46. Clay Shirky, Internet evangelist selected Amira al Hussaini, Journalist and blogger

Amira co-invented the curated, personal news feed ‘@JustAmira’ as a journalistic form. She exhibited skepticism that the Arab Spring would come to her native Bahrain, but as the Al Khalifas' reactions to the uprisings in Tunisia and Egypt became harsher, she questioned their motives and suggested that they should not be afraid of sharing political power with their people.

47. Iain Sinclair, Writer selected Don DeLillo, Writer

"It takes time to lose interest in things," DeLillo wrote. Historic time leaves you in difficult places- borders, transits, waiting rooms, deserts, runways, oceans, cities.

48. Juliana Rotich, Programme director, Ushahidi.com selected Deborah Estrin, Computer scientist

Deborah is innovating the development of embedded networks by laying the foundations for the internet of things, participatory sensing and the future of smart cities at the UCLA.

49. James Dyson, Inventor and entrepreneur selected Aidan Dwyer, Scientist

Aidan Dwyer, 13, became inquisitive about why the tree tops tangle in a seemingly random way. His studies revealed that trees grow their branches in a pattern dictated by the Fibonacci sequence of 1+1=2, 1+2=3, 2+3=5 and so on. He noticed that function guides form even in nature. Aidan further challenged the boundaries of his learning. He took his scientific knowledge of photosynthesis and applied it to the problem of solar-energy collection. He then built his own tree-inspired model of solar panels and tested it in his back garden.

50. Peter Diamandis, Chairman, X Prize Foundation selected Jeff Bezos, CEO, Amazon

“I first met Jeff in the early 80s when he was at Princeton. He has an underlying passion: opening up the space frontier. He's also one of the few individuals with sufficient wealth to actually pull it off...” said Peter.