A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

The Equinox defined



 
 
Thread Tools Display Modes
  #1  
Old March 19th 18, 09:14 PM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

Even in geocentric terms the Equinox is a special day with two distinct types of sunrises and sunsets.

The Sun will come into view for the one and only time this year at the North pole after it set last September while the Sun will turn out of view at the South pole until next September. It represents the fact that if daily rotation and all its effects are subtracted, the entire surface of the planet turns once to the Sun each year as a function of the Earth's orbital motion.

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif


The time lapse presently should show a mirror image where the polar points are at opposite sides of the fully illuminated Earth generating a mirror image but sadly the organization in charge of this satellite decide to give the Earth a zero degree inclination presently -

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


Once again, the Sun doesn't cross any celestial equator tomorrow within a celestial sphere - the Earth turns in two different ways to the Sun thereby generating the planet's two day/night cycles. Tomorrow is special as there is 24 hour sunrise/sunset and Polar sunrise/sunset, something that happens only once a year at the latter location.




  #2  
Old March 20th 18, 09:14 AM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

A question I often see, especially from Americans, is why the March Equinox is much colder than the September Equinox -

https://imgur.com/gallery/XrOef6e


I would leave this as an open question to answer were it not for nuisances who exert no discipline in this newsgroup by attempting to muddy what is fairly straightforward and much like everything else.


The reason the March Equinox is colder than its opposite in the Northern hemisphere relates to the fact that it is Polar sunrise today at the North pole while Polar sunset happens at the South pole. Much like sunrise is almost always colder than sunset during the 24 hour day/night cycle then likewise the same applies to orbital sunrise in the Northern hemisphere and best appreciated in isolation at the North pole.

So today is the astronomical event of two distinct types of sunrises and sunsets arising from two distinct surface rotations of the planet.
  #3  
Old March 20th 18, 11:37 AM posted to sci.astro.amateur
[email protected]
external usenet poster
 
Posts: 306
Default The Equinox defined

On Monday, March 19, 2018 at 8:14:14 PM UTC, Gerald Kelleher wrote:

if daily rotation and all its effects are subtracted, the entire surface of the planet turns once to the Sun each year as a function of the Earth's orbital motion.


Now apply the same reasoning to the Moon: as a function of its orbital motion around the Earth its entire surface should turn once to the Earth each month.

But it doesn't, it presents the same face (give or take) all month, because it rotates on its axis once per orbit.
  #4  
Old March 20th 18, 04:04 PM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

The recent rapid rise in celestial sphere descriptions of the Equinox can be in equal measure troubling as it is amazing by virtue that imaging has been manipulated to show a pivoting circle of illumination and our planet with a zero degree inclination (celestial sphere intellect) -

https://apod.nasa.gov/apod/ap170319.html

Multiple newspaper and magazine articles today now carry this dismal description allied with the misuse of the EPIC satellite which shows a planet with a zero degree inclination -

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


Even with unfamiliarity, the rotational inclination denoted by the North and South poles are always 66 1/2 degrees in respect to the orbital plane and equidistant to that plane at all times from the Equinox to the Solstice and back again -

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif

We all participate in the surface rotation which will cause the Sun to appear at the North polar latitude in a number of hours and the Sun to turn out of view at the South pole for 6 months. This orbital surface rotation makes it appear that the Sun rises dead East and West but by inspecting the actual inclination for the September Equinox and assigning a mirror image for the present March Equinox , it allows daily rotation more freedom in determining the seasons by breaking the shackles of a 'tilting' Earth.

This is all new so no fuss is going to be made one way or another but do people really want to go down the pivoting circle of illumination route which is a dishonor to astronomy or indeed the ability of people to reason things through ?.









  #5  
Old March 20th 18, 04:17 PM posted to sci.astro.amateur
Quadibloc
external usenet poster
 
Posts: 7,018
Default The Equinox defined

Yes, the reason for spring being colder is the same as for sunrise
being colder.

But it does not lie in a similarity between orbital and rotational
geometry in the two cases.

It is because the Earth and its atmosphere take time to warm up or
cool down in response to changes in sunlight.
  #6  
Old March 20th 18, 05:39 PM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif

Relative to the orbital plane, the Earth on the September Equinox will rotate in a roughly NW to SE direction (if orbital traits were given North, South, East and West Coordinates) whereas presently the Earth will rotate in a SW to NE direction.

Apart from the accurate time lapse above on the September Equinox, the EPIC satellite shows an accurate perspective on the December Solstice -

https://epic.gsfc.nasa.gov/?date=2017-12-21


The missing piece in the sequence of images is the present March Equinox which requires the South pole to turn parallel to the orbital plane as a function of the unseen orbital motion of the Earth from September to March.

There is the awful pivoting circle of illumination from NASA and the equally vapid rotating circle of illumination from NOAA -

https://twitter.com/NOAASatellites


Assuming there are people of integrity out there, the actual explanation for the Equinox event offers so many opportunities for research and gives back a thousand times the effort put into understanding the planet's two distinct day/night cycles and the rotations behind them. I do not denigrate this newsgroup as other are wont to do, this is perhaps one of the few places where original and meaningful work is accomplished.



  #7  
Old March 21st 18, 12:10 AM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

Among the present group of contributors, if they can be called that, a special case of 'diminished responsibility' has to apply as it falls within a spectrum which softens acts of willful or destructive intent while having no reasonable direction -

"Diminished responsibility is successful where the defendant did not have the rational capacity to order his actions according to rules, which must be due to an abnormality of mind." Diminished responsibility vs insanity

The rapid descent into celestial sphere descriptions of the Equinox as a pandemic would normally spur people into action but so far the opposite has occurred -

https://apod.nasa.gov/apod/ap170319.html


I do not ask how low people can go as they are already there with a pivoting circle of illumination acting in tandem with a Sun crossing the celestial equator with zero degree inclination planet. You guys are finished as reasonable people so spare me the worthless comments in future.


  #8  
Old March 21st 18, 04:02 PM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default The Equinox defined

What has changed today from the Equinox yesterday it is that the areas surrounding the North and South pole where the Sun is in view or out of sight have switched. The area where the Sun is completely in view at the North pole begins expanding and will do so until the June Solstice when that area is coincident with the Arctic circle as that is the distance where the polar latitude will be from the circle of illumination -

https://epic.gsfc.nasa.gov/?date=2017-06-21

Wish that NASA had provided the correct inclination for yesterday's Equinox but for whatever reasons known to themselves they waste a perfectly good satellite. People will have to be content with the September Equinox and that yesterday would have been a mirror image of the following time lapse -

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif





 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Atheism - Defined Florian Amateur Astronomy 0 May 28th 06 03:03 AM
GRAVITATION DEFINED ACE Astronomy Misc 0 January 8th 06 09:44 PM
GRAVITY DEFINED ACE Astronomy Misc 1 May 1st 05 08:42 PM
GRAVITATION DEFINED ACE Astronomy Misc 0 April 26th 05 12:42 PM
GRAVITATIION DEFINED GRAVITYMECHANIC2 Astronomy Misc 0 February 9th 05 02:06 AM


All times are GMT +1. The time now is 10:20 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.