Merged "Iron-rich spheres" - scienctific explanation?

[NoahFence]

It does ring a bell. You still haven't explained to us how that converts to a 5 second delay on the fall. For example what would be the acceleration if the atmosphere were twice as dense? What would be the drop time if the atmosphere were three times as dense? What if the atmosphere were dense enough to provide a 15,000 ton resistance to the downward travel. That's the type of numbers I'd expect from a 37 year expert in the field.

So you've gone beyond 9/11 and into hypothetical land?

 

[GlennB]

That's a catch question isn't it? A small brick vs really big one with the same shape and material? How can it have the same shape if it is bigger than the small one?

Not a catch question. Ratio of sides 4:2:2, say. Equal density.

eta: Galileo was quite lucky. He got the right answer from a bad experiment.

 

[tfk]

It does ring a bell. You still haven't explained to us how that converts to a 5 second delay on the fall. For example what would be the acceleration if the atmosphere were twice as dense? What would be the drop time if the atmosphere were three times as dense? What if the atmosphere were dense enough to provide a 15,000 ton resistance to the downward travel. That's the type of numbers I'd expect from a 37 year expert in the field.

Please answer 2 questions first. Then I'll answer this.

How long since you got your ee degree?
Where?

 

[tsig]

Lets see you start by saying the explosives would burn and render "the whole thing impossible" (not sure why you claim that as you haven't answered my question regarding that). Then when they need to make it to the street somehow now they can survive without going off. And now you center on explosives not thermite when you were all over the board on the fact that Gage said "thermite". Better yet things don't fully burn or get extinguished on the way down. But somehow enough makes it to WTC7 in such a way that it burns to the ground, yet the other buildings hit by debris don't burn down to the ground. Then your buddy comes and says it's not 1500ºC, but 1100ºC that's needed for the microspheres to form. Yet such temperatures were inferred by NIST and not actually observed in the collected debris. Unlike the microspheres which have not been inferred and quite on the contrary have been readily observed. And we haven't even gotten to the culprit of the thermite/explosive theory which is the absurdly high fall speed of the two towers.

The absurdly high fall speed of the two towers caused thermite to explode?

 

[Java Man]

Please answer 2 questions first. Then I'll answer this.

How long since you got your ee degree?
Where?

Are you going to address me or my arguments?

 

[tfk]

It does ring a bell. You still haven't explained to us how that converts to a 5 second delay on the fall.

And I'm not going to.

1. You pulled 5 seconds right out of your ass.

2. "5 seconds" is the WRONG amount of extended fall time.

3. The amount of extended fall time is YOUR particular irrelevant obsession. Not mine.

The EXACT, PRECISE, PERTINENT question is "how much resistive FORCE did the lower structure apply to the upper block as it descended?"

I gave you the pertinent, approximate answer to that question: "about 15,000 tons of force, during the measurable part of the upper block's descent."

For example what would be the acceleration if the atmosphere were twice as dense?

Stupidly irrelevant.

The atmosphere was not twice as dense.

What would be the drop time if the atmosphere were three times as dense?

Stupidly irrelevant.

The atmosphere was not 3x as dense.

What if the atmosphere were dense enough to provide a 15,000 ton resistance to the downward travel.

Stupidly irrelevant.

The atmosphere was not dense enough to provide 15,000 tons of resistance during its first 15 stories of fall.

That's the type of numbers I'd expect from a 37 year expert in the field.

And those are the type of questions that I'd expect from an undergraduate French Literature student.

Not an engineer.

Of ANY type.

I'll take you at your word, that you've got your EE degree. I strongly suspect that you're a baby engineer (<5 years out) or still an undergrad. (Sorry, I've just run into far, far too many truthers who claimed to have engineering degrees and clearly did not.)

Either way, you've got a LONG way to go.

I VERY STRONGLY urge you to read carefully & adopt those two points I made earlier about "the rules of engineering epistemology".

Meanwhile, sorry, JM. You're not bright enough for me to waste any more time on you.

 

[grandmastershek]

Are you going to address me or my arguments?

Irony

 

[Java Man]

I gave you the pertinent, approximate answer to that question: "about 15,000 tons of force, during the measurable part of the upper block's descent."

And I asked you a clear question. How much does that force delay the fall vs a drop with only air resistance.

That is fall time with that force applied minus (-) fall time without that force applied. How much does that give you? You must have a number because you're comparing my 5 seconds to that number and concluding my 5 seconds are bogus. So please share that number with us.

 

[Jackanory]

Are you going to address me or my arguments?

