Saturn’s moon Epimetheus is discovered by astronomer Richard Walker.
The South African Border War starts with the battle at Omugulugwombashe.
Vietnam War: The Battle of Long Tan ensues after a patrol from the 6th Battalion, Royal Australian Regiment clashes with a Viet Cong force in Ph??c Tuy Province.
Australian currency is decimalized.
Tashkent Declaration, a peace agreement between India and Pakistan signed that resolved the Indo-Pakistani War of 1965.
The Black Panther Party is founded.
The Ulster Volunteer Force declares war on the Irish Republican Army in Northern Ireland.
21 May: the UVF issued a statement:
From this day, we declare war against the Irish Republican Army and its splinter groups. Known IRA men will be executed mercilessly and without hesitation. Less extreme measures will be taken against anyone sheltering or helping them, but if they persist in giving them aid, then more extreme methods will be adopted… we solemnly warn the authorities to make no more speeches of appeasement. We are heavily armed Protestants dedicated to this cause.
British Guiana gets its independence to become Guyana.
Guyana became an independent nation on Thursday, 26 May 1966, but the independence celebrations began four days before and continued until 29 May. Public buildings and business places were brightly decorated with streamers and buntings bearing the colours of the Guyana flag. On the evening of 25 May, a grand cultural performance took place at the Queen Elizabeth Park. Dignitaries in the audience of thousands included the Duke and Duchess of Kent, representing Queen Elizabeth, and representatives of foreign governments. Then at midnight, the Union Jack, the symbol of British colonial rule for 163 years, was lowered and the new flag of Guyana, the Golden Arrowhead, was raised to the top of the mast. Just before the flag raising ceremony before a huge crowd, Prime Minister Forbes Burnham and Opposition Leader Cheddi Jagan publicly embraced each other, indicating their satisfaction that Guyana had finally won its political independence.
With the raising of the new flag, fireworks burst across the sky in various parts of the country. Then around mid-morning, the State opening of the Parliament of Guyana took place. It was preceded by a military parade accompanied by much pomp and pageantry. Significantly, for this occasion, a portrait of Sir Walter Raleigh decorating the wall of the Parliament chamber was removed and replaced with a portrait of Prime Minister Burnham.
The meeting of Parliament was chaired by the Speaker, Aubrey Alleyne. The Duke of Kent read a throne speech on behalf of the Queen, after which on behalf of the sovereign, Queen Elizabeth, he handed over to Prime Minister Burnham the constitutional instruments designating Guyana an independent nation. Immediately after, there were speeches by Prime Minister Forbes Burnham and Leader of the Opposition Cheddi Jagan.
Burnham, in an appeal to Guyanese nationalism, declared: “The days ahead are going to be difficult. Tomorrow, no doubt, we as Guyanese will indulge in the usual political conflicts and differences in ideology. But today, to my mind, is above such petty matters. For today Guyana is free.”
In welcoming independence, Dr. Jagan seized the opportunity to point out that the Burnham Government was abusing its powers through the extension of the state of emergency beyond the date of independence. This, he said, was generating fear throughout the country and was detrimental to the struggle for peace and security.
He also highlighted the view that his party was “the victim of repeated constitutional manipulations designed to keep it out of office.” He added, “We are confident that despite these manipulations the People’s Progressive Party can be triumphant at future elections if these are fairly held.”
Later that afternoon, Sir Richard Luyt was sworn in by the Duke of Kent as Guyana’s first Governor General at a ceremony in the ballroom of Guyana House, the official residence of the Governor General.
During the period of the independence celebrations, many public events were also held. These included carnival-style parties, exhibitions, float parades and public rallies addressed by Burnham and his Ministers.
On achieving independence, Guyana became the 23rd member of the British Commonwealth. The new state received instant recognition internationally. However, in its note of recognition signed by Foreign Minister Iribarren Borges, the Venezuelan Government stated that it “recognises as territory of the new State the one which is located on the east of the right bank of the Essequibo River”. The Venezuelan note claimed that the boundary between Guyana and Venezuela ran “through the middle line of the Essequibo River, beginning from its source and on to its mouth in the Atlantic Ocean”.
In a response to the Venezuelan Government sent on 18 August 1966, Burnham rejected this assertion and expressly stated that the “Guyana constitution stipulates that the territory of Guyana embraces all that area, which immediately before the 26th May, 1966, comprised the old Colony of British Guiana, together with the area which by Act of Parliament may be declared as part of the territory of Guyana.” He added: “The territory which extends between the middle line of the Essequibo on the east and the boundary of the old Colony of British Guiana all along the rivers Cuyuni and Wanamo on the west, was already included on the 26th May, 1966, judicially and administratively, within the old Colony of British Guiana and forms part of the State of Guyana.”
The Communist Party of China issues its May 16 Notice to start the Cultural Revolution.
The Cultural Revolution, formally the Great Proletarian Cultural Revolution, was a sociopolitical movement in China from 1966 until 1976. Launched by Mao Zedong, then Chairman of the Communist Party of China, its stated goal was to preserve ‘true’ Communist ideology in the country by purging remnants of capitalist and traditional elements from Chinese society, and to re-impose Maoist thought as the dominant ideology within the Party. The Revolution marked Mao’s return to a position of power after the Great Leap Forward. The movement paralyzed China politically and negatively affected the country’s economy and society to a significant degree.
