>"A beam of light can possess two kinds of angular momentum. The spin angular momentum of a ray of light can make objects it shines on rotate in place, whereas

>"A beam of light can possess two kinds of angular momentum. The spin angular momentum of a ray of light can make objects it shines on rotate in place, whereas its orbital angular momentum can make objects rotate around the center of the ray. A beam of light that carries orbital angular momentum resembles a vortex, moving through space with a spiraling pattern like a corkscrew. Whereas a conventional light beam is brightest at its center, vortex beams have ringlike shapes that are dark in the center, due to how some of the waves making up vortex beams can interfere with one another." Fascinating!