Infinite Universe not possible?

In summary, the conversation discusses the concept of the universe being infinite and how it relates to the Big Bang theory. The conclusion is that while the universe may expand forever, it is always finite at any given point in time. The idea of an infinite universe only applies to a static, infinite universe where it has always been infinite. This topic has also been discussed in a related thread.
  • #1
pivoxa15
2,255
1
I think I have read that the universe is or could be infinite. But that is not possible because we know that the Universe started from a Big Bang. And its size has been expanding ever since. At each point in the past through to the present, the Universe measures a finite size with 0 unit of size at t=0. Therefore the universe has always been and is to the present moment finite.

The universe might expand forever but it does not matter because at each specific time, the universe will always be of finite size hence to speak of an infinite universe is nonsense in the Big Bang model.

An infinite universe can only exist in a static, infinite universe where the universe has 'always been infinite'.
 
Astronomy news on Phys.org
  • #2

Related to Infinite Universe not possible?

1. What evidence suggests that the universe is not infinite?

There are multiple pieces of evidence that suggest the universe is not infinite. One is the observed expansion of the universe, which would not be possible if the universe were infinite. Additionally, the cosmic microwave background radiation, leftover from the Big Bang, is consistent with a finite universe. Finally, the distribution and density of matter in the universe also indicate a finite size.

2. Why is an infinite universe not possible?

An infinite universe is not possible because it would violate the laws of thermodynamics. In an infinite universe, matter and energy would be evenly distributed, leading to a state of maximum entropy. However, we observe that the universe is not in this state, indicating a finite amount of matter and energy.

3. Can the universe be infinite but still have a finite observable size?

No, if the universe were infinite, then the observable size would also be infinite. This is because light, the fastest known speed, has only been able to travel a finite distance since the beginning of the universe. If the universe were infinite, light would have had an infinite amount of time to travel, making the entire universe observable.

4. Is the concept of an infinite universe purely theoretical?

Yes, the concept of an infinite universe is purely theoretical and has not been observed or proven. While some theoretical models suggest the possibility of an infinite universe, there is currently no evidence to support this idea.

5. How does the concept of a finite universe impact our understanding of the origin of the universe?

A finite universe implies that the universe had a beginning, known as the Big Bang. This has significant implications for our understanding of the origin of the universe and the laws of physics that govern it. It also raises questions about what existed before the Big Bang and the ultimate fate of the universe.

Similar threads

B Was the universe is infinitely large at the big bang?
    • Astronomy and Astrophysics
Replies
11
Views
2K
I Universe is older than we think
    • Astronomy and Astrophysics
Replies
3
Views
753
B How does the observable Universe have meaning?
    • Astronomy and Astrophysics
Replies
25
Views
3K
I Infinity vs Expansion: Is an Infinite Universe Compatible with Expansion?
    • Astronomy and Astrophysics
Replies
17
Views
2K
Universe has to have finite size - doesn't it?
    • Astronomy and Astrophysics
Replies
12
Views
2K
A Largest Galaxy In An Infinite Universe
    • Cosmology
Replies
12
Views
1K
B Acceleration of time due to entropy
    • Astronomy and Astrophysics
Replies
1
Views
1K
B The infinite and the infinitesimal
    • Cosmology
Replies
10
Views
2K
B Distance of Stars / Size of the Universe calculation
    • Astronomy and Astrophysics
Replies
6
Views
2K
B The Hubble deep field photos and the edge of the universe
    • Astronomy and Astrophysics
Replies
17
Views
2K

Hot Threads

Recent Insights

Back
Top