Thor Heyerdahl (October 6, 1914 – April 18, 2002) was a Norwegian ethnographer and adventurer with a background in biology, zoology, botany and geography. He became notable for his Kon-Tiki expedition in 1947, in which he sailed 8,000 km (5,000 mi) across the Pacific Ocean in a self-built raft from South Americato the Tuamotu Islands. The expedition was designed to demonstrate that ancient people could have made long sea voyages, creating contacts between apparently separate cultures. This was linked to a diffusionist model of cultural development. Heyerdahl subsequently made other voyages designed to demonstrate the possibility of contact between widely separated ancient peoples. He was appointed a government scholar in 1984.