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🔗 Physics

Certain systems can achieve negative thermodynamic temperature; that is, their temperature can be expressed as a negative quantity on the Kelvin or Rankine scales. This should be distinguished from temperatures expressed as negative numbers on non-thermodynamic Celsius or Fahrenheit scales, which are nevertheless higher than absolute zero.

The absolute temperature (Kelvin) scale can be understood loosely as a measure of average kinetic energy. Usually, system temperatures are positive. However, in particular isolated systems, the temperature defined in terms of Boltzmann's entropy can become negative.

The possibility of negative temperatures was first predicted by Lars Onsager in 1949, in his analysis of classical point vortices confined to a finite area. Confined point vortices are a system with bounded phase space as their canonical momenta are not independent degrees of freedom from their canonical position coordinates. Bounded phase space is the essential property that allows for negative temperatures, and such temperatures can occur in both classical and quantum systems. As shown by Onsager, a system with bounded phase space necessarily has a peak in the entropy as energy is increased. For energies exceeding the value where the peak occurs, the entropy decreases as energy increases, and high-energy states necessarily have negative Boltzmann temperature.

A system with a truly negative temperature on the Kelvin scale is hotter than any system with a positive temperature. If a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system. A standard example of such a system is population inversion in laser physics.

Temperature is loosely interpreted as the average kinetic energy of the system's particles. The existence of negative temperature, let alone negative temperature representing "hotter" systems than positive temperature, would seem paradoxical in this interpretation. The paradox is resolved by considering the more rigorous definition of thermodynamic temperature as the tradeoff between internal energy and entropy contained in the system, with "coldness", the reciprocal of temperature, being the more fundamental quantity. Systems with a positive temperature will increase in entropy as one adds energy to the system, while systems with a negative temperature will decrease in entropy as one adds energy to the system.

Thermodynamic systems with unbounded phase space cannot achieve negative temperatures: adding heat always increases their entropy. The possibility of a decrease in entropy as energy increases requires the system to "saturate" in entropy. This is only possible if the number of high energy states is limited. For a system of ordinary (quantum or classical) particles such as atoms or dust, the number of high energy states is unlimited (particle momenta can in principle be increased indefinitely). Some systems, however (see the examples below), have a maximum amount of energy that they can hold, and as they approach that maximum energy their entropy actually begins to decrease. The limited range of states accessible to a system with negative temperature means that negative temperature is associated with emergent ordering of the system at high energies. For example in Onsager's point-vortex analysis negative temperature is associated with the emergence of large-scale clusters of vortices. This spontaneous ordering in equilibrium statistical mechanics goes against common physical intuition that increased energy leads to increased disorder.

🔗 Transport 🔗 Trains

The Cosmopolitan Railway was a proposed global railroad network advocated by William Gilpin, formerly the first territorial governor of Colorado (1861–62), in his 1890 treatise Cosmopolitan Railway: Compacting and Fusing Together All the World's Continents. Gilpin named his capital city of Denver as the "railroad centre of the West".

🔗 Cognitive science

Soar is a cognitive architecture, originally created by John Laird, Allen Newell, and Paul Rosenbloom at Carnegie Mellon University. (Rosenbloom continued to serve as co-principal investigator after moving to Stanford University, then to the University of Southern California's Information Sciences Institute.) It is now maintained and developed by John Laird's research group at the University of Michigan.

The goal of the Soar project is to develop the fixed computational building blocks necessary for general intelligent agents – agents that can perform a wide range of tasks and encode, use, and learn all types of knowledge to realize the full range of cognitive capabilities found in humans, such as decision making, problem solving, planning, and natural language understanding. It is both a theory of what cognition is and a computational implementation of that theory. Since its beginnings in 1983 as John Laird’s thesis, it has been widely used by AI researchers to create intelligent agents and cognitive models of different aspects of human behavior. The most current and comprehensive description of Soar is the 2012 book, The Soar Cognitive Architecture.

