Comment Math? (Score 5, Insightful) 202
"Our observable Universe is a pretty impressive entity: extending 46 billion light-years in all directions, filled with hundreds of billions of galaxies and having been around for nearly 14 billion years since the Big Bang."
The observable universe is observable because there has been time for the light to travel that far, which can not exceed the age of the universe. Therefor, if the universe is 14 billion years old, then the furthest we could see in any direction is only 14 billion light years, giving a maximum, diameter of 28 billion light years.
So why does the summary say it's 46 billion L.Y. across and only 14 billion Y. old?
The observable universe is observable because there has been time for the light to travel that far, which can not exceed the age of the universe. Therefor, if the universe is 14 billion years old, then the furthest we could see in any direction is only 14 billion light years, giving a maximum, diameter of 28 billion light years.
So why does the summary say it's 46 billion L.Y. across and only 14 billion Y. old?