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Polar night and a full moon



 
 
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  #21  
Old June 12th 17, 05:33 PM posted to sci.astro.amateur
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Default Polar night and a full moon

On Monday, June 12, 2017 at 1:31:45 PM UTC+1, Gerald Kelleher wrote:
At this case it wouldn't be a case of finding the old 'tilting' Earth explanation wrong


Can't say fairer than that, guvnor.
  #22  
Old June 12th 17, 10:07 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

The live imaging is fascinating -

https://epic.gsfc.nasa.gov/

What is missing is the circle of illumination by which to reference the expanding Arctic circle yet in 6 months it will show the Antarctic circle in roughly the same position relative to the terminator.

The Satellite is co-moving with the Earth and registers its forward motion through space as a change in position of the polar points as they turn as a function of the orbital motion of the Earth.





  #23  
Old June 13th 17, 08:10 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

Some awkward phrasing in the last posting.

https://epic.gsfc.nasa.gov/

The area in constant solar radiation with the North pole at its center is currently reaching its maximum, or similarly, the radius between North pole and circle of illumination is most distant. It makes understanding Arctic sea ice evolution fairly straightforward and especially that melting really begins post Solstice much like heating continues after noon in terms of daily rotation.

How long the educational community can hold out is anyone's guess, the old diagram of the Earth with a pole stuck through it in order to dither around with a tilting Earth looks as antiquated as a stationary Earth . With the racket of 'climate change' rapidly disappearing it is time to discover planetary climate within context of all planets in the solar system and how the rate of change across 6 months owing to planetary inclination influences what type of climate each planet has within a spectrum.

  #24  
Old June 14th 17, 01:12 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

The rapid descent back into darkness of polar night is due to the orbital position of the moon and the diminishing reflected light from a week ago -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

http://www.moongiant.com/phase/today/

In a world of swirling negativity where to be reasonable is drowned out by doom merchants or vapid political commentaries there are these issues to discuss and work out.

  #25  
Old June 15th 17, 08:36 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

The darkness of polar night has really set in after the reflected light of the moon wanes and the moon's position is almost at a right angle to the South pole which is a surface point that turns ever so slowly -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

The relationship of the moon to the polar day/night cycle is different to the relationship between the moon and daily rotation at lower latitudes but with a cheap webcam and no interest in planetary dynamics this topic goes unexplored.

  #26  
Old June 17th 17, 07:34 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

Going from broad reflected light to complete darkness in 5 days is one of those topics which should entertain students as adults come to appreciate what happens at the North and South poles and the dynamics which cause the spectacles -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

All life depends on the interaction between the two rotations and the inclination which appears to be just right for life on the planet and the swath of latitudes which experience the seasons, some more and some less.

Polar noon is only a few days off and much like daily noon temperatures will continue to rise in Northern latitudes through the next few months and therefore strengthening the conception of the dual rotations and day/night cycles responsible for life on Earth. Many like to think humanity is advanced and in some ways indeed it is however where the motions of the Earth combine with terrestrial science it is otherwise.
  #27  
Old June 20th 17, 07:19 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

Tomorrow is the day when there are two distinct noon events and also two distinct midnight events. Daily local noon is when a location is exactly midway in its daily trek between the circle of illumination but this doesn't happen at the North or South poles where the Sun comes into view once on the Equinox and sets on the opposite Equinox.

At 5:20 AM tomorrow it will be local noon at the North pole and local midnight at the South pole as those locations turn to the central Sun, within context of the orbital day/night cycle and its rotational cause.

The area where the Sun remains constantly in view is reaching its maximum an coincident with the Arctic circle and after the Solstice the area will shrink once more to the point before the September Equinox when only the local horizon at the North pole remains where the Sun is constantly in view.

Unlike the plethora of graphics trundled out at the moment relating to the Solstice there is so much research to do working with the planet's two distinct rotations in isolation and in combination.
  #28  
Old June 20th 17, 10:31 AM posted to sci.astro.amateur
Mike Collins[_4_]
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Default Polar night and a full moon

Gerald Kelleher wrote:
Tomorrow is the day when there are two distinct noon events and also two
distinct midnight events. Daily local noon is when a location is exactly
midway in its daily trek between the circle of illumination but this
doesn't happen at the North or South poles where the Sun comes into view
once on the Equinox and sets on the opposite Equinox.

At 5:20 AM tomorrow it will be local noon at the North pole and local
midnight at the South pole as those locations turn to the central Sun,
within context of the orbital day/night cycle and its rotational cause.

The area where the Sun remains constantly in view is reaching its maximum
an coincident with the Arctic circle and after the Solstice the area will
shrink once more to the point before the September Equinox when only the
local horizon at the North pole remains where the Sun is constantly in view.

Unlike the plethora of graphics trundled out at the moment relating to
the Solstice there is so much research to do working with the planet's
two distinct rotations in isolation and in combination.


Local noon is when the sun crosses the meridian. At the poles all meridians
converge. It's always local noon if the sun is visible at a pole.


  #29  
Old June 20th 17, 11:28 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

On Tuesday, June 20, 2017 at 11:35:12 AM UTC+2, Mike Collins wrote:

Local noon is when the sun crosses the meridian. At the poles all meridians
converge. It's always local noon if the sun is visible at a pole.


There is polar sunrise on the Equinox, polar noon on the Solstice, polar sunset on the opposite Equinox and finally polar midnight on the opposite Solstice with the North pole currently at polar noon and the South pole at polar midnight.

The motion that brings the North pole from its position on the circle of illumination on the Equinox to its current position midway to the circle of illumination is that the forward motion of the Earth through space turns the entire surface of the planet slowly and unevenly.

I am fortunate to visit the Jagiellonian University today and its link to Copernicus. He got the motion of the North and South poles right in his Commentariolus but traded it for axial precession in his De Revolutionibus.

"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" Copernicus , Commentariolus Circa 1514

What I have done is split the planet's dual day/night cycles apart by rotational cause thereby allowing the effects of those rotations in isolation and in combination.

  #30  
Old June 30th 17, 07:44 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar night and a full moon

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

For whatever reason the quality of images from the webcam this year insults those who visit the website, where the aurora would normally be clearly visible there is a worthless view that any camera in the 19th century would surpass. There are supposed to be astronomers and researchers at the South pole so nothing more needs to be said.

When observers become comfortable with the planet's two distinct day/night cycles and their rotational causes, they may begin to consider how observations play out from the surface. The Sun comes into view at dawn and moves higher before descending to the opposite horizon as part of the daily cycle. The polar day/night cycle at habitable latitudes also has this feature where polar dawn presents the Sun at its lowest point at noon on the December Solstice in the Northern hemisphere and at its highest at noon on the June Solstice.

These references for the height of the Sun due to the planet's orbital rotation are free and clear of the local horizon and replaced by a noon reference . Of course the wandering Sun 'analemma' provides an obstacle to the partitioning of the planet's two day/night cycles by cause and all the productive effects which accompany the insight but I am confident that the treasure of productive work before researchers will allow them to just get on with the new approach to the seasons and variations in the natural noon cycle.



 




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