While it is true that certain aspects of the multiverse concept are currently untestable, it does not necessarily mean that the entire concept is inaccurate or invalid. Scientific theories often go through a process of development, refinement, and testing, and some aspects may indeed be challenging to directly observe or test at present.
The multiverse theory, which proposes the existence of multiple universes, is based on various theoretical frameworks, such as inflationary cosmology and string theory. These theories provide mathematical models and explanations for phenomena observed in our universe, but verifying the existence of other universes within the multiverse is currently beyond our technological capabilities.
However, it is important to distinguish between ideas that are untestable in principle and those that are currently untestable due to technological limitations. For example, the concept of the Big Bang is supported by a substantial body of evidence from observations of cosmic microwave background radiation, redshift of galaxies, and other astrophysical phenomena. While we cannot directly observe the precise moment of the Big Bang, the available evidence strongly supports the theory.
Scientific theories are subject to ongoing investigation, and new evidence and technologies may emerge in the future that could potentially provide ways to test or further support aspects of the multiverse concept. Therefore, while the multiverse remains a speculative idea at present, it is not automatically dismissed solely on the basis of being untestable. Scientists continue to explore and refine these concepts within the boundaries of current knowledge and observational capabilities.