Care to Comment

[Tony Szamboti]

Wrong. Only in the vanishingly unlikely case of every column of the face making a simultaneous axial impact on the column below would a deceleration be observable. Any variation in the lengths of the initial column buckles, any significant amount of tilt or any significant degree of non-axial impact would distribute the impact sufficiently that no deceleration would be observable.

Dave

So now you are having to claim that each individual column on the north face had its own separate in time impact.

It really doesn't get any better than this Dave.

Besides the fact that you are straining credulity to an extreme with the above there is still another problem for your theory. That is the amount of energy dissipation which would occur, which we can use to calculate velocity loss. You attempted to explain this before with the separate in time impacts occurring while the upper section was falling. Even if your latest variant were possible, the extremely small time differentials which would occur in this situation would not allow for the velocity loss to be compensated for.

Your only hope is that most people on this forum won't understand what is being said here.

 

[femr2]

I used the term real deceleration to impress upon some here who attempted to say a reduction in acceleration was deceleration that it isn't.

Maybe you didn't follow.

No Tony, of course I don't follow you.

The graph I posted earlier includes reduction in velocity. It's not a change in the increase rate of the velocity. The drop rate of the NW corner slows down. The NW corner decelerates at that point.

You are basically saying that if an object falling at 9.8m/s^2 experiences a reduction in acceleration to 1m/s^2 that it HASN'T decelerated. Clearly it has. Please affirm this point. Decelerated is used correctly in that sentence, yeah ?

Or let's try this...I'm in a car doing 70mph and I hit the brakes. I slow down to 50mph. Have I accelerated or decelerated ?

Please also define exactly what you mean by real deceleration, as I'm befuzzled if I know. I assume you mean a velocity reduction. If so, you should simply say so.

(even getting myself confuzzled now )

 

[Dave Rogers]

So now you are having to claim that each individual column on the north face had its own separate in time impact.

Of course. It's utterly beyond me why you insist that all the impacts must be simultaneous. You're claiming, whether you realise it or not, that the initial buckles were all exactly the same length, that the entire face fell perfectly level, that no pieces of debris came between the upper and lower ends, and that the twisted ends of the columns impacted perfectly on one another. Any significant departure from this impossible ideal nullifies your analysis.

Besides the fact that you are straining credulity to an extreme with the above there is still another problem for your theory. That is the amount of energy dissipation which would occur, which we can use to calculate velocity loss. You attempted to explain this before with the separate in time impacts occurring while the upper section was falling. Even if your latest variant were possible, the extremely small time differentials which would occur in this situation would not allow for the velocity loss to be compensated for.

Firstly, what you describe as "velocity loss" is in fact a reduction of downward acceleration, which is clearly observed as an overall 0.7G acceleration of the falling block. Secondly, you're drawing conclusions from the values of quantities you don't know, because you've made no attempt to measure the initial buckle lengths and hence one component of the time difference between initial impacts. Any such conclusions are worthless.

Your only hope is that most people on this forum won't understand what is being said here.

I count one so far.

Dave

 

[Dave Rogers]

No Tony, of course I don't follow you.

The graph I posted earlier includes reduction in velocity. It's not a change in the increase of the velocity. The drop rate of the NW corner slows down. The NW corner decelerates at that point.

This much is fine. However...

You are basically saying that if an object falling at 9.8m/s^2 experiences a reduction in acceleration to 1m/s^2 that it HASN'T decelerated. Clearly it has. Please affirm this point.

No, it hasn't. If the acceleration drops from 9.8m/s^2 to 1m/s^2 but remains positive, then the object hasn't decelerated. If the 9.8m/s^2 is acceleration due to gravity, then a retarding force of m*8.8m/s^2 has also been applied, but that hasn't caused an actual deceleration.

Or let's try this...I'm in a car doing 70mph and I hit the brakes. I slow down to 50mph. Have I accelerated or decelerated ?

That bit, again, is fine; you've decelerated.

I haven't a clue what Tony means by real deceleration, or indeed by a fairly large proportion of the bizarre nonsense he posts, but your velocity curve clearly shows a real deceleration at two points, at least by the definition that competent scientists use.

Dave

 

[femr2]

If the acceleration drops from 9.8m/s^2 to 1m/s^2 but remains positive, then the object hasn't decelerated.

Linguistic befuzzlement Fair enough. So it has to be called a reduction in acceleration.

