You will be given a definition of a task first, then some input of the task.
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.

A weight of the nth power of this parameter is imputed to contributions to elements of an S matrix by nth-order Feynman diagrams; thus, this number can be considered the order of expansion in perturbative quantum electrodynamics. This constant is a measure of the electron anomalous magnetic moment, which explains its role in the relativistic splitting of atomic spectral lines that is its namesake. The coupling constant for the electromagnetic interactions of electrons, it is equal to the square of the ratio of the electron and Planck charges, or, in cgs units, the electron charge squared divided by the speed of light times Diracs constant. For ten points, name this physical constant usually denoted alpha and equal to about one over one hundred thirty-seven.
Output:
Science