Five great inventions that changed the world

Max Pearson presents a selection of this week’s Witness History stories.In 1999, Aibo: the world's first robot dog, hit the shops in Japan and sold out in just 20 minutes. We hear from Toshitada Doi who spent six years on the project when he worked at Sony. Plus we hear from Dr Ella Haig about the development of artificial intelligence.Japanese software developer Shigetaka Kurita created the first emoji in 1999. Valerie Hunter Gordon, from England, invented disposable nappies in 1947 after the birth of her third child. We hear from Valerie’s son, Nigel Hunter Gordon. Hungarian journalist László Bíró was sick of smudging the ink from his fountain pen and so he invented the ballpoint pen in 1938.Finally, a Hungarian architect Ernő Rubik invented what's known as the Rubik's Cube.Contributors:Toshitada Doi on developing Aibo: The world's first robot dog Dr Ella Haig, Reader in Artificial Intelligence, in the School of Computing at the University of Portsmouth in the UK Japanese software developer Shigetaka Kurita, who created the first emoji Nigel Hunter Gordon, the son of Valerie Hunter Gordon, on disposable nappies Hungarian journalist László Bíró, the inventor of the ballpoint pen Hungarian architect Ernő Rubik, the inventor of the Rubik's Cube(Photo: The original Aibo. Credit: Jun Sato/WireImage via Getty Images)