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Felix Dzerzhinsky

Felix Edmundovich Dzerzhinsky (Феликс Эдмундович Дзержинский; Feliks Edmundowicz Dzierżyński ; 11 September 1877 – 20 July 1926), nicknamed "Iron Felix", was a Soviet revolutionary and politician of Polish origin. From 1917 until his death in 1926, he led the first two Soviet secret police organizations, the Cheka and the OGPU, establishing state security organs for the Bolshevik regime. He was a key architect of the Red Terror and de-Cossackization.

Born to a Polish family of noble descent in the Minsk Governorate of the Russian Empire (now in Belarus), Dzerzhinsky embraced revolutionary politics from a young age, and was active in the Social Democracy of the Kingdom of Poland and Lithuania party. Active in Kaunas and Warsaw, he was frequently arrested and underwent several exiles to Siberia, from which he escaped every time. He evaded the tsarist secret police, the Okhrana, whose work he took interest in. Dzerzhinsky participated in the failed 1905 Revolution, and after a final arrest in 1912, was imprisoned until the February Revolution of 1917. He then joined Vladimir Lenin's Bolshevik party, and played an active role in the October Revolution which brought them to power.

In December 1917, Lenin named Dzerzhinsky head of the newly established All-Russian Extraordinary Commission (Cheka), tasking him with the suppression of counter-revolutionary activities in Soviet Russia. The Russian Civil War saw a vast expansion of the Cheka's authority, inaugurating a campaign of mass arrests, detentions (including in newly founded Gulag forced labour camps), and executions known as the Red Terror. An estimated 50,000 to 200,000 people were executed by the Cheka during the years of the civil war. The agency was reorganized as the State Political Directorate (GPU) in 1922, and then as the Joint State Political Directorate (OGPU) a year later, with Dzerzhinsky remaining as head of the powerful organization. He served as director of the Supreme Soviet of the National Economy (VSNKh) from 1924.

Dzerzhinsky died of a heart attack in 1926, and was buried in the Kremlin Wall Necropolis. Remembered by secret police agents (known as "Chekists" throughout the Soviet era) as a hero of the revolution, a large statue of him stood in front of the security service headquarters at Moscow's Lubyanka Building until 1991. Meanwhile, he also became a prominent symbol of repression and brutality to critics of the Soviet regime.

Early life
Felix Dzerzhinsky was born on 11 September 1877 to ethnically Polish parents of noble descent, at the Dzerzhinovo family estate, about 15 km from the small town of Ivyanets in the Minsk Governorate of the Russian Empire (now Belarus). In the Russian Empire, his family was of a type known as "column-listed nobility" (столбовое дворянство, stolbovoe dvorianstvo), whose nobility was formally acknowledged, but so old that they did not enjoy the privileges of the new nobility. His sister Wanda died at the age of 12, when she was accidentally shot with a hunting rifle on the family estate by one of her brothers. At the time of the incident, there were conflicting claims as to whether Felix or his brother Stanisław was responsible for the accident.

His father, Edmund-Rufin Dzierżyński graduated from the Saint Petersburg Imperial University in 1863 and moved to Vilnius, where he worked as a home teacher for a professor of Saint Petersburg University named Januszewski and eventually married Januszewski's daughter Helena Ignatievna, who also was of Polish origin. In 1868, after a short period in Kherson gymnasium, he worked as a gymnasium teacher of physics and mathematics at the schools of Taganrog in the Don Host Province, Russia, particularly the Chekhov Gymnasium. In 1875, Edmund Dzierżyński retired due to health conditions and moved with his family to his estate near Ivyanets and Rakaŭ. In 1882, Felix's father died from tuberculosis.

As a youngster Dzerzhinsky became a polyglot, speaking Polish, Russian, German and Latin. He attended the Vilnius Gymnasium from 1887 to 1895. One of the older students at this gymnasium was his future arch-enemy, Józef Piłsudski. Years later, as Marshal of Poland, Piłsudski recalled that Dzerzhinsky "distinguished himself as a student with delicacy and modesty. He was rather tall, thin and demure, making the impression of an ascetic with the face of an icon... Tormented or not, this is an issue history will clarify; in any case this person did not know how to lie." School documents show that Dzerzhinsky attended his first year in school twice, while he was not able to finish his eighth year. Dzerzhinsky received a school diploma which stated: "Dzerzhinsky Feliks, who is 18 years of age, of Catholic faith, along with a satisfactory attention and satisfactory diligence showed the following successes in sciences, namely: Divine law—"good"; Logic, Latin, Algebra, Geometry, Mathematical geography, Physics, History (of Russia), French—"satisfactory"; Russian and Greek—"unsatisfactory".

Political affiliations and arrests
Two months before he expected to graduate, the gymnasium expelled Dzerzhinsky for "revolutionary activity" and for posting signs with socialist slogans at the school. He had joined a Marxist group, the Union of Workers (Socjaldemokracja Królestwa Polskiego "SDKP"), in 1895. In late April 1896, he was one of 15 delegates at the first congress of the Lithuanian Social Democratic Party (LSDP). In 1897, he attended the second congress of the LSDP, where it rejected independence in favor of national autonomy. On 18 March 1897, he was sent to Kaunas to take advantage of the arrest of the Polish Socialist Party (PPS) branch. He worked in a book-binding factory and set up an illegal press. As an organizer of a shoemakers' strike, Dzerzhinsky was arrested for "criminal agitation among the Kaunas workers"; the police files from this time state: "Felix Dzerzhinsky, considering his views, convictions and personal character, will be very dangerous in the future, capable of any crime." Dzerzhinsky envisioned merging the LSDP with the Russian Social Democratic Labour Party (RSDLP) and took the same position as influential Social Democrat Rosa Luxemburg on what was referred to in contemporary writings as "The National Question," i.e., the right of nations to self determination.

He was arrested on a denunciation for his revolutionary activities for the first time in 1897, after which he served almost a year in the Kaunas prison. In 1898, Dzerzhinsky was exiled for three years to the Vyatka Governorate (city of Nolinsk) where he worked at a local tobacco factory. There Dzerzhinsky was arrested for agitating for revolutionary activities and was sent 500 verst north to the village of Kaigorod. In August 1899, he returned to Vilnius. Dzerzhinsky subsequently became one of the founders of Social Democracy of the Kingdom of Poland and Lithuania (Socjaldemokracja Królestwa Polskiego i Litwy, SDKPiL) in 1899. In February 1900, he was arrested again and served his time at first in the Alexander Citadel in Warsaw and later at the Siedlce prison. In 1902, Dzerzhinsky was sent deep into Siberia for the next five years to the remote town of Vilyuysk, while en route being temporarily held at the Alexandrovsk Transitional Prison near Irkutsk. While in exile, he escaped on a boat and later emigrated from the country. He traveled to Berlin, where at the SDKPiL conference Dzerzhinsky was elected a secretary of its party committee abroad (Komitet Zagraniczny, KZ) and met with several prominent leaders of the Polish Social Democratic movement, including Rosa Luxemburg and Leo Jogiches. They gained control of the party organization through the creation of a committee called the Komitet Zagraniczny (KZ), which dealt with the party's foreign relations. As secretary of the KZ, Dzerzhinsky was able to dominate the SDKPiL. In Berlin, he organized publication of the newspaper Czerwony Sztandar ("Red Banner"), and transportation of illegal literature from Kraków into Congress Poland. Being a delegate to the IV Congress of SDKPiL in 1903, Dzerzhinsky was elected as a member of its General Board.

Dzerzhinsky visited Switzerland, where his fiancée Julia Goldman, the sister of Boris Gorev, was undergoing treatment for tuberculosis. She died in his arms on 4 June 1904. Her illness and death depressed him – in letters to his sister, Dzerzhinsky explained that he no longer saw any meaning for his life. That changed with the Russian Revolution of 1905, as Dzerzhinsky became involved with work again. After the revolution failed he was again jailed in July 1905, this time by the Okhrana. In October, he was released on amnesty. As a delegate to the 4th Congress of the Russian Social Democratic Labour Party in Stockholm, Dzerzhinsky entered the central body of the party. From July through September 1906, he lived in Saint Petersburg and then returned to Warsaw, where he was arrested again in December of the same year. In June 1907, Dzerzhinsky was released on bail. At the 5th Congress of the Russian Social Democratic Labour Party in London in May–June 1907, he was elected in absentia as a member of the Central Committee of the Russian Social-Democratic Labor Party. In April 1908, Dzerzhinsky was arrested once again in Warsaw and again exiled to Siberia (Yeniseysk Governorate) in 1909. As before, Dzerzhinsky managed to escape (by November 1909). In 1910, he reached Italy, where he met Maxim Gorky on Capri; he then returned to Poland.

Back in Kraków in 1910, Dzerzhinsky married RSDLP party member Zofia Muszkat, who was already pregnant. A month later she was arrested; she gave birth to their son Janek in Pawiak prison. In 1911, Zofia was sentenced to permanent Siberian exile, and she left the child with her father. Dzerzhinsky saw his son for the first time in March 1912 in Warsaw. In attending the welfare of his child, Dzerzhinsky repeatedly exposed himself to the danger of arrest. On one occasion, Dzerzhinsky narrowly escaped an ambush that the police had prepared at the apartment of his father-in-law.

Dzerzhinsky continued to direct the Social Democratic Party (SDKPiL), while considering his continued freedom "only a game of the Okhrana". The Okhrana, however, was not playing a game; Dzerzhinsky simply was a master of conspiratorial techniques and was therefore extremely difficult to find. A police file from this time says: "Dzerzhinsky continued to lead the Social Democratic party and at the same time he directed party work in Warsaw, led strikes, published appeals to workers, and traveled on party matters to Łódź and Kraków." The police were unable to arrest Dzerzhinsky until the end of 1912, when they found the apartment where he lived in the name of Władysław Ptasiński.

