This book is written for anybody who is curious about nature and motion. Curiosity about how people, animals, things, images and empty space move leads to many adven- tures. This volume presents the best of them in the domains of relativity and cosmology. In the study of motion – physics – special and general relativity form two important building blocks. Special relativity is the exploration of the energy speed limit c. General relativity is the exploration of the force limit c4/4G. The text shows that in both domains, all equations follow from these two limit values.
Christoph Schiller, “The Adventure of Physics - Vol. II: Relativity,” Open Educational Resource (OER) , accessed February 25, 2021, http://oer.iain-padangsidimpuan.ac.id/items/show/2261.