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🔗 India 🔗 India/Kerala 🔗 India/Indian history

The Thomas of Cana copper plates (Malayalam: Knai Thoma Cheppedu), or Knanaya copper plates, dated variously between 345 C.E. and 811 C.E., are a lost set of copper-plate grants issued by the unidentified Chera/Perumal king of Kerala "Co-qua-rangon" to Syriac Christian merchants led by Knai Thoma (anglicized as Thomas of Cana) in the city of "Makotayar Pattinam" (present day Kodungallur), south India. The royal charters were reportedly engraved in ”Malabar”, Chaldean and Arabic on both sides of two copper plates (joined by a ring). Archbishop Francis Ros notes in his 1604 account M.S. ADD 9853 that the plates were taken to Portugal by the Franciscan Order.

Scholar M.G.S. Narayanan tentatively identifies king “Co-qua-rangon” with king Rama Rajasekhara (Co-qua-rangon → Ko Kotai Iraman → Rajadhiraja Rama) of the 9th century Chera Empire.

The Knanaya or the people of Knai Thoma were historically associated with the southern portion of the Chera/Perumal headquarters Kodungallur until in 1524 they were dispersed from the city due to conflict between the Kingdom of Cochin and the Kingdom of Calicut. The plate was cherished by the Knanaya as evidence of their arrival in Kerala under the leadership of Knai Thoma as well as a notation of the historical, economic, and social rights bestowed upon them by the Chera Perumal. The native Christian tradition places the arrival of Thomas of Cana in 345 C.E.

Translations of the existing Kollam Syrian Plates of the 9th century made by the Syrian Christian priest Ittimani in 1601 as well as the French Indologist Abraham Anquetil Duperron in 1758 both note that the one of the plates mentioned a brief of the arrival of Knai Thoma.It is believed that this was a notation of the previous rights bestowed upon the Christians by Cheraman Perumal. The contemporary set however does not mention this paragraph and is believed to be incomplete or a later inscription. Scholar of Early Christian history István Percvel theorizes that at one time the Kollam Syrian plates and the Thomas of Cana plates were kept together.

🔗 Yugoslavia 🔗 Economics

Despite common origins, the economy of the Socialist Federal Republic of Yugoslavia (SFRY) was significantly different from the economies of the Soviet Union and other Eastern European socialist states, especially after the Yugoslav-Soviet break-up in 1948. The occupation and liberation struggle in World War II left Yugoslavia's infrastructure devastated. Even the most developed parts of the country were largely rural and the little industry of the country was largely damaged or destroyed.

🔗 Physics

The Kelvin water dropper, invented by Scottish scientist William Thomson (Lord Kelvin) in 1867, is a type of electrostatic generator. Kelvin referred to the device as his water-dropping condenser. The apparatus is variously called the Kelvin hydroelectric generator, the Kelvin electrostatic generator, or Lord Kelvin's thunderstorm. The device uses falling water to generate voltage differences by electrostatic induction occurring between interconnected, oppositely charged systems. This eventually leads to an electric arc discharging in the form of a spark. It is used in physics education to demonstrate the principles of electrostatics.

🔗 Science

The Ortega hypothesis holds that average or mediocre scientists contribute substantially to the advancement of science. According to this hypothesis, scientific progress occurs mainly by the accumulation of a mass of modest, narrowly specialized intellectual contributions. On this view, major breakthroughs draw heavily upon a large body of minor and little-known work, without which the major advances could not happen.

🔗 California

Early on the morning of May 16, 1946, a U.S. Army B-17 Flying Fortress aircraft crashed into White's Hill (also known locally as "White Hill") near Fairfax, California. Two men were killed and six seriously injured. There were reports that the B-17 was carrying nuclear weapons materials for the Operation Crossroads tests at Bikini atoll, but these reports were not confirmed. However, due to the behavior and activities of the military authorities at the crash site and the reports of several credible witnesses, including several of the crewmembers, questions about the plane's cargo remain.

🔗 Greece 🔗 Politics 🔗 Elections and Referendums

In governance, sortition (also known as selection by lot, allotment, demarchy, or Stochocracy) is the selection of political officials as a random sample from a larger pool of candidates. Filling individual posts or, more usually in its modern applications, to fill collegiate chambers. The system intends to ensure that all competent and interested parties have an equal chance of holding public office. It also minimizes factionalism, since there would be no point making promises to win over key constituencies if one was to be chosen by lot, while elections, by contrast, foster it. In ancient Athenian democracy, sortition was the traditional and primary method for appointing political officials, and its use was regarded as a principal characteristic of democracy.

