Background: 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.
Context: 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.
Question: when did he write his book?
Answer:

Problem: Background: Slotin was the first of three children born to Israel and Sonia Slotin, Yiddish-speaking refugees who had fled the pogroms of Russia to Winnipeg, Manitoba. He grew up in the North End neighborhood of Winnipeg, an area with a large concentration of Eastern European immigrants. From his early days at Machray Elementary School through his teenage years at St. John's High School, Slotin was academically exceptional. His younger brother, Sam, later remarked that his brother "had an extreme intensity that enabled him to study long hours."
Context: The radiation doses received in these two accidents are not known with any semblance of accuracy. A large part of the dose was due to neutron radiation, which could not be measured by dosimetry equipment of the day. The available equipment, film badges, were not worn by personnel during the accident, and badges that were supposed to be planted under tables in case of disasters like these were not found. Disaster badges hung on the walls did provide some useful data about gamma radiation. A "tentative" estimate of the doses involved was made in 1948, based on dozens of assumptions, some of which are now known to be grossly incorrect. In the absence of personal dosimetry badges, the study authors relied on measurements of sodium activation in the victims' blood and urine samples as their primary source of data. This activation would have been caused by neutron radiation, but they converted all doses to equivalent doses of gamma or X-ray radiation. They concluded that Daghlian and Slotin had probably received doses equivalent to 290 and 880 rem (respectively) of gamma rays. Minimum and maximum estimates varied from about 50% to 200% of these values. The authors also calculated doses equivalent to a mix of soft 80 keV X-rays and gamma rays, which they believed gave a more realistic picture of the exposure than the gamma equivalent. In this model the equivalent X-ray doses were much higher, but would be concentrated in the tissues facing the source, whereas the gamma component penetrated the whole body. Slotin's equivalent dose was estimated to be 1930 R (roentgen) of X-ray with 114 R of gamma, while Daghlian's equivalent dose was estimated to be 480 R of X-ray with 110 R of gamma. Five hundred rem is usually a fatal dose for humans. In modern times dosimetry is done very differently. Equivalent doses would not be reported in roentgen; they would be calculated with different weighting factors, and they are not considered as relevant to acute radiation syndrome as absorbed doses. Recent documents have made various interpretations of Slotin's dose, ranging from 287 rad to 21 sievert. Based on citations and supporting reasoning, the most reliable estimate may be a 1978 Los Alamos memo which suggested 10 Gy(n) + 1.14 Gy(g) for Slotin and 2 Gy(n) + 1.1 Gy(g) for Daghlian. These doses are consistent with the symptoms they experienced.
Question: Anything else pertinent to the dosage?
Answer:
A "tentative" estimate of the doses involved was made in 1948, based on dozens of assumptions, some of which are now known to be grossly incorrect.