The EPR paradox, also known as the Einstein-Podolsky-Rosen paradox, is a concept in quantum mechanics that was proposed in 1935. Its spelling can be explained using the International Phonetic Alphabet (IPA): /ˈaɪ pi ˈɑɪ ˈpɒd ˌɒl ski ˈroʊ zən ˈpær əˌdɑks/. The EPR paradox highlights the apparent contradiction between the laws of quantum mechanics and the concept of local realism, which suggests that physical properties exist independently of observation. The paradox remains a subject of debate among physicists to this day.
The "EPR paradox," also known as the "Einstein-Podolsky-Rosen paradox," refers to a thought experiment presented by Albert Einstein, Boris Podolsky, and Nathan Rosen in 1935. This paradox challenges the completeness of quantum mechanics by proposing a situation in which two particles, often referred to as "entangled" particles, become inexplicably connected despite distance.
According to quantum mechanics, entangled particles share a quantum state, meaning that the state of one particle is directly connected to the state of the other. This implies that certain properties of one particle can influence the properties of the other, regardless of the distance between them.
The EPR paradox argues that if two entangled particles are spatially separated and measurements are performed on one particle, instantly determining a specific property, the other particle's property is likewise determined instantaneously, even if it is located far away. This seems to contradict the theory of relativity, which suggests that no information or influence can travel faster than the speed of light.
The paradox raises the question of whether quantum mechanics provides a complete description of reality or if there are additional hidden variables that determine the properties of the entangled particles. Since its proposal, the EPR paradox has been a significant topic of debate and has contributed to the development of quantum theory and our understanding of the nature of particles and their interactions.
The term "EPR paradox" is derived from the initials of three physicists: Albert Einstein, Boris Podolsky, and Nathan Rosen. In 1935, these scientists published a thought experiment known as the EPR (Einstein-Podolsky-Rosen) paper, intending to challenge the completeness of the quantum theory and raise questions about the nature of reality and the concept of "entanglement". The term "EPR paradox" refers to the apparent contradiction between certain predictions of quantum mechanics and classical physics, as highlighted in this influential paper.