11. Energy = mass time the velocity of light squared. 12. What must energy and mass be doing that connects them by the velocity of light squared? 13. In an anisotropic mineral, the velocity of light differs as the direction of the crystal changes. 14. Zorite is anisotropic, which means that the velocity of light is not the same in all directions. 15. The effective velocity of light in various transparent substances containing ordinary matter, is less than in vacuum. 16. Usually, such reports deal with a phase velocity or group velocity faster than the vacuum velocity of light . 17. Where h is the Planck constant, ? the optical frequency, ? the size of the velocity of light . 18. The phase velocity of light is not generally equal to c ( the vacuum speed of light ). 19. Which means that the velocity of light changes in crystallographic direction, this is easily identifiable in thin section. 20. The refractive index is the ratio of the velocity of light in a vacuum to that in the mineral.
