The observable universe, which is the region of space from which light has had time to reach us since the Big Bang, is about 93 billion light-years in diameter. This means the radius is roughly 46 billion light-years in every direction from Earth
. This size is much larger than the simple calculation of 13.8 billion years (the age of the universe) times the speed of light because the universe has been expanding since the Big Bang, stretching the distances between objects
. However, the entire universe is believed to be much larger than the observable part. Current scientific estimates suggest that the whole universe could be at least 250 times larger than the observable universe, potentially spanning around 7 trillion light-years or more, and it might even be infinite in size
. In summary:
- Observable universe diameter: ~93 billion light-years
- Observable universe radius: ~46 billion light-years
- Entire universe size: Unknown, but at least hundreds of times larger than observable, possibly infinite
This means what we can see is only a small fraction of the whole cosmos. The universe beyond the observable horizon remains beyond our current ability to detect or measure directly.
