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Gravitational waves and temporal geometry: SMM/DTT and Emergent and entropic gravity

What would a temporal origin of geometry imply for the speed, polarization and phase evolution of gravitational waves? This article compares the source-based construction with Emergent and entropic gravity, identifies their strongest point of contact, and works through a concrete example that separates a valid mathematical result from the further physical relation needed to explain observations.

In this article
  1. The question that matters
  2. The SMM/DTT contribution
  3. How Emergent and entropic gravity frames the problem
  4. Where the mechanisms agree and differ
  5. Worked example: assumptions, calculation and result
  6. An independent operational check
  7. What follows from the comparison
Key ideas · Continue on SMONAD

01The question that matters

Gravitational waves test dynamics directly: a theory must describe their production, propagation and detection through material instruments. In general relativity their weak-field vacuum limit contains two transverse tensor polarizations propagating on the metric null cone. Modified gravity can change that pattern, but a microscopic theory need not produce any observable deviation at accessible frequencies.

A temporal interpretation of curvature becomes predictive only after its effective wave operator is known. Claims of dispersion, echoes or additional polarizations require a particular mechanism and boundary conditions. A finite inner update frequency alone does not determine whether a gravitational wave is dispersive; it may disappear entirely from the long-wavelength limit or enter only through highly suppressed operators. [1] [2] [3]

02The SMM/DTT contribution

SMM/DTT seeks to interpret geometry as the organization of completed records. A gravitational wave could then be a propagating collective change in relational timing and distance rather than a deformation of a pre-existing substance. This can be a useful microscopic picture if the same source update also governs how mirrors, atoms and clocks respond.

The six nested inner levels should be understood as the generative organization supporting this effective response. They do not imply six gravitational-wave polarizations. Observable polarizations follow from the constraints and physical degrees of freedom of the effective field equations. A clear derivation could recover the standard two modes and then identify a restricted residual correction whose coefficient is fixed by the temporal dynamics.

Geometry, clocks and propagation as independent readouts
Geometry, clocks and propagation as independent readouts. A single source model should explain the relation between separately defined measurements. Sharing a diagram does not impose that relation. View full size ↗

03How Emergent and entropic gravity frames the problem

Thermodynamic and entropic approaches ask whether gravitational equations describe collective information or entropy response. Jacobson's local-horizon argument and Verlinde's entropic-force proposal are distinct constructions, with different assumptions and scopes. Their common lesson is that a familiar gravitational equation can emerge conditionally from nongeometric-looking inputs.

For DTT this creates an attractive bridge from retained histories to macroscopic geometry. However, an entropy count, a temperature and an energy normalization are physical ingredients that need justification. The comparison is strongest when a temporal model explains one of those ingredients and weakest when it simply imports all of them under the name of completion. [4] [5]

04Where the mechanisms agree and differ

A static entropic-force law does not determine the existence, speed or polarization of gravitational waves. This is an important limitation of comparing DTT temporal geometry with an entropy-based account of attraction. A successful gravitational theory must explain how changes propagate and how their energy is exchanged with matter.

Jacobson's local-horizon route can recover the Einstein equation under its assumptions, and the usual wave sector then follows within that effective metric theory. A more general entropic model may have different dynamics or none specified. DTT could add a microscopic account of the relaxation and transport processes that lead to that metric equation. The six nested inner levels would then organize actual causal response rather than label a static information count. The arrival-time example below shows why a proposed completion delay must be assigned to emission, propagation or detection. These are physically different effects. A strong bridge would derive a dynamic constitutive law from source generation and show that it yields the observed tensor-wave structure, with any residual correction controlled by the same parameters as the static gravitational response. [4] [5]

05Worked example: assumptions, calculation and result

For a simple nondispersive propagation comparison, take a source distance of 40 megaparsecs and an arrival-time difference of 1.7 s. Since 1 Mpc≈3.086×10²² m, the travel time is approximately 4.12×10¹⁵ s. Dividing gives |Δv|/c≈4.1×10⁻¹⁶ if the entire delay is attributed to propagation.

