[LEAPSECS] Leap Seconds schedule prior to 1972

[John Sauter]

I have updated my proposal for extending UTC to dates before 1972.
The principal changes are the removal of the section on NTP and a
somewhat hand-waving justification for using atomic time before the
invention of the atomic clock.  I have also addressed the other 
feedback provided here by going into more detail about the meaning of 
table 1, acknowledging UTC before 1972, and proposing a name for the 
time scale.

I am requesting additional feedback on the revised paper.

Here is the justification for using atomic time prior to the invention 
of atomic clocks:

``For a time scale to be useful for measuring events, it must be based
on some physical property that can be measured.  UTC is based on the
SI second, which is defined as the duration of 9,192,631,770 periods
of the radiation corresponding to the transition between the two 
hyperfine levels of the ground state of the cesium 133 atom when it is 
at rest with respect to the Earth, at a temperature of 0 degrees 
Kelvin, and located at mean sea level.  These measurements are made 
continuously by national laboratories around the world.  The data is 
sent to the International Bureau of Weights and Measures, which 
combines the information and disseminates International Atomic Time,
upon which UTC is based.

``A time scale used for scientific measurements must be rigorously 
defined and robustly measured, as International Atomic Time is.  If we 
try to extend this definition backward into ancient times, we run into 
the problem that there were no atomic clocks before 1955, and 
therefore nobody was measuring the SI second as it is presently 
defined.

``However, when describing ancient events, we do not need to actually 
measure time, we can instead imagine that we are measuring it.  For 
example, we say that the Big Bang that marked the start of the 
Universe took place 13.8 billion years ago.  In this context,
``years'' does not refer to the number of times that the Earth has 
gone around the Sun since the Big Bang, because the solar system has 
only been in existence for the last 4.54 billion years.  Instead, we 
take the present duration of a year and project it back in time,
thus imagining that we are measuring time using the year as it 
presently exists.

``Similarly, we can imagine that atomic clocks have been measuring
time for the last 3,000 years, and use that as our time scale.  This 
imaginary time scale does not have the precision of International 
Atomic Time, since there were not, in fact, atomic clocks 3,000 years 
ago, but it is sufficient for our limited purpose.''

Thank you,
    John Sauter (John_Sauter at systemeyescomputerstore.com)
-- 
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9A0B 511E

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