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Pressure-Based Theory — a mechanical, unified account of gravity, electromagnetism, spin, and entanglement

Einstein-Aether Theory

What it claims: Not PBT’s own invention — a real, peer-reviewed modified-gravity framework proposed by Ted Jacobson and David Mattingly (2001, Phys. Rev. D 64, 024028). It adds a dynamical, timelike unit vector field ($u^\mu$, “the aether”) to general relativity’s spacetime metric. Unlike the 19th-century luminiferous aether (see Disproven Theories), this aether is dynamical — it responds to and affects the gravitational field rather than sitting as a fixed, undetectable background — which is specifically what lets it introduce a locally preferred timelike direction at every point without reintroducing the kind of fixed, detectable rest frame Michelson-Morley already ruled out.

Catalog status: Unproven Systems At Large. This is a legitimate, actively-studied research program in the peer-reviewed literature — real physicists working within real institutions have published on it for over two decades. But it remains unconfirmed: ordinary general relativity (with no aether field at all) already fits every gravitational observation to date, and Einstein-aether’s own coupling constants ($c_1$–$c_4$) are tightly squeezed toward zero by real constraints — most significantly, the 2017 detection of gravitational waves alongside their electromagnetic counterpart (GW170817) requires gravitational waves to travel at essentially exactly $c$, which rules out large regions of the theory’s parameter space. Nothing currently requires this framework over plain GR; it survives as an actively-constrained, not-yet-falsified alternative.

Where PBT touches this: PBT’s own aether field, $u^\mu$, is explicitly built on this framework — Paper 2, 5, and 8 use Einstein-aether’s real action-integral structure and even cite specific coupling-constant values ($c_1\approx10^{-16}$, etc.) framed as consistent with real observational bounds. This is a case where PBT is honestly building on a real, credentialed, still-unconfirmed piece of physics — not disproven, not proven, genuinely open — rather than either fabricating a mechanism from nothing or reusing something already settled.

References

  1. Jacobson, T., Mattingly, D. (2001). “Gravity with a dynamical preferred frame.” Phys. Rev. D 64, 024028.
  2. Jacobson, T. (2008). “Einstein-aether gravity: a status report.” PoS QG-PH:020.
  3. Abbott, B.P. et al. (LIGO/Virgo). (2017). “GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral.” Phys. Rev. Lett. 119, 161101 — the multi-messenger detection whose tight constraint on gravitational-wave speed heavily restricts this theory’s viable parameter space.