multiversum

Multiversum is the hypothesis that multiple, causally disconnected universes exist beyond and alongside our own, collectively forming a broader reality. Each universe may have distinct physical constants, laws, or initial conditions. The term is related to the broader concept of the multiverse, and in scientific contexts it refers to several theoretically motivated frameworks rather than a single, testable model.

A common scheme divides multiversum ideas into levels. Level I posits regions beyond our observable universe with the same physical laws and constants but different initial conditions. Level II describes other bubble universes produced by eternal inflation, potentially with different constants. Level III corresponds to the many-worlds interpretation of quantum mechanics, where all possible outcomes are realized in branching histories. Level IV imagines that every coherent mathematical structure corresponds to a real universe.

Historically, ideas about multiple worlds date from philosophy and early cosmology. In modern physics, Hugh Everett proposed the many-worlds interpretation in 1957. The development of chaotic and eternal inflation in the 1980s–1990s gave rise to cosmological multiverses. Max Tegmark’s 2003 framework formalized the four levels and stimulated further debate about what counts as physical reality.

Status and evidence: Multiversum remains speculative. There is no direct empirical confirmation. Some researchers have proposed observational tests, such as signatures in the cosmic microwave background from collisions between bubble universes, but no unambiguous signals have been found. The concept intersects issues of falsifiability and scientific method. It is often discussed in connection with the string theory landscape, which posits a large number of possible vacua.