Age of Universe: 13.4 Billion Years Explained

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Discussion Overview

The discussion centers on the age of the universe, estimated at approximately 13.4 billion years, exploring its implications, frames of reference, and philosophical considerations. Participants examine the relativity of time, the significance of this age in the context of cosmic evolution, and the limitations of observational evidence in cosmology.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Philosophical

Main Points Raised

  • Some participants question the meaning of the universe's age, particularly regarding the frame of reference used in this measurement.
  • One viewpoint suggests that the age is measured from a frame at rest relative to the Cosmic Microwave Background (CMB), indicating that different observers may measure different times since the Big Bang.
  • Another participant affirms the age of the universe as approximately 13.7 billion years, citing evidence supporting this estimate.
  • Several participants express a sense of the universe's youth, pondering the implications of such a relatively short time for the development of cosmic structures.
  • There is a suggestion that the age estimate may need to be qualified, as it pertains primarily to our observable universe, with the unobservable universe potentially being much larger.
  • Some participants discuss the philosophical implications of what lies beyond the particle horizon, noting that while it may be scientifically irrelevant, it raises interesting questions about the universe's expansion and modeling different scenarios.
  • A comparison is made to illustrate the vastness of cosmic time, suggesting that if the time from the Big Bang to now were compressed into one year, human existence would represent only a minute before the new year.

Areas of Agreement / Disagreement

Participants express a range of views regarding the implications of the universe's age, with some agreeing on the measurement methods while others raise concerns about the limitations of these estimates. There is no consensus on the philosophical implications of the universe's age or what lies beyond the observable universe.

Contextual Notes

Participants highlight the relativity of time and the dependence of age estimates on specific frames of reference. There are unresolved questions regarding the implications of the unobservable universe and the philosophical considerations surrounding observational evidence.

cometraza
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It is told that the universe is 13.4 billion years old according to present estimates.
But as duration itself is a relative quantity what exactly is meant by this statement?
Which frame of reference are we talking about when considering this figure and why?
 
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The age of the universe in a frame in rest relative to CMB
In the other words, in rest to the local galaxies
These frames have the longest proper time along their worldlines since the Big Bang
All other observers (flying thru space) measure less time since the Big Bang,
 
Affirming dmitry, the universe appears to be no more than 13.7 billion years old as viewed from earth. We have an abundance of evidence supporting this assertion.
 
Thanks for clarifying.
 
That seems soooo "young" to me... I'm not doubting the validity of it - but it does seem like it's a short time for so much to have come about in the universe, I guess I just figured it'd be a lot older... hmm
 
encorp said:
That seems soooo "young" to me... I'm not doubting the validity of it - but it does seem like it's a short time for so much to have come about in the universe, I guess I just figured it'd be a lot older... hmm

We live in a lucky time (for us) when the elements required for our form of life exist, and before the universe devolves into a state of diffuse radiation. It is the very youth of our universe that gives us a chance at all.
 
encorp said:
That seems soooo "young" to me... I'm not doubting the validity of it - but it does seem like it's a short time for so much to have come about in the universe, I guess I just figured it'd be a lot older... hmm

The problem is that humans "are not fit" to think of such a long period of time. It' unnatural for us, since our lives only last decades. Think about the history of humanity. Look how much has changed in the last 4000 years or so. And that's nothing in 13.7 billions of years...
 
Maybe the 13-14 billion year age should be limited to statements about our Hubble Bubble - the unobservable universe is by most estimates much greater in size than the Hubble distance; depending upon the model used to describe the evolution, basing the age of the universe upon data contained in the Hubble may someday need to be qualified. As several cosmologist have mused - things would be nice and tidy if H turned out to be 42.
 
We can never observe anything beyond our particle horizon. Whatever may [or may not] lay beyond that is scientifically irrelevant.
 
  • #10
Chronos said:
We can never observe anything beyond our particle horizon. Whatever may [or may not] lay beyond that is scientifically irrelevant.

I would generally agree from the standpoint of actual verification -- but not philosophically - and not from the perspective of modeling different universes, even though there can never be any certainty in these matters. For example, what is beyond the particle horizon is worth pondering if it leads to a plausible explanation of the observed changes in the expansion profile.
 
  • #11
What philosophy would suffice as a substitute for observational evidence?
 
  • #12
Chronos said:
What philosophy would suffice as a substitute for observational evidence?

The answer would be subjective - for some (call them the faithful) the entire framework of happiness and satisfaction depends upon the absense of observational evidence. For others, the lack of complete observational evidence leads to the joy of speculating upon different resolutions that may never be confirmed..
 
  • #13
There was a very interesting comparison which made it easier to understand large time span involved.
So if we can imagine that the period from BB till today is 1 YEAR, than we started to exist as species 1 minute before the new year : )
 

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