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.

Example input: In one work this author details the life of a tomb-maker who makes extra money by playing the organ at an insane asylum, while another of his novels sees Swartz give a refugee proper documentation only after he tells him his life story in the title Portuguese city. In addition to The Black Obelisk and The Night in Lisbon, he also wrote about Robert and Otto selling their auto workshop and visiting Patrice in a Swiss tuberculosis sanatorium in his novel The Three Comrades, while the turbulent life of the German surgeon Ravic is told in The Arch of Triumph. Another of his novels, The Road Back, is thought to be a sequel to his most famous book, in which the patriotic teacher Kantorek convinces Paul Bumer and his friends to join the Germany Army during World War I. For 10 points, name this German author who wrote All Quiet on the Western Front.
Example output: Literature
Example explanation: The text is talking about an author and their works, so it belongs to theliterature category.
Q: The strength of this phenomenon in an atom is proportional to a function containing a "hyperbolic cotangent of x over 2J" term; that function is the Brillouin function, which is replaced in the classical formulation by the Langevin function. Second order perturbation theory includes a variety of this phenomenon named for Van Vleck, and the spin of free electrons on a crystal lattice causes a variant of this phenomenon named for (*) Pauli. In certain materials experiencing this phenomenon, the susceptibility is given by "C over (T minus T sub c)," and the susceptibility is inversely proportional to absolute temperature according to Curie's Law. This phenomenon occurs above the Neel temperature as well as above the Curie temperature, and it is caused by the aligning of dipoles. For 10 points, name this weak form of magnetism only present in an external magnetic field.
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Science