Originally posted by Alfie1
Originally posted by LaBTop
reply to post by -PLB-
Right side : Error margin +/- 1 sec max. for visual of video/photo (by NIST)
Left side : Arrival of signals at LDEO : 17 sec.
Left side : Delay Error margin +/- 1-2 sec (by LDEO)
That's a maximum combined uncertainty of 2 seconds.
LaBTop, I have to continue to take issue with you over how you treat the above tolerances. If the seismic signals took 17 seconds +/- 2 seconds from
the WTC to LDEO then surely that means the travel times could have been anything from 15 to 19 seconds; a range of 4 seconds. Similarly, your other
error margin of +/- 1 second on the vide/photo means a possible range of 2 seconds. So if you add them together you get a maximum combined
uncertainty of 6 seconds, not 2. This is vital when you are only arguing about a handful of seconds anyway.
Alfie1, damn, nearly missed your above post, cramped in between the litterers.
Btw, thank you for your well mannered posting behavior. Its a relief.
This is an UK site, that makes it easier for us both, I hope :
A Beginner’s Guide to Uncertainty of Measurement.
Do read the first paragraphs first, up to 3.2, and then take the time to contemplate on the case we have at hand. And yes, you can talk about a r a n
g e of uncertainties, but in this case it has no sense to use that expression, since we only take the worst case for my thesis in account.
I am arguing, that a certain, one time measurement, namely that pesky WTC7 seismogram, is declared by the operators of the seismograph it was written
on, at the LDEO institute, to have a margin of error (which is not the same as a margin of uncertainty) of 1-2 seconds. That means it has a max error
of + 2 secs. or - 2 secs.
This margin is usually obtained by collecting as many samples of earlier registered seismograms, also originating from Manhattan. And then calculate
them using the known formulas (see my link) for the standard acceptable margin of error. In this case it seems to be another margin again of 1 second,
since they use a margin of + 1 to + 2 secs., or - 1 to -2 secs., as found over perhaps a hundred years period, which resulted in thousands of
measurements to use as their sample collection for the error calcs.
For us it's not of importance how they achieved that value, since we have no access to their data bases of all these seismograms. So we have to take
them on their word.
Manhattan is a known quite active seismic region, which you perhaps would not expect, however, it is one. Usually within the lower boundaries for
Richter values of seismic activity.
So, thousands of seismograms is not out of the ordinary.
In this particular case, there is however an extra factor we have to take in account.
When you want to aim for the + 2 secs max error (19 secs travel time for seismic signals), please be my guest, because in that case, the Cianca
photo-time its registration (stamped on it) by the seismograph is shifted even 2 secs further in the future on the by LDEO printed time scale under
that WTC7 graph. Thus making the gap with the preceding huge pack of peaks even wider. Which would strengthen my case with an extra 2 secs max.
So in this one, particular case, I need only to defend my case against the for my theory worst case, being the - 2 secs max error margin deviation
from the mean norm, which is set by LDEO as being 17 secs for the first seismic signals to arrive at LDEO its seismograph's needle.
In that worse case, that thus the max error of 2 secs-less than the normal 17 secs arrival time for seismic events is taken in account, then it means
that the needle starts to oscillate to register the arrival of the Cianca dent event with its specific, known exact time stamp attached, at 15 seconds
after that event in reality took place at the WTC7 in Manhattan.
This will still place that Cianca dent-event at a point, 1 second after the whole pack of first, biggest peaks died out on the graph paper.
(Note that NIST added in 2005 an extra 5 secs to all their photo and video material, thus they let specific, known events like the Cianca photo, begin
even 5 seconds later on their time scale under the WTC7 seismogram at LDEO. I already showed you that that NIST decision is unreal).
As you can see, that sequence of biggest peaks events started with a slightly bigger oscillation by the needle, about 16.5 seconds on the graph its
paper, before that seismograph recorded the Cianca dent event in Palisades, upper N.Y. State.
The dent forming, being the first sign of any movement at all at WTC7.
It's 0.5 seconds after the point on my graph, where I drew in my vertical dark-blue line at the bottom of that WTC7 graph, with my "NIST time" text
in it. My black text ""20:46 Cianca photo time stamped"" under my horizontal dark-blue line, that expressed the 17 secs norm travel time through
the N.Y. State its upper crust.
Now we also have to take in account the error margin set by NIST for all photo and video material, the + or - 1 second margin in this case, for the
Cianca photo its time stamp.
That means, that in the most worse case scenario for my thesis, the Cianca time stamp must read as 20:46 - 1 sec = 20:45.
That would add another 1 sec to the already worse case its 2 secs, that's 3 secs in total.
Which means that in the most worse case for my thesis, the needle starts to write the Cianca event, at the EDT 17:21:00 point on the LDEO printed time
line, just after the first pack of the biggest peaks on that graph, died out.
However, as I already pointed out, the Cianca event has an error margin of much less than the max -1 sec, because that event could be cross checked by
many news media time stamped videos that shot the same event. By then tens of news crews were filming the WTC7 collapse sequence. Thus for that event,
the sample pool is bigger than for other photos or videos.
We may say that the Cianca time stamp is nearing the mean value of nearly zero error.
Which does get us back to the EDT 17:21:01 position on WTC7's graph, one second after the biggest peaks died out.
Shall we not further insist to insert those ridiculous extra 5 NIST seconds?
Because then the Cianca event ends up when the worse case scenario is used, at the EDT 17:21:07 position, which is 2 secs earlier than my red vertical
line with "LDEO" in it, at the top right of my WTC7 graph.
I hope you can follow my above explanation, if not, take three pieces of plastic foil, draw on one my 17 secs gap U-drawing, on the second one a 15
seconds gap U-drawing, and on the third a 19 secs gap U-drawing, and start to play around with those 3 foils over my WTC7 graph, then it will clear
everything up for you in one strike of insight.
Then you also understand that you do not have to make a tiny 1 sec gap U-drawing for the max error margin for the Cianca photo time, see for that my
Ignore that 1 sec max error gap, hold on to its original time stamp of 5:20:46 p.m.