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🔗 Robotics 🔗 Transhumanism

In aesthetics, the uncanny valley is a hypothesized relationship between the degree of an object's resemblance to a human being and the emotional response to such an object. The concept of the uncanny valley suggests that humanoid objects which imperfectly resemble actual human beings provoke uncanny or strangely familiar feelings of eeriness and revulsion in observers. "Valley" denotes a dip in the human observer's affinity for the replica, a relation that otherwise increases with the replica's human likeness.

Examples can be found in robotics, 3D computer animations, and lifelike dolls among others. With the increasing prevalence of virtual reality, augmented reality, and photorealistic computer animation, the "valley" has been cited in the popular press in reaction to the verisimilitude of the creation as it approaches indistinguishability from reality. The uncanny valley hypothesis predicts that an entity appearing almost human will risk eliciting cold, eerie feelings in viewers.

🔗 Statistics

Extreme value theory or extreme value analysis (EVA) is a branch of statistics dealing with the extreme deviations from the median of probability distributions. It seeks to assess, from a given ordered sample of a given random variable, the probability of events that are more extreme than any previously observed. Extreme value analysis is widely used in many disciplines, such as structural engineering, finance, earth sciences, traffic prediction, and geological engineering. For example, EVA might be used in the field of hydrology to estimate the probability of an unusually large flooding event, such as the 100-year flood. Similarly, for the design of a breakwater, a coastal engineer would seek to estimate the 50-year wave and design the structure accordingly.

🔗 Medicine 🔗 Viruses

Original antigenic sin, also known as antigenic imprinting or the Hoskins effect, refers to the propensity of the body's immune system to preferentially utilize immunological memory based on a previous infection when a second slightly different version of that foreign pathogen (e.g. a virus or bacterium) is encountered. This leaves the immune system "trapped" by the first response it has made to each antigen, and unable to mount potentially more effective responses during subsequent infections. Antibodies or T-cells induced during infections with the first variant of the pathogen are subject to a form of original antigenic sin, termed repertoire freeze.

The phenomenon of original antigenic sin has been described in relation to influenza virus, dengue fever, human immunodeficiency virus (HIV) and to several other viruses.

This phenomenon was first described in 1960 by Thomas Francis Jr. in the article "On the Doctrine of Original Antigenic Sin". It is named by analogy to the theological concept of original sin. According to Francis as cited by Richard Krause:

"The antibody of childhood is largely a response to dominant antigen of the virus causing the first type A influenza infection of the lifetime. [...] The imprint established by the original virus infection governs the antibody response thereafter. This we have called the Doctrine of the Original Antigenic Sin."

🔗 Companies 🔗 Computing

The STacy is a portable computer version of the Atari ST.

The computer was originally designed to operate on 12 standard C cell flashlight batteries for portability. When Atari realized how quickly the machine would use up a set of batteries (especially when rechargeable batteries of the time supplied insufficient power compared to the intended alkalines), they simply glued the lid of the battery compartment shut.

The STacy has features similar to the Macintosh Portable, a version of Apple's Macintosh computer which contained a built in keyboard and monitor.

With built-in MIDI, the STacy enjoyed success for running music-sequencer software and as a controller of musical instruments among both amateurs and well-known musicians.

🔗 Cryptography 🔗 Cryptography/Computer science

In cryptography, a random oracle is an oracle (a theoretical black box) that responds to every unique query with a (truly) random response chosen uniformly from its output domain. If a query is repeated, it responds the same way every time that query is submitted.

Stated differently, a random oracle is a mathematical function chosen uniformly at random, that is, a function mapping each possible query to a (fixed) random response from its output domain.

Random oracles as a mathematical abstraction were firstly used in rigorous cryptographic proofs in the 1993 publication by Mihir Bellare and Phillip Rogaway (1993). They are typically used when the proof cannot be carried out using weaker assumptions on the cryptographic hash function. A system that is proven secure when every hash function is replaced by a random oracle is described as being secure in the random oracle model, as opposed to secure in the standard model of cryptography.

