Everyone knows that Einstein's special relativity contains a theory of time measurements, which are no longer conceived as absolute, but are related to the state of motion of the clock and to the point of view of the observer, and the same happens to space measurements. Everyone also knows that the theory contains the deduction that a small material mass can be converted into a huge amount of energy according to a precise quantitative relationship.
But many who have tried to study the theory have failed to understand it; yet, to fully understand the part of Einstein's theory about time and space measurements, readers just need to know what speed and square root are, and to obtain a simplified but clear idea of the part regarding the concepts of mass and energy they need just to remember elementary high-school physics. Apparently something is missing in all the many books that describe relativity in a simple or higher level.
This book is written in a different way from any other. A rigorous but clear exposition will show all readers, provided they know what speed and square root are, that they can understand fully and perfectly the space-time theory and can judge it with their own intelligence. In addition, readers will have a clear idea of the equivalence between mass and energy and its logical relationship with space-time theory.
This book was written for beginners and for perplexed people who have unsuccessfully attempted to study special relativity: both will understand the exact meaning of the famous and difficult essay in which Einstein expounded the theory in 1905, which is examined word by word in this book. And all readers will have a clearer idea of the relevance of relativity for the twentieth (and twenty-first) century culture.