The movement was launched in May 1966, after Mao alleged that bourgeois elements had infiltrated the government and society at large, aiming to restore capitalism. To eliminate his rivals within the Communist Party of China, Mao insisted that these “revisionists” be removed through violent class struggle. China’s youth responded to Mao’s appeal by forming Red Guard groups around the country. The movement spread into the military, urban workers, and the Communist Party leadership itself. It resulted in widespread factional struggles in all walks of life. In the top leadership, it led to a mass purge of senior officials, most notably Liu Shaoqi and Deng Xiaoping. During the same period, Mao’s personality cult grew to immense proportions.
In the violent struggles that ensued across the country, millions of people were persecuted and suffered a wide range of abuses including public humiliation, arbitrary imprisonment, torture, hard labor, sustained harassment, seizure of property and sometimes execution. A large segment of the population was forcibly displaced, most notably the transfer of urban youth to rural regions during the Down to the Countryside Movement. Historical relics and artifacts were destroyed. Cultural and religious sites were ransacked.
Mao officially declared the Cultural Revolution to have ended in 1969, but its active phase lasted until the death of military leader and proposed Mao successor Lin Biao in 1971. After Mao’s death and the arrest of the Gang of Four in 1976, reformers led by Deng Xiaoping gradually began to dismantle the Maoist policies associated with the Cultural Revolution. In 1981, the Party declared that the Cultural Revolution was “responsible for the most severe setback and the heaviest losses suffered by the Party, the country, and the people since the founding of the People’s Republic”.
In May 16, 1966, an “expanded session” of the Politburo was called in Beijing. The conference, rather than being a joint discussion on policy, was essentially a campaign to mobilize the Politburo into endorsing Mao’s political agenda. The conference was heavily laden with Maoist political rhetoric on class struggle, and filled with meticulously-prepared ‘indictments’ on the recently ousted leaders such as Peng Zhen and Luo Ruiqing. One of these documents, released on May 16, was prepared with Mao’s personal supervision, and was particularly damning:
Those representatives of the bourgeoisie who have sneaked into the Party, the government, the army, and various spheres of culture are a bunch of counter-revolutionary revisionists. Once conditions are ripe, they will seize political power and turn the dictatorship of the proletariat into a dictatorship of the bourgeoisie. Some of them we have already seen through; others we have not. Some are still trusted by us and are being trained as our successors, persons like Khruschev for example, who are still nestling beside us.
This text, which became known as the “May 16 Notification”, summarized Mao’s ideological justification for the Cultural Revolution. Effectively it implied that there are enemies of the Communist cause within the Party itself: class enemies who “wave the red flag to oppose the red flag.” The only way to identify these people was through “the telescope and microscope of Mao Zedong Thought.” While the party leadership was relatively united in approving the general direction of Mao’s agenda, many Politburo members were not especially enthusiastic, or simply confused about the direction of the movement. The charges against esteemed party leaders like Peng Zhen rang alarm bells in China’s intellectual community and among the eight non-Communist parties.
Saturn’s moon Epimetheus is first discovered by astronomer Richard Walker.
Epimetheus is an inner satellite of Saturn. It is also known as Saturn XI. It is named after the mythological Epimetheus, brother of Prometheus.
Epimetheus occupies essentially the same orbit as the moon Janus. Astronomers assumed that there was only one body in that orbit, and accordingly had difficulty determining their orbital characteristics. Observations were photographic and spaced widely apart in time, so that while the presence of two objects was not obvious, the observations were difficult to reconcile with a reasonable orbit.
Audouin Dollfus observed a moon on 15 December 1966, which he proposed to be named “Janus”. On 18 December, Richard Walker made a similar observation which is now credited as the discovery of Epimetheus. However, at the time, it was believed that there was only one moon, unofficially known as “Janus”, in the given orbit.
Twelve years later, in October 1978, Stephen M. Larson and John W. Fountain realised that the 1966 observations were best explained by two distinct objects sharing very similar orbits. This was confirmed in 1980 by Voyager 1, and so Larson and Fountain officially share the discovery of Epimetheus with Walker.
Epimetheus received its name in 1983. The name Janus was approved by the IAU at the same time, although the name had been used informally since Dollfus proposed it shortly after the 1966 discovery.
Epimetheus’s orbit is co-orbital with that of Janus. Janus’s mean orbital radius from Saturn is, as of 2006, only 50 km less than that of Epimetheus, a distance smaller than either moon’s mean radius. In accordance with Kepler’s laws of planetary motion, the closer orbit is completed more quickly. Because of the small difference it is completed in only about 30 seconds less. Each day, the inner moon is an additional 0.25° farther around Saturn than the outer moon. As the inner moon catches up to the outer moon, their mutual gravitational attraction increases the inner moon’s momentum and decreases that of the outer moon. This added momentum means that the inner moon’s distance from Saturn and orbital period are increased, and the outer moon’s are decreased. The timing and magnitude of the momentum exchange is such that the moons effectively swap orbits, never approaching closer than about 10,000 km. At each encounter Janus’s orbital radius changes by ~20 km and Epimetheus’s by ~80 km: Janus’s orbit is less affected because it is four times more massive than Epimetheus. The exchange takes place close to every four years; the last close approaches occurred in January 2006, 2010 and 2014, and the next in 2018. This is the only such orbital configuration known in the Solar System.
The orbital relationship between Janus and Epimetheus can be understood in terms of the circular restricted three-body problem, as a case in which the two moons are similar in size to each other.