Answer the question at the end by quoting:

John Griffith "Jack" London (born John Griffith Chaney; January 12, 1876 - November 22, 1916) was an American novelist, journalist, and social activist. A pioneer in the world of commercial magazine fiction, he was one of the first writers to become a worldwide celebrity and earn a large fortune from writing. He was also an innovator in the genre that would later become known as science fiction.
London was vulnerable to accusations of plagiarism, both because he was such a conspicuous, prolific, and successful writer and because of his methods of working. He wrote in a letter to Elwyn Hoffman, "expression, you see--with me--is far easier than invention." He purchased plots and novels from the young Sinclair Lewis and used incidents from newspaper clippings as writing material.  In July 1901, two pieces of fiction appeared within the same month: London's "Moon-Face", in the San Francisco Argonaut, and Frank Norris' "The Passing of Cock-eye Blacklock", in Century Magazine. Newspapers showed the similarities between the stories, which London said were "quite different in manner of treatment, [but] patently the same in foundation and motive." London explained both writers based their stories on the same newspaper account. A year later, it was discovered that Charles Forrest McLean had published a fictional story also based on the same incident.  Egerton Ryerson Young claimed The Call of the Wild (1903) was taken from Young's book My Dogs in the Northland (1902). London acknowledged using it as a source and claimed to have written a letter to Young thanking him.  In 1906, the New York World published "deadly parallel" columns showing eighteen passages from London's short story "Love of Life" side by side with similar passages from a nonfiction article by Augustus Biddle and J. K Macdonald, titled "Lost in the Land of the Midnight Sun".  London noted the World did not accuse him of "plagiarism", but only of "identity of time and situation", to which he defiantly "pled guilty".  The most serious charge of plagiarism was based on London's "The Bishop's Vision", Chapter 7 of his novel The Iron Heel (1908). The chapter is nearly identical to an ironic essay that Frank Harris published in 1901, titled "The Bishop of London and Public Morality". Harris was incensed and suggested he should receive 1/60th of the royalties from The Iron Heel, the disputed material constituting about that fraction of the whole novel. London insisted he had clipped a reprint of the article, which had appeared in an American newspaper, and believed it to be a genuine speech delivered by the Bishop of London.

What resulted from this?

London noted the World did not accuse him of "plagiarism", but only of "identity of time and situation", to which he defiantly "pled guilty".



Answer the question at the end by quoting:

Thor Heyerdahl (Norwegian pronunciation: [tu:r 'haei@da:l]; October 6, 1914 - April 18, 2002) was a Norwegian adventurer and ethnographer with a background in 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 hand-built raft from South America to the Tuamotu Islands. The expedition was designed to demonstrate that ancient people could have made long sea voyages, creating contacts between separate cultures. This was linked to a diffusionist model of cultural development.
In 1947, Heyerdahl and five fellow adventurers sailed from Peru to the Tuamotu Islands, French Polynesia in a pae-pae raft that they had constructed from balsa wood and other native materials, christened the Kon-Tiki. The Kon-Tiki expedition was inspired by old reports and drawings made by the Spanish Conquistadors of Inca rafts, and by native legends and archaeological evidence suggesting contact between South America and Polynesia. The Kon-Tiki smashed into the reef at Raroia in the Tuamotus on August 7, 1947, after a 101-day, 4,300-nautical-mile (5,000-mile or 8,000 km) journey across the Pacific Ocean. Heyerdahl had nearly drowned at least twice in childhood and did not take easily to water; he said later that there were times in each of his raft voyages when he feared for his life.  Kon-Tiki demonstrated that it was possible for a primitive raft to sail the Pacific with relative ease and safety, especially to the west (with the trade winds). The raft proved to be highly manoeuvrable, and fish congregated between the nine balsa logs in such numbers that ancient sailors could have possibly relied on fish for hydration in the absence of other sources of fresh water. Other rafts have repeated the voyage, inspired by Kon-Tiki. Heyerdahl's book about The Kon-Tiki Expedition: By Raft Across the South Seas has been translated into 70 languages. The documentary film of the expedition entitled Kon-Tiki won an Academy Award in 1951. A dramatised version was released in 2012, also called Kon-Tiki, and was nominated for both the Best Foreign Language Oscar at the 85th Academy Awards and a Golden Globe Award for Best Foreign Language Film at the 70th Golden Globe Awards. It was the first time that a Norwegian film was nominated for both an Oscar and a Golden Globe.  Anthropologists continue to believe that Polynesia was settled from west to east, based on linguistic, physical, and genetic evidence, migration having begun from the Asian mainland. There are controversial indications, though, of some sort of South American/Polynesian contact, most notably in the fact that the South American sweet potato is served as a dietary staple throughout much of Polynesia. Blood samples taken in 1971 and 2008 from Easter Islanders without any European or other external descent were analysed in a 2011 study, which concluded that the evidence supported some aspects of Heyerdahl's hypothesis. This result has been questioned because of the possibility of contamination by South Americans after European contact with the islands. However, more recent DNA work (after Heyerdahl's death) contradicts the post-European-contact contamination hypothesis, finding the South American DNA sequences to be far older than that. Heyerdahl had attempted to counter the linguistic argument with the analogy that he would prefer to believe that African-Americans came from Africa, judging from their skin colour, and not from England, judging from their speech.

What did he struggle with
Heyerdahl had nearly drowned at least twice in childhood and did not take easily to water;