One of the biggest problems in modern theoretical physics is the quantization of gravity, which seeks to connect the three pillars of modern physics: general relativity, quantum theory, and statistical physics. The most successful attempt in recent decades is loop quantum gravity, developed by a team of leading theorists, including the author of this book, Carlo Rovelli. This theory has successfully defined the quanta of space and the quanta of time, and it seems that infinitely small dimensions and infinitely short time intervals do not actually exist. The consequences of this theory include the idea that "reality is not what it seems": distance cannot be divided infinitely, time does not exist at a fundamental level, unpleasant singularities disappear from the theory of black holes and the first moments after the Big Bang. The best medium for getting acquainted with this new concept and its consequences is this excellently written book: not only because it was written by one of the main authors of the entire theory, but especially because Rovelli has a rare talent for clearly, engagingly, and with a sense of perspective explaining the most complex physical theories. Moreover, it is currently the only popular treatment of this interesting and timely topic.
