Once, in early January, I decided I needed to escape from the city for a while so I went out to the easternmost point of Long Island. I ended up on an abandoned stretch of beach, and by this time it had already grown dark, but I nevertheless decided to go for a walk. Since there wasn't any light on the beach my eyes quickly picked up on something interesting. With each wave came little grains of sand that shined an intense blue light for a short time and then would die out (I