Heiwa's Pizza Box Experiment

[Sunstealer]

I really don't understand what is so hard to grasp. If the top part of the structure falls and the floor that is first impacted does not arrest the fall then global collapse MUST ensue simply because the next floor has to absorb the kinetic energy not only of the top part of the structure, but also the failed floor above it. It's like dominoes: if you don't push the first domino with enough force to make it topple then no others will fall, however, once that first domino falls then nothing will arrest the toppling of all the other dominoes in line.

 

[X]

For such a thing to happen, F₁ has to be greater than F₁

Dammit!

That bit should read:

For such a thing to happen, F₁ has to be greater than M₁g

 

[1337m4n]

I don't know what everyone's arguing about. I happen to think Heiwa's experiment is very realistice.

 

[Heiwa]

I really don't understand what is so hard to grasp. If the top part of the structure falls and the floor that is first impacted does not arrest the fall then global collapse MUST ensue simply because the next floor has to absorb the kinetic energy not only of the top part of the structure, but also the failed floor above it. It's like dominoes: if you don't push the first domino with enough force to make it topple then no others will fall, however, once that first domino falls then nothing will arrest the toppling of all the other dominoes in line.

This is what the authorities want you to think. Rigid top part falls on one floor, crushes it, then falls on next floor, crushes it too, and so on. Global collapse ensues. NWO physics!

In the real world the top part is not rigid and weaker than the structure below. There is no impact floor/floor because there are plenty of deformed columns in between preventing near free fall/impact and when contacts occur, they are between columns and floors (not floor against floor). And the columns damage the floors, the damaged floors get entangled into one another and ... further destruction is arrested. In the real world the WTC1,2 top parts would have remained up top with only local failures/deformation. A realistic sceanario is that columns just deform due fire/heat and that there is no floor/floor contacts at all.

Remember that is was total 5-6 m² cross area of solid steel in those columns up top only compressed at less than 0.3 yield = plenty of strength. No way that 5-6 m² of steel columns can 'disappear' as suggested by the authorities.

NYFD staff knew this and were no afraid of accessing to the risky areas and extinguishing the fires. The area was risky due to the local failures but NYFD knew that 'global collapse' was impossible. The fires at that time were very small.

 

[Heiwa]

No.

You assert the following:



But this is patently false. I have run through the calculations for you twice now. Dave Rogers has explained it to you.

If F₁ (the resistance force) is equal to M₁g (the accelerating force due to gravity) all you have done is canceled out the accelerations.

No acceleration will occur. This means the velocity does not change. The falling mass (which you must agree already has to be moving in order to be able to come into contact with the lower section) will therefore continue to fall downwards at a constant velocity. It does not matter if you consideer the falling mass as a solid block, a conglomerations of pieces, rubble, or whatever. It is mass, it is falling, and it can not and will not slow and halt the collapse if F₁ = M₁g.

For such a thing to happen, F₁ has to be greater than F₁

The situation is dynamic, not static.
The falling mass is falling! This means it is in motion! Which means you can not treat it as a static scenario!
You need to factor the motion into your calculations.

And yet you tell Dave Rogers he is wrong. When you make the fatal error of treating an obviously dynamic situation as if it were static, and assuming that having the resistive force equal to the gravity force will slow and halt the falling mass.



That is your error.

Only when a rubber ball bounces against ground F1 has to be greater than M1g, (due to absorbed/re-release energy) and we are not discussing that.

 

[Heiwa]

It has everything to do with the fact that a 15 to 30 floor section of the building just slammed into a single floor with all of it's weight which was more than the individual floor could handle, this transfer of forces did not fail the entire lower section as a unit, it failed it progressively where it was weakest.

Once that top section was in motion and imparting an entire array of moment and axial forces against whatever was still intact within the impact zone that ratio of empty space to solid mass doesn't make a helluva a lot of difference in whether or not the structure is sturdy enough to hold the building in a static vertical load, all of the forces enacting on the structure from this point forward are dynamic. I would think the columns would be the least of your concerns, particularly considering it was the connection points where two column sections met that suffered the most common failures. As an engineer of any callibur even you should be aware of this.

You don't know much about structural damage analysis, do you? A 15-30 floors (rigid) section slamming into a single (weak) floor! Not seen on any videos, as far as I am concerned.

 

[Dave Rogers]

Too long. And I hate algebra.

But I had the chance to contribute something worthwhile, and I did so.

Thanks, [X], I really should have set all that out myself but frankly I don't have the time to waste on Heiwa.

Dave

 

[Dave Rogers]

No, you didn't. And any forces, including friction, applied by the lower structure (static) on the upper block, still moving, are static and they cannot be greater than mg in neither the dynamic, nor the static phase..

Because these forces (smaller than mg), when applied on the upper moving part, consume/absorb energy ... and when the available energy is consumed/absorbed, the destruction is arrested. It takes some time. And then equilibrium is achieved (static condition) and the resisting forces are equal to mg.