This arithmetic is only an illustrative inference. Electromagnetic and gravitational signals can leave the source at different times, and cosmological propagation requires a more careful treatment. The published GW170817 analysis incorporates astrophysical assumptions in its bounds. A DTT wave-speed claim must specify those same assumptions and cannot equate the observed arrival delay directly with an intrinsic inner-time lag. [1] [2] [3]

Δv/c≈Δt/(D/c). For D=40 Mpc and Δt=1.7 s, the propagation-only estimate is 4.1×10⁻¹⁶.

D is the source distance in this approximation; the sign and magnitude of an intrinsic emission lag are separate inputs.

06An independent operational check

A proposed dispersion relation can be tested internally before fitting data. Its frequency must remain real for the intended wave numbers, its energy should be bounded in the physical sector, and its group velocity should be interpreted separately from its phase velocity. A higher-derivative term may introduce an extra mode or an instability if treated beyond the effective theory's domain. The source programme is strongest when it states that domain and derives the coefficient there. These checks connect microscopic temporal structure to a viable propagating signal; they also prevent an arbitrary frequency-dependent delay from being mistaken for a complete gravitational-wave theory.

07What follows from the comparison

The strongest experimental target is a correlated signature: the same effective coefficient might affect wave phase, matter clocks or another transport probe. Agreement among these effects would be more informative than fitting a single unusual signal. Until a source-derived coefficient exists, gravitational-wave observations provide consistency requirements and a way to translate possible models into bounds, rather than existing confirmation of temporal geometry.

THE SAME QUESTION, DIFFERENT STARTING POINTS

The comparison at a glance

QuestionSMM/DTTEmergent and entropic gravity
Starting physical structureOne nonspatial source; six nested inner functional levels produce records accessible through outer completion.Collective entropy and information variables in a specified thermodynamic construction.
The central mechanism in this topicSource dynamics could supply the causal response missing from a static entropy-force law.Wave behavior follows only after an effective dynamical metric theory is specified.
How the claim is made operationalA source-to-record map must define geometry, material response and physical clocks with shared inputs.Entropy-response laws, energy/temperature assignments and effective gravitational relations.
Meaning of agreementAgreement is a compatibility result; a source-selected relation or fixed residual would add explanatory content.The stated framework provides a benchmark within its own assumptions and established domain.

KEEP THE CONNECTION

Key ideas

  • The essential extension is from equilibrium attraction to a causal tensor response with consistent energy accounting.
  • The worked example establishes only the result stated under its explicit assumptions.
  • Six nested inner levels describe one generative organization; outer time orders accessible completion.

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Sources and further reading

References support the comparator and the specific mathematical or interpretive claims indicated. SMM/DTT connections are developed in the analysis above.

  1. LIGO Scientific Collaboration, Virgo Collaboration, Fermi Gamma-Ray Burst Monitor and INTEGRAL, Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A (2017) ↗Primary multimessenger observation and conditional bounds on relative gravitational/electromagnetic propagation speed.
  2. Clifford M. Will, The Confrontation between General Relativity and Experiment (2014) ↗Peer-reviewed Living Reviews article; equivalence principle, metric theories, post-Newtonian benchmarks and experimental methodology.
  3. John F. Donoghue, General relativity as an effective field theory: The leading quantum corrections (1994) ↗Peer-reviewed gravitational effective field theory; separation of infrared predictions from unknown short-distance coefficients.
  4. Ted Jacobson, Thermodynamics of Spacetime: The Einstein Equation of State (1995) ↗Peer-reviewed derivation conditional on local horizon thermodynamics, area entropy and the Clausius relation.
  5. Erik Verlinde, On the Origin of Gravity and the Laws of Newton (2010/2011) ↗Published entropic-gravity proposal; entropy, temperature and screen assumptions are separate physical inputs.

How these comparisons distinguish premises, results and physical claims