Q: 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.
This quantity can contribute an extra term to the thermodynamic identity, making possible an isentropic cooling method effective at low temperatures. The propagation of light along it induces a rotation in the polarization vector named for Faraday, and Landau levels are formed in metals when it is applied. An inhomogenous arrangement of this quantity in space was key to conducting the Stern-Gerlach experiment, and its breaking of degeneracies in atomic energy levels is known as the Zeeman effect. A material's delayed reaction to an externally applied one is known as hysteresis, and a spin will precess about one of these with the Larmor frequency. For ten points, identify this divergence-free component of a fundamental force whose cross-product with velocity is proportional to the Lorenz force with which it deflects charged particles.
A:
Science