Will Red Shift Eventually Make Distant Light Unobservable?

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Discussion Overview

The discussion revolves around the implications of redshift on the observability of distant light in the universe, particularly focusing on whether redshift will eventually render certain light unobservable. The scope includes theoretical considerations of cosmology and the nature of the observable universe.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that as light from distant galaxies becomes increasingly redshifted, there may come a time when it is no longer observable due to being shifted beyond the electromagnetic spectrum.
  • Others argue that redshift is a continuous process and that galaxies will not suddenly disappear from view, suggesting that they will remain observable even as they become more redshifted.
  • A participant expresses confusion regarding the relationship between the edge of the observable universe, redshift, and the time it takes for light to reach us, indicating a belief that the edge is more about time than redshift.
  • One participant mentions that while the Cosmic Microwave Background (CMB) will eventually become undetectable due to redshift, it will not leave the electromagnetic spectrum entirely.

Areas of Agreement / Disagreement

Participants express differing views on whether redshift will ultimately make distant light unobservable, with some asserting it will and others maintaining that it will not. The discussion remains unresolved regarding the implications of redshift on observability.

Contextual Notes

There are limitations in the understanding of how redshift interacts with the observable universe, particularly regarding the definitions of the edge of the observable universe and the role of time in this context.

stargazer843
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Since light emitted farther away from our point in the universe is more and more red shifted, would this mean that at a certain time we wouldn't be able to observe light further than a fixed distance since it's been red shifted beyond the electromagnetic spectrum?
 
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Yes. That's the edge of the observable universe. Every year, it gets several light-years farther out from us (not just 1 light-year, since space is expanding while the light is in transit).
 
Redshifted galaxies will become increasingly redshifted over time. They will never suddenly 'blink' out of view. Redshift is a continuous, not discrete, function.
 
@Chronos Eventually it will be redshifted out of the electromagnetic spectrum though right?
 
bcrowell said:
Yes. That's the edge of the observable universe. Every year, it gets several light-years farther out from us (not just 1 light-year, since space is expanding while the light is in transit).

Ben, I guess I have another misunderstanding that I need you to clear up. I thought the edge of the observable universe was the place at which objects exist from which emitted light has had time to reach us based on their position and their speed of recession from us and that we couldn't see beyond that point because the photons from those objects is now traveling away from us due to recession faster than they are traveling towards us due to their local speed. Clearly my concept IS tied up with red-shift so I'm having difficulty formulating my question well (another sign that I'm obviously confused). I guess at heart my belief is that the edge of the OU is based on time, not redshift and my question is an amorphous "HELP --- please get me unconfused"

Thanks.
 
The CMB will eventually move so far into the 'red' it will be cease to be detectable, but, never leave the EM spectrum.
 

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