Stedman has spent most of his life probing into the mysteries of theoretical physics and then communicating his discoveries to his students. Quantum theory, optics, and relativity have proven to be of special interest to him and have figured into much of his life's work. For example, in response to a series of thought experiments in a class on operational relativity, the author, as a young college student, became intrigued with a question regarding the speed of light and the possibility of variance depending on its direction. The matter nagged him for years and eventually led to the creation of the Canterbury ring laser projects. These were just the beginning, though, of Stedman's long involvement in research with ring lasers.
Intending his book for the individual who may be interested in the promise of ring laser research but who also may not be well-versed in the science behind it, Stedman offers a wealth of preliminary background materials to bring his audience up to speed. He starts with a detailed explanation of the Sagnac effect, a phenomenon caused by rotation that can be observed when a beam of light is split and caused to travel in opposite directions in a ring interferometer. He also includes helpful chapters on relativity and quantum mechanics which further de-mystify the main subject of the book. He then shifts to a more in-depth examination of ring lasers, some of the practical benefits of the research using them and the history so far of the ongoing project started in Christchurch, New Zealand, that has produced the world's largest examples of the devices. Stedman's book can be difficult to read in parts due to a lack of sufficient editing. However, the core content of his work is extremely informative, making his book useful for those interested in ground-breaking scientific research.