Boards.ie uses cookies. By continuing to browse this site you are agreeing to our use of cookies. Click here to find out more x
Post Reply  
 
Thread Tools Search this Thread
21-05-2020, 17:08   #1
oriel36
Registered User
 
Join Date: Jun 2011
Posts: 393
Knowth calendar stone

https://lh3.googleusercontent.com/pr...r7qxL2MA_o4KGg

It remains one of the loveliest and first astronomical interpretations in human history to survive including the few days where the Sun is lost to the glare of the Sun (new moon) or when the moon have moved to a position between the Earth and the stationary Sun in it's monthly circuit. The stone itself is part of the structure with an Equinox alignment where there is no roofbox as it is impractical that time of the year (September/March) when solar declination is far too rapid.

The circle turns as Mercury passes out Venus as both move in opposite directions in their smaller and faster circuits around the Sun -

https://www.theplanetstoday.com/

In a line-of-sight view from a slower moving Earth Venus will continue it's journey into the Sun's glare as it overtakes the Earth while Mercury moves in the opposite direction (by scrolling the dates forward) with a conjunction on May 22nd -

https://www.youtube.com/watch?v=w2uCtot1aDg


In a week or so, Venus will enter the view of the Lasco 3 camera and the glare of the Sun -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/


I love what the ancient people on this island could do while contemporaries have lost their ability to interpret planetary motions. The fact that I post this in an archaeology forum is proper as the methods and insights of those great astronomers have been lost to those who have absolutely no perceptive insights.
oriel36 is offline  
Advertisement
30-05-2020, 07:51   #2
oriel36
Registered User
 
Join Date: Jun 2011
Posts: 393
There is another astronomical event happening presently similar to the event depicted on the Knowth calendar stone where the moon is lost to the glare of the Sun for a number of days (new moon). In the present case, it is the planet Venus and an event that happens every 18 months or so as it is now lost to the glare of the Sun for a number of few weeks.

It is our 21st century version that is perhaps more elaborate but closes out a period of history that stretches across 5,200 years.

https://www.theplanetstoday.com/

Right now, the faster moving Venus is passing between our slower moving planet and the stationary Sun seen from a satellite tracking with the Earth's orbital motion -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

Venus is presently in retrograde motion or what effectively would have been recognised in older societies as a backward change in direction against the stars. In dynamical terms, the stars change position from left to right of the central Sun due to the orbital motion of the Earth, however, as Venus moves faster then it follows that it appears retrograde to the observer as it passes in front of the stationary Sun, likewise Mercury.

There is so much history attached to this observation as the slower moving Jupiter and Saturn are also in retrograde against a stationary field of background stars -

https://apod.nasa.gov/apod/ap011220.html


The astronomical spectacle of Venus happens every 18 months of so and fills in the narrow corridor between the beloved astrophotography of long term imaging with a short term transit -

https://imgur.com/5adXFsD

https://www.youtube.com/watch?v=_7U5VbasKr4&t=53s


It is not just something new but a beloved gesture to our astronomical ancestors on this island and their great monuments which speak silently in this sometimes scattered and hectic world with a competence and a confidence few choose to participate in.
oriel36 is offline  
31-05-2020, 20:42   #3
oriel36
Registered User
 
Join Date: Jun 2011
Posts: 393
https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

Also in the present time lapse is the bright star Sirius which is moving from an evening appearance (left of the Sun) to a morning appearance (right of the Sun) as it moves parallel to the orbital plane due to the orbital motion of the Earth.

".. on account of the procession of the rising of Sirius by one day in the course of 4 years,.. therefore it shall be, that the year of 360 days and the 5 days added to their end, so one day shall be from this day after every 4 years added to the 5 epagomenae before the new year" Canopus Decree 238 BC


Effectively 24 hour days represent individual rotations of the Earth so the Egyptian astronomers (or older astronomers from other societies) in antiquity realised that in order to keep their festivals fixed to the Solstice and Equinox points, they had to apply an extra day/rotation after the fourth cycle of 365 days.

In 21st century terms it means the Earth takes roughly 365 1/4 days to orbit the Sun but as we use individual days and rotations anchored to the noon cycle, we complete four circuits of the Sun in roughly 1461 days formatted as 3 years of 365 days and 1 year of 366 days.

It becomes possible to admire the care and considerate way our ancestors reasoned out observations but unfortunately we live in an era where these facts are lost to a late 17th century Royal Society contrivance which insists that 24 hour days do not represent one rotation of the Earth.
oriel36 is offline  
03-06-2020, 11:26   #4
oriel36
Registered User
 
Join Date: Jun 2011
Posts: 393
The crossover from archaeology and astronomy is a working principle rather than just a historical perspective much as the Newgrange Solstice alignment still happens in and around December 21st just as it did 5,200 years ago. It is easier for me to consider Newgrange as a working timekeeping monument that dither around speculating what our ancestors on this island did or did not know.

The system of Ptolemy where the Sun moves directly through the field of stars is unhelpful for discerning the process by which our ancestors created the monuments -

https://community.dur.ac.uk/john.luc...n_ecliptic.gif

The older framework where a star skips a first annual appearance at dawn by one day after the fourth 365 day cycle is far more productive and creative than the more recent Ptolemaic system and even more recent variants like the troublesome 17th century RA/Dec framework.

The fact that observers at Newgrange or Knowth witness the Solstice and Equinox alignments on the same day their ancestors did thousands of years ago should alert the astronomer/archaeologist that there is something wrong with the resolution for axial precession or the precession of the equinoxes and so there is.

The North and South Poles will be in the exact same position to the planet's circle of illumination and to the central/stationary Sun today as they were all those thousands of years ago. Unfortunately archaeologists are not astronomers and visa versa and a lot of history and technical issues are lost due to the deficiency, otherwise intellectual laziness is the cause.
oriel36 is offline  
Post Reply

Quick Reply
Message:
Remove Text Formatting
Bold
Italic
Underline

Insert Image
Wrap [QUOTE] tags around selected text
 
Decrease Size
Increase Size
Please sign up or log in to join the discussion

Thread Tools Search this Thread
Search this Thread:

Advanced Search



Share Tweet