Have a deep view into what people are curious about.

🔗 Textile Arts

Polar fleece is a soft napped insulating fabric made from polyester.

🔗 Classical Greece and Rome 🔗 Linguistics

A laconic phrase or laconism is a concise or terse statement, especially a blunt and elliptical rejoinder. It is named after Laconia, the region of Greece including the city of Sparta, whose ancient inhabitants had a reputation for verbal austerity and were famous for their blunt and often pithy remarks.

The frog galvanoscope was a sensitive electrical instrument used to detect voltage in the late eighteenth and nineteenth centuries. It consists of skinned frog's leg with electrical connections to a nerve. The instrument was invented by Luigi Galvani and improved by Carlo Matteucci.

The frog galvanoscope, and other experiments with frogs played a part in the dispute between Galvani and Alessandro Volta over the nature of electricity. The instrument is extremely sensitive and continued to be used well into the nineteenth century, even after electromechanical meters came into use.

🔗 Iran 🔗 Ancient Near East 🔗 Law 🔗 Assyria 🔗 Politics 🔗 Iraq 🔗 Israel

The Code of Hammurabi is a well-preserved Babylonian code of law of ancient Mesopotamia, dated to about 1754 BC (Middle Chronology). It is one of the oldest deciphered writings of significant length in the world. The sixth Babylonian king, Hammurabi, enacted the code. A partial copy exists on a 2.25-metre-tall (7.5 ft) stone stele. It consists of 282 laws, with scaled punishments, adjusting "an eye for an eye, a tooth for a tooth" (lex talionis) as graded based on social stratification depending on social status and gender, of slave versus free, man versus woman.

Nearly half of the code deals with matters of contract, establishing the wages to be paid to an ox driver or a surgeon for example. Other provisions set the terms of a transaction, the liability of a builder for a house that collapses, or property that is damaged while left in the care of another. A third of the code addresses issues concerning household and family relationships such as inheritance, divorce, paternity, and reproductive behavior. Only one provision appears to impose obligations on a government official; this provision establishes that a judge who alters his decision after it is written down is to be fined and removed from the bench permanently. A few provisions address issues related to military service.

The code was discovered by modern archaeologists in 1901, and its editio princeps translation published in 1902 by Jean-Vincent Scheil. This nearly complete example of the code is carved into a diorite stele in the shape of a huge index finger, 2.25 m (7.4 ft) tall. The code is inscribed in the Akkadian language, using cuneiform script carved into the stele. The material was imported into Sumeria from Magan - today the area covered by the United Arab Emirates and Oman.

It is currently on display in the Louvre, with replicas in numerous institutions, including the Oriental Institute at the University of Chicago, the Northwestern Pritzker School of Law in Chicago, the Clendening History of Medicine Library & Museum at the University of Kansas Medical Center, the library of the Theological University of the Reformed Churches in the Netherlands, the Pergamon Museum of Berlin, the Arts Faculty of the University of Leuven in Belgium, the National Museum of Iran in Tehran, the Department of Anthropology, National Museum of Natural History, Smithsonian Institution, the University Museum at the University of Pennsylvania, the Pushkin State Museum of Fine Arts in Russia, the Prewitt-Allen Archaeological Museum at Corban University, Garrett-Evangelical Theological Seminary, and Museum of the Bible in Washington, DC.

🔗 United States 🔗 Disaster management 🔗 Medicine 🔗 Viruses 🔗 Korea 🔗 COVID-19 🔗 Europe 🔗 China/Chinese history 🔗 Iran 🔗 North America 🔗 Medicine/Pulmonology 🔗 Italy 🔗 China 🔗 East Asia

The 2019–20 coronavirus pandemic is an ongoing pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The outbreak was first identified in Wuhan, Hubei, China, in December 2019, and was recognized as a pandemic by the World Health Organization (WHO) on 11 March. As of 28 March 2020, more than 663,000 cases of COVID-19 have been reported in over 190 countries and territories, resulting in approximately 30,800 deaths. More than 141,000 people have since recovered.

The virus is mainly spread during close contact and via respiratory droplets produced when people cough or sneeze. Respiratory droplets may be produced during breathing but the virus is not considered airborne. People may also catch COVID-19 by touching a contaminated surface and then their face. It is most contagious when people are symptomatic, although spread may be possible before symptoms appear. The time between exposure and symptom onset is typically around five days, but may range from 2 to 14 days. Common symptoms include fever, cough, and shortness of breath. Complications may include pneumonia and acute respiratory distress syndrome. There is no known vaccine or specific antiviral treatment. Primary treatment is symptomatic and supportive therapy. Recommended preventive measures include hand washing, covering one's mouth when coughing, maintaining distance from other people, and monitoring and self-isolation for people who suspect they are infected.

Efforts to prevent the virus spreading include travel restrictions, quarantines, curfews, workplace hazard controls, event postponements and cancellations, and facility closures. These include the quarantine of Hubei, national or regional quarantines elsewhere in the world, curfew measures in China and South Korea, various border closures or incoming passenger restrictions, screening at airports and train stations, and outgoing passenger travel bans. Schools and universities have closed either on a nationwide or local basis in more than 160 countries, affecting more than 1.5 billion students.

The pandemic has led to severe global socioeconomic disruption, the postponement or cancellation of sporting, religious, and cultural events, and widespread fears of supply shortages which have spurred panic buying. Misinformation and conspiracy theories about the virus have spread online, and there have been incidents of xenophobia and racism against Chinese and other East and Southeast Asian people.

