The Paradox of an Infinite Universe
Kurzgesagt – In a Nutshell・9 minutes read
The universe, born 14 billion years ago, is expanding, and we observe only what light has reached in that time, with around 200 billion galaxies in our observable sphere. Scientists debate whether the universe is infinite or finite, with gravity potentially creating a hypersphere where space curves back on itself, but its true scale remains uncertain.
Insights
- The observable universe, a sphere with a radius of 45 billion light years, contains around 200 billion galaxies, but its actual scale may be much larger, with the possibility of being truly infinite.
- Scientists have not identified a definitive "universe horizon," leaving the true nature of the cosmos uncertain, leading to questions about its eternal nature and the potential for infinite repetition, despite being considered finite for practical purposes within the observable universe.
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Recent questions
How old is the universe?
14 billion years
What is the observable universe?
A sphere with a radius of 45 billion light years
Is the universe infinite?
Uncertain, possibly infinite
What is the scale of the cosmic sphere?
Potentially much larger than observable
How is the universe considered for practical purposes?
Finite with an edge in time within the observable universe
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Summary
00:00
"Expanding Universe: Infinite or Finite?"
- The universe began 14 billion years ago and has been expanding ever since.
- Due to the speed of light, we can only see parts of the universe that light has reached in the last 14 billion years.
- The observable universe is a sphere with a radius of 45 billion light years, containing around 200 billion galaxies.
- The universe may be either truly infinite or finite, with the possibility of a hypersphere or hyperdonut shape.
- Gravity bends spacetime, potentially creating a hypersphere universe where space curves back on itself.
- Scientists have not found a "universe horizon" to determine the scale of the cosmic sphere, suggesting it may be much larger than observable.
- An infinite universe is described by most scientists, leading to questions about its eternal nature and the possibility of infinite repetition.
- While the universe's true nature remains uncertain, for practical purposes, it is considered finite with an edge in time within the observable universe.
