The book contains interesting and valuable data on the discoveries and inventions of scientists from the two main institutions of the physics community at the Bulgarian Academy of Sciences – the Institute of Physics with the National Observatory and the Institute of Solid State Physics. The content is presented in four chapters and is supplemented with extensive illustrative material. The first chapter examines the beginnings and development of the physical sciences at BAS in the 20th century, emphasizing the intellectual activity of physicists related to discoveries, inventions, and rationalizations. The second chapter examines the creative work of prominent representatives of applied physics at the Institute of Physics with ANEB and IFT in the 20th century. It describes the applied work of 46 scientists related to discoveries, inventions, and rationalizations, a significant part of which have been implemented. The third chapter summarizes the discoveries and inventions. For the period 1946-2000, out of 17 recognized Bulgarian discoveries, only two are by physicists, and out of 25,000 inventions in the State Patent Fund, over 2% are by representatives of the physics community. The participation of physicists in the Golden Book of Discoverers and Inventors in Bulgaria—a unique book about the original achievements of Bulgarian scientists—is reflected in the fourth chapter of the book. Two discoveries by Bulgarian physicists are included in the Golden Book: the discovery by Acad. Georgi Nadjakov of the photoelectric state of substances and the discovery by Corr. Pavel Markov of the change in the strong interaction of protons at high energies. The inventions of two physicists from the Institute of Theoretical and Experimental Physics are included in the Golden Book.