Originated by US physicist Hugh Everett in the late 1950s, this envisions our Universe as just one of numerous parallel worlds that branch off from each other, nanosecond by nanosecond, without intersecting or communicating.

The Copenhagen interpretation introduced the concept of wave function collapse but failed to precisely define the conditions that cause a collapse or why it collapses. The Everett interpretation (many-worlds) simply removes the idea of collapse and the all the unresolved questions regarding collapse.

The Many-Worlds Interpretation suggests that every time a quantum particle can exist in more than one state, the universe undergoes a branching. Each state the particle can occupy becomes a separate reality, creating a vast and ever-expanding quantum multiverse.

Many-worlds interpretation David Deutsch argues that the way to understand the double-slit experiment is that in each universe the particle travels through a specific slit, but its motion is affected by the interference with particles in other universes. This creates the observable fringes.