Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Input: It can occur in crystals lacking a center of symmetry via the Pockels effect. Nicol and Wollaston prisms utilize this property through the application of (*) calcite. When an electric field is applied to an anisotropic transparent substance, it occurs through the Kerr effect and it arises in materials possessing two different indices of refraction. For 10 points, identify this optical phenomenon that divides unpolarized light into an ordinary and an extraordinary ray traveling in different directions.
Output:
Science