ElMondoHummus
0.25 short of being half-witted
I was not talking about the objects falling down faster that the crushing, but flying sideways faster than the crushing advanced downward. and as I already posted earlier, in a collapse there should be nothing flying 90 degrees sideways at all. And if you are supposed to "bounce" or "spring" something sideways, you need to see that part first fall or be hit by something that falls. In the videos we see parts ejecting one after another without anything hitting them, or those pieces falling on anything.
Just nonsense. From years past: Why it's obvious there could be lateral motion during top down collapse.
Because, Like most ijit CT'ers, simplicity is in the eye of the be-holder.
the fact is that air resistance is negtligible for the steel elements falling even from the top. I won't argue that. Over 9.2 seconds tiime (falling from the top, and that's an approximation for convenience) Velocity will be about 295 feet/second, or 201 mph. That is not going to be terminal velocity for a steel chunk--heck, even humans can reach that felocity jumping out of airplanes. So I won't argue that approximation--it's valid.
What they ignore is that there are lateral forces acting on beams/bars/chunks . Buckling loads cause lateral forces internal to the beam elements--or columns if you insist (they are mostly vertical, but buckling also occurred in horizontal elements)
F=MA, and F and A are VECTORS!. So, believe it or don't--I could not care less--a horizontal force due to buckling loads gives a horizontal velocity.
And one will have to get into those nasty "load path" and "load sharing" things that CT'ers refuse to believe in.
Imagine a beam of steel and apply a moment at each end. Imagine then that each end fails catostropically such that the stored elastic energy of the bent beam is suddenly released. The beam will displace in a horizontal direction.
This is basic engineering concerning buckling and collapse. You can simulate this by taking something with a moderate elastic modulus and bending it between your thumb and forefinger and allowing it to slide off the fingers. Note how the sample flies outwards. Kids learn this trick at an early age. Why didn't you?
Lurker
Drop a pencil - inclined at some angle to the horizontal - onto the edge of your kitchen table. It will be "ejected sideways" with absolutely no energy being "applied horizontally" in any active sense.
A snowplough pushing snow off the road whilst driving straight along the road would be another example.
I think the concept is known as "vectors".
I've posted this before and it was ignored by Bill and his cronies. The following image was a screen shot from this video: http://www.youtube.com/watch?v=CkbGAzzidFI&feature=related
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This clearly shows the perimeter walls/steel falling sideways in an arc. I see no 4 ton steel section being ejected sideways by explosives. The pieces landing 600 feet away can clearly be explained by the perimeter walls falling sideways as the connections are being severed by the falling mass of debris.
Anyway, these are old, long refuted claims. Collapse mechanisms are far more complex than truthers try to present them. Furthermore, as Gamalon above among others over the years has shown, truthers all too often resort to either vaguery or distortion to make their claims appear anomalous. Fact of the matter is, Jbui's claim is not based on any understanding of what happened and what's known. The objections are based on a woefully incomplete, far-from-thought-out model of what must have happened. And again, as I pointed out, they're old claims.
Further reading:
- http://www.internationalskeptics.com/forums/showthread.php?t=72487 (This thread actually deals with the specific topic of lateral debris "ejection").
- http://www.internationalskeptics.com/forums/showthread.php?t=108273 (this and the following threads are simply on the mechanics involved in the collapse, and while the thread subject is not directly on the topic of lateral ejection, some individual posts touch on it. Even in threads with no discussion of lateral ejections, it's still necessary material for understanding the collapse dynamics. For example, this thread here deals in detail with vertical column buckling as a failure mode. A buckled column imparts sideways force as it fails, so anything attached by extention will have a lateral component to their motion that resulted from the vertical force applied to the column from above. All logically extending from the collapse and not needing explosives to be involved at all.)
- http://www.internationalskeptics.com/forums/showthread.php?t=111454
- http://www.internationalskeptics.com/forums/showthread.php?t=111677
- http://www.internationalskeptics.com/forums/showthread.php?t=104641
- http://www.internationalskeptics.com/forums/showthread.php?t=133271
- http://www.internationalskeptics.com/forums/showthread.php?t=137438
- http://www.internationalskeptics.com/forums/showthread.php?t=92090
- http://www.internationalskeptics.com/forums/showthread.php?t=138715
- http://www.internationalskeptics.com/forums/showthread.php?t=153252
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Aside: Yes, folks, I know I didn't link any posts from the mother of all threads regarding collapse dynamics: The "Realistice" thread. No way I'll throw a newbie into that! It would be too mean.