Several questions regarding the nature of the universe

  • Context: Graduate 
  • Thread starter Thread starter Rysiu
  • Start date Start date
  • Tags Tags
    Nature Universe
Click For Summary
SUMMARY

The discussion centers on the size of the universe during the Photon epoch, which occurred approximately 400,000 years after the Big Bang. Participants note that while the age of the universe at this epoch is known, calculating its dimensions is complex due to the unknowns in the universe's expansion history. The pressure during the Photon epoch is also queried, indicating a need for deeper understanding of early cosmic conditions. Accurate data on these topics remains elusive, highlighting gaps in current astronomical knowledge.

PREREQUISITES
  • Understanding of cosmology and the Big Bang theory
  • Familiarity with cosmic microwave background (CMB) radiation
  • Knowledge of the universe's expansion history
  • Basic principles of thermodynamics as they apply to early universe conditions
NEXT STEPS
  • Research the cosmic microwave background (CMB) and its significance in cosmology
  • Study the Friedmann equations to understand universe expansion
  • Explore the concept of the surface of last scattering in cosmological models
  • Investigate early universe conditions, including temperature and pressure during the Photon epoch
USEFUL FOR

Astronomers, cosmologists, and physics students interested in the early universe and its properties will benefit from this discussion.

Rysiu
Messages
2
Reaction score
0
I have a few questions about the nature of the universe. I'll start with the first question:

What was the size of the universe in Photon epoch? (in meters or light years)

How can it be calculated? On the Internet, unfortunately I did not find accurate data.

Sorry for my english - it is not good :wink:
 
Astronomy news on Phys.org
We can calculate the age of the universe at any given epoch, but, the dimensions of the universe is more complicated. For example, we know the age of the universe was a little under 400,000 years when the CMB was emitted, but, not the diameter of the surface of last scattering. You would need to know the entire expansion history of the universe for that, which is unknown.
 
Ok, thx.

Another question: We can estimate what was the pressure in the Photon epoch?
 

Similar threads

Undergrad A question about a popular example of expansion
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Some questions about Cosmic Inflation
  • · Replies 4 ·
Replies
4
Views
5K
Undergrad Energy conservation in Doppler (NOT cosmological) redshifts?
  • · Replies 13 ·
Replies
13
Views
3K
Graduate Accelerating Universal Expansion
  • · Replies 6 ·
Replies
6
Views
4K
I need help understanding this quote about recent Natural Selection
  • · Replies 20 ·
Replies
20
Views
5K
Graduate "The 7 Strangest Coincidences in the Laws of Nature" (S. Hossenfelder)
  • · Replies 62 ·
3
Replies
62
Views
12K
High School What is the size of the observable Universe?
  • · Replies 59 ·
2
Replies
59
Views
11K
Graduate Issues regarding the expansion of the Universe at the subatomic level
  • · Replies 15 ·
Replies
15
Views
5K
Undergrad Size of the Universe? I'm confused.
  • · Replies 7 ·
Replies
7
Views
5K
Graduate Understanding NOAA and Naval Observatory's Solar Calculations
  • · Replies 16 ·
Replies
16
Views
12K