BBC Four HD Wednesday

Biologist Ben Garrod explores the complex ways, from camouflage to deadly toxins, in which the skin helps animals defend themselves against threats of all kinds

Derek Brockway presents the second of two Dylan Thomas specials, walking to New Quay and Laugharne, both of which were important to the poet

Astrophysicists and engineers use new technologies to try and investigate the mystery of strange flying objects in the sky

Architect Norman Foster takes a look at the jumbo jet. First broadcast September 9, 1991

Dallas Campbell, Professor Danielle George and Dr Hugh Hunt mark 80 years since Britain's first TV broadcast by recreating the landmark event using authentic cameras and equipment

Jack Rosenthal's 1986 drama based on the BBC's first 'high-definition' television broadcast at London's Alexandra Palace on November 2, 1936. Starring Shaughan Seymour

A look at how television came to Alexandra Palace, with an insight into production routine. First broadcast November 2, 1936

The story of the inventor and electrical engineer, who was the first person to give a successful public demonstration of television

Leslie Mitchell traces the origins of television from the beginning of the 20th century to the first outside broadcast - the coronation of George VI in May 1937

Biologist Ben Garrod explores the complex ways, from camouflage to deadly toxins, in which the skin helps animals defend themselves against threats of all kinds

Derek Brockway presents the second of two Dylan Thomas specials, walking to New Quay and Laugharne, both of which were important to the poet