Quantum theory, discovered more than 100 years ago, has changed the rules of the game. It seems to be a disaster and also a godsend. In this article, I would like to introduce this rarely known turning point that changed classic to modern, analog to digital, and certainty to uncertainty. Few people notice that quanta appear everywhere, not only in the fields of science, but also in those strongly related to technology, contributing to our modern world. Let's take a look at the amazing quantum world. By the time Max Plank discovered light quanta in 1900, modern quantum physics had begun. Several years later, Niels Bohr discovered the quantum leap and brought out quantum theory. Quantum theory creates a totally mysterious world, redefining our understanding of reality. It seems a disaster that classical physics could be totally wrong. No one can predict where a quantum will go before making a measurement according to the uncertainty principle. This leads to a contrast with what we believed in classical physics. (Davies, 1982) Fortunately, this inte...