Brian explores a simple question that is causing a big stir today: what is time? Modern science shows it to be far stranger than we think. He recalls some highlights from his TV series that touch upon different aspects of this physics conundrum: from a mindboggling encounter with Doctor Who, to breaking the sound barrier in a Eurofighter in order to see two sunsets in one day, to witnessing one of the oldest animal life cycles on earth on a remote beach in Costa Rica. He also explores Chankillo, the oldest and best-preserved astronomical observatory in the Americas.
Source: BBC 2