A Neolithic conversation,"Will we do something different today?" "How do you mean?"" Why not build a big mound?" "What's a mound?" "It's a great circular structure where we can cremate our enemies and charge the neighbours a fee to see this" "Oh, you mean like an entrance admission?" "Exactly", "Well how much will we charge then?" "An enemy's arm and a leg should do the trick". "Fine by me, anyway I'm bored chasing deer all day". Comical maybe, but did our Neolithic ancestors simply decide to spontaneously build Knowth?
There are theories that suggest navigators crossed the sea to Ireland and set up communities in Mesolithic times, if so, then they had to acquire the means of navigation and that would require celestial marker guides for their journey. Since the open sea is a featureless landscape, newly arrived settlers may have had to plan out their journey to coincide with equal day/ equal night. Why? Because this would allow them to know that over a two week period the rising and setting suns on the ocean horizon would mark out true East and West directions. That would give them a good latitude guide wire to set sail to. Alternatively, they may have already been indigenous people who worshipped the heavenly skies through panthestic religion and ritual. It would have held them in awe, not being able to comprehend the nature of it.Therefore they would have sought out celestial markers, auspicious times whereby the Gods above intimated to their brethern below an opportune time to begin construction.
A series of unique celestial events occurred at Knowth that our Mesolithic forebarers could not have missed. Between the years 5541 BC and 5518 BC, one very bright star reached the Zenith point and another bright star came very close to the Zenith. at that location. This would mean that any observer situated there could look straight up at the night sky and clearly see this phenonomen in action.
1) Arcturus (Alpha Bootis) is the brighest star( Mag. 0.0) in the Northern hemisphere, situated in the constellation Bootes (the Bear Keeper) and the second brighest star is Vega (Alpha Lyrae) in Lyra (the lyre) a brilliant white star (Mag. 0.4).That would have meant defining the harvesting and sowing seasons so periennal crops could be cultivated. In my estimation they achieved this feat very simply and succinctly using just their eyes and some fashioned timber.
It would have stood probably 4 -5 metres high, made of a durable hardwood and worked into a straight wooden post for erecting upright. The top would have been tapered somewhat with a short, flat cross member attached at right angles to it. Cut out of the cross piece would have been two small holes or a long slit section that was used to sight through. When they erected it, they would have used an attached plumb line for vertical accuracy. The chief observer would stand with their back against the post and look directly up through the sight holes or slit. When Vega or Arcturus centred in the holes or slit they would have looked to the horizon, dialling around to note anything significant there. Any recordings made would have required setting coloured pegs or stakes on the ground in the direction of the object rising or setting.
So what did they note? I did what they did, I observed, tracked and recorded a single years worth of observations on one end of the 24 year span and then switched to the other end, repeating the procedure. I estimate that it would have taken them a minimum of 1.5 - 2 years to denote patterns emerging from their placement of pegs. At the earliest end of the span another unique event occurred that for me sealed the whole idea as highly feasible. Between 5520 BC and 5519 BC a specific event took place that would never be repeated ever again with these Zenith stars. If you look at the tables below, you'll immediately see what I mean.
Accuracy of table data BELOW increased from Skyglobe 3.6 => The Digital Universe Program
Skyglobe lacked both proper motion and horizon refraction
| SUN'S ALT | DATE 5520BC | OBJECT | HORIZON AZIMUTH | B=before, A=after | |
|---|---|---|---|---|---|
| 14.8° | Jan 2 | Moonset | 269.8° | 9 mins B | |
| 13° | Jan 14 | Moonrise | 88.8° | 39 mins B | |
| 12.1° | Jan 29 | Moonset | 265.4° | 44 mins B | |
| 12.8° | Feb 11 | Moonrise | 94° | 9 mins A | |
| 15° | Feb 26 | Moonset | 271° | EXACT | |
| 17.3° | Mar 09 | Moonrise | 90.3° | 17 mins A | |
| 21.5° | Mar 24 | Moonset | 268.8° | 14 mins B | |
| 26° | Apr 6 | Moonrise | 95.1° | 26 mins A | |
| 31.5° | Apr 20 | Moonset | 266° | 40 mins B | |
| 36° | May 03 | Moonrise | 91.1° | 13 mins B | |
| 37.3° | May 5 | Sunset | 270.2° | 69 mins B | |
| 39.4° | May 11 | Sunset | 274.4° | 30 mins B | |
| 34° | Nov 05 | Sunrise | 94° | 45 mins B |
| SUN'S ALT | DATE 5520BC | OBJECT | HORIZON AZIMUTH | B= before, A= after |
|---|---|---|---|---|
| 34° | Nov 5 | Jupiterset | 272.8° | 47 mins B |
| 31.5° | Nov 12 | Jupiterset | 272° | 38 mins B |
| 29.5° | Nov 17 | Jupiterset | 271.7° | 41 mins B |
| 26° | Nov 26 | Moonset | 270.8° | 55 mins B |
| 26° | Nov 26 | Jupiterset | 271° | 55 mins B |
| Jupiter | Slows | Down | Its | Motion |
| 25.2° | Nov 28 | Jupiterset | 270.8° | 45 mins B |
| 22.3° | Dec 06 | Jupiterset | 270.2° | 70 mins B |
| 21.7° | Dec 08 | Moonrise | 88.1° | 41 mins B |
| 16.4° | Dec 26 | Jupiterset | 269.5° | 62 mins B |
Looking at the table you will notice that there are no readings between the end of May and early November. This is due to Arcturus fading from view as dawn and daylight overtake it. However our observers would also have been tracking Vega as well. Vega overlaps recording from April to May but gives distinctly different results. I've included the Sun's altitude above the horizon to show how they would have determined shortest/ longest daytimes using the Zenith post as a Gnomoning device(sundial) during the day. On the far right column I've shown times when a horizon event coincided with the Arcturus Zenith point. Its also quite clear that what we are looking at is mostly the Moon oscillating back and forth over the ecliptic point on its nodal axis (nutation/declination) of 5°. There are a number of True East and West dates all in reference to the moon, 270° (Nov 26 ) within 55 mins of Arcturus reaching near the Zenith. 90° (Mar 9 ) within 7 mins of Arcturus at Zenith. The Sunset on May 05 is closest to due West
But most importantly of all is Jupiter setting on the west and in complete opposition to the Sun on Nov 05th. to within 2°. This would have created a line running from the sun up the horizon to roughly Arcturus and then down to the West to Jupiter. As the second brighest (-2.1mag.) planet in the night sky, on this occasion, Jupiter slows down to a 'stationary' position due to the arc of orbits between it and the Earth giving the impression that it 'stands still'. That stationary point is reached on Jan 2nd 5519BC at 270.9°. This is Jupiter's second stationary point over the true West point. It first reached stationary position on June 7, 5520BC at 269.7°, however this event would not have been visible due to the sun being up at that time. Jupiter repeats these stationary points at these azimuths once every 84 years!! Our observers would have found this an unexpected event just as I did and watched as this 'bright star' barely shifted position less than 1° off the true East-West axis.
Also noticable in their watchings would have been a small group of 4 stars positioned every night close to their Celestial South. This of course is Crux,(172°) the Southern Cross constellation marking the equinoctial coulure/axis and cutting right through Arcturus to the North. They could not have failed to have notice this. Crux is fully up just over the Southern horizon, in splendid view. This axis cuts as within 8° of a true North-South axis.
