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For those who appreciate logic and reasoning



 
 
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Old October 22nd 18, 06:40 PM posted to sci.astro.amateur
Gerald Kelleher
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Default For those who appreciate logic and reasoning

The Equator and indeed the entire surface of the Earth turns in two distinct ways to the Sun generating the daily 24 hour day/night cycle and separately another day/night cycle that is best understood via the Polar day/night cycle where one sunrise/sunset happens on the Equinoxes ,Polar noon/midnight on the Solstices and the Sun is either constantly in view or out of sight for 6 months at a time.

As a function of daily rotation, a location on the Equator covers a distance of 12,450 miles from the moment it exits the circle of illumination (sunrise) until it re-enters the circle of illumination (sunset) about 12 hours later. The Equatorial speed is therefore 1037.5 miles per hour via the Lat/Long system.

As a function of the orbital motion of the Earth, the North and South poles exit the circle of illumination on one Equinox (Polar sunrise) and travel a distance of 5,487.5 miles before re-entering the circle of illumination (Polar sunset) 6 months later. This works out as 10,975 miles/ 365.25 days or roughly 30 miles of rotation per day at the South and North Poles.

http://afewbitsmore.com/img/2015_ecliptic.png

Extended North and South to the maximum circumference of the Earth (denoted by the broken line as an ecliptic equator), the rate of rotation due to the orbital motion of the Earth is about 68 miles per day.

In short,

1. When daily rotation and all its effects are subtracted, the Earth still turns once to the Sun each year with that day/night cycle coincident with an orbital period.

2. The North and South Poles act like beacons for this surface rotation that turns parallel to the orbital plane and is uneven in response to the variable orbital speed of the Earth.

3. Where the two surface rotations combine we get the hemispherical seasons and the variations in the natural noon cycle.

4. The Earth has a daily rotational equator with a daily rotational speed of 1037.5 miles per hour and an ecliptic equator with a rotational speed of 68 miles per 24 hours.
  #2  
Old October 23rd 18, 10:27 PM posted to sci.astro.amateur
Gerald Kelleher
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Default For those who appreciate logic and reasoning

Lovely how it all fits together in a neat and intricate way, even if I say so myself. It is rare that I can stand back after years of effort and set an insight the way I wish like a musical composition but also open-ended for further work by others.



 




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