Splendid. As I'm sure you're aware, I've been looking for all possible signs of early *creep* for quite a while, given the numerous (incorrect) assertions that *progressive tilt* was not simply present, but visually observable, and for a period of 20 minutes or so.
Needless to say that even with high resolution digital photographs, allowing very small angular changes to be identified (far smaller than any visual inspection could possibly resolve), no progressive tilt was found.
Through application of tracing methods it has become possible to determine movement 9.5s before release, and also the point in time at which movement began or it's rate severely increased, that being, perhaps coincident to, the period of camera shake.
Again, before that point - no observable movement.
After that point - significant rates of movement.
Before that point - some movement (observable in some cases as cumulative displacement over time, not observable using available methods in other cases)
After that point - more/faster movement
Incorrect. I acknowledge that definition of t=0 must be parameterised, which is one reason why I use the word *release*, that being the point in time at which vertical velocity rapidly changes from effectively zero to full descent.
Once again, self-contradictory. A period of time over which the vertical velocity changes cannot be a point in time. There are no infinite accelerations.
You only get a point in time by assigning some specific value of velocity as a threshold value. You can then identify the point in time when the observed velocity reaches the threshold value. (ETA: Or you can similarly use a threshold value of displacement or acceleration.) But that is not t=0 in any physically meaningful sense. Some movement must have occurred before that time.
And the value you assign is arbitrary in any case. "Rapidly," "effectively zero," and "full descent" are not numbers.
Simultanaety is a physical impossibility, so there must be an order of sequence. Careful not to limit your viewpoint to a rigid body eh.
Yes, one definition of an event can overlap with any other, but...
Did failure of perimeter columns result in load transfer to core columns, or the other way around ?
The *failure* event did not occur on both* simultaneously.
*and of course *both* actually refers to many separate interconnected elements, all of which have their own separate behavioural timespans.
Simultaneity is certainly not a physical impossibility. As you yourself state, you are dealing with many separate elements connected in a not fully (and decreasingly) rigid structure, and many stages of actual failure of any single element. Is anyone claiming that every column of the south face reached, say fracture and/or buckling at least 30 degrees from vertical before any column of the core began distorting plastically, or anything of that nature? That's not what "failure began at the south face..." means.
In the real world, each increment of physical state change (elastic compression, elastic buckling, plastic compression or buckling, fracture) of each exterior column affected the load on every core column (and other exterior column) that remained connected, and each increment of physical state change of each core column affected the load on every exterior column (and other core column) that remained connected. So the correct answer to the question "Did failure of perimeter columns result in load transfer to core columns, or the other way around ?" is "definitely."
(If only there were some kind of rigorous quantitative
analysis that could be done, to calculate the complex interactions of all those many
elements. Perhaps using
finite numerical methods to deal with the otherwise intractably complex differential equations involved.)
Sure, you can define some arbitrary velocity of some arbitrary point as "the *failure* event" and sweep all that real-world complexity under the rug. But when you do that, you no longer have any basis to for instance declare it physically impossible for those *failure* events to occur simultaneously, or use them to establish causality. "Hey look, the antenna moved before the *failure* event of the south wall" becomes a big "so what?"
Respectfully,
Myriad
