Does space move? What is space?

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Discussion Overview

The discussion revolves around the nature of space and whether it can be said to move or expand. Participants explore concepts related to the bending and expansion of space-time, the implications of relative motion, and the observational consistency of these ideas.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants suggest that space-time is a framework that does not itself matter, and that it "bends" and "expands" in specific mathematical contexts.
  • Others propose that it might be more accurate to say that objects are moving away from each other through space, rather than space itself moving.
  • There is a challenge regarding the consistency of the idea that objects are moving through space, particularly for distant objects, with some arguing that this view is not consistent with observations.
  • A participant questions how one can observe space moving, emphasizing that only relative motion can be observed.
  • Another participant compares the hypothesis of space moving to the hypothesis of "there is no sun," suggesting that both are inconsistent with observations, albeit with more complex mathematics involved.
  • It is noted that there is no model that can reproduce observed redshifts solely through objects moving in space.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the movement of space and the interpretation of observational data, indicating that the discussion remains unresolved.

Contextual Notes

The discussion highlights limitations in the understanding of space movement, the dependence on mathematical models, and the challenges in reconciling different interpretations with observational evidence.

k9b4
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Does space move? What is space?
 
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Whether or not it is appropriate to say that space "bends / expands / curves" and so forth is a somewhat contentious issue. Basically, the math says that space-time is a framework in which things happen and does not itself matter. It "bends" in that geodesics near large bodies are not straight in the Euclidian sense. It "expands" in the sense that things get farther apart. Google "metric expansion" for further discussion.
 
phinds said:
It "expands" in the sense that things get farther apart.
Can't we just say that the objects are moving away from each other, through space, and the space itself is not moving?
 
k9b4 said:
Can't we just say that the objects are moving away from each other, through space, and the space itself is not moving?
For objects far away, this is not consistent with observations.
 
mfb said:
For objects far away, this is not consistent with observations.
But hang on, what do you mean it's not consistent with observations? How can you observe space moving? You can only observe relative motion, as dalespam pointed out in my other thread in this subforum.
 
k9b4 said:
But hang on, what do you mean it's not consistent with observations?
In the same way the hypothesis "there is no sun" is not consistent, just with more math involved.
How can you observe space moving? You can only observe relative motion, as dalespam pointed out in my other thread in this subforum.
Right, but there is no model that can reproduce the observed redshifts with objects moving in space.
 

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