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πŸ”— Planet Vulcan

πŸ”— Astronomy πŸ”— History of Science πŸ”— Astronomy/Astronomical objects πŸ”— Astronomy/Solar System

Vulcan was a theorized planet that some pre-20th century astronomers thought existed in an orbit between Mercury and the Sun. Speculation about, and even purported observations of, intermercurial bodies or planets date back to the beginning of the 17th century. The case for their probable existence was bolstered by the support of the French mathematician Urbain Le Verrier, who had predicted the existence of Neptune using disturbances in the orbit of Uranus. By 1859 he had confirmed unexplained peculiarities in Mercury's orbit and predicted that they had to be the result of the gravitational influence of another unknown nearby planet or series of asteroids. A French amateur astronomer's report that he had observed an object passing in front of the Sun that same year led Le Verrier to announce that the long sought after planet, which he gave the name Vulcan, had been discovered at last.

Many searches were conducted for Vulcan over the following decades, but despite several claimed observations, its existence could not be confirmed. The need for the planet as an explanation for Mercury's orbital peculiarities was later rendered unnecessary when Einstein's 1915 theory of general relativity showed that Mercury's departure from an orbit predicted by Newtonian physics was explained by effects arising from the curvature of spacetime caused by the Sun's mass.

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πŸ”— Sloyd

πŸ”— Education

Sloyd (SlΓΆjd), also known as Educational sloyd, is a system of handicraft-based education started by Uno Cygnaeus in Finland in 1865. The system was further refined and promoted worldwide, and was taught in the United States until the early 20th Century. It is still taught as a compulsory subject in Finnish, Danish, Swedish and Norwegian schools.

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  • "Sloyd" | 2017-10-22 | 131 Upvotes 38 Comments

πŸ”— Apollo 15 postage stamp incident

πŸ”— United States πŸ”— Spaceflight πŸ”— Philately πŸ”— Guild of Copy Editors

The Apollo 15 postal covers incident, a 1972 NASA scandal, involved the astronauts of Apollo 15, who carried about 400 unauthorized postal covers into space and to the Moon's surface on the Lunar Module Falcon. Some of the envelopes were sold at high prices by West German stamp dealer Hermann Sieger, and are known as "Sieger covers". The crew of Apollo 15, David Scott, Alfred Worden and James Irwin, agreed to take payments for carrying the covers; though they returned the money, they were reprimanded by NASA. Amid much press coverage of the incident, the astronauts were called before a closed session of a Senate committee and never flew in space again.

The three astronauts and an acquaintance, Horst Eiermann, had agreed to have the covers made and taken into space. Each astronaut was to receive about $7,000. Scott arranged to have the covers postmarked on the morning of the Apollo 15 launch on July 26, 1971. They were packaged for space and brought to him as he prepared for liftoff. Due to an error, they were not included on the list of the personal items he was taking into space. The covers spent July 30 to August 2 on the Moon inside Falcon. On August 7, the date of splashdown, the covers were postmarked again on the recovery carrier USSΒ Okinawa. One hundred were sent to Eiermann (and passed on to Sieger); the remaining covers were divided among the astronauts.

Worden had agreed to carry 144 additional covers, largely for an acquaintance, F. Herrick Herrick; these had been approved for travel to space. Apollo 15 carried a total of approximately 641 covers. In late 1971, when NASA learned that the Herrick covers were being sold, the astronauts' supervisor, Deke Slayton, warned Worden to avoid further commercialization of what he had been allowed to take into space. After Slayton heard of the Sieger arrangement, he removed the three as backup crew members for Apollo 17, though the astronauts had by then refused compensation from Sieger and Eiermann. The Sieger matter became generally known in the newspapers in June 1972. There was widespread coverage; some said astronauts should not be allowed to reap personal profits from NASA missions.

By 1977, all three former astronauts had left NASA. In 1983, Worden sued, and the covers were returned to them. One of the postal covers given to Sieger sold for over $50,000 in 2014.

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πŸ”— Human-powered helicopter

πŸ”— Aviation πŸ”— Cycling πŸ”— Aviation/rotorcraft project

A human-powered helicopter (HPH) is a helicopter powered solely by one or more humans carried on board. As in other human-powered aircraft, the power is usually generated by pedalling. It remains a considerable engineering challenge to obtain both the power-to-weight ratio and rotor efficiency required to sustain a helicopter in flight.

On 13 June 2013, the AeroVelo Atlas was the first to complete a flight that lasted 64 seconds and reached an altitude of 3.3 metres, thus winning the American Helicopter Society (AHS) International's Igor I. Sikorsky Human Powered Helicopter Competition.

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πŸ”— Gray Goo

πŸ”— Technology πŸ”— Science Fiction πŸ”— Transhumanism

Gray goo (also spelled grey goo) is a hypothetical global catastrophic scenario involving molecular nanotechnology in which out-of-control self-replicating machines consume all biomass on Earth while building more of themselves, a scenario that has been called ecophagy ("eating the environment", more literally "eating the habitation"). The original idea assumed machines were designed to have this capability, while popularizations have assumed that machines might somehow gain this capability by accident.

