Could frame dragging explain dark matter on a large scale?

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Discussion Overview

The discussion explores the idea of whether frame dragging, an effect observed near black holes, could explain the phenomena attributed to dark matter on a large scale, particularly in the context of galaxy motion. Participants consider the implications of this concept within theoretical frameworks and its potential observational consequences.

Discussion Character

  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant proposes that the motion of stars within a galaxy might subtly drag space along with them, potentially leading to an apparent velocity of stars that exceeds the escape velocity of the observable mass.
  • Another participant challenges this idea, suggesting that it has been previously considered and deemed negligible due to the slow and spread-out nature of stars.
  • A third participant echoes the sentiment that the idea has been thought of before, emphasizing that while it may not be novel, it is still valuable to explore such concepts.

Areas of Agreement / Disagreement

Participants express disagreement regarding the viability of the frame dragging concept as an explanation for dark matter. While one participant is open to exploring the idea, others assert that it has already been dismissed by experts in the field.

Contextual Notes

The discussion highlights the limitations of the proposed idea, particularly regarding the assumptions about the effects of frame dragging and its measurability in the context of galaxy dynamics.

RonH
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This is first post so bear with me.

This might be totally a blue sky thought ( ok it almost assuredly is ).

But when reading about the frame dragging near black holes I wondered if this effect might also be seen ( at a far lower intensity ) in the motion of galaxies.

Not suggesting that space is a fluid, but wondering if the billions of stars in a galaxy, moving in generally the same direction might be subtly dragging space, and the other stars, along with it.

This would, I think result in an observer outside of the galaxy noting that the stars of a galaxy having an apparent velocity exceeding the escape velocity of the observable mass. Particularly on the outer edges, as you rear the center of the mass the "flow" should be less apperent due to the shorter distances involved, but should be observable one would think. ( hears the branch creaking under me )

They could not observe that the space flowing with the stars lowers the actual velocity in respect the the local geometry.

On a massive scale could such a mechanism account for the discrepancy attributed to dark matter?

Respectfully,

Ron
 
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Do you really think no one had that idea before? Thousands of experts in general relativity overlooking one of the most basic effects of the theory in their whole working life?

It has been considered, of course. It is negligible. It would be taken into account if it would have any measurable effect. The stars are too slow and too spread out for that.
 
mfb said:
Do you really think no one had that idea before? Thousands of experts in general relativity overlooking one of the most basic effects of the theory in their whole working life?

It has been considered, of course. It is negligible. It would be taken into account if it would have any measurable effect. The stars are too slow and too spread out for that.
Figures
 
Like all good ideas someone has thought of it before. This is a mantra that would comeup in our patent review meetings at work. It doesn’t mean you shouldn’t keep thinking those good ideas.

Take care

Jedi
 

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