Post-quantum gravity: 'wobbly' time becomes testable
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- Jonathan Oppenheim at University College London developed "post-quantum gravity," a theory that leaves space-time continuous and non-quantum, making gravity the only fundamental force without quantum constituents.
- The theory's core prediction is that time would become "wobbly," with small random fluctuations in its flow at scales too small for human perception.
- When those time fluctuations are fed into standard quantum-mechanical calculations, they reproduce observed quantum behaviors including the collapse of Schrödinger's cat from a superposition into a single classical state.
- Oppenheim acknowledges the theory is highly controversial, saying "I don't know anyone who thinks it's more likely to be true than not true" — though many researchers agree the tests are worth running.
- Giuseppe Fabiano at Lawrence Berkeley National Laboratory, part of a team developing parameters for testing gravity theories, calls the theory's testability "useful" even while remaining agnostic on whether it is correct.
- Proposed experiments would measure gravitational properties between pairs of objects, because any unpredictability in time's flow would surface as unpredictability in gravity itself; reaching the necessary precision could take decades.
- The work is published in Physical Review X (DOI: 10.1103/2rcd-dzcf).
Why it matters: If experiments confirm post-quantum gravity, it would be the first empirical crack in the century-old assumption that all fundamental forces are quantum — resolving the long-standing clash between general relativity and quantum mechanics while raising entirely new questions about reality at its most basic level. The decades-long experimental timeline means physicists may debate the implications long before any verdict arrives.