🔗 Computer science

In computer science, the shunting-yard algorithm is a method for parsing mathematical expressions specified in infix notation. It can produce either a postfix notation string, also known as Reverse Polish notation (RPN), or an abstract syntax tree (AST). The algorithm was invented by Edsger Dijkstra and named the "shunting yard" algorithm because its operation resembles that of a railroad shunting yard. Dijkstra first described the Shunting Yard Algorithm in the Mathematisch Centrum report MR 34/61.

Like the evaluation of RPN, the shunting yard algorithm is stack-based. Infix expressions are the form of mathematical notation most people are used to, for instance "3 + 4" or "3 + 4 × (2 − 1)". For the conversion there are two text variables (strings), the input and the output. There is also a stack that holds operators not yet added to the output queue. To convert, the program reads each symbol in order and does something based on that symbol. The result for the above examples would be (in Reverse Polish notation) "3 4 +" and "3 4 2 1 − × +", respectively.

The shunting-yard algorithm was later generalized into operator-precedence parsing.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Business 🔗 Philosophy/Philosophy of science 🔗 Science

Wronger than wrong is a statement that equates two errors when one of the errors is clearly more wrong than the other. It was described by Michael Shermer as Asimov's axiom. The mistake was discussed in Isaac Asimov's book of essays The Relativity of Wrong as well as in a 1989 article of the same name in the Fall 1989 issue of the Skeptical Inquirer:

When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical, they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together.

Asimov explained that science is both progressive and cumulative. Even though scientific theories are later proven wrong, the degree of their wrongness attenuates with time as they are modified in response to the mistakes of the past. For example, data collected from satellite measurements show, to a high level of precision, how the Earth's shape differs from a perfect sphere or even an oblate spheroid or a geoid.

Shermer stated that being wronger than wrong is actually worse than being not even wrong (that is, being unfalsifiable).

According to John Jenkins, who reviewed The Relativity of Wrong, the title essay of Asimov's book is the one "which I think is important both for understanding Asimov's thinking about science and for arming oneself against the inevitable anti-science attack that one often hears – [that] theories are always preliminary and science really doesn't 'know' anything."

🔗 Geology

The Messinian Salinity Crisis (MSC), also referred to as the Messinian Event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partly or nearly complete desiccation throughout the latter part of the Messinian age of the Miocene epoch, from 5.96 to 5.33 Ma (million years ago). It ended with the Zanclean flood, when the Atlantic reclaimed the basin.

Sediment samples from below the deep seafloor of the Mediterranean Sea, which include evaporite minerals, soils, and fossil plants, show that the precursor of the Strait of Gibraltar closed tight about 5.96 million years ago, sealing the Mediterranean off from the Atlantic. This resulted in a period of partial desiccation of the Mediterranean Sea, the first of several such periods during the late Miocene. After the strait closed for the last time around 5.6 Ma, the region's generally dry climate at the time dried the Mediterranean basin out nearly completely within a thousand years. This massive desiccation left a deep dry basin, reaching 3 to 5 km (1.9 to 3.1 mi) deep below normal sea level, with a few hypersaline pockets similar to today's Dead Sea. Then, around 5.5 Ma, less dry climatic conditions resulted in the basin receiving more freshwater from rivers, progressively filling and diluting the hypersaline lakes into larger pockets of brackish water (much like today's Caspian Sea). The Messinian Salinity Crisis ended with the Strait of Gibraltar finally reopening 5.33 Ma, when the Atlantic rapidly filled up the Mediterranean basin in what is known as the Zanclean flood.

Even today, the Mediterranean is considerably saltier than the North Atlantic, owing to its near isolation by the Strait of Gibraltar and its high rate of evaporation. If the Strait of Gibraltar closes again (which is likely to happen in the near future on a geological time scale), the Mediterranean would mostly evaporate in about a thousand years, after which continued northward movement of Africa may obliterate the Mediterranean altogether.

Only the inflow of Atlantic water maintains the present Mediterranean level. When that was shut off sometime between 6.5 to 6 MYBP, net evaporative loss set in at the rate of around 3,300 cubic kilometers yearly. At that rate, the 3.7 million cubic kilometres of water in the basin would dry up in scarcely more than a thousand years, leaving an extensive layer of salt some tens of meters thick and raising global sea level about 12 meters.

🔗 United States 🔗 Technology 🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Canada 🔗 Aviation/aircraft 🔗 Engineering 🔗 Cold War 🔗 Military history/Military land vehicles 🔗 Military history/Canadian military history

The Avro Canada VZ-9 Avrocar was a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.

Originally designed as a fighter-like aircraft capable of very high speeds and altitudes, the project was repeatedly scaled back over time and the U.S. Air Force eventually abandoned it. Development was then taken up by the U.S. Army for a tactical combat aircraft requirement, a sort of high-performance helicopter. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in September 1961.

Through the history of the program, the project was referred to by a number of different names. Avro referred to the efforts as Project Y, with individual vehicles known as Spade and Omega. Project Y-2 was later funded by the U.S. Air Force, who referred to it as WS-606A, Project 1794 and Project Silver Bug. When the U.S. Army joined the efforts it took on its final name "Avrocar", and the designation "VZ-9", part of the U.S. Army's VTOL projects in the VZ series.

🔗 Spaceflight

HAL/S (High-order Assembly Language/Shuttle) is a real-time aerospace programming language compiler and cross-compiler for avionics applications used by NASA and associated agencies (JPL, etc.). It has been used in many U.S. space projects since 1973 and its most significant use was in the Space Shuttle program (approximately 85% of the Shuttle software is coded in HAL/S). It was designed by Intermetrics in 1972 for NASA and delivered in 1973. HAL/S is written in XPL, a dialect of PL/I. Although HAL/S is designed primarily for programming on-board computers, it is general enough to meet nearly all the needs in the production, verification, and support of aerospace and other real-time applications. According to documentation from 2005, it was being maintained by the HAL/S project of United Space Alliance.