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.
Q: The paper explaining this phenomenon begins with a section critical of the theory of blackbody radiation, showing that an integral of energy with respect to volume equals infinity. That problem is solved by assuming that energy "is discontinuously distributed in space." Some of the measurements of this effect, which used to be associated with ultraviolet light, were made by Philipp Lenard, who discovered that light intensity did not impact the amount of voltage required to stop rays produced by light striking metal. Name this effect explained when the Planck hypothesis was applied by Albert Einstein, leading to Einstein's Nobel Prize.
A:
Science