Textbook in PDF format This book is in honor of the late Professor Wolfgang Dreyer from the Weierstrass Institute for Applied Analysis and Stochastics (WIAS) in Berlin. Wolfgang Dreyer was born in Bielefeld on November 11, 1950. He passed away on May 12, 2024, in Gülpe (Germany). He retired from the Weierstraß-Institut für Angewandte Analysis und Stochastik (WIAS) in Berlin in 2015 where he had been the Head of the Group Thermodynamische Modellierung und Analyse von Phasenübergängen for many years. Mathematical Physics was the paramount topic of his professional career. This lifelong endeavor started with his diploma thesis in 1979 supported by Prof. Ingo Müller at the Universität Paderborn. It continued in his doctoral and habilitation theses at the Technische Universität Berlin in 1983 and 1990, respectively—also accompanied by Prof. Ingo Müller. Wolfgang Dreyer was the leading author of many important, internationally renowned, ground-breaking papers on thermodynamics, continuum mechanics and the kinetic theory of gases. He will remain in the memories of his many friends and colleagues in the Scientific Community