Is a Local Theory of Branching in the Many Worlds Interpretation Solipsism?

The concept of a local theory of branching within the Many Worlds Interpretation (MWI) of quantum mechanics raises intriguing philosophical questions, particularly in regards to its resemblance to solipsism. This article explores the relationship between these concepts and highlights the nuances that make a straightforward comparison between them potentially oversimplified.

Many Worlds Interpretation (MWI)

Proposed by Hugh Everett III in 1957, the Many Worlds Interpretation (MWI) posits that all possible outcomes of quantum measurements occur in separate, parallel realities. This interpretation suggests a multiverse where multiple worlds exist, each representing a different outcome of quantum events.

Solipsism

Solipsism is a philosophical view that argues only one's own mind is certain to exist. In its extreme form, it suggests that the external world and other minds cannot be known and may not exist outside one's own consciousness. This concept serves as a starting point for understanding the contrast with the MWI.

Local Theory of Branching

Locality in MWI

A local theory of branching implies that branching occurs based on local interactions and events, without requiring a global or universal perspective. In this view, each branch can be considered independently, focusing on the subjective experiences of observers within that branch.

Relationship Between MWI and Solipsism

Non-Solipsistic Elements

MWI includes the notion that multiple branches contain conscious observers. This inherently suggests a reality beyond a single observer's mind, as it posits that other branches and observers exist, even if they are not directly observable.

Locality and Observer Experience

If one adopts a strictly local perspective on branching, it might be argued that each observer only experiences their own branch. However, this does not mean that other branches or observers do not exist. Rather, it emphasizes the subjective experience of each observer, which is a core element of solipsism but not its foundational principle.

Philosophical Implications

Comparing a local theory of branching in MWI to solipsism can be a tempting simplification. However, the MWI, with its multiple branches and the concept of decoherence, supports a broader, more interconnected view of reality. Even if individual experiences are localized, the MWI acknowledges a multitude of observers and outcomes, which is a far cry from the solipsist's view that only one's own mind can be certain to exist.

Conclusion

Saying that a local theory of branching in MWI is solipsistic might be an oversimplification or a mischaracterization. While there are subjective elements to how observers experience their own branches, the essence of MWI supports a broader and more complex understanding of reality, including multiple observers and outcomes. Thus, it is not entirely ridiculous to explore this connection, but it is crucial to recognize the significant nuances involved in both MWI and solipsism.