I think Tony should state what he's talking about as a reduction in velocity. I'm fine with that

 

[Tony Szamboti]

Linguistic befuzzlement Fair enough. So it has to be called a reduction in acceleration.

I think Tony should state what he's talking about as a reduction in velocity. I'm fine with that

I have always called a deceleration a reduction in velocity as opposed to a reduction in acceleration, where velocity is still being gained but at a lesser rate.

A reduction in acceleration does not provide for load amplification, which is necessary in a natural collapse of a structure with a reserve strength several times the load it is carrying.

If there is any confusion on this it shouldn't be due to my terminology, but that of those who are either confused themselves or attempting to confuse others on the issue.

 

[carlitos]

I used the term real deceleration to impress upon some here who attempted to say a reduction in acceleration was deceleration that it isn't.

Maybe you didn't follow.

Well, to be fair, how could I possibly follow?

If the rate of acceleration decreases, but acceleration is still positive, what is this called?

If velocity decreases, what is this called?

 

[femr2]

If there is any confusion on this it shouldn't be due to my terminology, but that of those who are either confused themselves or attempting to confuse others on the issue.

A DOH! moment from me alas. Nearly 4am here

Too much real deceleration goin on.

There are points of deceleration (velocity reduction) in the NW corner trace though. Agreed ?

Do you get similar results from your new data-set ? Would hope so.

 

[femr2]

If the rate of acceleration decreases, but acceleration is still positive, what is this called?

That's where I went loco Has to be just that...a reduction in the rate of acceleration. (as long as there's no velocity reduction during the period)

If there is a word for that, am all ears. (am fine with average and instantaneous)

eta: de-acceleration ?

 

[Seymour Butz]

That's where I went loco Has to be just that...a reduction in the rate of acceleration. (as long as there's no velocity reduction during the period)

If there is a word for that, am all ears. (am fine with average and instantaneous)

eta: de-acceleration ?

Don't think of it as coming off the throttle and applying the brakes. That would be decel. (but of course when we're trying to relate it to gravity driven events, the throttle is always to the floor, and decel depends on the brakes applying varying decel energy. This is where it gets tricky to laymen.)

The diff between freefall accel and less than freefall is more akin to, if we use the car again, accelerating with full throttle vs part throttle. In both of these cases, you're still accelerating, just at different rates.

I think what you've found is the full vs part throttle case, with it varying back and forth.

Tony is advocating no throttle and braking, then part/full throttle, then no throttle and braking, then part/full throttle, etc.

He has yet to show, from what I've seen, good engineering that shows this should be the case in the real world. Instead, as has been pointed out countless times, he's attacking the hypothetical case that Bazant laid out, and saying that didn't happen in the real case.

So what, Tony. All you've proven is that the optimal case didn't happen. Big surprise .

Not.....

 

[Seymour Butz]

A reduction in acceleration does not provide for load amplification, which is necessary in a natural collapse of a structure with a reserve strength several times the load it is carrying.

Only if, in Tony-the-Twoofer World, stuff falls onto the columns and not the floors, and the falling stuff falls perfectly square onto them.

In the real world though, stuff end up on the floors. I've never seen stuff NOT fall onto the floors. In this reality based world, the only amplification would be based on the floor's strength and/or their connections to the columns.

It doesn't matter how strong the columns are, if the floor system is weaker by a couple orders of magnitude......

 

[Bell]

Other than counting pixels, does Tony have actual evidence of a controlled demolition of the WTC?

 

[Tony Szamboti]

Only if, in Tony-the-Twoofer World, stuff falls onto the columns and not the floors, and the falling stuff falls perfectly square onto them.

In the real world though, stuff end up on the floors. I've never seen stuff NOT fall onto the floors. In this reality based world, the only amplification would be based on the floor's strength and/or their connections to the columns.

It doesn't matter how strong the columns are, if the floor system is weaker by a couple orders of magnitude......

Really?

Have you ever heard and understood the term inertia?

The floors were not aligned with the columns, so your little theory here seems to be missing a force to shift the upper section of the building sideways as it falls. A sideways shift is not the same as tilt and even though tilt can produce a vertical misalignment away from its hinge, it doesn't at the hinge fulcrum, and it has been shown that there was very little tilt by the time the first collision between stories should have occurrred.

