Scientists say they have extraordinary new evidence to support a Big Bang Theory for the origin of the Universe.

Researchers believe they have found the signal left in the sky by the super-rapid expansion of space that must have occurred just fractions of a second after everything came into being.

The BBC's Tom Feilden discusses the significance of this new evidence, before Professor Stephen Hawking speaks to BBC Radio 4's Today programme, placing the latest discovery in the context of his previous work.

Professor Neil Turok also speaks to presenter Sarah Montague about a long-standing bet he has held with Mr Hawking, and how this latest discovery affects this.

First broadcast on BBC Radio 4's Today programme on Tuesday 18 March.