Eternalism and Reality

In his paper “Time and Physical Geometry”, Hilary Putnam argued that special relativity tells us that the past, present and future are equally real.

Spacetime is indeed more foundational than Euclidean space. However, that does not mean that all of spacetime exists in a physical or ontological sense.

For example, cosmology teaches us that spacetime is bounded: the universe is not expanding into something, it is just expanding. We should apply a similar discipline to the time dimension.

Reality has a natural meaning in terms of what is physically realizable not what is allowed under a single formalism. For reality to exist it needs to be accessible in principle subject to relevant constraints - available energy, entropy and information density

This calls for a more disciplined approach to conducting thought experiments. Rather than exploring the limits of one formalism, we need to consider everything we know about the physical world to make onthological statements

Not all of the past persists as we are unable to encode all information to describe it. The past survives through reduction, embedded in the increasing functional complexity of our current reality. Similarly, not all of the future exists as it would require infinite energy to access it.