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🔗 California 🔗 Companies 🔗 California/San Francisco Bay Area 🔗 Apple Inc. 🔗 Computing 🔗 Computing/Software 🔗 Media 🔗 Music theory

Napster was a peer-to-peer (P2P) file sharing application primarily associated with digital audio file distribution. Founded by Shawn Fanning and Sean Parker, the platform originally launched on June 1, 1999. Audio shared on the service was typically encoded in the MP3 format. As the software became popular, the company encountered legal difficulties over copyright infringement. Napster ceased operations in 2001 after losing multiple lawsuits and filed for bankruptcy in June 2002.

The P2P model employed by Napster involved a centralized database that indexed a complete list of all songs being shared from connected clients. While effective, the service could not function without the central database, which was hosted by Napster and eventually forced to shutdown. Following Napster's demise, alternative decentralized methods of P2P file-sharing emerged, including Gnutella, Freenet, FastTrack, and BitTorrent.

Napster's assets were eventually acquired by Roxio, and it re-emerged as an online music store commonly known as Napster 2.0. Best Buy later purchased the service and merged it with its Rhapsody streaming service on December 1, 2011. In 2016, the original branding was restored when Rhapsody was renamed Napster.

Clicking on the first link in the main text of a Wikipedia article, and then repeating the process for subsequent articles, would usually lead to the Philosophy article. As of February 2016, 97% of all articles in Wikipedia eventually led to the article Philosophy. The remaining articles lead to an article without any outgoing wikilinks, to pages that do not exist, or get stuck in loops. This has gone up from 94.52% in 2011.

There have been some theories on this phenomenon, with the most prevalent being the tendency for Wikipedia pages to move up a "classification chain." According to this theory, the Wikipedia Manual of Style guidelines on how to write the lead section of an article recommend that the article should start by defining the topic of the article, so that the first link of each page will naturally take the reader into a broader subject, eventually ending in wide-reaching pages such as Mathematics, Science, Language, and of course, Philosophy, nicknamed "the mother of all sciences".

🔗 Mass surveillance 🔗 Novels 🔗 Books 🔗 Novels/Science fiction 🔗 Science Fiction 🔗 Freedom of speech 🔗 Politics 🔗 Socialism

Nineteen Eighty-Four: A Novel, often published as 1984, is a dystopian novel by English novelist George Orwell. It was published in June 1949 by Secker & Warburg as Orwell's ninth and final book completed in his lifetime. The story was mostly written at Barnhill, a farmhouse on the Scottish island of Jura, at times while Orwell suffered from severe tuberculosis. Thematically, Nineteen Eighty-Four centres on the consequences of government over-reach, totalitarianism, mass surveillance, and repressive regimentation of all persons and behaviours within society.

The story takes place in an imagined future, the year 1984, when much of the world has fallen victim to perpetual war, omnipresent government surveillance, historical negationism, and propaganda. Great Britain, known as Airstrip One, has become a province of a superstate named Oceania that is ruled by the Party who employ the Thought Police to persecute individuality and independent thinking. Big Brother, the leader of the Party, enjoys an intense cult of personality despite the fact that he may not exist. The protagonist, Winston Smith, is a diligent and skillful rank-and-file worker and Party member who secretly hates the Party and dreams of rebellion. He enters a forbidden relationship with a co-worker, Julia.

Nineteen Eighty-Four has become a classic literary example of political and dystopian fiction. Many terms used in the novel have entered common usage, including Big Brother, doublethink, thoughtcrime, Newspeak, Room 101, telescreen, 2 + 2 = 5, prole, and memory hole. Nineteen Eighty-Four also popularised the adjective "Orwellian", connoting things such as official deception, secret surveillance, brazenly misleading terminology, and manipulation of recorded history by a totalitarian or authoritarian state. Time included it on its 100 best English-language novels from 1923 to 2005. It was placed on the Modern Library's 100 Best Novels, reaching No. 13 on the editors' list and No. 6 on the readers' list. In 2003, the novel was listed at No. 8 on The Big Read survey by the BBC. Parallels have been drawn between the novel's subject matter and real life instances of totalitarianism, mass surveillance, and violations of freedom of expression among other themes.

🔗 Medicine 🔗 Medicine/Ophthalmology

The Purkinje effect or Purkinje phenomenon (Czech: [ˈpurkɪɲɛ] (listen); sometimes called the Purkinje shift, often incorrectly pronounced ) is the tendency for the peak luminance sensitivity of the eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation. In consequence, reds will appear darker relative to other colors as light levels decrease. The effect is named after the Czech anatomist Jan Evangelista Purkyně. While the effect is often described from the perspective of the human eye, it is well established in a number of animals under the same name to describe the general shifting of spectral sensitivity due to pooling of rod and cone output signals as a part of dark/light adaptation.

This effect introduces a difference in color contrast under different levels of illumination. For instance, in bright sunlight, geranium flowers appear bright red against the dull green of their leaves, or adjacent blue flowers, but in the same scene viewed at dusk, the contrast is reversed, with the red petals appearing a dark red or black, and the leaves and blue petals appearing relatively bright.

The sensitivity to light in scotopic vision varies with wavelength, though the perception is essentially black-and-white. The Purkinje shift is the relation between the absorption maximum of rhodopsin, reaching a maximum at about 500 nanometres (2.0×10⁻⁵ in), and that of the opsins in the longer-wavelength cones that dominate in photopic vision, about 555 nanometres (2.19×10⁻⁵ in) (green).

In visual astronomy, the Purkinje shift can affect visual estimates of variable stars when using comparison stars of different colors, especially if one of the stars is red.

