OSLO, Norway — Experts scoffed at Thor Heyerdahl when he set off to cross the Pacific aboard a balsa raft in 1947, but the Norwegian adventurer's success thrilled the world and made him a hero in his homeland.
Heyerdahl, who died Thursday night at age 87, sold millions of copies of his book about the journey, "Kon-Tiki," and became a household name with his voyages aimed at proving his theories about human migration.
Heyerdahl died in his sleep at his home in Colla Michari, Italy, said his son, Thor Heyerdahl Jr. He had stopped taking food, water or medication in early April after being diagnosed with a terminal brain tumor.
"Norway has lost an original and spectacular researcher, explorer and adventurer," Prime Minister Kjell Magne Bondevik said.
When Heyerdahl set off to cross the Pacific, experts warned his raft would sink within days. After 101 days and 4,900 miles, he proved them wrong by reaching Polynesia from Peru in a bid to prove his unconventional theories of human migration.
His later expeditions included voyages aboard the reed rafts Ra, Ra II and Tigris. His wide-ranging archaeological studies were often controversial and challenged accepted views.
Until his illness, Heyerdahl had maintained a daunting pace of research, lectures and public debate over his migration theories. His third wife, Jacqueline, said he made 70 airline trips last year.
He spent his final days surrounded by family at Colla Michari, a Roman-era Italian village he bought and restored in the 1950s. His permanent home since 1990 was on the Spanish island Tenerife in the Atlantic off Morocco.
Though he lived and worked abroad for decades, Heyerdahl was a national hero in his homeland, where one newspaper crowned him Norwegian of the Century in a millennium reader poll. He is survived by his third wife, four of his five children, eight grandchildren and six great-grandchildren.
After Heyerdahl's 1947 voyage, conventional anthropologists dismissed the college dropout's theories, saying they were only the work of a gifted amateur. But the adventurer gained worldwide fame with the voyage. His book about that trip sold tens of millions of copies, and his 1951 movie about the Kon-Tiki voyage won an Academy Award for best documentary.
He followed that trip with expeditions on reed rafts, seeking to show that ancient people could have sailed from the Old World to the New.
His later studies focused on ancient step pyramids — including those in Peru and on Tenerife — which he believed could be evidence of maritime links between ancient civilizations.
His Kon-Tiki trip was intended to support his theory that the South Sea Islands were settled by explorers from pre-Inca South America. The prevailing theory is that Polynesia was settled from Southeast Asia.
Heyerdahl conceived his theory during a year spent on the Pacific island of Fatu Hiva in the Marquesas group. He noticed that stone figures of the Polynesian chief-god Tiki in the jungle were "remarkably like the monoliths left by extinct civilizations in South America."
His colorfully written book about the voyage and about his theories was published in more than 60 countries and sold more than 25 million copies.
In the 1950s, he took more conventional expeditions to the Galapagos and to Easter Island. The latter trip produced "Aku-Aku," a 1957 book about the origins of the remote island's enormous stone heads.
In 1969, he attempted to sail from Morocco to Barbados aboard the Ra, a boat made of papyrus reeds like those in ancient Egyptian wall drawings. But he hadn't followed the drawings closely and the boat broke up.
A year later he tried again, aboard the Ra II, which was held together by ropes as shown in the wall drawings. This time he succeeded, making the 3,200-mile crossing in 55 days.
In 1977, he launched another reed boat, the Tigris, in an attempt to sail from the Persian Gulf to see how far ancient Mesopotamians might have been able to sail and spread their ancient culture.
The Tigris sailed 4,200 miles in 144 days, only to be blocked on its way to the Red Sea by warfare in the Horn of Africa. He and his 10 member crew set the Tigris on fire "to protest what was happening in this war-torn region."
Heyerdahl also worried about humanity's future because of the pollution of the ocean and atmosphere, urging stronger international control through the United Nations.
He continued to challenge assumptions, often bringing outrage. In 1995, he claimed to have found evidence that Christopher Columbus reached America in 1477, rather than 1492, as a teen-age crewman on a Danish-Portuguese expedition.
In 1999, he claimed that Norseman Leif Eriksson sailed to North America a millennium earlier as a Christian missionary rather than as a Viking explorer as is generally believed.
Heyerdahl was born Oct. 6, 1914, the son of a widely traveled banker and a mother with a scientific bent. He remembered her giving him anthropology books instead of children's books to read when he was sick in bed.
He entered the University of Oslo to study zoology but quit before getting a degree because he was impatient to start field work. He switched to anthropology while doing field work in the Marquesas in 1937.
On the Net:
Kon-Tiki Museum: http://www.kontiki.no