This book offers a short journey into the surprising and spectacular world of modern physics characterized by disruptive ideas and theory from both a conceptual and applicative point of view. Starting from Einstein's theory of relativity in which the concepts of space, time, and gravity are completely revised, before arriving at the bizarre and fascinating universe of quantum physics which with its applications has completely changed our way of life. Particular attention is also paid to the conceptual foundations and paradoxes of quantum mechanics thanks to which the so-called second quantum revolution has developed in more recent times, destined to introduce a new generation of quantum technologies such as computers, cryptography, and teleportation into our lives. In addition to new quantum technologies, the operating principles of the most important applications of quantum mechanics which have become widespread in everyday life are illustrated simply and concisely. The book has an essentially informative character, without making use of complicated formulas or technicalities, therefore it does not require in-depth knowledge of physics or mathematics; the knowledge acquired in high school is sufficient to understand the topics covered.