Revolution
Dzerzhinsky spent the next $4 1/2$ years in prisons, first at the notorious Tenth Pavilion of the Warsaw Citadel. When World War I began in 1914, all political prisoners were relocated from Warsaw into Russia proper. Dzerzhinsky was taken to Oryol Prison. He was very concerned about the fate of his wife and son, with whom he did not have any communication. Moreover, the Russian guards administered Dzerzhinsky frequent beatings, which caused permanent disfigurement of his jaw and mouth. In 1916, Dzerzhinsky was transferred to the Moscow Butyrka prison, where he was soon hospitalized because the chains that he had been forced to wear were causing severe cramps in his legs. Despite the prospects of amputation, Dzerzhinsky recovered and was put to work sewing military uniforms.

Dzerzhinsky was freed from Butyrka after the February Revolution of 1917. Soon after his release, Dzerzhinsky's goal was to organize Polish refugees in Russia, then return to Poland and fight for the revolution there. He wrote to his wife, "Together with these masses, we will return to Poland after the war and become one whole with the SDKPiL." He remained in Moscow where he joined the Bolshevik party, writing to his comrades that "the Bolshevik party organization is the only Social Democratic organization of the proletariat, and if we were to stay outside of it, then we would find ourselves outside the proletarian revolutionary struggle." By April, he had entered the Moscow Committee of the Bolsheviks and soon thereafter was elected to the executive committee of the Moscow Soviet. Dzerzhinsky endorsed Vladimir Lenin's "April Theses", demanding uncompromising opposition to the new Russian Provisional Government, the transfer of all political authority to the Soviets, and the immediate withdrawal of Russia from the war. Dzerzhinsky's brother Stanisław was murdered on the Dzerzhinsky estate by deserting Russian soldiers that same year.

Subsequently, in late July, Dzerzhinsky was subsequently elected to the Bolshevik Central Committee at the Sixth Party Congress. He then relocated from Moscow to Petrograd to begin his new responsibilities. In Petrograd, Dzerzhinsky participated in the crucial session of the Central Committee in October, and he strongly endorsed Lenin's demands for the immediate preparation of a coup, after which Felix Dzerzhinsky had an active role with the Military Revolutionary Committee during the October Revolution. With the seizure of power by the Bolsheviks, Dzerzhinsky eagerly assumed responsibility for making security arrangements at the Smolny Institute where the Bolsheviks had their headquarters.

Director of Cheka
Lenin regarded Felix Dzerzhinsky as a revolutionary hero and appointed him to organize a force to combat internal threats. On 20 December 1917, the Council of People's Commissars officially established the All-Russia Extraordinary Commission to Combat Counter-revolution and Sabotage—commonly known as the Cheka (based on the Russian acronym ВЧК). Dzerzhinsky became its director. The Cheka received extensive resources, and became known for ruthlessly pursuing any perceived counterrevolutionary elements. As the Russian Civil War expanded, Dzerzhinsky also began organizing internal security troops to enforce the Cheka's authority.

The Cheka became notorious for mass summary executions, performed especially during the Red Terror and the Russian Civil War. The Cheka undertook drastic measures as tens of thousands of political opponents and saboteurs were shot without trial in the basements of prisons and in public places. Dzerzhinsky said: "We represent in ourselves organized terror—this must be said very clearly". In 1922, at the end of the Civil War, the Cheka was dissolved and reorganized as the State Political Directorate (Gosudarstvennoe Politicheskoe Upravlenie, or GPU), a section of the NKVD. With the formation of the Soviet Union later that year, the GPU was again reorganized as the Joint State Political Directorate (Obyedinyonnoye gosudarstvennoye politicheskoye upravleniye, or OGPU), directly under the Council of People's Commissars. These changes did not diminish Dzerzhinsky's power; he was Minister of the Interior, director of the Cheka/GPU/OGPU, Minister for Communications, and director of the Vesenkha (Supreme Council of National Economy) in 1921–24. Indeed, while the (O)GPU was theoretically supposed to act with more restraint than the Cheka, in time its de facto powers grew even greater than those of the Cheka.

At his office in Lubyanka, Dzerzhinsky kept a portrait of fellow Polish revolutionary Rosa Luxemburg on the wall. Besides his leadership of the secret police, Dzerzhinsky also took on a number of other roles; he led the fight against typhus in 1918, was chair of the Commissariat for Internal Affairs from 1919 to 1923, initiated a vast orphanage construction program, chaired the Transport Commissariat, organized the embalming of Lenin's body in 1924 and chaired the Society of Friends of Soviet Cinema.

Dzerzhinsky and Lenin

Dzerzhinsky became a Bolshevik as late as 1917. Therefore, it was wrong to assert (as official Soviet historians did subsequently) that Dzerzhinsky had been one of Lenin's oldest and most reliable comrades, or that Lenin had exercised some sort of spellbinding influence on Dzerzhinsky and the SDKPiL. Lenin and Dzerzhinsky frequently had opposing opinions about many important ideological and political issues of the pre-revolutionary period, and also after the October Revolution. After 1917, Dzerzhinsky would oppose Lenin on such crucial issues as the Treaty of Brest-Litovsk, the trade unions, and Soviet nationality policy. During the April 1917 Party Conference, when Lenin accused Dzerzhinsky of Great-Russian chauvinism, he replied: "I can reproach him (Lenin) with standing at the point of view of the Polish, Ukrainian and other chauvinists."

From 1917 to his death in 1926, Dzerzhinsky was first and foremost a Russian Communist, and Dzerzhinsky's involvement in the affairs of the Polish Communist Party (which was founded in 1918) was minimal. The energy and dedication that had previously been responsible for the building of the SDKPiL would henceforth be devoted to the priorities of the struggle for Bolshevik power in Russia, to the defence of the revolution during the civil war, and eventually, to the tasks of socialist construction.

Death and legacy

Dzerzhinsky died of a heart attack on 20 July 1926 in Moscow, immediately after a two-hour speech to the Bolshevik Central Committee during which, visibly quite ill, he violently denounced the United Opposition directed by Leon Trotsky, Grigory Zinoviev and Lev Kamenev. Upon hearing of his death, Joseph Stalin eulogized Dzerzhinsky as "a devout knight of the proletariat". Dzerzhinsky was buried in the Kremlin Wall Necropolis. Today his grave is one of the twelve individual tombs located between the Lenin Mausoleum and the Kremlin Wall.

Dzerzhinsky was succeeded as chairman of the OGPU by Vyacheslav Menzhinsky.

Dzierżyńszczyzna, one of the two Polish Autonomous Districts in the Soviet Union, was named to commemorate Dzerzhinsky. Located in Belarus, near Minsk and close to the Soviet-Polish border of the time, it was created on 15 March 1932, with the capital at Dzyarzhynsk (in Russian Dzerzhynsk, formerly known as Kojdanów), not far from the family estate. The Dzerzhinsky estate itself remained inside Poland from 1921 to the Soviet invasion of Poland in 1939. The district was disbanded in 1935 at the onset of the Great Purge, and most of its administration was executed.

Dzyarzhynskaya Hara (the highest point in Belarus), located near Dzyarzhynsk was named after Dzerzhinsky in 1958.

His name and image were used widely throughout the KGB and the Soviet Union and other communist countries; there were numerous places named after him. In Russia, there is the city of Dzerzhinsk, a village of Dzerzhinsk, and three other cities called Dzerzhinskiy; in other former Soviet republics, there was a city named for him in Armenia and the aforementioned Dzyarzhynsk in Belarus. To comply with decommunization laws, the Ukrainian cities Dzerzhynsk and Dniprodzerzhynsk reverted to their historic names Toretsk and Kamianske in February and May 2016. A Ukrainian village in the Zhytomyr Oblast was also named Dzerzhinsk until 2005, when it was renamed to Romaniv. The Dzerzhinskiy Tractor Works in Stalingrad were named in his honor and became a scene of bitter fighting during the Second World War. The FED camera, produced from 1934 to around 1996, is named for him, as was the FD class steam locomotive.

During the Communist era (1945–1989) in Poland, Dzerzhinsky was celebrated as a socialist hero. In 1951, a large-scale statue of Dzerzhinsky was designed by Zbigniew Dunajewski and erected in the northern side of Bank Square in Warsaw. The square bore Dzerzhinsky's name (Plac Dzierżyńskiego) until 1989. The statue was toppled on 16 November 1989, one of the many Soviet-era symbols removed that year to mark the end of Communism in Poland. The square was subsequently renamed Plac Bankowy (Bank Square).

Iron Felix

A 15-ton iron monument of Dzerzhinsky, which once dominated the Lubyanka Square in Moscow, near the KGB headquarters, also became known as "Iron Felix" (Железный Феликс – Zheleznyj Feliks). Sculpted in 1958 by Yevgeny Vuchetich, it served as a Moscow landmark during late Soviet times. Symbolically, the Memorial society erected the Solovetsky Stone, a memorial to the victims of the Gulag (using a simple stone from the Solovki prison camp in the White Sea) beside the Iron Felix statue on 30 October 1990). The Moscow Soviet (Mossovet) had the Dzerzhinsky statue removed to the Fallen Monument Park and laid on its side in August 1991, after the failed coup d'état attempt by hard-line Communist members of the government. A mock-up of the removal of Dzerzhinsky's statue can be found in the entrance hall of the International Spy Museum in Washington, D.C.

The figure of Dzerzhinsky remains controversial in Russian society. Between 1999 and 2013, six proposals called for the return of the statue to its plinth. The Monument Art Commission of the Moscow City Duma rejected the proposals due to concerns that the proposed return would cause "unnecessary tension" in society. According to a December 2013 VTsIOM poll, 46% of Russians favour the restoration of the statue to the Lubyanka Square, with 17% opposing it. The statue remained in a yard for old Soviet memorials at the Central House of Artists.

In April 2012, the Moscow authorities stated that they would renovate the "Iron Felix" monument in full and put the statue on a list of monuments to be renovated, as well as officially designating it an object of cultural heritage. On 26 April 2021, it was announced by the prosecutor office of Moscow that the removal of the statue had no legal basis and was therefore illegal.

Finally, the monument was reerected on 11 September 2023, but this time in front of the Russian Foreign Intelligence Service headquarters outside Moscow.

Other statues
A smaller bust of Dzerzhinsky in the courtyard of the Moscow police headquarters at Petrovka 38 was restored in November 2005 (police officers had removed this bust on 22 August 1991).

A 10-foot bronze replica of the original Iron Felix statue was placed on the grounds of the military academy in Minsk, Belarus, in May 2006.

