Knut Haugland Heyerdahl in 1944 at a paramilitary training camp in England. It was here that Haugland first heard of Heyerdahl's theories about Polynesian migration patterns, and his plans to cross the Pacific on a balsa wood raft. In 1947 Haugland was invited by Heyerdahl to join the Kon-Tiki expedition as a radio operator. On the expedition Haugland and Torstein Raaby (another former resistance member) were in frequent radio contact with American amateur operators, sending meteorological and hydrographic data to be passed on to the Meteorological Institute in Washington, DC. Despite the tiny radio which had an output of only 6 watts,
Thor Heyerdahl also criticised Heyerdahl's theory in his 2009 book "The Wayfinders", which explores the history of Polynesia. Davis says that Heyerdahl "ignored the overwhelming body of linguistic, ethnographic, and ethnobotanical evidence, augmented today by genetic and archaeological data, indicating that he was patently wrong." A 2009 study by Norwegian researcher Erik Thorsby suggested that there was some merit to Heyerdahl's ideas and that, while Polynesia was colonized from Asia, some contact with South America also existed. Some critics suggest, however, that Thorsby's research is inconclusive because his data may have been influenced by recent population contact. However, more recent work indicates