This is a fun thought experiment inspired by emergent gravity, condensed-matter field theory, and the idea that many effective fields arise from deeper microscopic quantum systems.
What happens if we treat spacetime in exactly the same way we treat emergent quantum fields? In other words, what if the spacetime we observe is the large-scale, phase-dependent behavior of underlying quantum degrees of freedom, rather than a fundamental field to be quantized.
In this framing, spacetime corresponds to a particular stable phase of the deeper system. The metric acts as a coarse-grained variable that describes the large-scale structure of this phase. General relativity would then be the effective large-scale behavior of that phase, in the same way that hydrodynamics or elasticity describe the large-scale behavior of emergent fields in ordinary condensed-matter systems.
Meanwhile, quantum mechanics would describe the underlying microscopic degrees of freedom that give rise to this phase in the first place. Other phases of the same underlying system could produce very different large-scale geometries, dimensionalities, or causal structures.
I am not proposing a new theory. I am trying to understand where this perspective appears in existing literature, or which current research programs come closest to treating spacetime in this fully emergent, phase-dependent manner. I am also curious whether any approaches explicitly treat spacetime the way condensed-matter physics treats emergent gauge fields, superfluid phases, or other effective field theories.
Any pointers to relevant frameworks or references would be very helpful as I continue exploring this thought experiment.
Thought Experiment: Treating Spacetime Exactly Like an Emergent Quantum Field
This is a fun thought experiment inspired by emergent gravity, condensed-matter field theory, and the idea that many effective fields arise from deeper microscopic quantum systems.
What happens if we treat spacetime in exactly the same way we treat emergent quantum fields? In other words, what if the spacetime we observe is the large-scale, phase-dependent behavior of underlying quantum degrees of freedom, rather than a fundamental field to be quantized.
In this framing, spacetime corresponds to a particular stable phase of the deeper system. The metric acts as a coarse-grained variable that describes the large-scale structure of this phase. General relativity would then be the effective large-scale behavior of that phase, in the same way that hydrodynamics or elasticity describe the large-scale behavior of emergent fields in ordinary condensed-matter systems.
Meanwhile, quantum mechanics would describe the underlying microscopic degrees of freedom that give rise to this phase in the first place. Other phases of the same underlying system could produce very different large-scale geometries, dimensionalities, or causal structures.
I am not proposing a new theory. I am trying to understand where this perspective appears in existing literature, or which current research programs come closest to treating spacetime in this fully emergent, phase-dependent manner. I am also curious whether any approaches explicitly treat spacetime the way condensed-matter physics treats emergent gauge fields, superfluid phases, or other effective field theories.
Any pointers to relevant frameworks or references would be very helpful as I continue exploring this thought experiment.