The Many-Worlds Interpretation (MWI) and String Theory are two distinct concepts in physics that address different aspects of our understanding of the universe. It's important to note that they are not directly comparable, as they pertain to different areas of physics and serve different purposes. Nevertheless, we can discuss some advantages of the Many-Worlds Theory over certain aspects of String Theory:
Simplicity: The Many-Worlds Interpretation is a straightforward and conceptually simple interpretation of quantum mechanics. It doesn't introduce any additional mathematical or conceptual complexity beyond the standard formalism of quantum mechanics. In contrast, String Theory is a complex and mathematically demanding framework that attempts to unify all the fundamental forces and particles of nature into a single theory.
Explanation of Quantum Measurement: The Many-Worlds Interpretation provides an explanation for the measurement problem in quantum mechanics. It suggests that when a quantum measurement occurs, the universe branches into multiple parallel universes, each corresponding to a different possible outcome of the measurement. This eliminates the need for wave function collapse or the introduction of additional variables to explain the measurement process.
Consistency with Quantum Mechanics: The Many-Worlds Interpretation is consistent with the mathematical formalism and predictions of quantum mechanics. It doesn't require any modifications or extensions to the existing framework of quantum mechanics. On the other hand, String Theory goes beyond quantum mechanics and attempts to provide a more fundamental description of nature, including gravity, by introducing extra spatial dimensions and vibrating strings.
Multiverse Perspective: The Many-Worlds Interpretation naturally leads to a multiverse perspective, where every possible outcome of quantum events exists in a separate parallel universe. This can provide a framework to address questions related to the existence of other universes, the nature of reality, and the anthropic principle. String Theory also allows for the possibility of a multiverse through various mechanisms, but it doesn't inherently provide a comprehensive explanation of it.
It's important to acknowledge that the Many-Worlds Interpretation is not the only interpretation of quantum mechanics, and it remains a topic of philosophical and scientific debate. Similarly, String Theory is a highly active area of research, although it has not yet been experimentally confirmed and faces significant challenges. Ultimately, the choice between these theories depends on the specific questions being addressed and the evidence and experimental results available.