How do we know the universe is 13.8 billion years old?

The video explores the age of the universe, estimated at 13.8 billion years, and the methods used to determine this figure, such as observing the universe's expansion and redshift. It discusses assumptions in cosmology, the role of dark matter and dark energy, and the intriguing Methuselah star, which may challenge current estimates. The video concludes with thoughts on future research and technological advancements.

What are the assumptions made about the universe to determine its age?

What methods are used to measure the age of the universe?

How does the Methuselah star challenge the current understanding of the universe's age?