🔗 Environment 🔗 London 🔗 History of Science

Fumifugium, or, The inconveniencie of the aer and smoak of London dissipated together with some remedies humbly proposed by J.E. esq. to His Sacred Majestie, and to the Parliament now assembled is a pamphlet published in London, 1661 (see 1661 in literature), by John Evelyn. It is one of the earliest known works on air pollution and is broken down into three parts which explain the problem, a proposed solution, and a way of improvement upon the air in London. The letter was specifically addressed to King Charles II of England and discussed problems with the capital's air pollution dating back to medieval times. Evelyn refers to Greek philosophers, who once believed that air was the principle of the earth and primary substance of the soul up until the time that air pollution began to cause ill health.

Evelyn was appointed to the newly formed Royal Society, and both Society and pamphlet are celebrated in the 1663 "Ballad of Gresham College". Stanza 23 (given here in modern English) describes how Evelyn

[...] shows that 'tis the sea-coal smoke

That always London does environ,
Which does our lungs and spirits choke,
Our hanging spoil, and rust our iron.
Let none at Fumifuge be scoffing

Who heard at Church our Sunday's coughing.

The sea-coal to which Evelyn referred was appropriately named because it came by sea from Newcastle. When burned, it gave off a terrible smell because of high amounts of sulfur in its composition. When burned the sea coal released sulfur dioxide, carbon dioxide, nitric oxide, soot, and particulates of organic matter into the atmosphere. The pamphlet suggests that burning wood, particularly aromatic woods, will be less harmful to the lungs and recommends relocating some of London's more polluting industries outside the capital, in particular lime-burning and brewing.

🔗 Soviet Union 🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Environment 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/Cold War 🔗 Russia/Russian, Soviet, and CIS military history 🔗 Military history/Russian, Soviet and CIS military history 🔗 Russia/history of Russia

The Soviet RDS-202 hydrogen bomb (code name Ivan or Vanya), known by Western nations as Tsar Bomba (Russian: Царь-бо́мба, tr. Tsar'-bómba, IPA: [t͡sarʲ ˈbombə], lit. 'Tsar bomb'), was the most powerful nuclear weapon ever created. Tested on 30 October 1961 as an experimental verification of calculation principles and multi-stage thermonuclear weapon designs, it also remains the most powerful human-made explosive ever detonated.

The bomb was detonated at the Sukhoy Nos ("Dry Nose") cape of Severny Island, Novaya Zemlya, 15 km (9.3 mi) from Mityushikha Bay, north of Matochkin Strait. The detonation was secret but was detected by US Intelligence agencies. The US apparently had an instrumented KC-135R aircraft (Operation SpeedLight) in the area of the test – close enough to have been scorched by the blast.

The bhangmeter results and other data suggested the bomb yielded about 58 megatons of TNT [Mt] (240 PJ), and that was the accepted yield in technical literature until 1991 when Soviet scientists revealed that their instruments indicated a yield of 50 Mt (210 PJ). As they had the instrumental data and access to the test site, their yield figure has been accepted as more accurate. In theory, the bomb would have had a yield in excess of 100 Mt (420 PJ) if it had included a uranium-238 tamper but, because only one bomb was built, that capability has never been demonstrated.

The remaining bomb casings are located at the Russian Atomic Weapon Museum in Sarov and the Museum of Nuclear Weapons, All-Russian Research Institute of Technical Physics, at Snezhinsk.

🔗 Philosophy 🔗 Greece 🔗 Cognitive science 🔗 Philosophy/Ancient philosophy 🔗 Alternative Views 🔗 Philosophy/Epistemology

The Allegory of the Cave, or Plato's Cave, is an allegory presented by the Greek philosopher Plato in his work Republic (514a–520a) to compare "the effect of education (παιδεία) and the lack of it on our nature". It is written as a dialogue between Plato's brother Glaucon and his mentor Socrates, narrated by the latter. The allegory is presented after the analogy of the sun (508b–509c) and the analogy of the divided line (509d–511e).