I think you have been addressed far too much on that argument pulled from your arse.

 

[DaveThomasNMSR]

And I asked you a clear question. How much does that force delay the fall vs a drop with only air resistance.

That is fall time with that force applied minus (-) fall time without that force applied. How much does that give you? You must have a number because you're comparing my 5 seconds to that number and concluding my 5 seconds are bogus. So please share that number with us.

Java Man, the amount of slowing due to atmospheric drag will be MINIMAL - at most lengthening the collapse time by a percent or two.

Truther Chandler measured the acceleration of the North Tower, and found it was about 2/3 gravity for the first 4 seconds of collapse.

I modeled the collapse as a series of free-falls, punctuated by brief collisions as the growing upper section took out each floor in turn, here. It's not air resistance, it is the impacts of the upper section upon the lower sectionn that slows the overall collapse time.

The result:

This chart compares heights of the top corner for Chandler's calculated acceleration (a = 6.31 m/s2, blue diamonds), the punctuated-freefall model presented here (a = 6.19 m/s2, thin red curve), and true free-fall (9.80 m/s2, thick blue curve). It's clear that Chandler's measurement of the downward acceleration of the tower is an excellent fit to the averaging of freefall periods with brief collisions.

I don't expect you to be able to understand this. It haas numbers and equations, and you're not doing too well with either at the moment.

Here's my only question for you:

I have something in the shape of a Square.

How big is it?

 

[tfk]

And I asked you a clear question. How much does that force delay the fall vs a drop with only air resistance.

That is fall time with that force applied minus (-) fall time without that force applied. How much does that give you? You must have a number because you're comparing my 5 seconds to that number and concluding my 5 seconds are bogus. So please share that number with us.

My last response to you.

The time of fall is completely & totally irrelevant.

Tell me what it would mean to you if the extended fall time was 5 seconds, or 7 seconds or 10 seconds. (Never mind, don't tell me. I'm not going to reply anyway.)

One would use the time to figure out the important quantity: the resistive force.

But I've ALREADY GIVEN YOU the resistive force.

The numbers that I've quoted to you (.70g & .75g) are acceleration values that were derived from careful analysis of the videos during the portion of the drop that they were visible (i.e., before entering the dust cloud).

A simple force diagram results in the resistive forces that I gave you.
___

Regarding the appropriate extended fall time, as long as you are comparing it to the time for something to fall from the roof, you are using the WRONG fall time as your basis of comparison.

___

Regarding the actual total fall time: this is a very difficult number to ascertain precisely. Because 80% of it happened behind a curtain of dust & debris.

However, there are photos (specifically of debris about to land on the Mariott Hotel) that show the free falling debris about 30 stories BELOW the crush zone.

The inexorable conclusion from this is that the building IS, in fact, producing a significant amount of resistive force to the upper block's descent.

I already gave you a better estimate for the first 15 stories of fall than one can possibly generate from the inaccurate crush down times available.

 

[GlennB]

....
However, there are photos (specifically of debris about to land on the Mariott Hotel) that show the free falling debris about 30 stories BELOW the crush zone.

The inexorable conclusion from this is that the building IS, in fact, producing a significant amount of resistive force to the upper block's descent.

Perhaps the air was much denser inside the building ?

 

[Java Man]

I modeled the collapse as a series of free-falls, punctuated by brief collisions as the growing upper section took out each floor in turn, here. It's not air resistance, it is the impacts of the upper section upon the lower sectionn that slows the overall collapse time.

Dave thank you for your response it was clear and non offensive and had numbers unlike Mr 37 Years.

Now getting back to the point of impacts. I totally agree with you that the floors and not air pose the greatest resistance. So if you'll allow me to get back to the brick example I'll drop it again from the roof top disregarding air resistance, but adding another brick half way down.

The brick would take 9.2 seconds to drop the full height. But halfway down in smashes into the other brick which is at stand still. Now supposing there is no energy lost in dislodging the second brick and that there is no energy lost in deformation of the bricks the bricks continue travelling at half the speed the first brick had upon hitting the second. We are conserving momentum. Thus it is impossible for the first brick to reach the ground in 9.2 seconds. Since it slows down to half its speed and then keeps accelerating under the same acceleration and not twice the acceleration. Thank you Glen for that comment and thank you all for making a prank out of my response.

We can repeat the process by adding more bricks until we have one for each floor and we'll realize that the amount of time it takes just by gaining mass is greater than what we see in the videos. And we are assuming it takes no energy to break the lower bricks free. Which it would in real life and thus slow down the fall even further.

