idealized one of models doesn't matter so much.
2) "Yes - because it actually happens" is correct, but inapplicable, as, from the point of view of a Truther (CD-all-the-way-down-variety), you're assuming the conclusion. Truther (C-a-t-w-d-variety) may claim that in theory it could not have happened the way it did without some stealthy means of assistance at every level. That throws us back to 1)
1) "Yes. Bazant got it right! as a limiting case even though that is not how the Towers actually collapsed" is correct - AND the limiting case has "how the Towers actually collapsed" inside its limits. Bazant and Zhou show that columns will be overwhelmed; since full column impact would be the best case towards survivability, it follows immediately that any case that mostly bypasses the columns will be even more overwhelmed

(N.b.: I am aware that this intuitive argument would require a few steps of argument if you want to be pedantic, but it is legitimate here to reverse the burden of proof and, once the Truther agrees with you that Bazant's limiting, though non-actual, case guarantees total collapse, he or she would have to explain out how the actual collapse mechanism could offer more reistance than full column impact, and increase the chance of survival significantly)

 

[ozeco41]

ozeco,

sometimes distinctions make less of a difference than you might think.

Sure. I am talking about a cat. Fred is talking about a dog. You say it doesn't matter because both of them have four legs.

I say "Why didn't you say that in the first place".

Somehow I'm hard to persuade that "getting the right answer for the wrong reasons" is a valid "proof". And I've had a couple of differences with some who post here* on that very point in recent weeks.

But then I could be too pedantic - look at all the thousands of posts we could avoid in this forum if getting the right answer for the wrong reasons was the criteria.

And that last sentence is not intended to make sense.


* and that awkward sentence construction is also deliberate.

(And before you ask - It is an Aussie "Dry White - Chateau Cardboard Box - circa 2012")

 

[Oystein]

Sure. I am talking about a cat. Fred is talking about a dog. You say it doesn't matter because both of them have four legs.

I say "Why didn't you say that in the first place".

Not exactly. The WTC is an individual cat. Bazant talks about an ideal, healthy, strong cat. Your option 3) talks about mammals.

If the question is "can a cat carry a Jockey and win the Royal Ascot", and Bazant shows that even an ideal cat could never do that because his legs are not strong enough, then this suffices even if the question had some individual cat in mind that didn't win the Royal Ascot because her back (not her legs) broke. If "cat" is meant as a placeholder for all mammals, then obviosly such a cat could win the Royal Ascot, and in fact some such cat wins it every year - we just call it "horse".

Somehow I'm hard to persuade that "getting the right answer for the wrong reasons" is a valid "proof". And I've had a couple of differences with some who post here* on that very point in recent weeks.

But then I could be too pedantic - look at all the thousands of posts we could avoid in this forum if getting the right answer for the wrong reasons was the criteria.

I understand what you say about wrong reasons, I just don't share the opinion that applying a limiting case to a scenario that isn't similar to the limiting, but certainly must be inside the space that the limiting case circumscribes, is a wrong reason to answer Travis's question with "Yes, 15 floors can crush 1 floor" - as long as you are aware that some assumptions go into that extension of the applicability of the limiting case, and as long as those assumptions are not outlandish. (I highlighted a word in the previous sentence to stress that the limiting case puts a "must" there. The switch to "can", which is taken from the OP's question, takes care of the residual possibility that the individual real-world case is, for some freak reasons, outside the limits)

(And before you ask - It is an Aussie "Dry White - Chateau Cardboard Box - circa 2012")

And why not - for three or four years, a cheap (bottled) Aussie white wine from a discounter was my house wine - it really stood its ground well against much more expensive French wines, I am sure you could have served it as superior Sancerre without anyone noticing.
As for Chateau Cardbord Box - last week, someone left me a cardboard box with a white "blend of wines from different countries in the European Community". I am scared. The text on the box comes in English, German, seven slavic languages and Hungarian, but not French, Spanish or Italian, not even Dutch. I am scared!

 

[ozeco41]

Not exactly...

I know but it was the best I could come up with for a casual bit of fun.

... and in fact some such cat wins it every year - we just call it "horse".

And it has four legs - one at each corner.

..."Yes, 15 floors can crush 1 floor"....the limiting case puts a "must" there...

Ah - the logic traps of false globals (Or false exclusives - same thing reversed.) I'm having a bit of fun elsewhere with that but....

...Aussie white wine from a discounter was my house wine...

...sure our Aussie Plonk can hold its own in any company - including the "Vin bloody ordinary" we put in cardboard boxes at 4 litres for $AU15

... "blend of wines from different countries in the European Community"....I am scared!

A conservative limiting case?

 

[Oystein]

... A conservative limiting case?

IF it can be shown that 4 litres of the weakest wine from the European Community MUST incapacitate me, THEN 4 litres of any blend of wines from the E.C. CAN, even if the weakest one is not included in the blend

 

[femr2]

Anyone interested in more accurate per-floor mass estimates is welcome to use my old model...

http://femr2.ucoz.com/load/3-1-0-9

The mass data is as accurate as you'll find, incorporating Greg's steel mass figures.

It's not difficult to separate floor mass from everything else, but obviously by default everything is in there.

 

[Miragememories]

You crush a structure as tall as the WTC the way you eat an elephant. ONE BITE AT A TIME.

Try and eat an elephant that fast.

MM

 

[Tony Szamboti]

You crush a structure as tall as the WTC the way you eat an elephant. ONE BITE AT A TIME.

It is interesting that in the case of the WTC the bites were on the order of about 7 floors per second.

 

[Bell]

It is interesting that in the case of the WTC the bites were on the order of about 7 floors per second.

Klunkety klunk.

 

[Tony Szamboti]

What would that distance be, at a minimum?
And what deceleration would be sufficient?

You seem to spend enough time on this subject to come up with your own calculation. So why don't you tell us?

(I hope you are aware that this "fall from a distance" is just an easy to visualize way of stating the more abstract concept "has momentum" or "center of mass has downward velocity" - the important value is the momentum/velocity, not the distance

The fall of the mass through a specified distance generates a certain amount of momentum, and finally it is the momentum transfer that counts.

I also hope you are aware that the mass of the 15 floors, when they come down on the intact structure below, will mostly bypass that part of the assembly that is "designed to hold up at least 45 floors", the vertical, fully braced columns, and instead hit elements designe to hold much less.

I am aware that some people like yourself attempt to say the columns would have missed each other. However, this is an unsupported claim. It has been proven that the upper section of the North Tower does not tilt more than 1 degree for the first couple of stories of the fall and that is nowhere near sufficient to move the columns out of alignment.