Self-replicating machines of the macroscopic variety were originally described by mathematician John von Neumann, and are sometimes referred to as von Neumann machines or clanking replicators. The term gray goo was coined by nanotechnology pioneer K. Eric Drexler in his 1986 book Engines of Creation. In 2004 he stated, "I wish I had never used the term 'gray goo'." Engines of Creation mentions "gray goo" in two paragraphs and a note, while the popularized idea of gray goo was first publicized in a mass-circulation magazine, Omni, in November 1986.

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πŸ”— Taxation of illegal income in the United States

πŸ”— United States πŸ”— Law πŸ”— Taxation

Taxation of illegal income in the United States arises from the provisions of the Internal Revenue Code (IRC), enacted by the U.S. Congress in part for the purpose of taxing net income. As such, a person's taxable income will generally be subject to the same Federal income tax rules, regardless of whether the income was obtained legally or illegally.

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πŸ”— Sure-thing principle

In decision theory, the sure-thing principle states that a decision maker who would take a certain action if he knew that event E has occurred, and also if he knew that the negation of E has occurred, should also take that same action if he knows nothing about E.

The principle was coined by L.J. Savage:

A businessman contemplates buying a certain piece of property. He considers the outcome of the next presidential election relevant. So, to clarify the matter to himself, he asks whether he would buy if he knew that the Democratic candidate were going to win, and decides that he would. Similarly, he considers whether he would buy if he knew that the Republican candidate were going to win, and again finds that he would. Seeing that he would buy in either event, he decides that he should buy, even though he does not know which event obtains, or will obtain, as we would ordinarily say. It is all too seldom that a decision can be arrived at on the basis of this principle, but except possibly for the assumption of simple ordering, I know of no other extralogical principle governing decisions that finds such ready acceptance.

He formulated the principle as a dominance principle, but it can also be framed probabilistically. Richard Jeffrey and later Judea Pearl showed that Savage's principle is only valid when the probability of the event considered (e.g., the winner of the election) is unaffected by the action (buying the property). Under such conditions, the sure-thing principle is a theorem in the do-calculus (see Bayes networks). Blyth constructed a counterexample to the sure-thing principle using sequential sampling in the context of Simpson's paradox, but this example violates the required action-independence provision.

The principle is closely related to independence of irrelevant alternatives, and equivalent under the axiom of truth (everything the agent knows is true). It is similarly targeted by the Ellsberg and Allais paradoxes, in which actual people's choices seem to violate this principle.

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πŸ”— Hagia Triada Sarcophagus

πŸ”— Death πŸ”— Classical Greece and Rome πŸ”— Archaeology

The Hagia Triada Sarcophagus is a late Minoan 137Β cm (54Β in)-long limestone sarcophagus, dated to about 1400 BC or some decades later, excavated from a chamber tomb at Hagia Triada, Crete in 1903, and now on display in the Heraklion Archaeological Museum ("AMH") in Crete.

Uniquely for such a piece from this date on Crete, it is coated in plaster and painted in fresco on all faces. Otherwise the Minoans (unlike the ancient Egyptians) only used frescoes to decorate palaces and houses for the enjoyment of the living and not in funerary practice. It is the only limestone sarcophagus of its era discovered to date; there are a number of smaller terracotta "ash-chests" (larnax), painted far more crudely, usually in a single colour. It is the only object with a series of narrative scenes of Minoan funerary ritual (later sarcophagi found in the Aegean were decorated with abstract designs and patterns). It was probably originally used for the burial of a prince.

It provides probably the most comprehensive iconography of a pre-Homeric thysiastikis ceremony and one of the best pieces of information on noble burial customs when Crete was under Mycenaean rule, combining features of Minoan and Mycenaean style and subject matter, as well as probable influence from Ancient Egyptian religion.

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πŸ”— Erewhon

πŸ”— Novels πŸ”— Novels/19th century πŸ”— Novels/Science fiction πŸ”— New Zealand πŸ”— Sociology

Erewhon: or, Over the Range () is a novel by English writer Samuel Butler, first published anonymously in 1872, set in a fictional country discovered and explored by the protagonist. The book is a satire on Victorian society.

The first few chapters of the novel dealing with the discovery of Erewhon are in fact based on Butler's own experiences in New Zealand, where, as a young man, he worked as a sheep farmer on Mesopotamia Station for about four years (1860–64), and explored parts of the interior of the South Island and wrote about in his A First Year in Canterbury Settlement (1863).

The novel is one of the first to explore ideas of artificial intelligence, as influenced by Darwin's recently published On the Origin of Species (1859) and the machines developed out of the Industrial Revolution (late 18th to early 19th centuries). Specifically, it concerns itself, in the three-chapter "Book of the Machines", with the potentially dangerous ideas of machine consciousness and self-replicating machines.

πŸ”— Yuan Longping has died

πŸ”— Biography πŸ”— China πŸ”— Biography/science and academia

Yuan Longping (Chinese: θ’ιš†εΉ³; September 7, 1930 – May 22, 2021) was a Chinese agronomist, member of the Chinese Academy of Engineering, known for developing the first hybrid rice varieties in the 1970s.

Hybrid rice has since been grown in dozens of countries in Africa, America, and Asiaβ€”providing a robust food source in areas with a high risk of famine. For his contributions, Yuan is always called the "Father of Hybrid Rice" by the Chinese media. On May 22, 2021, Yuan Longping died of multiple organ failure at the age of 90.

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