We are in the central chamber of a stone age tomb, a vault of crudely cut megalith blocks above us and outside that, a great mound of earth covered in grass. The guide turns off the tourist friendly electric lights and the chamber goes completely dark except for some dim light spilling in through the passageway. She turns on the light simulating the equinox sun and a golden ray shoots along the floor, filling the passage with brilliant golden light and grows in luminescence until it culminates in a thin point on a spot precisely calculated by ancient astronomers. Though it is just an effect and though the guide keeps babbling on in the background, I still feel some of the wonder that the real thing would induce in me. So much calculation, such a massive undertaking, just for a simple ray of light, but the beauty of that golden light seems completely worth the effort, I just wish I could see the real thing.