Several questions regarding the nature of the universe

In summary, the size of the universe in the Photon epoch cannot be accurately calculated due to the complexity of its expansion history. However, we can estimate the age of the universe during this epoch. Additionally, the pressure in the Photon epoch can also be estimated, but it requires further information that is currently unknown.
  • #1
Rysiu
2
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
  • #2
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.
 
  • #3
Ok, thx.

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

1. What is the Big Bang Theory and how does it explain the origin of the universe?

The Big Bang Theory is a widely accepted scientific explanation for the origin and development of the universe. It proposes that the universe began as a single, infinitely dense point or singularity and has been expanding and cooling ever since. This expansion created the space, time, and matter that make up our universe today.

2. How old is the universe and how do we know?

The current estimated age of the universe is approximately 13.8 billion years old. This age is determined through various methods including measuring the cosmic microwave background radiation, the rate of expansion of the universe, and the ages of the oldest stars and galaxies.

3. Is the universe infinite or finite?

The answer to this question is still debated among scientists. Some theories suggest that the universe is infinite and has no boundary, while others propose that it is finite and has a specific shape or size. The current evidence is inconclusive, and more research is needed to determine the true nature of the universe.

4. What is dark matter and how does it affect the universe?

Dark matter is a theoretical form of matter that does not interact with light and cannot be detected through traditional methods. It is believed to make up about 85% of the total matter in the universe and plays a significant role in the structure and evolution of galaxies. However, its exact nature and properties are still largely unknown.

5. Will the universe continue to expand forever or will it eventually collapse?

The answer to this question is uncertain and depends on the amount of matter and energy in the universe. If the universe contains enough matter, its gravitational pull may eventually overcome the expansion and cause it to collapse in a "Big Crunch." However, if the expansion continues to accelerate, the universe may continue to expand forever in a "Big Freeze" scenario.

Similar threads

I Some questions about Cosmic Inflation
    • Cosmology
Replies
4
Views
1K
I A question about a popular example of expansion
    • Astronomy and Astrophysics
Replies
7
Views
2K
I Energy conservation in Doppler (NOT cosmological) redshifts?
    • Astronomy and Astrophysics
Replies
13
Views
1K
Schools Question About Relevance of a HBSc degree at UofT Compared to US Universities
    • STEM Academic Advising
Replies
23
Views
776
I Some questions about Cosmic Microwave Background radiation
    • Cosmology
Replies
13
Views
2K
I Three questions regarding QG theories
    • Beyond the Standard Models
Replies
12
Views
945
Admissions Exploring the Universe: Pursuing a PhD in High Energy Physics
    • STEM Academic Advising
Replies
8
Views
916
B What is the size of the observable Universe?
    • Cosmology
2
Replies
59
Views
7K
B Theory of Loop Quantum Gravity
    • Beyond the Standard Models
Replies
4
Views
2K
I Does the universe have a definite "size"?
    • Cosmology
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top