The north face was the hinge for WTC 1 and it shows no signs of deceleration.

 

[Tony Szamboti]

There are points of deceleration (velocity reduction) in the NW corner trace though. Agreed ?

Do you get similar results from your new data-set ? Would hope so.

No, and I know of nobody else who has seen it in their measurements. It seems only your data shows any signs of this.

At what point in the fall do these little blips in your data occur and what is the velocity loss you calculate from the distance vs. time measurement for them?

 

[Tony Szamboti]

Don't think of it as coming off the throttle and applying the brakes. That would be decel. (but of course when we're trying to relate it to gravity driven events, the throttle is always to the floor, and decel depends on the brakes applying varying decel energy. This is where it gets tricky to laymen.)

The diff between freefall accel and less than freefall is more akin to, if we use the car again, accelerating with full throttle vs part throttle. In both of these cases, you're still accelerating, just at different rates.

I think what you've found is the full vs part throttle case, with it varying back and forth.

Tony is advocating no throttle and braking, then part/full throttle, then no throttle and braking, then part/full throttle, etc.

He has yet to show, from what I've seen, good engineering that shows this should be the case in the real world. Instead, as has been pointed out countless times, he's attacking the hypothetical case that Bazant laid out, and saying that didn't happen in the real case.

So what, Tony. All you've proven is that the optimal case didn't happen. Big surprise .

Not.....

It happens in every Verinage demolition, which are due to natural forces.

If WTC 1 was a natural collapse after falling one story, then why doesn't it show deceleration like the Verinage demolitions?

It has been shown that the small tilt cannot account for the lack of deceleration.

It seems the only rational explanation for the lack of deceleration is that the column strength was largely removed prior to the collisions between stories.

 

[twinstead]

If WTC 1 was a natural collapse after falling one story, then why doesn't it show deceleration like the Verinage demolitions?

Do you think every engineer who disagrees with you (and that's the majority, btw) is incompetent or 'in on it'?

 

[Tony Szamboti]

Do you think every engineer who disagrees with you (and that's the majority, btw) is incompetent or 'in on it'?

I know of no engineers who have looked at this and disagree with me other than the few on this forum, all of whom are anonymous except for Ryan Mackey, and he has been shown to be incorrect on the factor of safety of the core columns and the amount of tilt in WTC 1 when it begins its descent.

Every colleague I show this information to concludes that the reason for no deceleration occurring in the collapse of WTC 1 is that the column strength had to be largely removed prior to the impacts between stories.

By the way, Jonathan Cole, a professional engineer whose video on this issue is the subject of this thread, has just put out an additional two part video on the issue aimed at helping those who might have a hard time understanding the principles involved. They are here

http://www.youtube.com/watch?v=ww8hBFNY8jk

and here

http://www.youtube.com/watch?v=dgZLXI3whGA&feature=related

 

[GlennB]

...
and it has been shown that there was very little tilt by the time the first collision between stories should have occurrred.

Can you describe - at this moment of "first collision between stories" - your vision of what is hitting what within either building? Please include a description of the condition of the what and what prior to the collision, if you'd be so kind.

 

[Tony Szamboti]

Can you describe - at this moment of "first collision between stories" - your vision of what is hitting what within either building? Please include a description of the condition of the what and what prior to the collision, if you'd be so kind.

The first collision should have been largely column on column and over 90% of the columns in the 97th floor at the top of the lower section were undamaged, and none of those on the 99th floor at the bottom of the upper section were damaged.

 

[femr2]

No, and I know of nobody else who has seen it in their measurements. It seems only your data shows any signs of this.

Really ? How did you manage to miss the enourmous volume of work posted by Achimspok ? ...

(One of many views he's produced)

Will say I'm pretty sure my methods are near-definitive though. Ridiculous amount of effort went into extracting the velocity data from the Sauret footage.

See any periods of velocity reduction in that set of data ?

At what point in the fall do these little blips in your data occur

Seriously ? The x-axis of the graph is time in seconds.
Am sure you can see where the velocity reduces. I'll let you define your own t0.

and what is the velocity loss you calculate from the distance vs. time measurement for them?

Wouldn't use distance-v-time. T'would be silly. Will have to work it out, as the vertical axis for the velocity data is not scaled, but as you already know....not a lot. The tracing method was honed over quite a period of time, and so for the velocity graph, you're looking at very fine detail...