Psikey, just wading here to ask a couple of questions as the physics is way out of my league, but after viewing your video two items caught my interest: first I’m a model builder and I wonder why you don’t build a more complete replica of the towers using a medium that would better replicate the concete and steel structures (there’s plenty of material available including plastic sheeting and plaster with dowls to represent the beams or light aluminum found in any hobby store and model aircraft to replicate the planes loaded with fuel. Of course this is a pricey experiment but might be more accurate and secondly, as to your reference to the post office building at Hiroshima withstanding the atomic blast, the bombardier used this as a ground zero target so the bomb was intentionally airbursted over it at around two thousand feet. The shock wave burst out over the post office for a mile and a half to destroy the business district, so the blast hit it from above and not to the side. Although the structure sustained major damage it would have been completely flattened an probably swept away if hit by a perpindicular shock wave. A great deal of the steel was melted by the intense heat anyway and caused the collapse of part of the building, but notice the dome frame is still intact even now. I have an interesitng anecdote about that building if you’re interested. I’m really asking for clarification only.

Cap’t Jack

First of all I assumed a true scale model could not collapse because of the square cube law. I spent years not even trying to build a model because it was obvious it would not collapse and therefore prove nothing. That is why my model is not really a model of the WTC, it is a model for demonstrating the physical principles involved in the supposed destruction of the WTC. A collapse from the top means that the falling portion must accelerate the stationary mass and thus involving the Conservation of Momentum but it must also damage the supports which must be, at a minimum, strong enough to support the static load. So I deliberately made something to just meet that minimum to the best of my available materials. So if a model with the minimum support will not collapse than how could a real building with a safety factor collapse?

But I did not just want people to take my word from a video. I wanted lots of people to duplicate the experiment for themselves. So I wanted something cheap and easy. That model is cheap and easy.

Now actually the paper loops turned out to be stronger than I expected relative to the weight than I originally thought when I conceived the model. So a better test would be a much bigger and heavier model with a tube-in-tube design. I could not afford to build such a thing but our engineering schools could. But It mostly looks like they don’t even want to deal with 9/11. After almost 12 years they have another problem. If they now prove the collapse could not happen because of plane and fire then how would they explain not figuring that out and telling us years ago? They now have a vested interest in doing nothing. But the Laws of Physics will NEVER CHANGE or go away.

The whole point of the Hiroshima Memorial business is that the force came STRAIGHT DOWN. But supposedly the north tower was destroyed by force coming STRAIGHT DOWN. So this supposed force was working against the greatest strength of the building. So I was using the Hiroshima Memorial as somewhat of a propaganda ploy to show the absurdity of the official story. I admit it is a bit of somewhat cheap sensationalism but the force vector is correct.

If you have a huge solid block of concrete and reduce one dimension to 1/1000th isn’t that going to reduce the mass to 1/1000th the original value?

psik

Exactly. If you reduce the size of an object by one dimension, it becomes a thousand times less massive. If you reduce the size of an object by two dimensions, it becomes a million times less massive. If you reduce the size of an object by three dimensions, it becomes a billion times less massive. This presumes exactly equal material density and distribution.

So when you build a model of something that is 1:1000 the volume of an original sized object, assuming identical material density and makeup, the model’s mass is only a billionth that of the original model.

You cannot claim a 1:1000 scaled model will behave like the original unless all variables are equally scaled, including mass. And this cannot happen with mass as demonstrated above and you yourself pointed out. This is why experts use computer models and not models made of paper and washers. No engineer in their right mind would ever use a model like you did because they understand this fundamental issue of scaling of mass and volume. Mass and volume do not scale equally, therefore a 1:1000 model will not behave at all like the original.

Hence why your model tower does not collapse but a full scale one will. Because it’s at bare minimum a billion times heavier than your thousand times smaller model.

If you have a huge solid block of concrete and reduce one dimension to 1/1000th isn’t that going to reduce the mass to 1/1000th the original value?

psik

Exactly. If you reduce the size of an object by one dimension, it becomes a thousand times less massive. If you reduce the size of an object by two dimensions, it becomes a million times less massive. If you reduce the size of an object by three dimensions, it becomes a billion times less massive. This presumes exactly equal material density and distribution.