In 2017, on the 140th anniversary of Dzerzhinsky's birth, a monument to Dzerzhinsky was erected in the city of Ryazan, Russia.

On 20 January 2017, the People's Public Security Academy in Hanoi, Vietnam, inaugurated a Dzerzhinsky statue.

Dzerzhinovo

In 1943, the manor house of Dzerzhinovo, where Dzerzhinsky was born, was destroyed and family members (including Dzerzhinsky's brother Kazimierz) were killed by the Germans, because of their support for the Polish Home Army. In 2005, the Government of Belarus rebuilt the house (now on Belarusian territory) and established a museum. The graduating class of their KGB academy holds its annual swearing-in at the manor.

title: Felix Dzerzhinsky


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West Nile fever

West Nile fever is an infection by the West Nile virus, which is typically spread by mosquitoes. In about 80% of infections people have few or no symptoms. About 20% of people develop a fever, headache, vomiting, or a rash. In less than 1% of people, encephalitis or meningitis occurs, with associated neck stiffness, confusion, or seizures. Recovery may take weeks to months. The risk of death among those in whom the nervous system is affected is about 10 percent.

West Nile virus (WNV) is usually spread by mosquitoes that become infected when they feed on infected birds, which often carry the disease. Rarely the virus is spread through blood transfusions, organ transplants, or from mother to baby during pregnancy, delivery, or breastfeeding, but it otherwise does not spread directly between people. Risks for severe disease include being over 60 years old and having other health problems. Diagnosis is typically based on symptoms and blood tests.

There is no human vaccine. The best way to reduce the risk of infection is to avoid mosquito bites. Mosquito populations may be reduced by eliminating standing pools of water, such as in old tires, buckets, gutters, and swimming pools. When mosquitoes cannot be avoided, mosquito repellent, window screens, and mosquito nets reduce the likelihood of being bitten. There is no specific treatment for the disease; pain medications may reduce symptoms.

The virus was discovered in Uganda in 1937, and was first detected in North America in 1999. WNV has occurred in Europe, Africa, Asia, Australia, and North America. In the United States thousands of cases are reported a year, with most occurring in August and September. It can occur in outbreaks of disease. Severe disease may also occur in horses, for which a vaccine is available. A surveillance system in birds is useful for early detection of a potential human outbreak.

Signs and symptoms
About 80% of those infected with West Nile virus (WNV) show no symptoms and go unreported. About 20% of infected people develop symptoms. These vary in severity, and begin 3 to 14 days after being bitten. Most people with mild symptoms of WNV recover completely, though fatigue and weakness may last for weeks or months. Symptoms may range from mild, such as fever, to severe, such as paralysis and meningitis. A severe infection can last weeks and can, rarely, cause permanent brain damage. Death may ensue if the central nervous system is affected. Medical conditions such as cancer and diabetes, and age over 60 years, increase the risk of developing severe symptoms.

Headache can be a prominent symptom of WNV fever, meningitis, encephalitis, meningoencephalitis, and it may or may not be present in poliomyelitis-like syndrome. Thus, headache is not a useful indicator of neuroinvasive disease.
 * West Nile fever (WNF), which occurs in 20 percent of cases, is a febrile syndrome that causes flu-like symptoms. Most characterizations of WNF describe it as a mild, acute syndrome lasting 3 to 6 days after symptom onset. Systematic follow-up studies of patients with WNF have not been done, so this information is largely anecdotal. Possible symptoms include high fever, headache, chills, excessive sweating, weakness, fatigue, swollen lymph nodes, drowsiness, pain in the joints and flu-like symptoms. There may be gastrointestinal symptoms including nausea, vomiting, loss of appetite, and diarrhea. Fewer than one-third of patients develop a rash.
 * West Nile neuroinvasive disease (WNND), which occurs in less than 1 percent of cases, is when the virus infects the central nervous system resulting in meningitis, encephalitis, meningoencephalitis or a poliomyelitis-like syndrome. Many patients with WNND have normal neuroimaging studies, although abnormalities may be present in various cerebral areas including the basal ganglia, thalamus, cerebellum, and brainstem.
 * West Nile virus encephalitis (WNE) is the most common neuroinvasive manifestation of WNND. WNE presents with similar symptoms to other viral encephalitis with fever, headaches, and altered mental status. A prominent finding in WNE is muscular weakness (30 to 50 percent of patients with encephalitis), often with lower motor neuron symptoms, flaccid paralysis, and hyporeflexia with no sensory abnormalities.
 * West Nile meningitis (WNM) usually involves fever, headache, stiff neck and pleocytosis, an increase of white blood cells in cerebrospinal fluid. Changes in consciousness are not usually seen and are mild when present.
 * West Nile meningoencephalitis is inflammation of both the brain (encephalitis) and meninges (meningitis).
 * West Nile poliomyelitis (WNP), an acute flaccid paralysis syndrome associated with WNV infection, is less common than WNM or WNE. This syndrome is generally characterized by the acute onset of asymmetric limb weakness or paralysis in the absence of sensory loss. Pain sometimes precedes the paralysis. The paralysis can occur in the absence of fever, headache, or other common symptoms associated with WNV infection. Involvement of respiratory muscles, leading to acute respiratory failure, sometimes occurs.
 * West-Nile reversible paralysis, Like WNP, the weakness or paralysis is asymmetric. Reported cases have been noted to have an initial preservation of deep tendon reflexes, which is not expected for a pure anterior horn involvement. Disconnect of upper motor neuron influences on the anterior horn cells possibly by myelitis or glutamate excitotoxicity have been suggested as mechanisms. The prognosis for recovery is excellent.
 * Nonneurologic complications of WNV infection that may rarely occur include fulminant hepatitis, pancreatitis, myocarditis, rhabdomyolysis, orchitis, nephritis, optic neuritis and cardiac dysrhythmias and hemorrhagic fever with coagulopathy. Chorioretinitis may also be more common than previously thought.
 * Skin manifestations, specifically rashes, are common; however, there are few detailed descriptions in case reports, and few images are available. Punctate erythematous, macular, and papular eruptions, most pronounced on the extremities have been observed in WNV cases and in some cases histopathologic findings have shown a sparse superficial perivascular lymphocytic infiltrate, a manifestation commonly seen in viral exanthems. A literature review provides support that this punctate rash is a common cutaneous presentation of WNV infection.

Virology
WNV is one of the Japanese encephalitis antigenic serocomplex of viruses. Image reconstructions and cryoelectron microscopy reveal a 45–50 nm virion covered with a relatively smooth protein surface. This structure is similar to the dengue fever virus; both belong to the genus Flavivirus within the family Flaviviridae. The genetic material of WNV is a positive-sense, single strand of RNA, which is between 11,000 and 12,000 nucleotides long; these genes encode seven nonstructural proteins and three structural proteins. The RNA strand is held within a nucleocapsid formed from 12-kDa protein blocks; the capsid is contained within a host-derived membrane altered by two viral membrane proteins.

West Nile virus has been seen to replicate faster and spread more easily to birds at higher temperatures; one of several ways climate change could affect the epidemiology of this disease.

Transmission
The prime method of spread of the West Nile virus (WNV) is the female mosquito. In Europe, cats were identified as being hosts for West Nile virus. The important mosquito vectors vary according to area; in the United States, Culex pipiens (Eastern United States, and urban and residential areas of the United States north of 36–39°N), Culex tarsalis (Midwest and West), and Culex quinquefasciatus (Southeast) are the main vector species. In Europe, Culex pipiens is the principal vector.

The mosquito species that are most frequently infected with WNV feed primarily on birds. Different species of mosquitos take a blood meal from different types of vertebrate hosts, Mosquitoes show further selectivity, exhibiting preference for different species of birds. In the United States, WNV mosquito vectors feed preferentially on members of the Corvidae and thrush family. Among the preferred species within these families are the American crow, a corvid, and the American robin (Turdus migratorius).

Some species of birds develop sufficient viral levels (>~104.2 log PFU/ml; ) after being infected to transmit the infection to biting mosquitoes that in turn go on to infect other birds. In birds that die from WNV, death usually occurs after 4 to 6 days. In mammals and several species of birds, the virus does not multiply as readily and so does not develop high viremia during infection. Mosquitoes biting such hosts are not believed to ingest sufficient virus to become infected, making them so-called dead-end hosts. As a result of the differential infectiousness of hosts, the feeding patterns of mosquitoes play an important role in WNV transmission, and they are partly genetically controlled, even within a species.

Direct human-to-human transmission initially was believed to be caused only by occupational exposure, such as in a laboratory setting, or conjunctival exposure to infected blood. The US outbreak identified additional transmission methods through blood transfusion, organ transplant, intrauterine exposure, and breast feeding. Since 2003, blood banks in the United States routinely screen for the virus among their donors. As a precautionary measure, the UK's National Blood Service initially ran a test for this disease in donors who donate within 28 days of a visit to the United States, Canada, or the northeastern provinces of Italy, and the Scottish National Blood Transfusion Service asks prospective donors to wait 28 days after returning from North America or the northeastern provinces of Italy before donating. There also have been reports of possible transmission of the virus from mother to child during pregnancy or breastfeeding or exposure to the virus in a lab, but these are rare cases and not conclusively confirmed.

Recently, the potential for mosquito saliva to affect the course of WNV disease was demonstrated. Mosquitoes inoculate their saliva into the skin while obtaining blood. Mosquito saliva is a pharmacological cocktail of secreted molecules, principally proteins, that can affect vascular constriction, blood coagulation, platelet aggregation, inflammation, and immunity. It clearly alters the immune response in a manner that may be advantageous to a virus. Studies have shown it can specifically modulate the immune response during early virus infection, and mosquito feeding can exacerbate WNV infection, leading to higher viremia and more severe forms of disease.

Vertical transmission
Vertical transmission, the transmission of a viral or bacterial disease from the female of the species to her offspring, has been observed in various West Nile virus studies, amongst different species of mosquitoes in both the laboratory and in nature. Mosquito progeny infected vertically in autumn may potentially serve as a mechanism for WNV to overwinter and initiate enzootic horizontal transmission the following spring, although it likely plays little role in transmission in the summer and fall.

