In the context of quantum physics, the term "world" does not have a precise or universally accepted definition. The concept of "worlds" is often used in the interpretation of quantum mechanics to describe different possible outcomes or branches of a quantum system.
One interpretation of quantum mechanics that incorporates the notion of multiple worlds is the Many-Worlds Interpretation (MWI), proposed by physicist Hugh Everett in the 1950s. According to the MWI, whenever a measurement or observation occurs, the universe splits into multiple branches, each representing a different possible outcome. These branches coexist in parallel, forming a "multiverse" composed of all the different worlds that could have occurred.
In this interpretation, each branch or world represents a distinct reality, and all possible outcomes of a quantum event are realized in different branches. Each world evolves independently, following the laws of quantum mechanics, and experiences a unique sequence of events and observations.
It's important to note that the Many-Worlds Interpretation is just one of several interpretations of quantum mechanics, and there are alternative interpretations that do not involve the concept of multiple worlds. The choice of interpretation is a matter of philosophical and scientific debate, and different interpretations offer different perspectives on the nature of quantum reality.
In summary, in the context of quantum physics, a "world" often refers to a distinct branch or outcome within the Many-Worlds Interpretation, where each branch represents a different possibility or measurement outcome of a quantum system.