Re: Earth Deceleration theory likely a farce

Moshiachyozif wrote:
"Greg Neill" <gneillRE@xxxxxxxxxxxxxxxx> wrote in message
news:4972c58b$0$23013$9a6e19ea@xxxxxxxxxxxxxxxxxxxxxxx
Moshiachyozif wrote:
"Greg Neill" <gneillRE@xxxxxxxxxxxxxxxx> wrote in message
news:4972364d$0$23000$9a6e19ea@xxxxxxxxxxxxxxxxxxxxxxx
Moshiachyozif wrote:


But I don't believe that their "hours" were uniform in length.
Uniform hours was a concept that came in, I believe, only after
the introduction of mechanical clocks in the middle ages.

Well, your cultural bias is showing. The Egyptians as early as the
Amarna Period had a concept of the hour as determined by atomic clocks,

Atomic clocks in 1350 BC? Surely you jest.

and particularly in astronomy was this a consistent reference. The
Egyptian day began at midnight just as it does now and each period from
midnight to noon was divided into 12 hours each. Water clocks were used
to measure the "hours." So that's one reference.

A second one is in this case a confirmation of how long the hour was.
First, the actual "language" used is "1-2/3 double hours" which calculates
out to 3 hours and 20 minutes if we presume 60 minutes per hour. But
the precise time of the ecilpse is provided by Ptolemy which states this
eclipse occurred "one hour before midnight." So we know from a separate
reference with 1-2/3 "double hours" actually occurred. So all we have to
do is determine that length of time in relation to when "night" begins
which
is a division of the night following sunset. That is, the 1-2/3 double
hours
are timed "after night" but not after sunset. The Babylonians rounded
to 4 minutes. So sunset was at 7:09. I we introduce 32 minutes for the
beginning of night then add 3:20 we get 11:01 for this eclipse. So it is
pretty much confirmed that the "hour" in reference is 60 minutes, IN THIS
CASE. So at this point we wouldn't presume the Babylonians were not
capable of measuring the hour by various means, including water clocks,
and
that that technique was not standard during this time since astronomers of
Assyria, Babylon, Persia and Egypt were often sharing expertise in this
regard. In fact, during the Seleucid Era most royals and many high
ranking
officials were sent to Egyptian universities. Even Thales did a 7-year
apprenticeship in astronomy in Egypt. So the concept of the 60-minute
"hour" is at least as old as New Kingdom Egypt. Further, the Babylonians
had references of minutes as well. So the hour definitely was 60 minutes.
So, the hour was exactly the same and non varying: 60 minutes, especially
in
practice for the astronomers.

The Babylonians used the motion of the constellations at night to track
time, assigning about 30 degrees or two hours to each sign. The length
of time spent in each constellation would vary throughout the nights of
the year, although for Babylon, being relatively close to the equator,
this would not pose great problems.

It was, I believe the Greeks that first proposed the use of equal length
hours in order to support the mathematics of predictive calculations (as
opposed to simple period multpliers). Hipparchus proposed dividing the
day into 24 equal hours (called equinoctial hours, because days and nights
are of equal length on the equinoxes). It wasn't until the introduction
of mechanical clocks that equal length hours became commonplace for
ordinary use.


.

Relevant Pages

  • Re: Earth Deceleration theory likely a farce
    ... Amarna Period had a concept of the hour as determined by atomic clocks, ... and particularly in astronomy was this a consistent reference. ... So at this point we wouldn't presume the Babylonians were not ...
    (sci.astro.amateur)
  • Re: Earth Deceleration theory likely a farce
    ... the introduction of mechanical clocks in the middle ages. ... Amarna Period had a concept of the hour as determined by atomic clocks, ... The Babylonians used the motion of the constellations at night to track ... the selection of the specific constellations which were selected. ...
    (sci.astro.amateur)
  • Re: operating a 50hz clock radio on a 60hz power supply
    ... Certainly true with mechanical clocks. ... I had a co-worker who moved from the UK and brought along his European clothes washer with a mechanical timer. ...
    (misc.consumers)
  • Islamic contribution to time keeping?
    ... "A variety of mechanical clocks were produced by Spanish Muslim ... Europe through Latin translations of Islamic books on mechanics. ...
    (alt.horology)
  • Re: operating a 50hz clock radio on a 60hz power supply
    ... It'll run 20% fast, so you'll have to take this into account, keep track ... Certainly true with mechanical clocks. ... clocks use a crystal freq. ...
    (misc.consumers)