This is completely and utterly wrong, and you are either lying when you claim it's correct or lying when you claim you're an engineer. You're suggesting that the dynamic friction force is less than mg. Okay, let's call the dynamic friction force F_d, and from your analysis F_d < mg. The resultant upward force on the falling block is therefore F_d-mg, and we can rearrange the above inequality to get F_d-mg < 0. There is therefore a net downward acceleration of the top block. This will not cause it to stop.

Your energy argument is equally invalid. If the friction force is less than mg, then the rate of energy absorption from friction is less than the rate of gravitational energy release due to the top block falling. This is mathematically equivalent to the above calculation, of course, because energy = force x distance.

Pls do not suggest that I lie.

It's not a suggestion, it's an accusation. You are either lying when you claim that you believe your calculations that support your assertions, or when you claim that you are a professional engineer. It is simply inconceivable that a trained engineer would be unable to work out a simple one-dimensional resultant force, yet you cannot.

NIST and Bazant of NWO physics fame, suggest that no forces are applied to the upper part(s) and that the upper part(s) is (are) thus accelerating destroying everything below. This is not in accordance with Newtons's third law.

They make no such claim. You are lying again.

Force are applied at every point of contact, they create, i.a. friction and deceleration, and in 99.99% of the incidents the destruction is arrested. It seems the 0.01% remaining cases would be WTC1,2 but I doubt it.

It seems that I have probability on my side.

Ah, the last resort of the desperate: make up some probabilities. Would you like to cite your claimed 19,998 cases in which a progressive top-down collapse of a structure has self-arrested? Or were you lying again when you claimed that this happens in 99.99% of cases?

Dave, you are putting your money on a losing horse. NIST and Bazant have no credibility. They just invent things because in NWO physics there is no real physics.

You don't even understand the one-dimensional application of Newton's laws; you're inventing probability calculations based on non-existent data; and you're making up your physics as you go along. And you claim that someone else has no credibility. Priceless.

Dave

 

[JimBenArm]

I don't know what everyone's arguing about. I happen to think Heiwa's experiment is very realistice.

Eerie, isn't it?

 

[twinstead]

Yup. Another huge thread with somebody arguing a clearly untenable position against people who know what they are talking about. Realistice it is.

 

[Grizzly Bear]

A 15-30 floors (rigid) section slamming into a single (weak) floor! Not seen on any videos, as far as I am concerned.

 

[X]

Only when a rubber ball bounces against ground F1 has to be greater than M1g, (due to absorbed/re-release energy) and we are not discussing that.

No, you are discussing why the collapse would come to a halt.

Stopping the upper section from moving downwards requires that F₁ be greater than M₁g.


I have show the calculations for this twice now.
Here and here.


This is a very big error. Especially given it's elementary-school level physics.

There is no excuse for making this.

Acknowledge your mistake and correct your work.

 

[Heiwa]

No, you are discussing why the collapse would come to a halt.

Stopping the upper section from moving downwards requires that F₁ be greater than M₁g.


I have show the calculations for this twice now.
Here and here.


This is a very big error. Especially given it's elementary-school level physics.

There is no excuse for making this.

Acknowledge your mistake and correct your work.

??? If a mass m with an acceleration g applies a force on another body it cannot be greater than mg. In my work, when this happens, the other body evidently applies the same force to mg that is in turn affected in many ways; decelerated, split into smaller masses, etc. And then you have to look at the smaller masses or the original m and see what they are up to. Some are stopped, some continue to drop, some are displaced outside the action. At every action energy is consumed/absorbed.
And this mass m is not dropping on a body like a house of cards. The body that m contacts is much bigger than m. And stronger. The body has carried m on top for 30 years.

According Bazant/NIST m applies an enormous (sic) force on this another body = lower structure (and global collapse ensues). But they forget that the another body applies the same enormous force on m. Goodbye m. m would of course also globally collapse, but - NWO at work - m remains intact all the time. Becuse it was rigid.

Simple question - do you really suggest that collapse arrest of structures cannot occur?

 

[HawksFan]

Ignore? Ignore?!? What? You didn't like my experiment suggestion? Why not? Surely, according to Heiwa physics, the only thing you'd need to fix are a few shingles on your neighbor's house and a few floor joists on yours. That cost is undoubtably worth it for proving your case, isn't it?

 

[Dave Rogers]

??? If a mass m with an acceleration g applies a force on another body it cannot be greater than mg.

OK, let's consider the case of a 500kg bomb dropping from 15,000 feet on the roof of a house. The bomb is accelerating at less than g because it will be approaching terminal velocity, but let's imagine that it is still accelerating at 1G. Since the roof of the house is easily capable of withstanding a force of mg, where m=500kg and g=9.81ms^-2, your assertion is equivalent to a statement that the bomb must fail to penetrate the roof of the house, and instead the pitch of the roof will cause it to fall outside the footprint of the building. Based on historical events circa 1939-1945, is this in general an accurate result?

