Sir Roger Penrose has developed a new theory on what happened before the Big Bang.
Stephen Sackur talks to Sir Roger Penrose about his latest theory on what may have existed before the Big Bang.
The universe began with a big bang.
That's the most popular, though by no means the unanimous view of the world's leading physicists.
Sir Roger Penrose has devoted his life to the biggest questions; from the origins of the universe to human consciousness.
Stephen Sackur asks if his latest theory is perhaps a step too far?
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