🔗 Espionage 🔗 Internet 🔗 Russia 🔗 Russia/mass media in Russia 🔗 Russia/Russian, Soviet, and CIS military history 🔗 Russia/politics and law of Russia

Russian web brigades, also called Russian trolls, Russian bots, or more recently Kremlin Bots (after the Kremlin in Moscow) / Kremlins (a pejorative allusion to Gremlin) are state-sponsored anonymous Internet political commentators and trolls linked to the Government of Russia. Participants report that they are organized into teams and groups of commentators that participate in Russian and international political blogs and Internet forums using sockpuppets, social bots and large-scale orchestrated trolling and disinformation campaigns to promote pro-Putin and pro-Russian propaganda. Articles on the Russian Wikipedia concerning the MH17 crash and the 2014 Ukraine conflict were targeted by Russian internet propaganda outlets.

🔗 International relations 🔗 France 🔗 Law 🔗 Politics 🔗 Basque 🔗 Islands 🔗 Spain

Pheasant Island (French: Île des Faisans/Île de la Conférence, Spanish: Isla de los Faisanes, Basque: Konpantzia) is an uninhabited river island in the Bidasoa river, located between France and Spain, whose administration alternates between both nations.

🔗 Aviation 🔗 Oregon 🔗 Textile Arts 🔗 Aviation/airport

The carpet at Portland International Airport (PDX) in Portland, Oregon, featured geometric shapes on a teal background, representing the intersection of the north and south runways seen by air traffic controllers from the airport's tower at night. SRG Partnership designed it in 1987, and since then, the carpet has received much media attention.

In 2013, the Port of Portland announced the carpet's replacement with a new pattern conceptualized by the Portland-based firm Zimmer Gunsul Frasca Architects. The announcement generated a social media "phenomenon" and gained attention from local and national news outlets. Removal of the original carpet began in January 2015, with the airport recycling worn portions and making remaining pieces available for sale by local retail vendors.

In 2015, Portland Trail Blazers point guard Damian Lillard released his first PDX carpet colorway on the Adidas D Lillard 1 sneaker. In 2016, Lillard released the colorway on the D Lillard 2, also inspired by the carpet.

In February of 2022, it was announced that the iconic carpet would be returning to the airport when a new terminal opens in 2024.

🔗 Philosophy 🔗 Psychology

Kettle logic (la logique du chaudron in the original French) is a rhetorical device wherein one uses multiple arguments to defend a point, but the arguments are inconsistent with each other.

Jacques Derrida uses this expression in reference to the humorous "kettle-story", that Sigmund Freud relates in The Interpretation of Dreams (1900) and Jokes and Their Relation to the Unconscious (1905).

🔗 Philosophy 🔗 Philosophy/Logic

Erotetics or erotetic logic is a part of logic, devoted to logical analysis of questions. It is sometimes called the logic of questions and answers.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Palestine 🔗 Western Asia 🔗 Military history/Middle Eastern military history 🔗 Western Asia/Kuwait

The Highway of Death (Arabic: طريق الموت ṭarīq al-mawt) is a six-lane highway between Kuwait and Iraq, officially known as Highway 80. It runs from Kuwait City to the border town of Safwan in Iraq and then on to the Iraqi city of Basra. The road was used by Iraqi armored divisions for the 1990 invasion of Kuwait. It was repaired after the Gulf War and used by U.S. and British forces in the initial stages of the 2003 invasion of Iraq.

During the American-led coalition offensive in the Persian Gulf War, American, Canadian, British and French aircraft and ground forces attacked retreating Iraqi military personnel attempting to leave Kuwait on the night of February 26–27, 1991, resulting in the destruction of hundreds of vehicles and the deaths of many of their occupants. Between 1,400 and 2,000 vehicles were hit or abandoned on the main Highway 80 north of Al Jahra.

The scenes of devastation on the road are some of the most recognizable images of the war, and it has been suggested that they were a factor in President George H. W. Bush's decision to declare a cessation of hostilities the next day. Many Iraqi forces successfully escaped across the Euphrates river, and the U.S. Defense Intelligence Agency estimated that upwards of 70,000 to 80,000 troops from defeated divisions in Kuwait might have fled into Basra, evading capture.