Does age of Universe reveal its size?

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Discussion Overview

The discussion revolves around the relationship between the age of the universe and its size, particularly focusing on the observable universe and the implications of its size for cosmic expansion and potential ultimate fates such as a big crunch or big rip.

Discussion Character

  • Debate/contested, Conceptual clarification, Exploratory

Main Points Raised

  • Some participants argue that knowing the age of the universe does not provide information about its overall size beyond the observable universe.
  • Others propose that the universe could be infinite, which complicates the understanding of its size.
  • A participant questions whether the uncertainty about the universe's size contributes to the inability to determine if cosmic expansion will end in a big crunch.
  • Another participant asserts that current knowledge indicates the universe will not end in a big crunch.
  • One participant suggests that the future of the universe's expansion is influenced by dark energy, and whether it ends in a big rip remains an open question dependent on the dark energy equation of state.

Areas of Agreement / Disagreement

Participants express differing views on the implications of the universe's size and age, with some asserting that the universe will not end in a big crunch while others highlight the uncertainty surrounding dark energy and its effects on cosmic expansion.

Contextual Notes

The discussion reflects limitations in understanding the universe's overall size and the implications of dark energy, with unresolved questions about the future of cosmic expansion.

Pjpic
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Does knowing the age of the universe (13.8 billion? ) say anything about size of the universe (besides the observable size)?
 
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No. We know the size of the observable universe, but not what lies outside of our horizon. The size could be infinite.
 
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phyzguy said:
No. We know the size of the observable universe, but not what lies outside of our horizon. The size could be infinite.

Is not knowing the size the reason we don't know if the expansion will ultimately end in a big crunch?
 
Pjpic said:
Is not knowing the size the reason we don't know if the expansion will ultimately end in a big crunch?
No. We now know that it will not.
 
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Pjpic said:
Is not knowing the size the reason we don't know if the expansion will ultimately end in a big crunch?
We are in the early stages of a dark energy dominated universe. The expansion rate will continue to get faster and faster. Whether the universe ends in a big rip, according to current models, is still an open question. It depends on the exact form of the dark energy equation of state.
 

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