🔗 Food and drink 🔗 Fisheries and Fishing 🔗 Food and drink/Desserts

Pumpable ice (PI) technology is a technology to produce and use fluids or secondary refrigerants, also called coolants, with the viscosity of water or jelly and the cooling capacity of ice. Pumpable ice is typically a slurry of ice crystals or particles ranging from 5 micrometers to 1 cm in diameter and transported in brine, seawater, food liquid, or gas bubbles of air, ozone, or carbon dioxide.

🔗 Architecture 🔗 Classical Greece and Rome

The Roman architectural revolution, also known as the concrete revolution, is the name sometimes given to the widespread use in Roman architecture of the previously little-used architectural forms of the arch, vault, and dome. For the first time in history, their potential was fully exploited in the construction of a wide range of civil engineering structures, public buildings, and military facilities. These included amphitheatres, aqueducts, baths, bridges, circuses, dams, roads, and temples.

A crucial factor in this development that saw a trend to monumental architecture was the invention of Roman concrete (also called opus caementicium), which led to the liberation of the shape from the dictate of the traditional materials of stone and brick.

For the first time in recorded history we find evidence of an interest in the shapes of the space contained strong enough to outweigh the functional logic of the masonry masses that contained it. There was nothing new in the employment of curvilinear or polygonal forms, as such...But in so far as such buildings incorporated curvilinear or polygonal rooms and corridors, the shapes of these were determined by the form of the building as a whole, not by any aesthetic principle.

The development of Roman architecture, however, did not remain limited to these new forms and materials. An unrelated process of architectural innovation continued unabated, which, although less conspicuous, proved their usefulness for solving structural problems and found their way permanently into Western architecture, such as the lintel arch, the independent corbel, and the metal-tie.

During the Age of Augustus, almost the entire city of Rome was rebuilt causing an influx of craftsman and architects from all across Europe. Emperor Augustus aimed to develop new ideas in the construction of his buildings that would forever defy the limits that were ever thought possible. The Mausoleum in Campus Martius was one of the major monuments built by Augustus during his reign that was made almost entirely of concrete using updated construction techniques. The concrete is used in concentric rings that support the structure of the building like walls. The Theatre of Marcellus was another concrete triumph completed during the Age of Augustus, dedicated to the nephew of the emperor. The brick-faced concrete structure construction started under Julius Caesar but was completed under Augustus. It was this building that shows the integration of new concrete building techniques of Augustus's architects as opposed to those of Caesar. The Theatre of Marcellus uses a variety of materials that aid in the growth of the concrete revolution using readily available volcanic stones such as Tuscolo tuff and Tufo Lionato as aggregates in pozzolanic concretes.

These newly concocted recipes for concrete provided durability to walls and barrelled vaults as well as a unique aesthetic appeal. The integrated stone and masonry design illustrate a refinement that came with the concrete revolution as a result of the new techniques and styles developed under Augustus. The craftsmanship of the Theatre Marcellus demonstrated a skilled employment as well as rigorous technical supervision.

🔗 India 🔗 Numismatics

The Indian rupee sign (sign: ₹; code: INR) is the currency symbol for the Indian rupee, the official currency of India. Designed by Udaya Kumar, it was presented to the public by the Government of India on 15 July 2010, following its selection through an "open" competition among Indian residents. Before its adoption, the most commonly used symbols for the rupee were Rs, Re or, in texts in Indian languages, an appropriate abbreviation in the language used.

The design is based on the Devanagari letter "र" (ra) with a double horizontal line at the top. It also resembles the Latin capital letter "R", especially R rotunda (Ꝛ).

The Unicode character for the Indian rupee sign is U+20B9 ₹ INDIAN RUPEE SIGN. Other countries that use a rupee, such as Sri Lanka, Pakistan and Nepal, still use the generic U+20A8 ₨ RUPEE SIGN character.

🔗 Visual arts 🔗 Morocco

Zellige (Arabic: [zˈliʑ]; Arabic: الزليج‎; also zelige or zellij or zileej) is mosaic tilework made from individually chiseled geometric tiles set into a plaster base. This form of Islamic art is one of the main characteristics of Moroccan architecture. It consists of geometrically patterned mosaics, used to ornament walls, ceilings, fountains, floors, pools and tables. The Moroccan traditional patterns and styles are found inside famous buildings such as Al-Qarawiyyin Mosque in Fez, the Alhambra in Granada, Spain, the Great Mosque of Cordoba, the Ben Youssef Madrasa in Marrakech, and the Hassan II mosque in Casablanca, which adds a new color palette with traditional designs.

🔗 Ships

CS Alert, or HMTS Alert, was a cable-laying ship that had a significant role in World War I. She was launched in 1871 for the Submarine Telegraph Company with the name The Lady Carmichael. In 1890 the ship was acquired by the General Post Office (GPO) as part of the nationalisation of the British telegraph network. At the outbreak of World War I, Alert was immediately dispatched to cut German telegraph cables in the English Channel, seriously damaging Germany's ability to securely communicate with the rest of the world. Alert was taken out of service as a cable ship in 1915 but her cable-handling gear was retained for fitting on her replacement. After the war, she worked as a merchant ship under various names, finally being wrecked at Redcar under the name Norham in 1932.

🔗 California 🔗 California/San Francisco Bay Area 🔗 Photography

Group f/64 or f.64 was a group founded by seven 20th-century San Francisco Bay Area photographers who shared a common photographic style characterized by sharply focused and carefully framed images seen through a particularly Western (U.S.) viewpoint. In part, they formed in opposition to the pictorialist photographic style that had dominated much of the early 20th century, but moreover, they wanted to promote a new modernist aesthetic that was based on precisely exposed images of natural forms and found objects.