Accomodating relativity to dark matter

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Discussion Overview

The discussion revolves around the relationship between dark matter and the principles of relativity, particularly focusing on how weakly interacting dark matter may challenge the application of special and general relativity. The scope includes theoretical considerations and implications for understanding dark matter's properties and interactions.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions how special or general relativity can be applied to weakly interacting dark matter, noting the difficulty in defining signaling or lightlike geodesics in the absence of electromagnetic interactions.
  • Another participant explains that dark matter is detected through its gravitational effects, such as the curvature of space-time observed in galaxy rotation curves and gravitational lensing, suggesting that photons still follow null-geodesics that are influenced by dark matter's presence.

Areas of Agreement / Disagreement

Participants express differing views on the implications of dark matter's interaction (or lack thereof) with photons and how this affects the application of relativity, indicating that the discussion remains unresolved.

Contextual Notes

The discussion highlights limitations in defining certain concepts related to dark matter and relativity, particularly regarding the assumptions about electromagnetic interactions and their role in the framework of general relativity.

Loren Booda
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If weakly acting dark matter does not interact with photons, how is special (or general) relativity applied in its case? Signaling (or lightlike geodesics) would be hard to define where there is no electromagnetic objectivity. I guess this inertness may be a problem in determining a neutrino's mass and velocity.
 
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Dark Matter is detected by its gravitational interaction. The curvature of space-time caused by the presence of DM is detected by galaxy rotation curves, the dynamics of galaxy clusters and the lensing of distant quasars. Photons continue to travel on null-geodesics, those null-geodesics are perturbed by the said curvature of space-time, and the deflection of these null-geodesics is a measure of the presence of both seen and unseen mass, the DM is the unseen component.

Garth
 
Last edited:
Thanks, Garth!
 
Well said Garth.
 

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