"OG" wrote in message ...
"Oriel36" wrote in message
m...
(George G. Dishman) wrote in message
. com...
(Oriel36) wrote in message
. com...
My goodness,it seems so long ago since you first introduced the
passage from the Principia into the discussion and while I have moved
on and expanded on the subject beyond all recognition you now would
not dare discuss Newton's absolute/relative time definition like you
did years ago,

When we previously discussed it, I assumed you were familiar
with the simpler aspects of astronomy.

I became familiar long ago with the most fundamental rotation of
all,the rotation of the Earth on its axis,one full revolution
corresponding to 24 hours.You believe the value to be 23 hrs 56 min 04
sec and this constitutes an error.

Excuse me for joining in, but what exactly are you saying?

The earth orbits the sun once every 365 1/4 days - which we call a year, and
it makes a total of 366 1/4 rotations in that time.


You have to define a constant 24 hour day FIRST before you divide the
axial cycle into the annual cycle(the capitalisation is not done out
of irritation or loss of patience but because of it is of the utmost
importance).

The astronomical means to derive a constant 24 hour day is from the
natural unequal day and the EoT computation using ONLY the Sun as a
reference for the motions of the Earth.












This means that in an average 24 hours the earth has to rotate more than 360
degrees.


The noon determination occurs at any given moment at a longitude
meridian location on the Earth,the determination of the exact moment
when a longitude meridian rotates to face the Sun directly (noon)
varies from one complete axial rotation to the next and constitutes
the natural unequal day.

The EoT, with its positive and negative values facilitates the
transition from one constant 24 hour day to the next and
astronomically this was made from the noon determination,we still
retain the AM and PM prefix when the astronomical day began at noon.


http://ourworld.compuserve.com/homep...powers/EoT.htm










If the daily rotation of the earth is measured against a 'fixed' frame, i.e.
the fixed stars; then clearly the true 360 degrees is achieved in 23hrs,
56m, 04 sec.


No,you have already lost the significance of the 24 hour/360 deg
equivalency which provides the basis for the sidereal figure of 23
hours 56 min 04 sec.The original purpose for determination of the 24
hour day allied to civil longitude coordinates remains based on the
axial rotation of the Earth isolated from the variation in orbital
motion.

It stands to reason that axial rotation acting in concert with the
orbital motion reflected by Kepler's second law generates an
inequality registered by the variation in the pace of a shadow across
the face of a sundial.The EoT equalises the shadow's natural pace to a
constant pace and 24 hour clocks were developed to keep a constant
pace as a product of the EoT ,the equable 24 hour day which it
generates and subsequently the division of the 24 hour day into
subdivisions of hours,minutes and seconds.

Again,you have to define a 24 hour day first and subsequently hours
minutes and seconds before you determine that the annual cycle is
365.25 days.This is where the error exists in linking the Earth's
axial rotation directly to the stellar circumpolar figure.






The equation of time is an unrelated concept, being the adjustment made to
smooth out the Solar clock to take into account the elliptical orbit
relected in the solar analemma. It enables us to have equal length seconds,
minutes days etc, throughout the year.


Without the EoT you have no 24 hour clocks,with no 24 hour clocks you
cannot make the determination of the sidereal value,the value for the
annual cycle or the pace of anything else.



Newton's comments about absolute time are intended to lay out the difference
between the 'imperfect' solar time and the 'perfect' absolute time. The
point that is made is that all perfect times are equally perfect.


Newton's definitions and distinctions between absolute and relative
time contain a definite mathematical component,the EoT.He is being
pragmatic for he is aware that astronomers base their calculations and
modelling of the motions of the primary planets on the constant 24
hour day from observances conditioned by the natural unequal day.

"The duration or perseverance of the existence of things remains the
same, whether the motions are swift or slow, or none at all: and
therefore, it ought to be distinguished from what are only sensible
measures thereof; and out of which we collect it, by means of the
astronomical equation."

In his description of absolute time he remarks accurately that there
is no observed equable motion corresponding to the pace of a 24 hour
clock yet a more sensitive examination of the material reveals that
the constant day is based solely on the axial rotation of the Earth
free of the variation in the natural unequal day,the variation is due
to Kepler's second law.




Clearly sidereal time, being regulated by the rotational momentum of the
earth is much closer to perfection than solar time.


The overall importance of countering the direct linkage of the
rotation of the Earth to stellar circumpolar motion or what amounts to
the same thing - sidereal time,is that the original determination of
the 24 hour day via the EoT permits the isolation of constant axial
rotation from its orbital variation.The sidereal value creates a
stellar circumpolar framework whereas the original absolute time(as
Newton phrasedit) reflects only the axial rotation of the Earth
without any outside reference.Crucially,it is easier to begin with
axial rotation,then consider orbital motion around the Sun and then
consider the Earth's along with the rest of the solar system's
rotation about the galactic axis.



In terms of these ideas, could you explain where your view differs.
Thanks

It is a geometric treatment of clocks and their historic and
observational relationship to geometry and astronomy.