So when you build a model of something that is 1:1000 the volume of an original sized object, assuming identical material density and makeup, the model’s mass is only a billionth that of the original model.

You cannot claim a 1:1000 scaled model will behave like the original unless all variables are equally scaled, including mass. And this cannot happen with mass as demonstrated above and you yourself pointed out. This is why experts use computer models and not models made of paper and washers. No engineer in their right mind would ever use a model like you did because they understand this fundamental issue of scaling of mass and volume. Mass and volume do not scale equally, therefore a 1:1000 model will not behave at all like the original.

Hence why your model tower does not collapse but a full scale one will. Because it’s at bare minimum a billion times heavier than your thousand times smaller model.

First of all have you just changed the subject and now admit the model should not weigh 450 metric tons?

First of all have you just changed the subject and now admit the model should not weigh 450 metric tons?

psik

Your model should weigh 450 metric tons if you want to claim all variables are scaled equally. They are not. That is why your model is invalid. If your variables are not all equal, results will not be identical to the original, hence why your model did not collapse. Mass scales faster than volume, this is very basic engineering stuff you should be aware of if you’re going to make engineering claims like you’re doing.

First of all have you just changed the subject and now admit the model should not weigh 450 metric tons?

psik

Your model should weigh 450 metric tons if you want to claim all variables are scaled equally. They are not. That is why your model is invalid. If your variables are not all equal, results will not be identical to the original, hence why your model did not collapse. Mass scales faster than volume, this is very basic engineering stuff you should be aware of if you’re going to make engineering claims like you’re doing.

Well I never claimed all variables are scaled equally.

In fact I never claimed my model was scaled.

But if all three linear dimensions are scaled equally then mass will not scale equally. That is all there is too it.

Unless you scale those four basic variables equally, then your model is inaccurate. Simple physics dictates that by definition your model being smaller makes equal variable reduction impossible, unless you start adding massive amounts of mass to compensate for this effect. Clearly you did not, or your model would weigh 450 metric tons if you scaled it down to 1:1000 for volume.

Unless you scale those four basic variables equally, then your model is inaccurate. Simple physics dictates that by definition your model being smaller makes equal variable reduction impossible, unless you start adding massive amounts of mass to compensate for this effect. Clearly you did not, or your model would weigh 450 metric tons if you scaled it down to 1:1000 for volume.

The whole point of the Hiroshima Memorial business is that the force came STRAIGHT DOWN. But supposedly the north tower was destroyed by force coming STRAIGHT DOWN. So this supposed force was working against the greatest strength of the building. So I was using the Hiroshima Memorial as somewhat of a propaganda ploy to show the absurdity of the official story. I admit it is a bit of somewhat cheap sensationalism but the force vector is correct.

Thanks for clearing that up, I was wondering how the bomb blast correlated with the tower collapse and now I see what you mean. BTW there are Many other examples of buildings destroyed by the blast not to mention exposed steel being twisted and melted, e.g. steel rails. But you made your point.

I keep saying this is grade school physics and I never claimed to have a degree in mechanical engineering.

psik

Oh, well in that case, why don’t you use your high school grade understanding of physics and explain how increasing a model’s dimensions by three orders of magnitude and it’s mass by nine orders of magnitude is supposed to yield two models with identical properties and behaviors with regards to something like structural collapse?

I keep saying this is grade school physics and I never claimed to have a degree in mechanical engineering.

psik

Oh, well in that case, why don’t you use your high school grade understanding of physics and explain how increasing a model’s dimensions by three orders of magnitude and it’s mass by nine orders of magnitude is supposed to yield two models with identical properties and behaviors with regards to something like structural collapse?

You are the one talking about so scaling you explain it.

Provide a link to where I claimed the model was scaled. Your concept of winning is accusing me of saying what I never said and then making a hash of the square cubed law. It is because of the square cubed law that I did not even try to make a scale model. I knew it would not work. If I could make one it would be even less likely to collapse than the model I built which did not collapse anyway.

It is you people who claim the airliner impact and fire could cause the collapse who have to prove it. Build a model that can collapse. I want to see.