Congratulations, Heiwa. You just debunked the Blitz.

Dave

 

[X]

??? If a mass m with an acceleration g applies a force on another body it cannot be greater than mg.

It can be, if the system is dynamic.

In my work, when this happens, the other body evidently applies the same force to mg that is in turn affected in many ways; decelerated, split into smaller masses, etc. And then you have to look at the smaller masses or the original m and see what they are up to. Some are stopped, some continue to drop, some are displaced outside the action. At every action energy is consumed/absorbed.

Irrelevant to the point I'm making. Stop trying to side-track the issue.

And this mass m is not dropping on a body like a house of cards. The body that m contacts is much bigger than m. And stronger. The body has carried m on top for 30 years.

Idiotic. The system is no longer static. And still irrelevant to the point I'm making.

According Bazant/NIST m applies an enormous (sic) force on this another body = lower structure (and global collapse ensues). But they forget that the another body applies the same enormous force on m. Goodbye m. m would of course also globally collapse, but - NWO at work - m remains intact all the time. Because it was rigid.

Bazant support his assumptions that the upper section remains largely intact.
But ultimately, it does not much matter.

Where in the equation F=ma do you see a variable to the physical state of the mass?

Simple question - do you really suggest that collapse arrest of structures cannot occur?

It can certainly occur.

But such an even would require F₁ be greater than M₁g.

Simple physics.


Netwon's First Law: "A particle will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced net force."

Newton's Second Law: "F = ma: the net force on an object is equal to the mass of the object multiplied by its acceleration."


In order for the upper section to stop its descent (i.e. collapse arrest), the net force acting on the upper section MUST be greater than the force due to gravity (M₁g).

Remember, this situation is dynamic, not static.


I'm left to wonder if you are delibberately avoiding this issue because you do not want to admit to your error, or if you are truly this incompetent.

 

[phunk]

??? If a mass m with an acceleration g applies a force on another body it cannot be greater than mg.

Really?

Gently place a 1kg brick on your head. The brick is exerting 9.8N of force on your head. Now lift it 1 meter, and drop it on your head. You should be safe right, since it can't exert more than 9.8N of force on your head?

 

[Heiwa]

Really?

Gently place a 1kg brick on your head. The brick is exerting 9.8N of force on your head. Now lift it 1 meter, and drop it on your head. You should be safe right, since it can't exert more than 9.8N of force on your head?

?? whatever force you apply to my head, my head apply the same force to what you apply. Newton's third law. Doesn't matter if static or dynamic.

 

[Heiwa]

It can be, if the system is dynamic.






Irrelevant to the point I'm making. Stop trying to side-track the issue.






Idiotic. The system is no longer static. And still irrelevant to the point I'm making.






Bazant support his assumptions that the upper section remains largely intact.
But ultimately, it does not much matter.

Where in the equation F=ma do you see a variable to the physical state of the mass?






It can certainly occur.

But such an even would require F₁ be greater than M₁g.

Simple physics.


Netwon's First Law: "A particle will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced net force."

Newton's Second Law: "F = ma: the net force on an object is equal to the mass of the object multiplied by its acceleration."


In order for the upper section to stop its descent (i.e. collapse arrest), the net force acting on the upper section MUST be greater than the force due to gravity (M₁g).

Remember, this situation is dynamic, not static.


I'm left to wonder if you are delibberately avoiding this issue because you do not want to admit to your error, or if you are truly this incompetent.

??? Topic is supposed to be the Pizza Tower experiment where the upper block does not initiate a global collapse when dropping on the Pizza Tower. It stops at once at impact. Did you try it? You side track in various ways ... and I reply to every question. I like that.

So, back to basics, why does the Pizza Tower stop the upper block dropping on it? The Pizza Tower is static! And a force is applied (upper block dropping on it). All is quite static! Pizza Tower is not flying away. Actually - any collapse is arrested before it is even initiated.

And that's what should have happened at WTC1,2 on 9/11. If anything else happened ... it was caused by something else than gravity.

Ever heard of Sherlock Holmes? Much smarter than John Edgar Hoover and his later staff at FBI ... or NIST for that matter.

 

[defaultdotxbe]

??? Topic is supposed to be the Pizza Tower experiment where the upper block does not initiate a global collapse when dropping on the Pizza Tower. It stops at once at impact. Did you try it? You side track in various ways ... and I reply to every question. I like that.

So, back to basics, why does the Pizza Tower stop the upper block dropping on it? The Pizza Tower is static! And a force is applied (upper block dropping on it). All is quite static! Pizza Tower is not flying away. Actually - any collapse is arrested before it is even initiated.

And that's what should have happened at WTC1,2 on 9/11. If anything else happened ... it was caused by something else than gravity.

Ever heard of Sherlock Holmes? Much smarter than John Edgar Hoover and his later staff at FBI ... or NIST for that matter.

i remember reading something about planes and maybe fires, but i wasnt really following the news