Risk factors
Risk factors independently associated with developing a clinical infection with WNV include a suppressed immune system and a patient history of organ transplantation. For neuroinvasive disease the additional risk factors include older age (>50+), male sex, hypertension, and diabetes mellitus.

A genetic factor also appears to increase susceptibility to West Nile disease. A mutation of the gene CCR5 gives some protection against HIV but leads to more serious complications of WNV infection. Carriers of two mutated copies of CCR5 made up 4.0 to 4.5% of a sample of people with West Nile disease, while the incidence of the gene in the general population is only 1.0%.

The most at risk occupations in the U.S. are outdoor workers, for example farmers, loggers, landscapers/groundskeepers, construction workers, painters, summer camp workers and pavers. Two reports of accidental exposure by laboratory personnel working with infected fluids or tissues have been received. While this appears to be a rare occurrence, it highlights the need for proper handling of infected materials. The World Health Organization states that there are no known cases of health care workers acquiring the virus from infected patients when the appropriate infection control precautions are observed.

Diagnosis
Preliminary diagnosis is often based on the patient's clinical symptoms, places and dates of travel (if patient is from a nonendemic country or area), activities, and epidemiologic history of the location where infection occurred. A recent history of mosquito bites and an acute febrile illness associated with neurologic signs and symptoms should cause clinical suspicion of WNV.

Diagnosis of West Nile virus infections is generally accomplished by serologic testing of blood serum or cerebrospinal fluid (CSF), which is obtained via a lumbar puncture. Initial screening could be done using the ELISA technique detecting immunoglobulins in the sera of the tested individuals.

Typical findings of WNV infection include lymphocytic pleocytosis, elevated protein level, reference glucose and lactic acid levels, and no erythrocytes.

Definitive diagnosis of WNV is obtained through detection of virus-specific antibody IgM and neutralizing antibodies. Cases of West Nile virus meningitis and encephalitis that have been serologically confirmed produce similar degrees of CSF pleocytosis and are often associated with substantial CSF neutrophilia. Specimens collected within eight days following onset of illness may not test positive for West Nile IgM, and testing should be repeated. A positive test for West Nile IgG in the absence of a positive West Nile IgM is indicative of a previous flavivirus infection and is not by itself evidence of an acute West Nile virus infection.

If cases of suspected West Nile virus infection, sera should be collected on both the acute and convalescent phases of the illness. Convalescent specimens should be collected 2–3 weeks after acute specimens.

It is common in serologic testing for cross-reactions to occur among flaviviruses such as dengue virus (DENV) and tick-borne encephalitis virus; this necessitates caution when evaluating serologic results of flaviviral infections.

Four FDA-cleared WNV IgM ELISA kits are commercially available from different manufacturers in the U.S., each of these kits is indicated for use on serum to aid in the presumptive laboratory diagnosis of WNV infection in patients with clinical symptoms of meningitis or encephalitis. Positive WNV test results obtained via use of these kits should be confirmed by additional testing at a state health department laboratory or CDC.

In fatal cases, nucleic acid amplification, histopathology with immunohistochemistry, and virus culture of autopsy tissues can also be useful. Only a few state laboratories or other specialized laboratories, including those at CDC, are capable of doing this specialized testing.

Differential diagnosis
A number of various diseases may present with symptoms similar to those caused by a clinical West Nile virus infection. Those causing neuroinvasive disease symptoms include the enterovirus infection and bacterial meningitis. Accounting for differential diagnoses is a crucial step in the definitive diagnosis of WNV infection. Consideration of a differential diagnosis is required when a patient presents with unexplained febrile illness, extreme headache, encephalitis or meningitis. Diagnostic and serologic laboratory testing using polymerase chain reaction (PCR) testing and viral culture of CSF to identify the specific pathogen causing the symptoms, is the only currently available means of differentiating between causes of encephalitis and meningitis.

Prevention
Many of the guidelines for preventing occupational West Nile virus exposure are common to all mosquito-borne diseases.

Public health measures include taking steps to reduce mosquito populations. Personal recommendations are to reduce the likelihood of being bitten. General measures to avoid bites include:
 * Using insect repellent on exposed skin to repel mosquitoes. Repellents include products containing DEET and picaridin. DEET concentrations of 30% to 50% are effective for several hours. Picaridin, available at 7% and 15% concentrations, needs more frequent application. DEET formulations as high as 30% are recommended for children over two months of age. The CDC also recommends the use of: IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone. Protect infants less than two months of age by using a carrier draped with mosquito netting with an elastic edge for a tight fit.
 * When using sunscreen, apply sunscreen first and then repellent. Repellent should be washed off at the end of the day before going to bed.
 * Wear long-sleeve shirts, which should be tucked in, long trousers, socks, and hats to cover exposed skin (although most fabrics do not totally protect against bites). Insect repellents should be applied over top of protective clothing for greater protection. Do not apply insect repellents underneath clothing.
 * Repellents containing permethrin (e.g., Permanone) or other insect repellents may be applied to clothing, shoes, tents, mosquito nets, and other gear. (Permethrin is not suitable for use directly on skin.) Most repellent is generally removed from clothing and gear by a single washing, but permethrin-treated clothing is effective for up to five washings.
 * Most mosquitoes that transmit disease are most active at dawn and in the evening dusk. A notable exception is the Asian tiger mosquito, which is a daytime feeder and is more apt to be found in, or on the periphery of, shaded areas with heavy vegetation. They are now widespread in the United States, and in Florida they have been found in all 67 counties.
 * In an at-risk area, staying in air-conditioned or well-screened room, or sleeping under an insecticide-treated bed net is recommended. Bed nets should be tucked under mattresses, and can be sprayed with a repellent if not already treated with an insecticide.

Monitoring and control
West Nile virus can be sampled from the environment by the pooling of trapped mosquitoes via ovitraps, carbon dioxide-baited light traps, and gravid traps, testing blood samples drawn from wild birds, dogs, and sentinel monkeys, and testing brains of dead birds found by various animal control agencies and the public.

Testing of the mosquito samples requires the use of reverse-transcriptase PCR (RT-PCR) to directly amplify and show the presence of virus in the submitted samples. When using the blood sera of wild birds and sentinel chickens, samples must be tested for the presence of WNV antibodies by use of immunohistochemistry (IHC) or enzyme-linked immunosorbent assay (ELISA).

Dead birds, after necropsy, or their oral swab samples collected on specific RNA-preserving filter paper card, can have their virus presence tested by either RT-PCR or IHC, where virus shows up as brown-stained tissue because of a substrate-enzyme reaction.

West Nile control is achieved through mosquito control, by elimination of mosquito breeding sites such as abandoned pools, applying larvacide to active breeding areas, and targeting the adult population via lethal ovitraps and aerial spraying of pesticides.

Environmentalists have condemned attempts to control the transmitting mosquitoes by spraying pesticide, saying the detrimental health effects of spraying outweigh the relatively few lives that may be saved, and more environmentally friendly ways of controlling mosquitoes are available. They also question the effectiveness of insecticide spraying, as they believe mosquitoes that are resting or flying above the level of spraying will not be killed; the most common vector in the northeastern United States, Culex pipiens, is a canopy feeder.

Treatment
No specific treatment is available for WNV infection. Most people recover without treatment. In mild cases, over-the-counter pain relievers can help ease mild headaches and muscle aches in adults. In severe cases supportive care is provided, often in hospital, with intravenous fluids, pain medication, respiratory support, and prevention of secondary infections.

Prognosis
While the general prognosis is favorable, current studies indicate that West Nile Fever can often be more severe than previously recognized, with studies of various recent outbreaks indicating that it may take as long as 60 to 90 days to recover. Patients with milder WNF are just as likely as those with more severe manifestations of neuroinvasive disease to experience multiple somatic complaints such as tremor, and dysfunction in motor skills and executive functions for over a year. People with milder symptoms are just as likely as people with more severe symptoms to experience adverse outcomes. Recovery is marked by a long convalescence with fatigue. One study found that neuroinvasive WNV infection was associated with an increased risk for subsequent kidney disease.

Epidemiology

WNV was first isolated from a feverish 37-year-old woman at Omogo in the West Nile District of Uganda in 1937 during research on yellow fever virus. A series of serosurveys in 1939 in central Africa found anti-WNV positive results ranging from 1.4% (Congo) to 46.4% (White Nile region, Sudan). It was subsequently identified in Egypt (1942) and India (1953), a 1950 serosurvey in Egypt found 90% of those over 40 years in age had WNV antibodies. The ecology was characterized in 1953 with studies in Egypt and Israel. The virus became recognized as a cause of severe human meningoencephalitis in elderly patients during an outbreak in Israel in 1957. The disease was first noted in horses in Egypt and France in the early 1960s and found to be widespread in southern Europe, southwest Asia and Australia.

The first appearance of WNV in the Western Hemisphere was in 1999 with encephalitis reported in humans, dogs, cats, and horses, and the subsequent spread in the United States may be an important milestone in the evolving history of this virus. The American outbreak began in College Point, Queens in New York City and was later spread to the neighboring states of New Jersey and Connecticut. The virus is believed to have entered in an infected bird or mosquito, although there is no clear evidence. West Nile virus is now endemic in Africa, Europe, the Middle East, west and central Asia, Oceania (subtype Kunjin), and most recently, North America and is spreading into Central and South America.

Outbreaks of West Nile virus encephalitis in humans have occurred in Algeria (1994), Romania (1996 to 1997), the Czech Republic (1997), Congo (1998), Russia (1999), the United States (1999 to 2009), Canada (1999–2007), Israel (2000), Greece (2010), and Israel (2024).

Epizootics of disease in horses occurred in Morocco (1996), Italy (1998), the United States (1999 to 2001), and France (2000), Mexico (2003) and Sardinia (2011).

Outdoor workers (including biological fieldworkers, construction workers, farmers, landscapers, and painters), healthcare personnel, and laboratory personnel who perform necropsies on animals are at risk of contracting WNV.

In 2012, the US experienced one of its worst epidemics in which 286 people died, with the state of Texas being hard hit by this virus.

Weather
Drought has been associated with a higher number of West Nile virus cases in the following year. As drought can decrease fish and other populations that eat mosquito eggs, higher numbers of mosquitoes can result. Higher temperatures are linked to decreased time for replication and increased viral load in birds and mosquitoes.

