Red Shift & Time: Can Time Be Expanding Too?

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Discussion Overview

The discussion revolves around the concept of red shift and whether time, as a dimension, could also be subject to expansion similar to the three spatial dimensions. Participants explore theoretical implications and seek literature on the topic.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if time could expand at the same rate as spatial dimensions, suggesting a potential relationship between red shift and time.
  • Another participant argues that if all dimensions were to expand equally, it would result in no physical change, merely a rescaling of the coordinate system.
  • A third participant provides a simpler response, stating that the universe's expansion does not imply any unusual behavior of time or clocks.
  • A later reply acknowledges the previous points about coordinate transformations and expresses a personal realization about the implications of equal expansion.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between time and spatial expansion, with some agreeing on the implications of equal expansion while others maintain that time does not exhibit the same behavior as spatial dimensions. The discussion remains unresolved.

Contextual Notes

Participants reference the complexities of coordinate transformations and the intuitive understanding of physical behavior, indicating that assumptions about dimensional expansion may vary based on definitions and interpretations.

Exmech
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Hello! I'm brand new to the forum and have a question that has been nagging at me for some time. I've read a great number of articles regarding the red shift, as well as time being a dimension. I was wondering if anyone has addressed the possibility that time might also be subject to the red shift. That is, the dimension is expanding at the same rate as the 3 spatial dimensions. Any literature anyone has on this would be most appreciated.
 
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Exmech said:
Hello! I'm brand new to the forum and have a question that has been nagging at me for some time. I've read a great number of articles regarding the red shift, as well as time being a dimension. I was wondering if anyone has addressed the possibility that time might also be subject to the red shift. That is, the dimension is expanding at the same rate as the 3 spatial dimensions. Any literature anyone has on this would be most appreciated.
If you make it so that all dimensions expand equally, it turns out that nothing physical changes: all you've done is made a change in your equations that rescales the coordinate system. Instead, an expansion is only physical if some dimensions expand relative to other dimensions. In our case, it is usually written as the three dimensions of space expanding relative to the time dimension. Of course, if you wanted to, you could massage the equations so that the time dimension would instead change while the spatial dimensions remain the same, but that would be a much less intuitive way of understanding the physical behavior.
 
I agree with Chalnoth's answer.

A simpler answer is just no. This avoids getting into co-ordinate transformations or definitions. The universe expands, which means things are moving apart from each other. There's nothing funny going on with time or clocks.
 
Chalnoth said:
If you make it so that all dimensions expand equally, it turns out that nothing physical changes: all you've done is made a change in your equations that rescales the coordinate system.

That, my friend, is what I surmised when I began thinking about this. However I recognize I'm not the cleverest person in the world. Thank you.
 

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