Kacser has much knowledge of the One Thousand Children (OTC), Kindertransport, and related WWII child refugee programs such as HIAS, GJCA, "the Joint" and OSE. In part, this is because Kacser is himself one of the One Thousand Children. Kacser actually is very heavily involved in OTC matters, and has gained much expertise in OTC and the various related bodies mentioned above.
Kacser has much knowledge of the Holocaust, and some knowledge of many other WWII events. Explicitly, Kacser is a fully trained practicing Docent for the Permanent Exhibition at the United States Holocaust Memorial Museum.
Kacser is an Associate Professor of Physics Emeritus, which gives him much physics knowledge. He has especial knowledge of the Special Theory of Relativity, and has written an Undergraduate textbook on the subject.