Are Galaxies the Same Age if they are the Same Distance From Us?

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    Age Galaxies
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Discussion Overview

The discussion centers on the relationship between the distance of galaxies from Earth and their ages. Participants explore whether galaxies at the same distance can be assumed to be of similar age or if significant age variations exist among them.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions the assumption that equidistant galaxies are approximately the same age, suggesting there may be significant age differences among them.
  • Another participant asserts that distance is irrelevant to the age of galaxies, indicating that there are indeed younger galaxies compared to the Milky Way.
  • A third participant provides context by stating the estimated age of the Milky Way and explains that distant galaxies are observed as they were in the past, which implies they could be younger than the Milky Way when their light left them.
  • This participant also mentions a belief regarding the formation timeline of galaxies after the Big Bang, suggesting that the Milky Way is among the oldest galaxies.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the relationship between distance and age, with some arguing for a connection and others asserting that distance does not determine age. The discussion remains unresolved.

Contextual Notes

There are limitations in the assumptions made about galaxy formation times and the implications of light travel time on age estimates. The discussion does not resolve these complexities.

EskWIRED
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Do we assume that all galaxies which are equidistant from Earth are approximately the same age? Or are there galaxies at roughly the same distance from Earth but which vary greatly in age?

Are we aware of any galaxies which are significantly younger than the Milky way?
 
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As I understand it, the Milky Way is quite old and there are many younger galaxies. Distance from us is utterly irrelevant.
 
The estimated age of the Milky Way is about 13.2 billion years, making it nearly as old as the universe [13.7 billion years]. Distant galaxies are seen as they appeared in the past, so, for example, a galaxy 1 billion light years distant had to be less than 12.7 billion years old when its photons departed. It is currently believed 500 million years is about as soon after the BB that galaxies could have formed, meaning the MW is among the most ancient galaxies in the universe.
 
Thanks. That's exactly the type of thing I was wondering about.
 

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