Research
A vaccine for horses (ATCvet code: ) based on killed viruses exists; some zoos have given this vaccine to their birds, although its effectiveness is unknown. Dogs and cats show few if any signs of infection. There have been no known cases of direct canine-human or feline-human transmission; although these pets can become infected, it is unlikely they are, in turn, capable of infecting native mosquitoes and thus continuing the disease cycle. AMD3100, which had been proposed as an antiretroviral drug for HIV, has shown promise against West Nile encephalitis. Morpholino antisense oligos conjugated to cell penetrating peptides have been shown to partially protect mice from WNV disease. There have also been attempts to treat infections using ribavirin, intravenous immunoglobulin, or alpha interferon. GenoMed, a U.S. biotech company, has found that blocking angiotensin II can treat the "cytokine storm" of West Nile virus encephalitis as well as other viruses.

As of 2019, six vaccines had progressed to human trials but none had been licensed in the United States. Only the two live attenuated vaccines produced strong immunity after a single dose.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: West Nile fever


text:
Hilbert's paradox of the Grand Hotel

Hilbert's paradox of the Grand Hotel (colloquial: Infinite Hotel Paradox or Hilbert's Hotel) is a thought experiment which illustrates a counterintuitive property of infinite sets. It is demonstrated that a fully occupied hotel with infinitely many rooms may still accommodate additional guests, even infinitely many of them, and this process may be repeated infinitely often. The idea was introduced by David Hilbert in a 1925 lecture "Über das Unendliche", reprinted in, and was popularized through George Gamow's 1947 book One Two Three... Infinity.

The paradox
Hilbert imagines a hypothetical hotel with rooms numbered 1, 2, 3, and so on with no upper limit. This is called a countably infinite number of rooms. Initially every room is occupied, and yet new visitors arrive, each expecting their own room. A normal, finite hotel could not accommodate new guests once every room is full. However, it can be shown that the existing guests and newcomers — even an infinite number of them — can each have their own room in the infinite hotel.

Finitely many new guests
With one additional guest, the hotel can accommodate them and the existing guests if infinitely many guests simultaneously move rooms. The guest currently in room 1 moves to room 2, the guest currently in room 2 to room 3, and so on, moving every guest from their current room n to room n+1. The infinite hotel has no final room, so every guest has a room to go to. After this, room 1 is empty and the new guest can be moved into that room. By repeating this procedure, it is possible to make room for any finite number of new guests. In general, when k guests seek a room, the hotel can apply the same procedure and move every guest from room n to room n + k.

Infinitely many new guests
It is also possible to accommodate a countably infinite number of new guests: just move the person occupying room 1 to room 2, the guest occupying room 2 to room 4, and, in general, the guest occupying room n to room 2n (2 times n), and all the odd-numbered rooms (which are countably infinite) will be free for the new guests.

Infinitely many coaches with infinitely many guests each
It is possible to accommodate countably infinitely many coachloads of countably infinite passengers each, by several different methods. Most methods depend on the seats in the coaches being already numbered (or use the axiom of countable choice). In general any pairing function can be used to solve this problem. For each of these methods, consider a passenger's seat number on a coach to be $$n$$, and their coach number to be $$c$$, and the numbers $$n$$ and $$c$$ are then fed into the two arguments of the pairing function.

Prime powers method
Send the guest in room $$i$$ to room $$2^i$$, then put the first coach's load in rooms $$3^n$$, the second coach's load in rooms $$5^n$$; in general for coach number $$c$$ we use the rooms $$p_{c}^n$$ where $$p_{c}$$ is the $$c$$th odd prime number. This solution leaves certain rooms empty (which may or may not be useful to the hotel); specifically, all numbers that are not prime powers, such as 15 or 847, will no longer be occupied. (So, strictly speaking, this shows that the number of arrivals is less than or equal to the number of vacancies created. It is easier to show, by an independent means, that the number of arrivals is also greater than or equal to the number of vacancies, and thus that they are equal, than to modify the algorithm to an exact fit.) (The algorithm works equally well if one interchanges $$n$$ and $$c$$, but whichever choice is made, it must be applied uniformly throughout.)

Prime factorization method
Each person of a certain seat $$s$$ and coach $$c$$ can be put into room $$2^s 3^c$$ (presuming c=0 for the people already in the hotel, 1 for the first coach, etc.). Because every number has a unique prime factorization, it is easy to see all people will have a room, while no two people will end up in the same room. For example, the person in room 2592 ($$2^5 3^4$$) was sitting in on the 4th coach, on the 5th seat. Like the prime powers method, this solution leaves certain rooms empty.

This method can also easily be expanded for infinite nights, infinite entrances, etc. ( $$2^s 3^c 5^n 7^e...$$ )

Interleaving method
For each passenger, compare the lengths of $$n$$ and $$c$$ as written in any positional numeral system, such as decimal. (Treat each hotel resident as being in coach #0.) If either number is shorter, add leading zeroes to it until both values have the same number of digits. Interleave the digits to produce a room number: its digits will be [first digit of coach number]-[first digit of seat number]-[second digit of coach number]-[second digit of seat number]-etc. The hotel (coach #0) guest in room number 1729 moves to room 01070209 (i.e., room 1,070,209). The passenger on seat 1234 of coach 789 goes to room 01728394 (i.e., room 1,728,394).

Unlike the prime powers solution, this one fills the hotel completely, and we can reconstruct a guest's original coach and seat by reversing the interleaving process. First add a leading zero if the room has an odd number of digits. Then de-interleave the number into two numbers: the coach number consists of the odd-numbered digits and the seat number is the even-numbered ones. Of course, the original encoding is arbitrary, and the roles of the two numbers can be reversed (seat-odd and coach-even), so long as it is applied consistently.

Triangular number method
Those already in the hotel will be moved to room $$(n^2+n)/2$$, or the $$n$$th triangular number. Those in a coach will be in room $$ ((c+n-1)^2+c+n-1)/2+n$$, or the $$(c+n-1)$$ triangular number plus $$n$$. In this way all the rooms will be filled by one, and only one, guest.

This pairing function can be demonstrated visually by structuring the hotel as a one-room-deep, infinitely tall pyramid. The pyramid's topmost row is a single room: room 1; its second row is rooms 2 and 3; and so on. The column formed by the set of rightmost rooms will correspond to the triangular numbers. Once they are filled (by the hotel's redistributed occupants), the remaining empty rooms form the shape of a pyramid exactly identical to the original shape. Thus, the process can be repeated for each infinite set. Doing this one at a time for each coach would require an infinite number of steps, but by using the prior formulas, a guest can determine what their room "will be" once their coach has been reached in the process, and can simply go there immediately.

Arbitrary enumeration method
Let $$ S := \{(a, b) \mid a, b \in \mathbb{N}\}$$. $$ S $$ is countable since $$\mathbb{N}$$ is countable, hence we may enumerate its elements $$s_1, s_2, \dots$$. Now if $$s_n = (a, b)$$, assign the $$b$$th guest of the $$a$$th coach to the $$n$$th room (consider the guests already in the hotel as guests of the $$0$$th coach). Thus we have a function assigning each person to a room; furthermore, this assignment does not skip over any rooms.

Further layers of infinity
Suppose the hotel is next to an ocean, and an infinite number of car ferries arrive, each bearing an infinite number of coaches, each with an infinite number of passengers. This is a situation involving three "levels" of infinity, and it can be solved by extensions of any of the previous solutions.

The prime factorization method can be applied by adding a new prime number for every additional layer of infinity ( $$2^s 3^c 5^f$$, with $$f$$ the ferry).

The prime power solution can be applied with further exponentiation of prime numbers, resulting in very large room numbers even given small inputs. For example, the passenger in the second seat of the third bus on the second ferry (address 2-3-2) would raise the 2nd odd prime (5) to 49, which is the result of the 3rd odd prime (7) being raised to the power of his seat number (2). This room number would have over thirty decimal digits.

The interleaving method can be used with three interleaved "strands" instead of two. The passenger with the address 2-3-2 would go to room 232, while the one with the address 4935-198-82217 would go to room #008,402,912,391,587 (the leading zeroes can be removed).

Anticipating the possibility of any number of layers of infinite guests, the hotel may wish to assign rooms such that no guest will need to move, no matter how many guests arrive afterward. One solution is to convert each arrival's address into a binary number in which ones are used as separators at the start of each layer, while a number within a given layer (such as a guest's coach number) is represented with that many zeroes. Thus, a guest with the prior address 2-5-1-3-1 (five infinite layers) would go to room 10010000010100010 (decimal 295458).

As an added step in this process, one zero can be removed from each section of the number; in this example, the guest's new room is 101000011001 (decimal 2585). This ensures that every room could be filled by a hypothetical guest. If no infinite sets of guests arrive, then only rooms that are a power of two will be occupied.

Infinite layers of nesting
Although a room can be found for any finite number of nested infinities of people, the same is not always true for an infinite number of layers. Even if a finite number of elements exists at each layer.

Analysis
Hilbert's paradox is a veridical paradox: it leads to a counter-intuitive result that is provably true. The statements "there is a guest to every room" and "no more guests can be accommodated" are not equivalent when there are infinitely many rooms.

Initially, this state of affairs might seem to be counter-intuitive. The properties of infinite collections of things are quite different from those of finite collections of things. The paradox of Hilbert's Grand Hotel can be understood by using Cantor's theory of transfinite numbers. Thus, in an ordinary (finite) hotel with more than one room, the number of odd-numbered rooms is obviously smaller than the total number of rooms. However, in Hilbert's Grand Hotel, the quantity of odd-numbered rooms is not smaller than the total "number" of rooms. In mathematical terms, the cardinality of the subset containing the odd-numbered rooms is the same as the cardinality of the set of all rooms. Indeed, infinite sets are characterized as sets that have proper subsets of the same cardinality. For countable sets (sets with the same cardinality as the natural numbers) this cardinality is $\aleph_0$.