In the allegory "The Cave", Plato describes a group of people who have lived chained to the wall of a cave all their lives, facing a blank wall. The people watch shadows projected on the wall from objects passing in front of a fire behind them and give names to these shadows. The shadows are the prisoners' reality, but are not accurate representations of the real world. The shadows represent the fragment of reality that we can normally perceive through our senses, while the objects under the sun represent the true forms of objects that we can only perceive through reason. Three higher levels exist: the natural sciences; mathematics, geometry, and deductive logic; and the theory of forms.

Socrates explains how the philosopher is like a prisoner who is freed from the cave and comes to understand that the shadows on the wall are actually not the direct source of the images seen. A philosopher aims to understand and perceive the higher levels of reality. However, the other inmates of the cave do not even desire to leave their prison, for they know no better life.

Socrates remarks that this allegory can be paired with previous writings, namely the analogy of the sun and the analogy of the divided line.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Books 🔗 Classical Greece and Rome 🔗 Greece 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Military history/Roman and Byzantine military history 🔗 Military history/Medieval warfare 🔗 Greece/Byzantine world 🔗 Military history/Balkan military history 🔗 Military history/European military history

The Strategikon or Strategicon (Greek: Στρατηγικόν) is a manual of war traditionally regarded as written in the late 6th century and usually attributed to the Byzantine Emperor Maurice. It is moreover a practical manual, "a rather modest elementary handbook" in the words of its introduction, "for those devoting themselves to generalship". This book gives a general guide, handbook, of the Byzantine military's strategies. In his introduction to his 1984 translation of the text, George T. Dennis noted "The Strategikon is written in a very straightforward and generally uncomplicated Greek."

The Strategikon may have been written in an effort to codify the military reforms brought about by the soldier-emperor Maurice. There is debate in academic circles as to the true author of the Strategikon. Maurice may have only commissioned it; perhaps his brother Peter, or another general of his court, was the true author. The dating is also debated. If it was written in the 6th century, the Strategikon may have been produced to codify the experience of the Balkan and Persian campaigns, or the campaigns may have been carried out in compliance with the manual. However, starting in the late 19th century, some historians have argued for a later date in the eighth or ninth century, on philological or technological grounds. In any case, it is considered one of the most important military texts of the medieval years, along with the 10th century military treatises attributed to the Byzantine emperors Leo VI (Tactica) and Nicephorus Phocas (De velitatione and Praecepta Militaria); Leo's Tactica in particular drew heavily from the Strategikon.

The text consists of 12 chapters, or "books", on various aspects of the tactics employed by the Byzantine military of the 6th and 7th century A.D. It is primarily focused on cavalry tactics and formations, yet it also elaborates on matters of infantry, sieges, baggage trains, drilling and marching. The author was familiar with classical military treatises, especially Onasander and Aelian, which he used as conceptional models rather than sources of content. Each book has a general topic to be discussed, and each book goes into great detail even separating each book further into subsections and including maps. These maps are not large and extravagant but more symbols to show positions and a standard design of the formations the Byzantine military used at this time. Books seven and eight contain practical advice to the General in the form of instructions and maxims. The eleventh book has ethnographic interest, with its portrayal of various Byzantine enemies (Franks, Lombards, Avars, Turks, and Slavs). The Strategikon also belongs to Byzantine legal literature, since it contains a list of military infractions and their suitable penalties.

🔗 Russia 🔗 Physics 🔗 Physics/relativity 🔗 Russia/science and education in Russia

The Novikov self-consistency principle, also known as the Novikov self-consistency conjecture and Larry Niven's law of conservation of history, is a principle developed by Russian physicist Igor Dmitriyevich Novikov in the mid-1980s. Novikov intended it to solve the problem of paradoxes in time travel, which is theoretically permitted in certain solutions of general relativity that contain what are known as closed timelike curves. The principle asserts that if an event exists that would cause a paradox or any "change" to the past whatsoever, then the probability of that event is zero. It would thus be impossible to create time paradoxes.