Macroscopic World and Quantum Phenomena: Schrodinger's Cat

Abstract

As we are accustomed to everyday life, we may find quantum phenomena to be strange. If quantum phenomena were to happen often in our macroscopic world, we would react as if we had seen a ghost. A person to whom we were talking could move to another seat out of our sight in a moment, or his/her face could change. We might question if we are who we are. Fortunately experiencing quantum phenomena in everyday life is extremely hard. However, interestingly, quantum physics predicts that quantum phenomena can occur in the macroscopic world, regardless of our everyday experience. If that prediction is correct, why is experiencing quantum phenomena hard? Such a seemingly contradictory discussion was clearly raised by Schrodinger in his thought experiment, the so-called ‘Schrodinger cat paradox.’ Haroche’s group and Wineland’s group have independently performed experiments on the paradox. In this article, I discuss the historical background and the physical implications of the Schrodinger cat paradox.