Scientists know that the universe is about 13.8 billion years old. But how do they know this?
Scientists use telescopes that allow them to look into space at different distances and therefore different points of time in cosmic history. There are several factors scientists consider at when determining the age of the universe:
- Background radiation left over from the big bang
- The age of stars
- The expansion rate of the universe
- The age of elements and planets
Listen to Dr. Jennifer Wiseman discuss how we know the age of this short video.
