Spring equinox 2017 occurred on March 20 at around 7 pm in Japan. Chika-san has provided photos of the changing spotlight patterns on the floor of Iwaya-Iwakage. This time, she concentrated on the change in the shape of the spotko as it went from oval to triangular. It is fascinating that the same beam of sunlight can be so shaped by the megaliths!
We start with this photo taken at 9:21 on March 20 as the spotlight first appears as a partial oval on Stone a. Notice the right-angular carvings on the stone. They are meant as a kind of grid for tracking the movement of the spotlight during equinox time. See Guidebook, page 53.
The next three photos were taken at 9:25, 9:30:00 and 9:35:30 am on 20 March. They show the progression of the oval spotko on Stone a, toward our right which is east (as the morning sun moves westward). An oval stone measurement tool has been discovered inside Iwaya. We had suspected that its purpose is to serve as a template for the spotlight shape and size. So the oval stone was placed on Stone a at seemingly appropriate places. See pages 52 and 53 in the Guidebook.
By time 9:43, the spotko has moved off Stone a and is starting to elongate. Time 10:23, the shape is now a triangle. An equilateral triangle at 12:02, a more acute triangle at 12:30. This is the triangular shape we saw in the previous post. And so, we have seen how the shape has changed from oval to obtuse to equilateral to acute triangle in the course of less than four hours.
In the next two posts, we show you time-lapse photos of the oval spotlight on March 19 and March 20.
We conclude that the oval stone was intended to serve as a template for the equinox observations on stone a. The construction of the megalith chamber and the associated markings and tools are an indication of the high sophistication of the ancient people who built this megalithic site in the mountains of Kanayama.