To stay up to date you can also follow on Mastodon.

🔗 London 🔗 British Museum 🔗 Classical Greece and Rome 🔗 History of Science 🔗 Archaeology 🔗 Visual arts 🔗 Glass

The Lycurgus Cup is a 4th-century Roman glass cage cup made of a dichroic glass, which shows a different colour depending on whether or not light is passing through it: red when lit from behind and green when lit from in front. It is the only complete Roman glass object made from this type of glass, and the one exhibiting the most impressive change in colour; it has been described as "the most spectacular glass of the period, fittingly decorated, which we know to have existed".

The cup is also a very rare example of a complete Roman cage-cup, or diatretum, where the glass has been painstakingly cut and ground back to leave only a decorative "cage" at the original surface-level. Many parts of the cage have been completely undercut. Most cage-cups have a cage with a geometric abstract design, but here there is a composition with figures, showing the mythical King Lycurgus, who (depending on the version) tried to kill Ambrosia, a follower of the god Dionysus (Bacchus to the Romans). She was transformed into a vine that twined around the enraged king and restrained him, eventually killing him. Dionysus and two followers are shown taunting the king. The cup is the "only well-preserved figural example" of a cage cup.

The dichroic effect is achieved by making the glass with tiny proportions of nanoparticles of gold and silver dispersed in colloidal form throughout the glass material. The process used remains unclear, and it is likely that it was not well understood or controlled by the makers, and was probably discovered by accidental "contamination" with minutely ground gold and silver dust. The glass-makers may not even have known that gold was involved, as the quantities involved are so tiny; they may have come from a small proportion of gold in any silver added (most Roman silver contains small proportions of gold), or from traces of gold or gold leaf left by accident in the workshop, as residue on tools, or from other work. The very few other surviving fragments of Roman dichroic glass vary considerably in their two colours.

🔗 Computing

In computer storage, Bélády's anomaly is the phenomenon in which increasing the number of page frames results in an increase in the number of page faults for certain memory access patterns. This phenomenon is commonly experienced when using the first-in first-out (FIFO) page replacement algorithm. In FIFO, the page fault may or may not increase as the page frames increase, but in Optimal and stack-based algorithms like LRU, as the page frames increase the page fault decreases. László Bélády demonstrated this in 1969.

In common computer memory management, information is loaded in specific-sized chunks. Each chunk is referred to as a page. Main memory can hold only a limited number of pages at a time. It requires a frame for each page it can load. A page fault occurs when a page is not found, and might need to be loaded from disk into memory.

When a page fault occurs and all frames are in use, one must be cleared to make room for the new page. A simple algorithm is FIFO: whichever page has been in the frames the longest is the one that is cleared. Until Bélády's anomaly was demonstrated, it was believed that an increase in the number of page frames would always result in the same number of or fewer page faults.

🔗 Death 🔗 Korea 🔗 Skepticism 🔗 Alternative Views 🔗 Korea/Korean popular culture working group

Fan death is a widely held belief in Korean culture, where it is thought that running an electric fan in a closed room with unopened or no windows will prove fatal. Despite no concrete evidence to support the concept, belief in fan death persists to this day in Korea, and also to a lesser extent in Japan and Russia.

🔗 Computing 🔗 BBC 🔗 Comedy 🔗 Retailing

"Computer says no" is a catchphrase first used in the British sketch comedy television programme Little Britain in 2004. In British culture, the phrase is used to criticise public-facing organisations and customer service staff who rely on information stored on or generated by a computer to make decisions and respond to customers' requests, often in a manner which goes against common sense. It may also refer to a deliberately unhelpful attitude towards customers and service-users commonly experienced within British society, whereby more could be done to reach a mutually satisfactory outcome, but is not.

🔗 United States/U.S. Government 🔗 United States 🔗 Terrorism

The 1983 U.S. Senate bombing was a bomb explosion at the United States Senate on November 7, 1983, motivated by United States military involvement in Lebanon and Grenada. The attack led to heightened security in the DC metropolitan area, and the inaccessibility of certain parts of the Senate Building. Six members of the radical left-wing Resistance Conspiracy were arrested in May 1988 and charged with the bombing, as well as related bombings of Fort McNair and the Washington Navy Yard which occurred April 25, 1983, and April 20, 1984, respectively.

🔗 Germany 🔗 Poetry

"First they came ..." is the poetic form of a post-war confessional prose by the German Lutheran pastor Martin Niemöller (1892–1984). It is about the cowardice of German intellectuals and certain clergy—including, by his own admission, Niemöller himself—following the Nazis' rise to power and subsequent incremental purging of their chosen targets, group after group. Many variations and adaptations in the spirit of the original have been published in the English language. It deals with themes of persecution, guilt, repentance, and personal responsibility.

🔗 Biology 🔗 Engineering 🔗 Science

Xenobots, named after the African clawed frog (Xenopus laevis), are synthetic organisms that are automatically designed by computers to perform some desired function and built by combining together different biological tissues.

Xenobots are less than a 1 millimeter (0.039 inches) wide and composed of just two things: skin cells and heart muscle cells, both of which are derived from stem cells harvested from early (blastula stage) frog embryos. The skin cells provide rigid support and the heart cells act as small motors, contracting and expanding in volume to propel the xenobot forward. The shape of a xenobot's body, and its distribution of skin and heart cells, are automatically designed in simulation to perform a specific task, using a process of trial and error (an evolutionary algorithm). Xenobots have been designed to walk, swim, push pellets, carry payloads, and work together in a swarm to aggregate debris scattered along the surface of their dish into neat piles. They can survive for weeks without food and heal themselves after lacerations.

🔗 Libraries 🔗 Belgium

The Universal Decimal Classification (UDC) is a bibliographic and library classification representing the systematic arrangement of all branches of human knowledge organized as a coherent system in which knowledge fields are related and inter-linked. The UDC is an analytico-synthetic and faceted classification system featuring detailed vocabulary and syntax that enables powerful content indexing and information retrieval in large collections. Since 1991, the UDC has been owned and managed by the UDC Consortium, a non-profit international association of publishers with headquarters in The Hague (Netherlands).

Unlike other library classification schemes that have started their life as national systems, the UDC was conceived and maintained as an international scheme. Its translation in world languages started at the beginning of the 20th century and has since been published in various printed editions in over 40 languages. UDC Summary, an abridged Web version of the scheme, is available in over 50 languages. The classification has been modified and extended over the years to cope with increasing output in all areas of human knowledge, and is still under continuous review to take account of new developments.

Albeit originally designed as an indexing and retrieval system, due to its logical structure and scalability, UDC has become one of the most widely used knowledge organization systems in libraries, where it is used for either shelf arrangement, content indexing or both. UDC codes can describe any type of document or object to any desired level of detail. These can include textual documents and other media such as films, video and sound recordings, illustrations, maps as well as realia such as museum objects.

🔗 Game theory

In game theory, a focal point (or Schelling point) is a solution that people tend to choose by default in the absence of communication. The concept was introduced by the American economist Thomas Schelling in his book The Strategy of Conflict (1960). Schelling states that "(p)eople can often concert their intentions or expectations with others if each knows that the other is trying to do the same" in a cooperative situation (at page 57), so their action would converge on a focal point which has some kind of prominence compared with the environment. However, the conspicuousness of the focal point depends on time, place and people themselves. It may not be a definite solution.

🔗 United States/U.S. Government 🔗 United States

This article deals with the activities of the Central Intelligence Agency of the Federal government of the United States, that violate human rights.