 

[NoahFence]

Dave thank you for

Which does absolutely nothing to support the twoofer theory of controlled demoliton.

 

[GlennB]

We can repeat the process by adding more bricks until we have one for each floor and we'll realize that the amount of time it takes just by gaining mass is greater than what we see in the videos. And we are assuming it takes no energy to break the lower bricks free. Which it would in real life and thus slow down the fall even further.

Using your own example, by the time we hit the 20th brick it only adds 5% to the weight of the total.

The 50th brick, 2% etc.

Meanwhile - any thoughts on tfk's observation about WTC debris that was in free-fall vs. the main collapse front (see photo, where the collapse zone isn't even in shot yet) ?

The point is, JM, claims that "it fell too fast" don't cut the mustard. Folks have done the calculations. I'll bet hostile Cuban, N Korean and Iranian scientists have done the calculation and just said "dang".

 

[Java Man]

Using your own example, by the time we hit the 20th brick it only adds 5% to the weight of the total.

The 50th brick, 2% etc.

Yes you are correct.

Meanwhile - any thoughts on tfk's observation about WTC debris that was in free-fall vs. the main collapse front (see photo, where the collapse zone isn't even in shot yet) ?

It's consistent with what I'm saying. They are falling faster than the main collapse front.

 

[DaveThomasNMSR]

Dave thank you for your response it was clear and non offensive and had numbers unlike Mr 37 Years.

Now getting back to the point of impacts. I totally agree with you that the floors and not air pose the greatest resistance. So if you'll allow me to get back to the brick example I'll drop it again from the roof top disregarding air resistance, but adding another brick half way down.

The brick would take 9.2 seconds to drop the full height. But halfway down in smashes into the other brick which is at stand still. Now supposing there is no energy lost in dislodging the second brick and that there is no energy lost in deformation of the bricks the bricks continue travelling at half the speed the first brick had upon hitting the second. We are conserving momentum. Thus it is impossible for the first brick to reach the ground in 9.2 seconds. Since it slows down to half its speed and then keeps accelerating under the same acceleration and not twice the acceleration. Thank you Glen for that comment and thank you all for making a prank out of my response.

We can repeat the process by adding more bricks until we have one for each floor and we'll realize that the amount of time it takes just by gaining mass is greater than what we see in the videos. And we are assuming it takes no energy to break the lower bricks free. Which it would in real life and thus slow down the fall even further.

Java Man, you are pulling numbers out of your excretory orifice.

The collisions don't slow the speed to "half".

The only thing you got right is that Momentum will be Conserved.

Please read these two articles:

How Does a Building Crush Itself?
The Towers' Collapse: Fast, But Not Freefall

These are the background maths supporting the one I already mentioned:
Chandler's Data Support a Gravitational Collapse!


Now get to reading.

 

[Java Man]

Java Man, you are pulling numbers out of your excretory orifice.

The collisions don't slow the speed to "half".

Then what do they slow down to? 1/4? 1/3? 1/10?

 

[tsig]

Then what do they slow down to? 1/4? 1/3? 1/10?

You can't calculate it yourself?

 

[DaveThomasNMSR]

Then what do they slow down to? 1/4? 1/3? 1/10?

Here's how this works, Java Man.

You see, when I include a hyperlink like so, that indicates that this is something you click on.

It then takes you to a new page, where you can learn more about the topic of discussion.

Had you taken some of the three minutes between my post and your response to actually click through to the articles I mentioned, and actually read them (the evidence indicates you are a poor speed reader), then you would have had the answer to your question already.

So, let's try again.

Here is something for you to click on. It will take you to a new Tab or Window.

VVVVV CLICK HERE VVVVV
The Towers' Collapse: Fast, But Not Freefall
^^^^^ CLICK HERE ^^^^^

On this new page, you will see images like this one:

This is for the first impact. For this (particular) impact, my simple model indicates that the reduction in speed was from 8.63 m/s to 8.05 m/s, or a reduction of some 6 %.

This works out to a loss of 1/15th of the initial speed.

But that's just one floor.

The next floors will be different (and you will actually need to read the article to see why.) The percentage of reduction is less for each subsequent floor.

When you look at the first few dozen floors, the results of my model match Chandler's measurements very well.

When you look at the complete collapse, the overall times match observed collapse times very well.

In summary, the answer to your question is
"About 14/15".

But's that's the first impact only.

I should add you are not being a very effective spokesperson for the Truth Movement.

But, I appreciate the Comedy Gold! Who would have thought we'd have someone who makes even Ergo look smart?