Beyond the Speed of Light: Objects Beyond the Observable Universe

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SUMMARY

Objects beyond the observable universe cannot be said to move faster than the speed of light in any meaningful way. The concept of redshift indicates that objects at the edge of the observable universe are maximally redshifted, and those beyond are theoretically even more so, which leads to the conclusion that their light will never reach us. This does not imply that such objects do not exist; rather, it highlights the limitations of our observational capabilities. The discussion clarifies that relative speed cannot be defined for objects that are not in proximity, emphasizing the coordinate-dependent nature of such measurements.

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  • Understanding of redshift and its implications in cosmology
  • Familiarity with the observable universe and its boundaries
  • Basic knowledge of spacetime and general relativity
  • Concept of coordinate systems in physics
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Sachabloke
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Are objects beyond the observable universe in some sense moving faster the the speed of light. Given that objects at the edge of the observable universe are "maximally" red shifted, objects beyond that theoretically must be more red shifted, which is impossible. Is it therefore a nonsense to believe that anything exists beyond 13.8 billions light years away? I understand the answer is no, but I thought it an interesting topic.
 
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Sachabloke said:
Are objects beyond the observable universe in some sense moving faster the the speed of light.

Only in a coordinate dependent sense which has no physical relevance. If you want to be rigorous, there is no way of saying that two objects are moving with a particular relative speed unless they are at the same place (or sufficiently close so that spacetime can be considered locally flat).

Sachabloke said:
Given that objects at the edge of the observable universe are "maximally" red shifted, objects beyond that theoretically must be more red shifted, which is impossible.
This is a logical fallacy. It only means that the light from those objects will never reach you - which is the same statement that you started with.
 
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