But you were using this arbitrary reference point to make claims about the time at which the shots occurred.
It appears that you are still confused. Here is my post that you are responding to:
Here is an example of using a zero reference point that will hopefully help clear up any confusion:
An architect is drawing up a set of plans for a multistory building with an underground parking deck below the building. He needs to draw some elevation views to show the distances between floors, ceiling heights, window sill heights, etc. And he needs a reference point (zero point) that he can calculate the various elevation distances from. Lets say he selects the main (ground) floor as his reference point. He can designate the finished ground floor as zero and show the elevations of the other items as a distance from his zero reference point. In this case the underground items would have a negative number for their elevations.
However, he could have selected, for example, the floor of the lowest level of the underground parking deck to be his zero reference point, designated the distances to the other items accordingly, and still ended up with, for practical purposes, the same resulting building. Provided of course that the builder followed the plans properly.
So, in a sense, the selection of what to use for the zero reference point is arbitrary. And I believe that that is what Dale Meyers is trying to say in that sentence.
The above example indicates that the building can be accurately built repeatedly using different zero-points of reference. So arbitrarily selecting a zero-base reference point to use does not affect the building. However, placing that building in the real world is a different process. The designated elevation of the (arbitrarily selected) zero-point of the building, as it relates to mean sea level, fixes the building to a world-wide standard. And similarly, the derived time of 12:29 for the start of the open-mike transmission fixes every thing that happens in that continuous section of the recording to “real” time. The accuracy of the building’s elevation as it relates to average mean sea level depends upon the methods and accuracy of the instruments used. Similarly the accuracy of the “real” time in Bowles’ report depends upon his methods and the accuracy of his stopwatch. Bowles clearly states that his “real” time is a rational assumption. He explains his methods of developing that rational assumption; and invites others to examine his methods and decide for themselves how accurate they believe them to be. I am saying that the selection of the beginning of the open-mike transmission as his zero-point of reference (whether you believe this selection to be arbitrary or not) is not what matters with regard to accuracy. His method is what you need to examine if you want to argue about accuracy.