Rephrased, for any countably infinite set, there exists a bijective function which maps the countably infinite set to the set of natural numbers, even if the countably infinite set contains the natural numbers. For example, the set of rational numbers—those numbers which can be written as a quotient of integers—contains the natural numbers as a subset, but is no bigger than the set of natural numbers since the rationals are countable: there is a bijection from the naturals to the rationals.

title: Hilbert's paradox of the Grand Hotel


text:
Thor Heyerdahl

Thor Heyerdahl KStJ (6 October 1914 – 18 April 2002) was a Norwegian adventurer and ethnographer with a background in biology with specialization in zoology, botany and geography.

Heyerdahl is notable for his Kon-Tiki expedition in 1947, in which he drifted 8,000 km (5,000 mi) across the Pacific Ocean in a primitive hand-built raft from South America to the Tuamotu Islands. The expedition was supposed to demonstrate that the legendary sun-worshiping red-haired, bearded, and white-skinned "Tiki people" from South America drifted and colonized Polynesia first, before actual Polynesian peoples. His hyperdiffusionist ideas on ancient cultures has been widely rejected by the scientific community, even before the expedition.

Heyerdahl made other voyages to demonstrate the possibility of contact between widely separated ancient peoples, notably the Ra II expedition of 1970, when he sailed from the west coast of Africa to Barbados in a papyrus reed boat. He was appointed a government scholar in 1984.

He died on 18 April 2002 in Colla Micheri, Italy, while visiting close family members. The Norwegian government gave him a state funeral in Oslo Cathedral on 26 April 2002.

In May 2011, the Thor Heyerdahl Archives were added to UNESCO's Memory of the World Register. At the time, this list included 238 collections from all over the world. The Heyerdahl Archives span the years 1937 to 2002 and include his photographic collection, diaries, private letters, expedition plans, articles, newspaper clippings, and original book and article manuscripts. The Heyerdahl Archives are administered by the Kon-Tiki Museum and the National Library of Norway in Oslo.

Youth and personal life
Heyerdahl was born in Larvik, Norway, the son of master brewer Thor Heyerdahl (1869–1957) and his wife, Alison Lyng (1873–1965). As a young child, Heyerdahl showed a strong interest in zoology, inspired by his mother, who had a strong interest in Charles Darwin's theory of evolution. He created a small museum in his childhood home, with a common adder (Vipera berus) as the main attraction.

He studied zoology and geography at the faculty of biological science at the University of Oslo. At the same time, he privately studied Polynesian culture and history, consulting what was then the world's largest private collection of books and papers on Polynesia, owned by Bjarne Kroepelien, a wealthy wine merchant in Oslo. (This collection was later purchased by the University of Oslo Library from Kroepelien's heirs and was attached to the Kon-Tiki Museum research department.)

After seven terms and consultations with experts in Berlin, a project was developed and sponsored by Heyerdahl's zoology professors, Kristine Bonnevie and Hjalmar Broch. He was to visit some isolated Pacific island groups and study how the local animals had found their way there.

On the day before they sailed together to the Marquesas Islands in 1936, Heyerdahl married Liv Coucheron-Torp (1916–1969), whom he had met at the University of Oslo, and who had studied economics there. He was 22 years old and she was 20 years old. Eventually, the couple had two sons: Thor Jr. and Bjørn. The marriage ended in divorce shortly before the 1947 Kon-Tiki expedition, which Liv had helped to organize.

After the occupation of Norway by Nazi Germany, he served with the Free Norwegian Forces from 1944, in the far north province of Finnmark.

In 1949, Heyerdahl married Yvonne Dedekam-Simonsen (1924–2006). They had three daughters: Annette, Marian, and Helene Elisabeth. They were divorced in 1969. Heyerdahl blamed their separation on his being away from home and differences in their ideas for bringing up children. In his autobiography, he concluded that he should take the entire blame for their separation.

In 1991, Heyerdahl married Jacqueline Beer (born 1932) as his third wife. They lived in Tenerife, Canary Islands, and were very actively involved with archaeological projects, especially in Túcume, Peru, and Azov until his death in 2002. He had still been hoping to undertake an archaeological project in Samoa before he died.

Fatu Hiva
In 1936, on the day after his marriage to Liv Coucheron Torp, the young couple set out for the South Pacific Island of Fatu Hiva. They nominally had an academic mission, to research the spread of animal species between islands, but in reality they intended to "run away to the South Seas" and never return home.

Aided by expedition funding from their parents, they nonetheless arrived on the island lacking "provisions, weapons or a radio". Residents in Tahiti, where they stopped en route, did convince them to take a machete and a cooking pot.

They arrived at Fatu Hiva in 1937, in the valley of Omo‘a, and decided to cross over the island's mountainous interior to settle in one of the small, nearly abandoned, valleys on the eastern side of the island. There, they made their thatch-covered stilted home in the valley of Uia.

Living in such primitive conditions was a daunting task, but they managed to live off the land, and work on their academic goals, by collecting and studying zoological and botanical specimens. They discovered unusual artifacts, listened to the natives' oral history traditions, and took note of the prevailing winds and ocean currents.

It was in this setting, surrounded by the ruins of the formerly glorious Marquesan civilization, that Heyerdahl first developed his theories regarding the possibility of pre-Columbian trans-oceanic contact between the pre-European Polynesians, and the peoples and cultures of South America.

Despite the seemingly idyllic situation, the exposure to various tropical diseases and other difficulties caused them to return to civilisation a year later. They worked together to write an account of their adventure.

The events surrounding his stay on the Marquesas, most of the time on Fatu Hiva, were told first in his book På Jakt etter Paradiset (Hunt for Paradise) (1938), which was published in Norway but, following the outbreak of World War II, was never translated and remained largely forgotten. Many years later, having achieved notability with other adventures and books on other subjects, Heyerdahl published a new account of this voyage under the title Fatu Hiva (London: Allen & Unwin, 1974). The story of his time on Fatu Hiva and his side trip to Hivaoa and Mohotani is also related in Green Was the Earth on the Seventh Day  (Random House, 1996).

Kon-Tiki expedition
In 1947 Heyerdahl and five fellow adventurers sailed from Peru to the Tuamotu Islands, French Polynesia in a 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 7 August 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.

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.

Expedition to Easter Island
In 1955–1956, Heyerdahl organised the Norwegian Archaeological Expedition to Easter Island. The expedition's scientific staff included Arne Skjølsvold, Carlyle Smith, Edwin Ferdon, Gonzalo Figueroa and William Mulloy. Heyerdahl and the professional archaeologists who travelled with him spent several months on Easter Island investigating several important archaeological sites. Highlights of the project include experiments in the carving, transport and erection of the notable moai, as well as excavations at such prominent sites as Orongo and Poike. The expedition published two large volumes of scientific reports (Reports of the Norwegian Archaeological Expedition to Easter Island and the East Pacific) and Heyerdahl later added a third (The Art of Easter Island). Heyerdahl's popular book on the subject, Aku-Aku was another international best-seller.

In Easter Island: The Mystery Solved (Random House, 1989), Heyerdahl offered a more detailed theory of the island's history. Based on native testimony and archaeological research, he claimed the island was originally colonised by Hanau eepe ("Long Ears"), from South America, and that Polynesian Hanau momoko ("Short Ears") arrived only in the mid-16th century; they may have come independently or perhaps were imported as workers. According to Heyerdahl, something happened between Admiral Roggeveen's discovery of the island in 1722 and James Cook's visit in 1774; while Roggeveen encountered white, Indian, and Polynesian people living in relative harmony and prosperity, Cook encountered a much smaller population consisting mainly of Polynesians and living in privation. Heyerdahl notes the oral tradition of an uprising of "Short Ears" against the ruling "Long Ears." The "Long Ears" dug a defensive moat on the eastern end of the island and filled it with kindling. During the uprising, Heyerdahl claimed, the "Long Ears" ignited their moat and retreated behind it, but the "Short Ears" found a way around it, came up from behind, and pushed all but two of the "Long Ears" into the fire. This moat was found by the Norwegian expedition and it was partly cut down into the rock. Layers of fire were revealed but no fragments of bodies.

Theory on Polynesian origins
The basis of the Kon-Tiki expedition was Heyerdahl's belief that the original inhabitants of Easter Island (and the rest of Polynesia) were the "Tiki people", a race of "white bearded men" who supposedly originally sailed from Peru. He described these "Tiki people" as being a sun-worshipping fair-skinned people with blue eyes, fair or red hair, tall statures, and beards. He further said that these people were originally from the Middle East, and had crossed the Atlantic earlier to found the great Mesoamerican civilizations. By 500 CE, a branch of these people were supposedly forced out into Tiahuanaco where they became the ruling class of the Inca Empire and set out to voyage into the Pacific Ocean under the leadership of "Con Ticci Viracocha".

Heyerdahl said that when the Europeans first came to the Pacific islands, they were astonished that they found some of the natives to have relatively light skins and beards. There were whole families that had pale skin, hair varying in colour from reddish to blonde. In contrast, most of the Polynesians had golden-brown skin, raven-black hair, and rather flat noses. Heyerdahl claimed that when Jacob Roggeveen discovered Easter Island in 1722, he supposedly noticed that many of the natives were white-skinned. Heyerdahl claimed that these people could count their ancestors who were "white-skinned" right back to the time of Tiki and Hotu Matua, when they first came sailing across the sea "from a mountainous land in the east which was scorched by the sun". The ethnographic evidence for these claims is outlined in Heyerdahl's book Aku-Aku: The Secret of Easter Island. He argued that the monumental statues known as moai resembled sculptures more typical of pre-Columbian Peru than any Polynesian designs. He believed that the Easter Island myth of a power struggle between two peoples called the Hanau epe and Hanau momoko was a memory of conflicts between the original inhabitants of the island and a later wave of "Native Americans" from the Northwest coast, eventually leading to the annihilation of the Hanau epe and the destruction of the island's culture and once-prosperous economy. Heyerdahl described these later "Native American" migrants as "Maori-Polynesians" who were supposedly Asians who crossed over the Bering land bridge into Northwest America before sailing westward towards Polynesia (the westward direction is because he refused to accept that Polynesians were capable of sailing against winds and currents). He associated them with the Tlingit and Haida peoples and characterized them as "inferior" to the Tiki people.

