"Horizon" is the BBC's long-running documentary series that explores topical scientific issues and their potential impact on the future. The first episode, broadcast on May 2, 1964, explored the theories and structures of entrepreneur Buckminster Fuller, who made a fortune from patenting domes. Audience figures for the 1965/66 series were between 50,000 and 150,000 when BBC Two's transmission coverage was still limited. An average of just under two million watched the programme during the 1970s, although viewing figures fluctuated between 400,000 and five million. Ratings rose to more than two million during the 1980s and the show now regular attracts audiences of around three million. The most-watched episode was Inside the Shark which transmitted on March 1, 1976. As a result of 1972 film Whales, Dolphins and Men, pet food companies stopped using whale meat in their products and within a year the government banned all imports of whale meat. The 1975 film A Time to Be Born led to an official investigation into the widespread use of induced births and Life Story in 1988 won a Bafta for best drama. Horizon broadcast the first TV documentary ever about Aids in 1983. Horizon's original mission statement was to provide a platform for some of the world's leading scientists and philosophers to communicate their curiosity, observations and reflections. More than 1,000 editions had been made by the time of its 40th birthday in 2004. New episodes are still being broadcast on BBC Two and old episodes are shown on Eden.