Hi,
On a slightly tangential note to this interesting discussion: do we
have a term, equivalent to 'equinox', to describe the four days in a year
when the Equation of Time in zero?
Peter Mayer
--
Peter Mayer
From William Lee Kennon, Astronomy:
-quote-
The actual values of the equation of time from day to day throughout the
year will depend on the point where the real sun and the fictitious sun are
made to coincide in right ascension. It is desirable that this point be so
chosen that the values of
Daniel Lee Wenger wrote:
Luke
Your statement that eccentricity will always be synchonous to
the passage of perihelion needs, I believe, amplification. There
is no a priori reason that I know of that the mean sun and the
actual sun should have the same right ascension at perihelion.
Luke
Your statement that eccentricity will always be synchonous to the passage
of perihelion needs, I believe, amplification. There is no a priori reason that
I know of that the mean sun and the actual sun should have the same right
ascension at
perihelion. The fact is that one may choose the
Thibaud Taudin-Chabot wrote
it is simple arithmetic: our watch shows mean time, so the mean of the
correction should be 0, otherwise your watch is fast or slow after a year.
I thought just the same when I first saw the question - but then I thought
again. I believe that the above condition
Bill
I think that it was not a choice to index to those dates but instead to
place the
analemma such that the number of days that the EoT is positive is the same as
the number of days that the EoT is negative. If the analemma is displaced this
balance cannot occur. I discuss this average on my
Luke, I really liked your clear explanation, but I think you meant to say
the ANALEMMA has two components, the EOT and the declination. The EOT is
not dependent upon the obliquity; we would still have it even if the axis
were perpendicular to the ecliptic. Luckily, both independent components
I don't really know, but I would think that the zero level is chosen so
that the total area of the EQT curve above the line matches that below the
line. This would make the annual mean of the EQT would be zero minutes.
At 23:02 3/04/2000 -0400, [EMAIL PROTECTED] wrote:
4/3/00
Does anyone
Hi Bill,
If you mean to ask why the EoT was made to be zero at a given
set of dates, I think the answer is that it wasn't. One can't
arbitrarily make the EoT zero points (four of) synchronous to a set of
dates. The EoT has two components, obliquity (the tilt of our axis
relative to the
Hi Fritz,
The analemma is in essence just a graph of the EoT vs Declination, in
discussing the components of the EoT the analemma need not be mentioned,
the analemma is just another way of expressing the EoT. The dynamics of
the EoT define the shape of the analemma.
As regards
it is simple arithmetic: our watch shows mean time, so the mean of the
correction should be 0, otherwise your watch is fast or slow after a year.
At 23:02 3-4-00 EDT, you wrote:
-Original Message/Oorspronkelijk bericht--
4/3/00
Does anyone know why the equation of time is
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