Despite these claims, DNA sequence analysis of Easter Island's current inhabitants indicates that the 36 people living on Rapa Nui who survived the devastating internecine wars, slave raids, and epidemics of the 19th century and had any offspring were Polynesian. Furthermore, examination of skeletons offers evidence of only Polynesian origins for Rapa Nui living on the island after 1680.

Heyerdahl's hypothesis of Polynesian origins from the Americas is considered pseudoscientific, racially controversial, and has not gained acceptance among scientists (even prior to the voyage). It is overwhelmingly rejected by scientists today. Archaeological, linguistic, cultural, and genetic evidence all support a western origin (from Island Southeast Asia) for Polynesians via the Austronesian expansion. "Drift voyaging" from South America was also deemed "extremely unlikely" in 1973 by computer modeling.

The 1976 voyage of the Hōkūleʻa, a performance-accurate replica of a Polynesian double-hulled wa'a kaulua voyaging canoe, from Hawaiʻi to Tahiti was partly a demonstration to prove that Heyerdahl was wrong. The Hōkūleʻa sailed against prevailing winds and exclusively used wayfinding and celestial Polynesian navigation techniques (unlike the modern equipment and charts of the Kon-Tiki). Hōkūleʻa also remains fully operational, and has since completed ten other voyages, including a three-year circumnavigation of the planet from 2014 to 2017, with other sister ships.

Heyerdahl's hypothesis was part of early Eurocentric hyperdiffusionism and the westerner disbelief that (non-white) "stone-age" peoples with "no math" could colonize islands separated by vast distances of ocean water, even against prevailing winds and currents. He rejected the highly skilled voyaging and navigating traditions of the Austronesian peoples and instead argued that Polynesia was settled from boats following the wind and currents for navigation from South America. As such, the Kon-Tiki was deliberately a primitive raft and unsteerable, in contrast to the sophisticated outrigger canoes and catamarans of the Austronesian people.

Anthropologist Robert Carl Suggs included a chapter titled "The Kon-Tiki Myth" in his 1960 book on Polynesia, concluding that "The Kon-Tiki theory is about as plausible as the tales of Atlantis, Mu, and 'Children of the Sun.' Like most such theories, it makes exciting light reading, but as an example of scientific method it fares quite poorly." Anthropologist and National Geographic Explorer-in-Residence Wade Davis 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."

Boats Ra and Ra II
In 1969 and 1970, Heyerdahl built two boats from papyrus and attempted to cross the Atlantic Ocean from Morocco in Africa. Based on drawings and models from ancient Egypt, the first boat, named Ra (after the Egyptian Sun god), was constructed by boat builders from Lake Chad using papyrus reed obtained from Lake Tana in Ethiopia and launched into the Atlantic Ocean from the coast of Morocco. The Ra crew included Thor Heyerdahl (Norway), Norman Baker (US), Carlo Mauri (Italy), Yuri Senkevich (USSR), Santiago Genovés (Mexico), Georges Sourial (Egypt), and Abdullah Djibrine (Chad). Only Heyerdahl and Baker had sailing and navigation experience. Genovés would go on to head the Acali Experiment.

After a number of weeks, Ra took on water. The crew discovered that a key element of the Egyptian boatbuilding method had been neglected, a tether that acted like a spring to keep the stern high in the water while allowing for flexibility. Water and storms eventually caused it to sag and break apart after sailing more than 6,400 km (4,000 miles). The crew was forced to abandon Ra, some hundred miles (160 km) before the Caribbean islands, and was saved by a yacht.

The following year, 1970, a similar vessel, Ra II, was built from Ethiopian papyrus by Bolivian citizens Demetrio, Juan and José Limachi of Lake Titicaca, and likewise set sail across the Atlantic from Morocco, this time with great success. The crew was mostly the same; though Djibrine had been replaced by Kei Ohara from Japan and Madani Ait Ouhanni from Morocco. The boat became lost and was the subject of a United Nations search and rescue mission. The search included international assistance including people as far afield as Loo-Chi Hu of New Zealand. The boat reached Barbados, thus demonstrating that mariners could have dealt with trans-Atlantic voyages by sailing with the Canary Current. The Ra II is now in the Kon-Tiki Museum in Oslo, Norway.

The book The Ra Expeditions and the film documentary Ra (1972) were made about the voyages. Apart from the primary aspects of the expedition, Heyerdahl deliberately selected a crew representing a great diversity in race, nationality, religion and political viewpoint in order to demonstrate that, at least on their own little floating island, people could co-operate and live peacefully. Additionally, the expedition took samples of marine pollution and presented its report to the United Nations.

Tigris
Heyerdahl built yet another reed boat in 1977, Tigris, which was intended to demonstrate that trade and migration could have linked Mesopotamia with the Indus Valley civilization in what is now Pakistan and western India. Tigris was built in Al Qurnah Iraq and sailed with its international crew through the Persian Gulf to Pakistan and made its way into the Red Sea.

After about five months at sea and still remaining seaworthy, the Tigris was deliberately burnt in Djibouti on 3 April 1978 as a protest against the wars raging on every side in the Red Sea and Horn of Africa. In his Open Letter to the UN Secretary-General Kurt Waldheim, Heyerdahl explained his reasons:

Today we burn our proud ship ... to protest against inhuman elements in the world of 1978 ... Now we are forced to stop at the entrance to the Red Sea. Surrounded by military airplanes and warships from the world's most civilised and developed nations, we have been denied permission by friendly governments, for reasons of security, to land anywhere, but in the tiny, and still neutral, Republic of Djibouti. Elsewhere around us, brothers and neighbours are engaged in homicide with means made available to them by those who lead humanity on our joint road into the third millennium.

To the innocent masses in all industrialised countries, we direct our appeal. We must wake up to the insane reality of our time ... We are all irresponsible, unless we demand from the responsible decision makers that modern armaments must no longer be made available to people whose former battle axes and swords our ancestors condemned.

Our planet is bigger than the reed bundles that have carried us across the seas, and yet small enough to run the same risks unless those of us still alive open our eyes and minds to the desperate need of intelligent collaboration to save ourselves and our common civilisation from what we are about to convert into a sinking ship.

In the years that followed, Heyerdahl was often outspoken on issues of international peace and the environment.

The Tigris had an 11-man crew: Thor Heyerdahl (Norway), Norman Baker (US), Carlo Mauri (Italy), Yuri Senkevich (USSR), Germán Carrasco (Mexico), Hans Petter Bohn (Norway), Rashad Nazar Salim (Iraq), Norris Brock (US), Toru Suzuki (Japan), Detlef Soitzek (Germany), and Asbjørn Damhus (Denmark).

Background
Heyerdahl made four visits to Azerbaijan in 1981, 1994, 1999 and 2000. Heyerdahl had long been fascinated with the rock carvings that date back to about at Gobustan (about 30 miles/48 km west of Baku). He was convinced that their artistic style closely resembled the carvings found in his native Norway. The ship designs, in particular, were regarded by Heyerdahl as similar and drawn with a simple sickle-shaped line, representing the base of the boat, with vertical lines on deck, illustrating crew or, perhaps, raised oars.

Based on this and other published documentation, Heyerdahl proposed that Azerbaijan was the site of an ancient advanced civilisation. He believed that natives migrated north through waterways to present-day Scandinavia using ingeniously constructed vessels made of skins that could be folded like cloth. When voyagers travelled upstream, they conveniently folded their skin boats and transported them on pack animals.

Snorri Sturluson
On Heyerdahl's visit to Baku in 1999, he lectured at the Academy of Sciences about the history of ancient Nordic Kings. He spoke of a notation made by Snorri Sturluson, a 13th-century historian-mythographer in Ynglinga Saga, which relates that "Odin (a Scandinavian god who was one of the kings) came to the North with his people from a country called Aser." (see also House of Ynglings and Mythological kings of Sweden). Heyerdahl accepted Snorri's story as literal truth, and believed that a chieftain led his people in a migration from the east, westward and northward through Saxony, to Fyn in Denmark, and eventually settling in Sweden. Heyerdahl claimed that the geographic location of the mythic Aser or Æsir matched the region of contemporary Azerbaijan – "east of the Caucasus mountains and the Black Sea". "We are no longer talking about mythology," Heyerdahl said, "but of the realities of geography and history. Azerbaijanis should be proud of their ancient culture. It is just as rich and ancient as that of China and Mesopotamia."

In September 2000 Heyerdahl returned to Baku for the fourth time and visited the archaeological dig in the area of the Church of Kish.

Revision of hypothesis
One of the last projects of his life, Jakten på Odin, 'The Search for Odin', was a sudden revision of his Odin hypothesis, in furtherance of which he initiated 2001–2002 excavations in Azov, Russia, near the Sea of Azov at the northeast of the Black Sea. He searched for the remains of a civilisation to match the account of Odin in Snorri Sturlusson, significantly further north of his original target of Azerbaijan on the Caspian Sea only two years earlier. This project generated harsh criticism and accusations of pseudoscience from historians, archaeologists and linguists in Norway, who accused Heyerdahl of selective use of sources, and a basic lack of scientific methodology in his work.

His central claims were based on similarities of names in Norse mythology and geographic names in the Black Sea region, e.g. Azov and Æsir, Udi and Odin, Tyr and Turkey. Philologists and historians reject these parallels as mere coincidences, and also anachronisms, for instance the city of Azov did not have that name until over 1,000 years after Heyerdahl claims the Æsir dwelt there. The controversy surrounding the Search for Odin project was in many ways typical of the relationship between Heyerdahl and the academic community. His theories rarely won any scientific acceptance, whereas Heyerdahl himself rejected all scientific criticism and concentrated on publishing his theories in popular books aimed at the general public.

, Heyerdahl's Odin hypothesis has yet to be validated by any historian, archaeologist or linguist.

Pyramids of Güímar
In 1991 he studied the Pyramids of Güímar on Tenerife and declared that they were not random stone heaps but pyramids. Based on the discovery made by the astrophysicists Aparicio, Belmonte and Esteban, from the Instituto de Astrofísica de Canarias that the "pyramids" were astronomically orientated and being convinced that they were of ancient origin, he claimed that the ancient people who built them were most likely sun worshippers. Heyerdahl hypothesised that the Canarian pyramids formed a temporal and geographic stopping point on voyages between ancient Egypt and the Maya civilization, initiating a controversy in which historians, esoterics, archaeologists, astronomers, and those with a general interest in history took part.

