Just as a prism splits light into a spectrum of colors, birefringence is the optical phenomenon when light is split into two rays of the same color as it passes through certain materials. Birefringence can be found in nature as seen in this freshwater protozoa. Molecules within the protozoa refract light into different beams as a polarized filter is rotated. In medicine, birefringence can be used to determine the thickness of the optic nerve to help monitor glaucoma or to help determine embryos that have the highest chance for successful pregnancy for in vitro fertilization.
Video by Edwin Lee.
Robin Grey (via Gorilla Perfume)
Have Cat. Will Travel.
(Ralph Crane. 1961)