Today, sortition is commonly used to select prospective jurors in common law-based legal systems and is sometimes used in forming citizen groups with political advisory power (citizens' juries or citizens' assemblies).

🔗 Biography 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Astronomy 🔗 Smithsonian Institution Archives

Cecilia Helena Payne-Gaposchkin (née Payne; (1900-05-10)May 10, 1900 – (1979-12-07)December 7, 1979) was a British-born American astronomer and astrophysicist who proposed in her 1925 doctoral thesis that stars were composed primarily of hydrogen and helium. Her groundbreaking conclusion was initially rejected because it contradicted the scientific wisdom of the time, which held that there were no significant elemental differences between the Sun and Earth. Independent observations eventually proved she was actually correct

🔗 Economics

"The Market for Lemons: Quality Uncertainty and the Market Mechanism" is a well-known 1970 paper by economist George Akerlof which examines how the quality of goods traded in a market can degrade in the presence of information asymmetry between buyers and sellers, leaving only "lemons" behind. In American slang, a lemon is a car that is found to be defective after it has been bought.

Suppose buyers cannot distinguish between a high-quality car (a "peach") and a "lemon". Then they are only willing to pay a fixed price for a car that averages the value of a "peach" and "lemon" together (p_avg). But sellers know whether they hold a peach or a lemon. Given the fixed price at which buyers will buy, sellers will sell only when they hold "lemons" (since p_lemon < p_avg) and they will leave the market when they hold "peaches" (since p_peach > p_avg). Eventually, as enough sellers of "peaches" leave the market, the average willingness-to-pay of buyers will decrease (since the average quality of cars on the market decreased), leading to even more sellers of high-quality cars to leave the market through a positive feedback loop.

Thus the uninformed buyer's price creates an adverse selection problem that drives the high-quality cars from the market. Adverse selection is a market mechanism that can lead to a market collapse.

Akerlof's paper shows how prices can determine the quality of goods traded on the market. Low prices drive away sellers of high-quality goods, leaving only lemons behind. In 2001, Akerlof, along with Michael Spence, and Joseph Stiglitz, jointly received the Nobel Memorial Prize in Economic Sciences, for their research on issues related to asymmetric information.

🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Numismatics 🔗 Numismatics/Cryptocurrency

Hashcash is a proof-of-work system used to limit email spam and denial-of-service attacks, and more recently has become known for its use in bitcoin (and other cryptocurrencies) as part of the mining algorithm. Hashcash was proposed in 1997 by Adam Back and described more formally in Back's 2002 paper "Hashcash - A Denial of Service Counter-Measure".

🔗 Astronomy

Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) is a program which utilizes high-altitude balloon instrument package intended to measure the heating of the universe by the first stars and galaxies after the big bang and search for the signal of relic decay or annihilation. In July 2006 a strong residual radio source was found using the radiometer, approximately six times what is predicted by theory. This phenomenon is known as "space roar" and remains an unsolved problem in astrophysics.

ARCADE has been funded by the NASA's Science Mission Directorate under the Astronomy and Physics Research and Analysis Suborbital Investigation program. The program is composed of a team led by Alan Kogut of NASA's Goddard Space Flight Center. ARCADE was launched from NASA's Columbia Scientific Balloon Facility in Palestine, Texas, conducted under the auspices of the Balloon Program Office at Wallops Flight Facility. The balloon flew to an altitude of 120,000 feet (37 km), viewing about 7% of the sky during its observations.

The instrument is designed to detect radiation at centimeter wavelengths. The craft contained seven radiometers which were cooled to 2.7 K (−270.45 °C; −454.81 °F) using liquid helium, with the intent to measure temperature differences as small as 1/1000 of a degree against a background which is only 3 K (−270.15 °C; −454.27 °F). The optics in the instrument package were placed near the top of the dewar flask which cooled them in order to prevent the instruments from seeing the walls of the container, thereby simplifying the processing of the observational data. This design choice necessitated the use of superfluid pumps in order to drench the radiometers in liquid helium. The design also utilized heaters in order to create a cloud of helium gas, in place of using a (relatively warm) window, which also simplified processing of the observational data.