Re: analemmatic guy

On Mar 6, 11:19 pm, "oriel36" <geraldkelle...@xxxxxxxxx> wrote:
On Mar 6, 4:06 pm, "John Carruthers" <joncarruth...@xxxxxxxxxxx>
wrote:





On 4 Mar, 21:55, "oriel36" <geraldkelle...@xxxxxxxxx> wrote:

"If you looked at the Sun at the same time each day, from the same
place, would it appear at the same location in the sky? If the Earth
were not tilted, and if its orbit around the Sun were perfectly
circular, then, yes, it would."

http://solar-center.stanford.edu/art/analemma.html

Tell me analemmatic guy what the analemma looks like at the Equator
over the course of a year seeing you are intent on proposing axial
tilt as a component in the Equation of Time.

The variations in the Sun's position is a consequence of the orbital
path of the Earth and unless you are entirely stupid,I would not
recommend that you include the apparent arc of the Sun across the sky
as a factor in the Equation of Time,no figure 8,no nothing,in fact
take up birdwatching where you can be less destructive.

The Equation of Time is a global phenomena and has nothing whatsoever
to do with axial tilt but it has quite a lot to do with rotation and
the rate of change of the orbital orientation of the planet due to
orbital motion.

Now,the human devised creation of the 24 hour day may be of little
consequence to celestial sphere astrologers and their pseudo-dynamic
of a variable tilting Earth but it would be nice to see somebody who
can actually appreciate the brilliance of our ancestors in creating
the 24 hour day and applying it to axial rotation as a clock
correlation.

First go outside, yes, you can do it, then observe the sun with your
own eyes instead of reitterating distorted imaginings.
Have you ever made an accurate sundial ? (Google for 'Shadows').
If you have trouble comprehending the article just come back here and
ask for help.
Remember Jezza, this model works for a great many intelligent,
curious, people.

The analemma is a late 17th century creation,a meaningless exercise in
turning the human creation of the equable 24 hour day into a parody
based on where the Sun is using that human devised cycle.

There is no analemmatic figure 8 at the Equator for the Earth for the
equality of time a location at the Equatorial coordinate spends in
solar radiation and in the orbital shadow does not change over the
course of an annual orbit.To spend time on this artificial 'analemma'
creation is an absolute waste of effort however it does draw attention
to the pseudo-dynamic of variable axial tilt by which you explain the
seasons and how a location experiences differing amounts of time spent
in solar radiation and in the orbital shadow over the course of an
annual orbit.

Unlike many of you I have a clear sense of the neccessary modification
based on getting rid of variable axial inclination and replacing it
with a change in the solar radiation/orbital shadow boundary based on
the dynamic of orbital motion and the path that orbit takes.

It fits and accounts for the observations. On the





other hand of course there's you...

http://myweb.tiscali.co.uk/moonkmft/Articles/EquationOfTime.html
The Analemma. At noon, according to mean clock time (GMT if on the
Gweenwich zero meridian), the sun will be almost due south. Its
altitude will vary substantial throughout the year, as its declination
varies from -23.5 to +23.5 degrees. It will also generally vary
slightly in position, to the east or west of due south, due to the
mean clock time not being the same as sundial time. If one could
support a camera stationary throughout the year, pointing due south,
and upwards at an angle of about 40 degrees to the horizontal; and
expose the film very briefly at exactly noon (mean time) every few
days, whenever the sky was clear, throughout the year, then the
multiple images of the sun on the resultant multi-exposure photograph
would form a very narrow, elongated, figure-of-eight, with the top
(northern) lobe smaller than the bottom (southern) part. Such a figure
is known as an analemma. In actual fact, if one could travel westwards
along the equator at a uniform speed such that we took exactly 24
hours to arrive back where we started (more than 1000 miles per hour),
then the Sun would not appear to move noticeably during the course of
the day. If however, we continued for a whole year, the Sun would
appear to trace out this slender figure-of-eight we call the analemma.

All you are doing is using a 24 hour day,a human creative construct,to
determine the position of the Sun,t means nothing and certainly not in
respect to the Total length of the natural unequal day through which
the Equation of Time equalises the natural variations to an equable 24
hours.

The Equation of Time creates the 24 hour cycle and as the Sun's
apparent motion at the Equator is steady throughout the year,yet the
Equation of Time is required here as everywhere else,a reasonably
intelligent person should at least grasp the difference between the
Total length of the natural day as opposed to seasonal variations in
daylight/darkness at highere and lower latitudes.

The 17th century vandalism which forced a variable axial tilt
component into the Equation of Time or created your beloved 'analemma'
as a fudge factor to 'prove' constant axial rotation to celestial
sphere geometry is by far the worst act ever visited on human
involvement in astronomy.





If instead, one points the camera in a different direction, and takes
the exposures at a different time of day, e.g. late afternoon, one
will get a similar effect, but the figure-of-eight will not be
vertical, as here. An analemma for Mars can be seen here, from a
multiple exposure photograph taken in late afternoons on Mars by the
Pathfinder Project. This, instead of being a figure-of-eight, is
shaped like a pear. As stated above, due to the eccentricity of its
orbit, the Equation of Time on Mars just follows one cycle per Martian
year, and the analemma does not cross over itself.

There is an encyclopedia article about the analemma here, which shows
the Earth's and Mars' analemmas.http://en.wikipedia.org/wiki/Analemma.

Have a ball and keep up the trolling.
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I have a very difficult task and it is not made easier by the fact
that there is no self-correcting mechanism in place,no authority
exists to handle the matter in the dignified procedure it deserves.

You can keep your analemmas,as far as I am concerned they are for
people who know no better and have never had to think of the physical
considerations seriously.The fact is that orbital motion can do the
job that is presently assigned to variable axial tilt and knowing that
it involves modifying Copernican reasoning for the first time since
Keplerian orbital geometry should provide for some real excitement for
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To tidy up that last posting



At the Equator,the length of time a location spends in daylight and
darkness is steady over the course of an annual orbit however the
Total length of the natural cycles varies just like everywhere else.

As axial orientation remains fixed then so does the Equator -

http://astro.wsu.edu/worthey/astro/html/im-sky/south-pole-star-trails.jpg

This leaves the orbital motion,orbital path and the change in the
solar radiation/orbital shadow boundary to explain why locations
either side of the Equator experience variations in day and night
(radiation/shadow) but not locations at the Equator.

The Equation of Time is a different matter,it has nothing to do with
axial tilt but it has quite a lot to do with the Total length of each
cycle .In its geocentric aspect, there is no variation in the apparent
arc of the Sun at the Equator throughout the year but there is a
variation in the length of Time the Sun returns to noon.In its
heliocentric aspect this reflects that axial rotation passing through
the changing solar radiation/orbital shadow boundary which reflects
Keplerian orbital geometry .

This is a major modification to the reason for the seasons,it is not
easy to deal with as it is a combination of Keplerian orbital motion
and the path the Earth takes over an annual orbit.If you can live
comfortably with variable inclination then good for you,it spares you
having to deal with matters such as how to accurately mesh
astronomical data with terrestrail climatological consequences and
this is the major reason for the modification.

That being said,the cretion of the 24 hour cycle from the natural
unequal cycle is still a magnificent achievement borne out of the
recognition that no two cycles are the same .Most never get passed the
notion of differening amounts of daylight/darkness however timekeeping
astronomers did hence we have the Equation of Time correction which
generates the equable 24 hour cycle.




.

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