Between 1991 and 1998, archaeological excavations of the site were conducted by archaeologists of the University of La Laguna. Preliminary findings were presented at a colloquium in 1996, providing evidence for the dating of the pyramids. According to the preceding geophysical Georadar-Survey eight locations adjacent to the pyramids, each with an area of 25 m2, were investigated in layers down to the solid lava-floor. In doing so it was possible to establish three specific sediment layers. Starting from the top these were:

 * 1) A layer of thickness averaging 20 cm, consisting of humus-rich earth with many plant remains and roots; tracks from ploughing were clearly identifiable as were a broad spectrum of readily datable finds from the second half of the 20th century.
 * 2) A layer of thickness averaging 25 cm, similar in composition to the first layer, however containing less humus and a larger amount of small stones; a large variety of finds which could be dated to the 19th and 20th century were found, of which an official seal from 1848 deserves particular mention.
 * 3) A layer of thickness between 25 and 150 cm, composed out of small volcanic rocks, most likely put in place in one movement, which levelled the uneven stone underneath; the stones contained only very few finds, mostly a small number of pottery shards, of which some was local and some imported, both kinds were roughly estimated as belonging to the 19th century. The pyramids stand stratigraphically directly on top of this bottom layer, therefore allowing for an earliest date of construction of the pyramids within the 19th century.

Furthermore, under the border edge of one of the pyramids, a natural lava cave was discovered. It had been walled up and yielded artefacts from the time of the Guanches. Since the pyramids lie stratigraphically above the cave, the Guanche finds from between 600 and 1000 AD can only support conclusions on the date of human use of the cave. The above survey indicates that the pyramids themselves cannot be older than the 19th century.

Other projects
Heyerdahl also investigated the mounds found on the Maldive Islands in the Indian Ocean. There, he found sun-orientated foundations and courtyards, as well as statues with elongated earlobes. Heyerdahl believed that these finds fit with his theory of a seafaring civilisation which originated in what is now Sri Lanka, colonised the Maldives, and influenced or founded the cultures of ancient South America and Easter Island. His discoveries are detailed in his book The Maldive Mystery.

Heyerdahl was also an active figure in Green politics. He was the recipient of numerous medals and awards. He also received 11 honorary doctorates from universities in the Americas and Europe.

In subsequent years, Heyerdahl was involved with many other expeditions and archaeological projects. He remained best known for his boatbuilding, and for his emphasis on cultural diffusionism.

Death
Heyerdahl died on 18 April 2002 aged 87 from a brain tumour in Colla Micheri, Liguria, where he had gone to spend the Easter holidays with some of his closest family members. After receiving the diagnosis, he prepared for death, by refusing to eat or take medication.

The Norwegian government honored him with a state funeral in the Oslo Cathedral on 26 April 2002. He is buried in the garden of the family home in Colla Micheri. He was an atheist.

Legacy
Although much of his work was not accepted by the scientific community for many years, Heyerdahl nevertheless increased public interest in ancient history and anthropology. He also showed that long-distance ocean voyages were possible with ancient designs. As such, he was a major practitioner of experimental archaeology. The Kon-Tiki Museum on the Bygdøy peninsula in Oslo, Norway houses vessels and maps from the Kon-Tiki expedition, as well as a library with about 8,000 books.

The Thor Heyerdahl Institute was established in 2000. Heyerdahl himself agreed to the founding of the institute and it aims to promote and continue to develop Heyerdahl's ideas and principles. The institute is located in Heyerdahl's birth town of Larvik, Norway. In Larvik, the birthplace of Heyerdahl, the municipality began a project in 2007 to attract more visitors. Since then, they have purchased and renovated Heyerdahl's childhood home, arranged a yearly raft regatta in his honour at the end of summer and begun to develop a Heyerdahl centre.

Heyerdahl's grandson, Olav Heyerdahl, retraced his grandfather's Kon-Tiki voyage in 2006 as part of a six-member crew. The voyage, organised by Torgeir Higraff and called the Tangaroa Expedition, was intended as a tribute to Heyerdahl, an effort to better understand navigation via centreboards ("guara ") as well as a means to monitor the Pacific Ocean's environment.

A book about the Tangaroa Expedition by Torgeir Higraff was published in 2007. The book has numerous photos from the Kon-Tiki voyage 60 years earlier and is illustrated with photographs by Tangaroa crew member Anders Berg (Oslo: Bazar Forlag, 2007). "Tangaroa Expedition" has also been produced as a documentary DVD in English, Norwegian, Swedish and Spanish.

Paul Theroux, in his book The Happy Isles of Oceania, criticises Heyerdahl for trying to link the culture of Polynesian islands with the Peruvian culture. Recent scientific investigation that compares the DNA of some of the Polynesian islands with natives from Peru suggests that there is some merit to Heyerdahl's ideas and that while Polynesia was colonised from Asia, some contact with South America also existed; several papers have in the last few years confirmed with genetic data some form of contacts with Easter Island. More recently, some researchers published research confirming a wider impact on genetic and cultural elements in Polynesia due to South American contacts.

Decorations and honorary degrees

Asteroid 2473 Heyerdahl is named after him, as are HNoMS Thor Heyerdahl, a Norwegian Nansen class frigate, along with MS Thor Heyerdahl (now renamed MS Vana Tallinn), and Thor Heyerdahl, a German three-masted sail training vessel originally owned by a participant of the Tigris expedition. Heyerdahl Vallis, a valley on Pluto, and Thor Heyerdahl Upper Secondary School in Larvik, the town of his birth, are also named after him. Google honoured Heyerdahl on his 100th birthday by making a Google Doodle.

Heyerdahl's numerous awards and honours include the following:

Governmental and state honours

 * Grand Cross of the Royal Norwegian Order of St Olav (1987) (Commander with Star: 1970; Commander: 1951)
 * Grand Cross of the Order of Merit of Peru (1953)
 * Grand Officer of the Order of Merit of the Italian Republic (21 June 1965)
 * Knight in the Order of Saint John of Jerusalem
 * Knight of the Order of Merit, Egypt (1971)
 * Grand Officer of the Order of Ouissam Alaouite (Morocco; 1971)
 * Officer, Order of the Sun (Peru) (1975) and Knight Grand Cross
 * International Pahlavi Environment Prize, United Nations (1978)
 * Knight of the Order of the Golden Ark, Netherlands (1980)
 * Commander, American Knights of Malta (1970)
 * Civitan International World Citizenship Award
 * Austrian Decoration for Science and Art (2000)
 * St. Hallvard's Medal

Academic honours

 * Retzius Medal, Royal Swedish Society for Anthropology and Geography (1950)
 * Mungo Park Medal, Royal Scottish Society for Geography (1951)
 * Bonaparte-Wyse Gold Medal, Société de Géographie de Paris (1951)
 * Elisha Kent Kane Gold Medal, Geographical Society of Philadelphia (1952)
 * Honorary Member, Geographical Societies of Norway (1953), Peru (1953), Brazil (1954)
 * Elected Member Norwegian Academy of Sciences (1958)
 * Fellow, New York Academy of Sciences (1960)
 * Vega Gold Medal, Swedish Society for Anthropology and Geography (1962)
 * Lomonosov Medal, Moscow State University (1962)
 * Gold Medal, Royal Geographical Society, London (1964)
 * Distinguished Service Award, Pacific Lutheran University, Tacoma, Washington, US (1966)
 * Member American Anthropological Association (1966)
 * Kiril i Metodi Award, Geographical Society, Bulgaria (1972)
 * Honorary Professor, Instituto Politécnico Nacional, Mexico (1972)
 * Bradford Washburn Award, Museum of Science, Boston, US, (1982)
 * President's Medal, Pacific Lutheran University, Tacoma, US (1996)
 * Honorary Professorship, Western University, Baku, Azerbaijan (1999)

Honorary degrees

 * Doctor Honoris Causa, University of Oslo, Norway (1961)
 * Doctor Honoris Causa, USSR Academy of Science (1980)
 * Doctor Honoris Causa, University of San Martin, Lima, Peru, (1991)
 * Doctor Honoris Causa, University of Havana, Cuba (1992)
 * Doctor Honoris Causa, University of Kyiv, Ukraine (1993)
 * Doctor Honoris Causa, University of Maine, Orono (1998)

Publications

 * På Jakt efter Paradiset (Hunt for Paradise), 1938; Fatu-Hiva: Back to Nature (changed title in English in 1974).
 * The Kon-Tiki Expedition: By Raft Across the South Seas (Kon-Tiki ekspedisjonen, also known as Kon-Tiki: Across the Pacific in a Raft), 1948.
 * American Indians in the Pacific: The Theory Behind the Kon-Tiki Expedition (Chicago: Rand McNally, 1952), 821 pages.
 * Aku-Aku: The Secret of Easter Island, 1957.
 * Archaeology of Easter Island, vol. 1 (London: George Allen and Unwin, 1961), vol. 2 (1965)
 * Sea Routes to Polynesia: American Indians and Early Asiatics in the Pacific (Chicago: Rand McNally, 1968), 232 pages.
 * The Ra Expeditions ISBN 0-14-003462-5.
 * Early Man and the Ocean: The Beginning of Navigation and Seaborn Civilizations, 1979
 * The Tigris Expedition: In Search of Our Beginnings
 * The Maldive Mystery, 1986
 * Green Was the Earth on the Seventh Day: Memories and Journeys of a Lifetime
 * Pyramids of Tucume: The Quest for Peru's Forgotten City
 * Skjebnemøte vest for havet [Fate Meets West of the Ocean], 1992 (in Norwegian and German only) the Native Americans tell their story, white and bearded Gods, infrastructure was not built by the Inkas but their more advanced predecessors.
 * In the Footsteps of Adam: A Memoir (the official edition is Abacus, 2001, translated by Ingrid Christophersen) ISBN 0-349-11273-8
 * Ingen Grenser (No Boundaries, Norwegian only), 1999
 * Jakten på Odin (Theories about Odin, Norwegian only), 2001

title: Thor Heyerdahl