When Countdown first aired on November 2nd, 1982, Channel 4 was born - created in response to Margaret Thatcher's bid to 'shake up television'. 40 years on and the station has certainly hit the brief.

The date was 2 November 1982. The time 4.45pm. As spiralling colourful fragments jumped into action to light up our screens, tumbling together to create a now iconic number four, a voice said ...