Solstice
19th December 2011 was an overcast cloudy day and pretty dark in the cave. We readjusted the window-box.
20th December 2011 was significantly brighter in the cave even though it was much darker outside and raining.
21st December 2011 was fine day. We were in the cave about 1-30pm .It was very bright there. At 1-40pm a beam of light came in the window-box, it ended as a spot on the floor of the southern roofed section of the souterrain at its junction with the small "creep" passage. This spot slowly made its way eastwards along the floor (as the sun was travelling west) to a central position at 2pm.Briefly its intensity was diminished here by cloud. So bright was the spot it could defy camera flash, and looks even better defined in these pictures? By 2-10pm the spot had risen from the floor to shine on the south east corner-stone of the "creep" passage. It kept moving east but dissolved away quite quickly once it reached the east wall of the large part of the cave. At 2-21pm the show was over.
22nd December 2011. The swans were on the turlough and the sun was trying to break through a dark overcast day. At 1-30pm the spot appeared in the same corner but deeper into it. It became obvious that this corner is not a right angle but set slightly obtuse to frame the light. The spot lasted a few minutes but disappeared as the sun was clouded over and did not return.
23rd December 2011 was a fairly fine day. The beam and spot arrived in the centre at 2pm and made its way eastwards and upwards onto the cornerstone (maybe not quite as high as on the 21st) and dissolved away after 2-15pm as before. The display was truly breath-taking. Because the Earth is tilted at a slightly different angle in relation to the sun now than it was when the souterrain was built the light follows a slightly different path. Because the souterrain is designed to catch the sun when it is risen in the sky, rather than at sunrise or sunset, this difference is magnified. It does not require a great leap of imagination to see that the spot would have shone out through the small creep" passage and into the (now reburied) section beyond. Amazing that the spot should rise along its journey as this would be necessary for it to maintain its height, while moving over the first five west stones of the twist, with the declining sun. It is humbling to know that because the Earth wobbles around the sun in a cycle that lasts somewhere between 25,800 and 26,000 years ,this souterrain will sometime in the future reach the same alignment as when it was first constructed, and function properly again. This should help to estimate approximately when the souterrain was built.
Material removed from the cave during excavation might help to give an estimate for when it was abandoned. One can only but speculate the reasons for this. Because it dates from a time when Religion and Science were one and the same discipline, and given that its location is right at the
interface of Christianity and Druidism (Sts Eithne and Fidelma were baptised by St. Patrick at Ogulla less than a mile from here), it is tempting to believe that there might have been some spiritual/religious reason for this. However experience of other souterrains suggests we should expect a date somewhere at the end of the first millennium A.D. Maybe then it was buried simply because it was not functioning properly anymore, or because its calendrical function was superseded by other methods.
The reason for its alignment to the sun at 2pm is probably best illustrated by the absence of an event at sunrise at the more modern facility in the Boyne valley at Newgrange on either 21/12/2011
or 22/12/2011
