December Solstice 2015

As the Earth travels through space, this enormous object varies in speed and to my mind this is astonishing and indicative of the influences acting on our planet. The orbital surface rotation responds to the variation in speed as an observed effect where the total length of time the Sun returns to noon varies with each cycle even though the rotation runs parallel with the observed motion of the North and South poles across the fully illuminate face of the Earth and not with daily rotation across the same face.

I can't imagine why something as obvious as the rotation behind the polar day/night cycle or the seasons (where it combines with daily rotation) is completely ignored other than some meaningless personal dislike.

To see two types of rotations to the central Sun in plain view and beginning roughly 49 seconds in should be enough to make people adapt to this more productive view and as a symbol of 21st century tools -

https://www.youtube.com/watch?v=612gSZsplpE

In a few weeks the newspapers will haul out the old 'tilt towards and away from the Sun' explanation for the Solstice instead of this fresh perspective which requires only a second look at the Earth dual day/night cycles.

This is not the 20th century where people have to die to facilitate academic inertia, this is simply for the astronomer visiting this forum who wishes to add to the life enhancing experience of astronomy beyond the magnification exercise.

The relevance of the Arctic circle is that it represents the maximum circumference radiating from the North pole where either the Sun is absent or visible in its entirety at either Solstice.

It is a great shame that the ever expanding or decreasing circles, due the the transverse motion of the poles across the fully illuminated face of the Earth doesn't make it into wider circulation and especially at this time of the year when the Earth's orbital motion turns the entire planet so that the poles are midway between the circle of illumination.

It has even been touched by human investigation even though it is within reach of any person who has a capacity for joy and spirit.

http://imgur.com/8wx48U4

While I took that picture on the Equinox, in context of the Newgrange December Solstice alignment, there are a lot of astronomical practicalities involved in the choice of date and location for the human construction 5200 years ago and especially the alignment with the appearance of the Sun on Dec 21st.

http://www.knowth.com/ireland/newgrange.jpg

The rapid motion in declination occurs around the Equinox so a roofbox is impractical then however the Solstice or 'Sun-stopped' provides a number of days when a narrow channel could be built to create the spectacle for a longer period.

I noticed that the Sun's height above the horizon is crucial insofar as at sea level where I took the photo the sunlight was weak when the Sun appeared above the local horizon so the effect was not dazzling while the ancient astronomers chose two hills at just the right distance apart to achieve the dramatic explosion of light entering the chamber.

There are dozens of different practicalities involved when seen through the eyes of an astronomer, everything from the choice of materials,to quarrying, sea navigation, construction techniques ,social cohesion ,festive/ceremonial appreciation and just signs of a practical society which had roughly the same daily concerns as everyone has today.

Like most of what I do, it belongs to a different type of society able to absorb the different components without creating a monster out of things. It is this wider view that would have prevented a world where today they will announce that humans will control the planet's temperature to our shame.

While it is nice to see the explanation for the Solstice change over the years and away from the 'Earth tilts towards/away from the Sun', these explanations still focus too much on 'tilt' -

http://host.madison.com/wsj/weather/...479b525d8.html

It is easier to just split the Earth's two day/night cycles apart by rotational causes and then join them in terms of the seasons and why natural noon cycles vary.

The North/South poles afford observer's the ability to look at what the entire planet does as it moves through space and around the Sun as it is not just the poles that are turning as a function of the plane's orbital motion but the entire planet itself turns unevenly as the orbital speed varies (hence the variable component of the natural noon cycle).

No doubt there will be more Solstice explanations which drop the 'tilting' Earth notion in future while not adopting the dual surface rotations and although a great shame, at least they are heading in the right direction.

Rather than concede that dual surface rotations are responsible for the seasons, including the Solstice event, a certain group introduced the tilting circle of illumination -

https://earthsky.org/earth/solstice-tale-of-two-cities


The Earth's circle of illumination always runs North to South and at right angles to the orbital plane as it travels along its orbital route so it is dismaying to see the space agency distort imaging -

http://eoimages.gsfc.nasa.gov/images..._2010-2011.jpg

Pivoting the circle of illumination off the Earth's rotational equator over the course of an orbit is nothing short of vandalism and an obscenity.

There is no pleasure bringing this up apart from the fact that there is only one way to explain the seasons and the upcoming Solstice event using dual surface rotations coinciding with dual day/night cycle going on simultaneously.

The original statement of Copernicus in his 1514 Commentariolis is basically correct in referring the small circles of the North/South poles in a rotational motion across the fully illuminated face of the Earth parallel to the orbital plane -

"The third is the motion in declination. For, the axis of the daily rotation is not parallel to the Grand Orb's axis, but is inclined [to it at an angle that intercepts] a portion of a circumference, in our time about 23 1/2°. Therefore, while the earth's center always remains in the plane of the ecliptic, that is, in the circumference of a circle of the Grand Orb, the earth's poles rotate, both of them describing small circles about centers [lying on a line that moves] parallel to the Grand Orb's axis. The period of this motion also is a year, but not quite, being nearly equal to the Grand Orb's [revolution]." Copernicus, Commentarilis

http://copernicus.torun.pl/en/archiv...=transkrypcja&

It is a wonderful journey for anybody willing to take it and escape into visual imaging of the 21st century to adjust and remove some of the notions to which Copernicus was bound as his contemporaries worked off a geocentric framework.

It is because the entire Earth turns once over the course of an annual orbit as a function of its orbital motion and does so with an uneven motion,when combined with daily rotation it produces a global variation in the length of time from one noon cycle to the next. It perhaps makes it easier to understand why 'axial precession' is a property of the annual motion of the stars and the proportion to the number of times the planet turns inside an orbital circumference rather than the view Copernicus later took in De Revolutionibus where he dropped the more accurate small circles scribed by the North/South poles parallel to the orbital plane and inserted a flawed notion of a variable tilting Earth -

"To this circle, which goes through the middle of the signs, and to
its plane, the equator and the earth's axis must be understood to have
a variable inclination. For if they stayed at a constant angle, and
were affected exclusively by the motion of the centre, no inequality
of days and nights would be observed. On the contrary,it day or the
day of equal daylight and darkness, or summer or winter, or whatever
the character of the season, it would remain identical and
unchanged." Copernicus, De Revolutionibus

I suppose to a certain mind that statement would have as much meaning as software code would to a general audience insofar as the distinction with the statement of Copernicus in the Commentariolis shows a man trying to satisfy timekeeping astronomy and structural astronomy at the same time - something that can't be done.

In short, to understand the Solstice event properly requires a modification to a lot of perspectives in order to make way for dual surface rotations to the central Sun with the annual orbital surface rotation looking roughly like this -

https://upload.wikimedia.org/wikiped...precession.svg

In the absence of daily rotation, the North/South poles would represent points on the Earth's surface that are 1600 miles above and below the fully illuminated face of the Earth. As the planet moves through space it turns unevenly to the central Sun so that these polar points (where daily rotation is absent or residual) represent that surface rotation as a function of its orbital motion.

It is clear that people,even those calling themselves amateur astronomers, just don't want to know and would suffer a tilting circle of illumination or referencing the geocentric motion Sun to the tropic of capricorn/cancer than accept the dual surface rotations responsible for so much terrestrial science and experience. Not even a size comparison between Earth and Sun will shake observes out of a lethargy nor the utter tragic misuse of satellite imaging which pivots the circle of illumination off the Earth's Equator -

http://thesuntoday.wpengine.netdna-c...l62011.001.png