In his theories of special and general relativity in the early 20th century, Albert Einstein fundamentally changed how science views time and space. Marina Cortês, cosmologist from the Royal Observatory, Edinburgh, explains the concept of a block universe, the arguments for and against this theory, and alternative explanations where time is fundamental.

You can also watch this interview as a series of shorter clips:

• What is a block universe?
• Why do physicists say time is symmetric?
• Why do we feel time moves forward in a block universe?
• How unlikely was the big bang?
• Why don't you agree with the block universe?
• What are the alternatives to the block universe?

You can read more in our package of articles Stuff Happens: Time in a Block Universe.