Crowd analysis is a popular topic in computer vision, with important applications to video surveillance, social media analysis, and multimedia retrieval, to name just a few areas. In this paper, we review some of the physics-based methods for group and crowd analysis in computer vision. In particular, we examine approaches for physics-based analysis of groups, crowds, and the simulation of crowds. The purpose of this review is to categorize and delineate the various physics-based and physics-inspired approaches that have been applied to the examination of groups and crowds in video.